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  • 1. ‫‪ - munthear@gmail.com‬الدكتور المهندس محمد منذر القادري -‬
  • 2. ‫تحدٌات ......‬ ‫• تقلبات سوق الكهرباء تدعو الشركات إلى إعادة التقٌٌم النوعً للكهرباء.‬‫• نمو الطلب على الطاقة غالبا ما ٌسبق التزوٌد خصوصا مع األسالٌب الجدٌدة لتولٌد الكهرباء‬ ‫وانتظار الشركات نتائج األبحاث لمعرفة إلى أٌن ستؤول مشاكل عدم التنظٌم.‬‫•الطاقة الرخٌصة المولدة من الطاقة النووٌة أو من الفحم أو المحطات المائٌة هً لٌست حلوال‬‫سهلة للغاٌة لخصوصٌات البٌئة, أنظمة نقل الطاقة مصممة لنقل استطاعات محددة, وإن بناء‬ ‫إمكانات إضافٌة ٌتطلب 01 سنوات.‬ ‫• جودة القدرة فً تغٌرات سوق الكهرباء تخلق مشكالت إضافٌة للشركات ومراكز البحث.‬ ‫• تسوٌة موضوع جودة القدرة ٌبدأ بتحدٌد االستطاعات المستهلكة على الشبكات الكهربائٌة.‬ ‫• األجهزة الجدٌدة هً أكثر حساسٌة لمشكلة القدرة الناجمة عن زٌادة سرعة وكثافة الدارات‬ ‫التكاملٌة.‬ ‫• كلفة مشاكل القدرة اآلن وصلت إلى آالف الدوالرات فً الدقٌقة فً العدٌد من الشركات.‬ ‫الدكتور المهندس محمد منذر القادري-‬ ‫‪munthear@gmail.com‬‬
  • 3. ‫هل تعلم أن؟‬ ‫أجهزة الكومبٌوتر النظامٌة عرضة إلضطرابات كهربائٌة مدمرة أكثر من 521 مرة كل شهر!‬ ‫إنقطاع التغذٌة لمدة ساعة ٌكلف مالكً شبكات الكومبٌوتر المتوسطة النظامٌة 000,81£!‬ ‫إنقطاع التغذٌة لمدة ساعة ٌكلف قطاع النقل والمواصالت 000,09£!‬ ‫ٌكلف مراكز البورصة الكبٌرة ‪!£6.5 million‬‬ ‫000,05£!‬ ‫ٌكلف استرجاع ‪ one megabyte‬من المعطٌات‬ ‫أن ثلث المعطٌات تفقد بسبب مشاكل القدرة!‬ ‫نصف أعطال الحواسب بسبب مشاكل التغذٌة الكهربائٌة!‬ ‫رداءة التغذٌة الكهربائٌة ٌكلف قطاع األعمال فً أمرٌكا أكثر من ‪ $26 billion‬كل سنة!‬‫نقال عن ‪ Silicon Valley Power‬أن كلفة انقطاع التغذٌة عن ‪ Sun Microsystems‬أكثر من ‪ $1 million‬كل دقٌقة.‬ ‫الدكتور المهندس محمد منذر القادري-‬ ‫‪munthear@gmail.com‬‬
  • 4. ‫أنواع إضطرابات القدرة الكهربائٌة‬ ‫إنقطاع كامل للتوتر‬ ‫حالة عابرة‬ ‫إنقطاع لحظً‬ ‫جهوط إبرٌة, مسمارٌة, نبضٌة‬ ‫إزدٌاد مؤقت‬ ‫إرتفاع جهد‬ ‫تغٌرات فً التردد‬ ‫هبوط مؤقت‬ ‫توافقٌات‬ ‫إنخفاض جهد‬ ‫ضجٌج تردد عالً‬ ‫‪Power Factor‬‬ ‫معامل القدرة المنخفض‬ ‫عدم توازن األطوار الثالثة ‪Unbalance On three-phase systems‬‬‫‪, three-phase motors with 5% voltage unbalance exhibit 25% decrease‬‬
  • 5. ‫نسب إضطرابات التغذٌة‬
  • 6. ‫إحصائٌات جدٌدة‬ ‫النسب القٌاسٌة للتشوهات فً الشبكات األمرٌكٌة‬ Electrical Noise & Transients 62.6/Month 48.79% Spikes Transients 50.7/Month 39.52% Sags, Surges-‫الدكتور المهندس محمد منذر القادري‬ Mains Failures & Brownouts 14.4/Monthmunthear@gmail.com 0.6/Month 11.22% 0.47%
  • 7. ‫‪Elements of a Power Quality Problem‬‬ ‫عناصر ردائة القدرة‬‫التولٌد‬ ‫النقل‬ ‫التوزٌع‬ ‫المستهلك‬ ‫المرسل‬ ‫قناة الربط‬ ‫المستقبل‬ ‫( المنبع)‬ ‫(الشبكة)‬ ‫(الحمل)‬‫إي تغٌر فً تردد أو قٌمة أو شكل موجة الجهد ٌسمى اضطرابا فً خط الشبكة ‪ ,line disturbance power‬وهذا ٌسب‬ ‫مشاكل فً تشغٌل األجهزة الكهربائٌة.‬ ‫أسباب حدوث اإلضراب فً الشبكة ٌنسب إلى ثالثة عناصر‬ ‫الدكتور المهندس محمد منذر القادري-‬ ‫‪munthear@gmail.com‬‬
  • 8. ‫مىببع الخغزيت : ‪Source‬‬ ‫جهذ ثببج: / حردد ثببج )‪DC, 1-Phase/ 3-Phase AC ( 50 / 60 hz‬‬ ‫مىببغ صغٍرة : رٌبح / خالٌب ضىئٍت /مذخراث / خالٌب انىقىد‬ ‫مىبع مخىسطت : دٌسل /حىربٍه غبزي‬ ‫مىببغ كبٍرة : مبئٍت / حرارٌت / وىوٌت‬ ‫األحمبل: ‪Load‬‬ ‫أمثهت ػهى األحمبل ومخطهببث حشغٍههب:‬ ‫مشبرٌغ كهراكٍمبوٌبث: ‪Low DC Voltage, High Current‬‬ ‫أفران ححرٌضٍت: ‪1-phase , High Frequency, AC 50hz‬‬ ‫أدواث حشغٍم: ‪Variable DC Voltage‬‬‫مشبرٌغ حسخخذو محركبث: ‪Variable Voltage Variable Frequency ( VVVF) AC‬‬ ‫أحمبل حىاسٍب: )‪Un-interrupted Power Supply ( UPS‬‬ ‫أوظمت حسود انطبئراث : )‪Variable Speed Constant Frequency ( VSCF‬‬ ‫أوظمت انخىحر انؼبنً انمسخمر : / ‪AC/ DC & DC‬‬
  • 9. ‫أسباب ردائة القدرة الكهربائٌة‬ ‫األحمال اللخطٌة‬ ‫•‬ ‫منابع التوافقٌات‬ ‫•‬ ‫منابع اإلرتعاش‬ ‫•‬ ‫منابع ‪sage‬‬ ‫•‬ ‫المبدالت المختلفة‬ ‫•‬ ‫الدكتور المهندس محمد منذر القادري-‬ ‫‪munthear@gmail.com‬‬
  • 10. ‫طرق الترابط ‪coupling methods‬‬ ‫الترابط المنقول‬ ‫الترابط المشع‬ ‫الترابط من خالل ممانعة مشتركة: ٌحدث عندما ٌمر تٌار دارتٌن من خالل ممانعة مشتركة واحدة , مثال ممانعة األرضً.‬ ‫وباتالً فإن الجهدالهابط على الممانعة ٌؤثر على كال الدارتٌن.‬‫الحقول الكهرامغناطٌسٌة المشعة تحدث بسبب آالت لحام القوس الكهربائً والصواعق أو أحمال متقطعة أو محطات إرسال‬ ‫إذاعً أو محطات رادار‬ ‫الدكتور المهندس محمد منذر القادري-‬ ‫‪munthear@gmail.com‬‬
  • 11. ‫تداخل ‪RFI EMI‬‬ ‫التداخل الكهرامغناطٌسً )‪Electromagnetic Interference (EMI‬‬ ‫تداخل التردد الرادٌوي ‪Interference (RFI) Radio Frequency‬‬‫- التداخل الكهرمغناطٌسً أو الرادٌوي عادة ماٌكون بتردد ٌزٌد عن ‪ 100khz‬وٌنتقل كما األمواج‬‫الرادٌوٌة . وبالتالً فإن خطوط القدرة وكبالتها الغٌر محجبة تسلك سلوك هوائً إستقبال ومنه تعمل‬ ‫على إدخال هذه األمواج إلى األنظمة الكهربائٌة.‬ ‫- ‪ٌ EMI/RFI‬مكن أن ٌحدث عن طرٌق الترابط السعوي أو الترابط التحرٌضً‬ ‫- بعض أنماط إضطرابات الجهد مثل الضجٌج والحاالت العابرة تحدث إما كإضطراب نمط‬ ‫عادي ‪normal mode‬أوكإضطراب نمط مشترك ‪.common mode‬‬ ‫- إضطراب النمط العادي أو المتعارض ‪A normal or transverse mode‬هو‬ ‫عبارة عن فرق فً الجهد غٌر مرغوب به ٌخلق بٌن خطٌن دارة ٌحمالن تٌارا , مثال فً‬ ‫دارة تغذٌة إحادٌة الطور المعنٌان هما الحٌادي وخط الفاز.‬ ‫- إضطراب النمط المشترك ‪ A common mode disturbance‬هو فرق جهد غٌر‬ ‫مرغوب به بٌن جمٌع الخطوط الحاملة للتٌار وخط األرضً. وهً تتضمن نبضات وضجٌج‬ ‫‪ EMIRFI‬بالنسبة لألرضً.‬
  • 12. ‫من أٌن تأتً إضطرابات التغذٌة الكهربائٌة؟‬ ‫‪ ‬تجهٌزات المعامل‬ ‫‪ ‬تجهٌزات المكاتب‬ ‫‪ ‬المكٌفات الكهربائٌة والمصاعد‬
  • 13. ‫من أٌن تأتً اإلضطرابات الكهربائٌة‬ ‫اصطدام الطٌور بخططوط التوتر العالً ‪O/H lines‬‬ ‫•‬ ‫تأثٌرالرٌاح على خطوط التوتر العالً.‬ ‫•‬ ‫معظم الصواعق تقع على خطوط التوتر العالً.‬ ‫•‬ ‫إنهٌار بعض المعدات الكهربائٌة ( محوالت ...)‬ ‫•‬ ‫أخطاء عملٌاتٌة.‬ ‫•‬ ‫عناصر مسٌئة:‬ ‫•‬ ‫– إعادة اإلغالق اآللً‬‫الدكتور المهندس محمد منذر القادري-‬ ‫– تقفً العطل ‪Fault tracing‬‬‫‪munthear@gmail.com‬‬
  • 14. ‫الحلول‬ ‫- تحسٌن نوعٌة الكهرباء هذا ٌتضمن‬ Uninterruptible power supplies ‫• وحدات التغذٌة عدٌمة اإلنقطاع‬ Power conditioning ‫• منظمات الجهد مكٌفات القدرة‬ transient voltage surge suppressor ‫• مخمد هضبة الجهد العابرة‬ RFI Filter ‫• مرشح‬ Line Filters ‫• مرشح جهد الشبكة‬ Isolation Transformer ‫• محول العزل‬ Power Factor Correction ‫• تصحٌح معامل القدرة‬ generation Backup emergency and on-site‫• الطوارئ اإلحتٌاطً والتولٌد الجاهز‬ .shielding ‫• التحجٌب‬ .Grounding ‫• التأرٌض‬-‫الدكتور المهندس محمد منذر القادري‬munthear@gmail.com
  • 15. ITIC ‫منحنً السماحٌة للتوتر وفق‬ ITIC Voltage Tolerance Curve EQUIPMENT DAMAGE RISK EQUIPMENT MALFUNCTIONITIC (Information Technology Industry Council) formally CBEMA curve
  • 16. ‫منحنً السماحٌة فً الصناعة‬
  • 17. SEMI F47 voltage immunity standardSEMI, the industry association for the semiconductor industry, has developed two voltage sag immunitystandards.•SEMI F47 sets out the required voltage sag tolerance for semiconductor fab equipment.•SEMI F42 explains how to test compliance with SEMI F47. (PSL helped write SEMI F42.)You can purchase copies of these standards from SEMI for $50 each, or you can quickly and easily obtain a freeset of Application Notes on a CD-ROM from PSL -- just send us an e-mail at FreeCD@PowerStandards.com withyour name and address. (Trouble with this link? Just give us a call at +1-510-658-9600 and well take care of it.)In essence, SEMI F47 requires that semiconductor processing equipment tolerate voltage sags on their ac powerline. Specifically, they must tolerate sags to 50% for up to 200 ms, sags to 70% for up to 0.5 seconds, and sags to80% for up to one second. In addition to these requirements, SEMI F47 recommends that equipment tolerate sagsto 0% for one cycle, sags to 80% for 10 seconds, and continuous sags to 90%, but these are not part of therequirements.SEMI F47 suggests that semiconductor manufacturers may use this sag standard when procuring equipment.Major semiconductor manufacturers are beginning to take this approach, including Intel, Texas Instruments,Motorola, IBM, and others.SEMI F42 explains how to test compliance with F47. It describes safety procedures, processing modes, testsequences, phase connections, and reporting requirements.SEMI F42 also distinguishes between testing equipment for "characterization" (determining the depth and durationof sags that equipment can tolerate) and "compliance" (a pass/fail test determining if equipment complies with therequirements and recommendations of SEMI F47).PSLs sag generators are designed specifically to test according to SEMI F47 and SEMI F42
  • 18. Voltage sags(dips) and swells A typical voltage sag‫فترة الهبوط تستمر من 01 مٌلً ثانٌة إلى عدة ثوان‬
  • 19. SagVoltage sags -- or dips which are the same thing -- are brief reductions in voltage, typically lasting from acycle to a second or so, or tens of milliseconds to hundreds of milliseconds. Voltage swells are briefincreases in voltage over the same time range.(Longer periods of low or high voltage are referred to as "undervoltage" or "overvoltage".)Voltage sags are caused by abrupt increases in loads such as short circuits or faults, motors starting, orelectric heaters turning on, or they are caused by abrupt increases in source impedance, typically caused bya loose connection. Voltage swells are almost always caused by an abrupt reduction in load on a circuit with a poor or damagedvoltage regulator, although they can also be caused by a damaged or loose neutral connection.A typical voltage sag.Voltage sags are the most common power disturbance. At a typical industrial site, it is not unusual to seeseveral sags per year at the service entrance, and far more at equipment terminals.Voltage sags can arrive from the utility; however, in most cases, the majority of sags are generated inside abuilding. For example, in residential wiring, the most common cause of voltage sags is the starting currentdrawn by refrigerator and air conditioning motors.Sags do not generally disturb incandescent or fluorescent lighting, motors, or heaters. However, someelectronic equipment lacks sufficient internal energy storage and, therefore, cannot ride through sags in thesupply voltage. Equipment may be able to ride through very brief, deep sags, or it may be able to ride throughlonger but shallower sags.
  • 20. ‫‪Sources of Sags‬‬ ‫أسباب غور التوتر‬ ‫إقالع أحمال كبٌرة‬ ‫•‬ ‫– محركات كبٌرة جدا‬ ‫هبوط الشبكة‬ ‫•‬ ‫– أحمال كبٌرة .‬ ‫– حدوث أعطال.‬ ‫أزمنة إزالة العطل على المغذٌات فً محطات التوزٌع: ‪5 to15 cycles‬‬ ‫•‬ ‫مجال ضعف التوتر ‪20 to 50% Sag‬‬ ‫•‬ ‫الدكتور المهندس محمد منذر القادري-‬ ‫‪munthear@gmail.com‬‬
  • 21. voltage sags ‫أسباب‬Voltage sags are brief reductions in the voltage on ac power systems. (The American "sag"and the British "dip" have exactly the same meaning, and may be used interchangeably.)How brief? Between 1/2 cycle and a few seconds. Disturbances that last less than 1/2 cycleare commonly called "low frequency transients"; voltage reductions that last longer than afew seconds are commonly called "undervoltage." Power systems have non-zeroimpedances, so every increase in current causes a corresponding reduction in voltage.Usually, these reductions are small enough that the voltage remains within normaltolerances. But when there is a large increase in current, or when the system impedance ishigh, the voltage can drop significantly. So conceptually, there are two sources of voltagesags:•Large increases in current•Increases in system impedanceAs a practical matter, most voltage sags are caused by increases in current. It is convenientto think of the power system as a tree, with your sensitive load connected to one of thetwigs. Any voltage sag on the trunk of the tree, or on a branch leading out to your twig, willcause a voltage sag at your load. But a short circuit out on a distant branch can cause thetrunk voltage to diminish, so even faults in a distant part of the tree can cause a sag at yourload.
  • 22. It is important to understand the source of the voltage sags before trying toeliminate them, because the wrong solution can actually make the problem worse.For example, if you install a ferro-resonant transformer as a voltage regulator, or abattery-operated UPS (a reasonable and common approach), but inadvertentlyinstall it upstream from the motor that is causing your voltage sags, the voltagesags will get worse, not better.In most cases, the correct solution is to adjust the equipment so that it is lesssensitive to voltage sags.Sag sensitivity - Five ways equipment fails during voltage sagsCBEMA curve - voltage sag depth and duration at world-wide semiconductor plants -‫الدكتور المهندس محمد منذر القادري‬ munthear@gmail.com
  • 23. ‫إرتفاع أو إنخفاض التوتر‬High or Low Voltages Sustained high and low voltages areusually caused by the distribution system. This system ofwires and transformers that connects all electrical loads tothe utility generators has impedance. This impedancecauses the voltage to drop when current flows through thesystem. The further you are from the power source and themore current drawn, the more the voltage will drop. Tomaintain the voltage as best they can, the utility will increasethe voltage so customers close to the power source willhave higher than nominal voltage while the furthestcustomers will have lower than nominal voltage (maybemuch lower). Because the utility will only increase thevoltage by a certain amount, and because additional voltagedrop is caused in the user’s building wiring, voltages are
  • 24. Most voltage sags originate within your facility. The three most common causes of facility-sourcedvoltage sags are:•Starting a large load, such as a motor or resistive heater. Electric motors typically draw 150%to 500% of their operating current as they come up to speed. Resisitive heaters typically draw150% of their rated current until they warm up.•Loose or defective wiring, such as insufficiently tightened box screws on power conductors.This effective increases your system impedance, and exaggerates the effect of current increases.•Faults or short circuits elsewhere in your facility. Although the fault will be quickly removed bya fuse or a circuit breaker, they will drag the voltage down until the protective device operates,which can take anywhere from a few cycles to a few seconds.Experts can identify the specific source of a voltage sag with an advanced power quality monitor,such as those found at PQMonitoring.com. Voltage sags can also originate on your utilityselectric power system. The most common types of utility-sourced voltage sags are:•Faults on distant circuits, which cause a corresponding reduction in voltage on your circuit.Typically, these faults are removed by "reclosers", or self-resetting circuit breakers. Thesereclosers typically delay 1 to 5 seconds before self-resetting. If the fault is still present when therecloser resets, you may see a series of voltage sags, spaced 1 to 5 seconds apart. Faults onutility systems may be phase-to-phase, or phase-to-earth; depending on the transformersbetween you and the fault, you will see different levels of voltage reduction.• Voltage regulator failures are far less common. Utilities have automated systems to adjustvoltage (typically using power factor correction capacitors, or tap switching transformers), andthese systems do occasionally fail.
  • 25. ‫ كحالة عابرة‬overvaltage ‫تجاوز الجهد‬Example capacitor switching transient -‫الدكتور المهندس محمد منذر القادري‬ munthear@gmail.com
  • 26. The reasons for these categories were explained as follows: •The 90% level provides an indication of performance for the most sensitive equipment. •The 80% level corresponds to an important break point on the ITI curve and some sensitive equipment may be susceptible to even short sags at this level. •The 70% level corresponds to the sensitivity level of a wide group of industrial and commercial equipment and is probably the most important performance level to specify. •The 50% level is important, especially for the semiconductor industry, since they have adopted a standard that specifies ride through at this level. •Interruptions affect all customers so it is important to specify this level separately. These will usually have longer durations than the voltage sags. •The first range of durations is up to 0.2 seconds (12 cycles at 60 Hz). This is the range specified by the semiconductor industry that equipment should be able to ride through sags as long as the minimum voltage is above 50%. •The second range is up to 0.5 seconds. This corresponds to the specification in the ITIC standard for equipment ride through as long as the minimum voltage is above 70%. It is also an important break point in the definition of sag durations in IEEE 1159 (instantaneous vs. momentary). •The third duration range is up to 3 seconds. This is an important break point in IEEE 1159 and in IEC standards (momentary to temporary). •The final duration is up to one minute. Events longer than one minute are characterized as long duration events and are part of the system voltage regulation performance, rather than voltage sags.
  • 27. voltage sag sensitivityWhy does equipment fail when there are voltage sags on ac power systems? There is one obvious way, andfour not-so-obvious ways. 1. Equipment fails because there isnt enough voltage. This is the obvious way -- if there is not enoughvoltage on the ac power system to provide the energy that the equipment needs, it is going to fail. Actually, theproblem is slightly more subtle. In a typical sensitive load, the ac voltage is rectified and coverted to pulsed dc.With a bridge rectifier, the pulsing will typically be either twice the power line frequency (for single-phase loads)or six times the power line frequency (for three-phase loads). This pulsing DC is stored in a filter capacitor,which in turn supplies smooth DC as raw material for the rest of the power supply: regulators, etc.If the DC supplied by the filter capacitor drops below some critical level, the regulators will not be able to delivertheir designed voltage, and the system will fail. Note that the filter capacitor always stores energy, so there isalways an ability to ride through some sags -- after all, the ac power system delivers zero voltage 100 or 120times each second! But with a deep enough sag that lasts long enough, the filter capacitor voltage will dropbelow a critical level.2. Equipment fails because an undervoltage circuit trips. Careful system designers may include a circuitthat monitors the ac power system for adequate voltage. But "adequate voltage" may not be well defined, orunderstood. For example, if the sensitive system is running at half load, it may be able to operate at only 70%ac voltage, even though it may be specified to operate with 90% - 110% ac voltage. So the voltage sags to70%; the equipment can operate without a problem; but the undervoltage monitor may decide to shut thesystem down.
  • 28. 3. Equipment fails because an unbalance relay trips.On three-phase systems, voltage sags are oftenasymmetrical (they affect one or two phases more than the remaining phases). Three-phase motors andtransformers can be damaged by sustained voltage unbalance; it can cause the transformer or motor tooverheat. So it makes sense to put in an unbalance relay, which is a device that shuts down the system if thevoltage unbalance exceeds some threshold, typically a few percent.But a voltage sag that causes 20-50% unbalance for a second or two is never going to cause a motor ortransformer to overheat. It just doesnt last long enough. Still, unbalance relays with inadequate delays cancause the sensitive system to shut down, even for a brief voltage sag.4. A quick-acting relay shuts the system down, typically in the EMO circuit. The EMO (emergency off)circuit in an industrial load typically consists of a normally-closed switch that can disconnect power to alatched relay coil. If the relay operates quickly enough, it may interpret a brief voltage sag as an operatorhitting the EMO switch. The whole system will shut down unnecessarily.5. A reset circuit may incorrectly trip at the end of the voltage sag. This is the most subtle problemcaused by voltage sags. Many electronic reset circuits are designed to operate at "power up" -- when youfirst turn on the equipment, these circuits will ensure that the microprocessors all start up properly, thelatches are all properly initialized, the displays are in their correct mode, etc. These circuits are difficult todesign, because they must operate correctly when power is uncertain.One common design detects a sudden increase in voltage, which always happens when you turn theequipment on. Unfortunately, it also happens at the end of a voltage sag. If the reset circuit misinterprets theend of a voltage sag, the equipment will operate perfectly during the voltage sag, but will abruptly reset itselfwhen the voltage returns to normal.To make this problem even more difficult, it is quite common for different parts of a system to have differentreset circuits, so it is possible for one part of the system to be reset even when the rest of the system is not.Without a sag generator with a good data acquisition system, this problem is very difficult to detect andsolve.
  • 29. ‫تنظٌم التوتر‬The term "voltage regulation" is used to discuss long-term variations in voltage. It does not include short termvariations, which are generally called sags, dips, or swells.The ability of equipment to handle steady state voltage variations varies from equipment to equipment. Thesteady state voltage variation limits for equipment is usually part of the equipment specifications. TheInformation Technology Industry Council (ITIC) specifies equipment withstand recommendations for ITequipment according to the ITI Curve (formerly the CBEMA curve). The 1996 ITI Curve specifies that equipmentshould be able to withstand voltage variations within +/- 10% (variations that last longer than 10 seconds).Voltage regulation standards in North America vary from state to state and utility to utility. The national standardin the U.S.A. is ANSI C84.1. Voltage regulation requirements are defined in two categories:•Range A is for normal conditions and the required regulation is +/- 5% on a 120 volt base at the serviceentrance (for services above 600 volts, the required regulation is -2.5% to +5%).•Range B is for short durations or unusual conditions. The allowable range for these conditions is -8.3% to+5.8%. A specific definition of these conditions is not provided.Voltage regulation requirements from ANSI C84.1. This is not a universal standard; it is only used in NorthAmerica.Other countries have different standards. For example, IEC 61000-2-2 mentions that the normal operationaltolerances are +/- 10% of the declared voltage. This is the basis of requirements for voltage regulation in EN50160 for the European Community. EN 50160 requires that voltage regulation be within +/- 10% for 95% of the10 minute samples in a one week period, and that all 10 minute samples be within -15% to +10%, excludingvoltage dips.
  • 30. voltage sag ‫كٌف نحسن من المناعة ضد‬1. Find and fix the problem.2. 2. Add a power quality relay.3. 3. Switch power supply settings.4. Connect your single-phase power supply phase-to-phase.5. Reduce the load on your power supply.6. Increase the rating of your power supply.7. Use a three-phase power supply instead of a single-phase supply.8. Run your power supply from a DC bus.9. Change the trip settings.10. Slow the relay down.11. Get rid of the voltage sag itself. -‫الدكتور المهندس محمد منذر القادري‬ munthear@gmail.com
  • 31. ‫ اإلرتفاع /اإلنخفاض‬Sags / SurgesSags / Surges are short duration changes in voltage level.Sags (low voltage) are much more common than surges(high voltage). Starting electric motors and otherequipment, ground faults, undersized power systems, andlightning all produce voltage sags.Surges may be generated when large electrical loads areshut off. -‫الدكتور المهندس محمد منذر القادري‬ munthear@gmail.com
  • 32. Surge ‫إندفاع هضبة التوتر‬• EN61000-4-5• Performance Criteria B• The surge waveform simulates the transients induced onto the AC power line by lightning events• The wave-shape is 1.2/50 S open circuit voltage through a 2 ohm resistor (line to line) or 12 ohm resistor (line to ground). The short circuit current wave-form is 8/20S -‫الدكتور المهندس محمد منذر القادري‬ munthear@gmail.com
  • 33. ‫‪ surge‬ماذا تعنً؟‬‫‪ Surge ‬هً رشقة قصٌر من الجهد ( جهود دفقٌة أو هضبة جهد) تعرض‬‫الحمل إلى االف الفولت. وتكون أحٌانا على شكل نبضة مسمارٌة وأحٌانا على‬ ‫شكل حالة عابرة‬ ‫‪ ‬فترة قصٌرة ‪Short Duration --- Microseconds‬‬ ‫‪ ‬طاقة عالٌة ‪High Energy‬‬ ‫‪ ‬مولدة خارجٌا ‪Externally Generated‬‬ ‫‪ ‬مولدة داخلٌا ‪Internally Generated‬‬
  • 34. ‫هضبة الجهد ‪ Surges‬هً‬ ‫نبضة زمنها أكبر من 4.8 مٌلً ثانٌة‬ ‫•‬ ‫توصف بالموجة المربعة أو األسٌة‬ ‫•‬ ‫عادة ما تترافق بمنبع ذو ممانعة منخفضة‬ ‫•‬‫إرتفاع الهضبة فً %09 من الحاالت ٌكون أقل من ضعفً قٌمة الجهد التشغٌل االسمً.‬ ‫•‬
  • 35. ‫من أٌن تأتً ‪Surges‬؟‬ ‫النوع المولد خارجٌا:‬ ‫‪ ‬المدمرة – ‪ Destructive‬من الجو مثل الصواعق‬ ‫‪ ‬المعطلة – ‪ Disruptive‬فصل الشبكة الكهربائٌة‬ ‫النوع المولد داخلٌا:‬‫‪ ‬مسٌئة – ‪Degradative‬األحمال التحرٌضٌة وأجهزة التقطٌع‬ ‫الدكتور المهندس محمد منذر القادري-‬ ‫‪munthear@gmail.com‬‬
  • 36. ‫ماهً المشاكل التً تسببها ‪surges‬؟‬ ‫‪ ‬عطل مباشر في التجهيزات قد تسب تلف ‪.IC‬‬‫‪ ‬هضبة الجهد المسٌئة ‪ degradative surges‬قد تسبب أعطال غٌر قابلة للشرح.‬ ‫‪ ‬فشل أداء بعض األجهزة بسبب ترابط ‪ surges‬مع خطوط معطٌات.‬ ‫الدكتور المهندس محمد منذر القادري-‬ ‫‪munthear@gmail.com‬‬
  • 37. ‫08% من األعطال الناجمة عن رداءة القدرة هً‬ ‫بسبب الجهود اإلبرٌة و‪ surge‬المولدة داخلٌا‬ ‫الدكتور المهندس محمد منذر القادري-‬ ‫‪munthear@gmail.com‬‬
  • 38. ‫ماهً وسائل الحماٌة من‬surge ‫؟‬ A high voltage relief valve It insulates during normal operation It clamps voltage by diverting excess current toground during a surge It is basically a variable resistor Acts like an open circuit with high impedance normally During a surge it acts like a short circuit with lowimpedance
  • 39. ‫تقنٌات الحماٌة من ‪Surge‬‬ ‫انمهفبث‬ ‫-‬ ‫األوببٍب انغبزٌت‬ ‫-‬ ‫مقىمبث انسٍهٍىٍىو‬ ‫-‬ ‫انفبٌرسخىر‪MOV‬‬ ‫-‬‫ثىبئٍبث ‪ Avalanche‬انسهكىوٍت‪SAD‬‬ ‫-‬ ‫انمكثفبث‬ ‫-‬‫الدكتور المهندس محمد منذر القادري-‬‫‪munthear@gmail.com‬‬
  • 40. ‫خواص العناصر‬ ‫مقىمبث انسٍهٍىٍىو‬ ‫انمكثفبث‬ ‫‪ surge ‬قذرة ػبنٍت‬ ‫‪ surge ‬قذرة ػبنٍت‬‫‪ ‬جهذ إقفبل ػبنً ‪clamping‬‬ ‫‪ ‬حخسن طبقت كبٍرة‬ ‫‪ ‬اسخجببت بطٍئت‬ ‫‪ ‬حخصرف كذارة قصر‬ ‫األوببٍب انغبزٌت‬ ‫انمهفبث‬ ‫‪ surge ‬قذرة ػبنٍت‬ ‫‪ surge ‬قذرة ػبنٍت‬ ‫‪ ‬اسخجببت بطٍئت‬ ‫‪ ‬حخسن قذرة كبٍرة‬ ‫‪ ‬غٍر ثببخت‬ ‫‪ ‬حخصرف كذارة مفخىحت‬ ‫الدكتور المهندس محمد منذر القادري-‬ ‫‪munthear@gmail.com‬‬
  • 41. ‫خواص العناصر‬ ‫ثىبئٍبث ‪ Avalanche‬انسهكىوٍت‪SAD‬‬ ‫‪ ‬إسخجببت سشيعت للغبيت أصغش مه‪1 nsec‬‬ ‫‪ surge ‬لذسة مىخفضت‬ ‫‪ ‬حخميذ صغيشة مسبحت‬ ‫فبٌرسخىر أكسٍذ مؼذن ‪MOV‬‬ ‫‪ ‬اسخجببت سشيعت مه مشحبت ‪1 nsec‬‬ ‫‪ ‬جهذ إلفبل محكم ‪clamping‬‬ ‫‪ surge ‬عبليت لذسة‬‫الدكتور المهندس محمد منذر القادري-‬‫‪munthear@gmail.com‬‬
  • 42. ‫الحاالت العابرة & الجهودالنبضٌة واإلبرٌة‬Impulses, Spikes & Transients are all names used to describe veryshort duration, high amplitude voltage pulses on the power lines.These voltage pulses often reach 6,000 volts. They are caused bylightning that strikes on or near the power lines, utility switching, staticelectricity, and switching electrical devices on or off. Impulses damage all types of electronic and electrical equipment. Thehigh voltage levels puncture or weaken insulation. The fast rate ofvoltage change stresses the turn-to-turn insulation of windings inmotors, transformers, solenoids, etc. The damage may not causeimmediate failure. Often the equipment is weakened and may fail daysor weeks after the event. Besides equipment damage, impulses causemachine resets, data processing errors, and other apparently randommalfunctions. -‫الدكتور المهندس محمد منذر القادري‬ munthear@gmail.com
  • 43. Transient ‫ماهً الحالة العابرة‬• Definition: an unanticipated change in voltage caused by a unpredictable occurrence.• One must differentiate between a voltage transient and a power surge.• Transients can be categorized in 4 basic threats. – Lightning. – Nuclear electromagnetic pulse. – Electrostatic Discharge. – Inductive switching.
  • 44. ‫الحالة العابرة‬ ‫القدرة النظامٌة .‪50Hz‬‬‫‪Transient‬‬‫‪waveform‬‬
  • 45. ‫الحالة العابرة هً‬ ‫نبضة زمنها أقل من 4.8 مٌلً ثانٌة‬ ‫•‬ ‫توصف بالموجة الجٌبٌة أو األسٌة عادة ما تترافق بمنبع ذو ممانعة عالٌة.‬ ‫•‬‫قٌمتها تتراوح بٌن بضع مٌلً فولت و 00081 فولت بشروط التشغٌل الطبٌعٌة.‬ ‫•‬ ‫حىصيفهب وفك المعيبس 2-4-00016 ‪IEC‬‬
  • 46. ‫كٌف نخمد الحالة العابرة‬ : ‫ٌجب األخذ بعٌن اإلعتبار اإلرشادات التالٌة‬– TVS Parameters • Stand-off Voltage (Vwm) >= Operating Voltage (Vop) • Peak Pulse Current (Ippm) >= Source Transient Current (Is) • Clamping Voltage (Vc) =< Voltage Withstand (Vws) -‫الدكتور المهندس محمد منذر القادري‬ munthear@gmail.com
  • 47. ‫لماذا‬TVSS‫؟‬ Increasing Awareness of power quality Increased speed and density of integrated circuits Microprocessor based electronics throughout facility Conversion from analog to digital Switch-mode power supplies -‫الدكتور المهندس محمد منذر القادري‬ munthear@gmail.com
  • 48. ‫منحنً خواص ‪TVS‬‬
  • 49. TVS‫مكثفات متناهٌة الصغر‬ • Available from 3volt to 24volt in unidirectional and bidirectional configurations • GBLC series
  • 50. ‫ ذات سعات صغٌرة جدا‬TVS ‫مصفوفات‬ • Can be utilized for unidirectional common mode and bidirectional common mode or differential mode protection applications
  • 51. ‫ متناهٌة الصغر‬TVS ‫مصفوفات‬ • SLVU2.8-4 – 4 lines of protection
  • 52. ‫إرتعاش الجهود المتناوبة‬ AC Voltage Flicker• “Flicker” is the effect caused when a large load current is switched, creating a short-duration dip in the AC voltage (e.g. refrigerator, when compressor switches on the lights dim momentarily)• Can only be measured with a custom-built test equipment - but could be evaluated using a light bulb connected to the same AC outlet ?
  • 53. ‫اإلرتعاش‬ ‫‪Flicker‬‬‫اإلرتعاش مشكلة خاصة جدا وتهم اإلنسان العادي . وهً ال تقع تحت مصطلح تغٌرات الجهد.‬ ‫اإلنسان حساس جدا إلرتعاش اإلضاءة الناجم عن تموج الجهد.‬ ‫الدكتور المهندس محمد منذر القادري-‬ ‫‪munthear@gmail.com‬‬
  • 54. Brownouts ‫إنخفاض الجهد‬Brownouts are intentional under-voltages instituted by theutility. When power demand exceeds the capacity of theutility generators, the utility lowers the voltage to all orsome customers. This reduces the load on the generatorsso they won’t burn out, but causes even more acuteequipment malfunctions and damage. -‫الدكتور المهندس محمد منذر القادري‬ munthear@gmail.com
  • 55. ‫عدم توازن األطوار‬Three Phase Voltage Unbalance simply means the voltages on a three-phase system arenot equal.Utilities generate three-phase AC power because it is produced and distributed at lower costthan single phase AC or DC power, and because three phases are needed to producesteady torque in AC generators and motors. To power single phase loads, any two of thethree power wires are connected. Voltage unbalance is usually caused by connecting moresingle phase loads to one of the three phases. This situation produces unbalanced loadcurrents, uneven voltage drops, and thus, unbalanced voltages.For three-phase loads, a voltage unbalance of one or two percent is usually not a problem.However, larger voltage unbalances can cause many problems. For example, three-phasemotors with 5% voltage unbalance exhibit 25% decrease in torque, 50% increase in losses,40% increase in temperature, and a whopping 80% decrease in life. In transmitterapplications, voltage unbalance causes severe ripple in high voltage power supplies,straining the power supply filtering and increasing AM noise.
  • 56. ‫معامل القدرة‬ ( PF ) Power factor ‫• معامل القدرة‬ PF = kW / kVA – ‫– معامل القدرة للمحرك متأخر‬– 100HP motor, 460V, 93% eff, 119A : ‫- مثال‬ • (100HP x 0.746kW/HP) / 0.93 = 80.2kW • 119A x 460V x 1.73 / 1000 = 94.8kVA • PF = 80.2kW / 94.8kVA = 84.6% @ FL • But … at actual load, more like 70% or less -‫الدكتور المهندس محمد منذر القادري‬ munthear@gmail.com
  • 57. ElectroMagnetic Compatibility ‫المالئمة الكهرامغناطٌسٌة‬• All electronic equipment is capable of radiating and absorbing radio frequency (RF) energy.• The principle behind ElectroMagnetic Compatibility is that equipment should limit radiation to below a specified level, and be able to withstand a certain level of incident RF radiation.• The levels are given in the EMC regulations. – BS EN 55022 (Computers) – BS EN 55020 (Radio & TV)• These are only a guide as circumstances vary for each location.
  • 58. EMC ‫1-إعتبارات‬• Good RF house keeping is vital . . .• Spurious outputs from transmitters – Along with unintended leakage wanted RF.• Too much power radiated. – Leading to excessive field strength.• Only use as much power necessary to make the contact. – This will reduce the EMC potential• Your set-up – Mode used, Antenna location, Antenna type used (Next session).
  • 59. EMC ‫2-إعتبارات‬• Considerations . . .• Filters used (EMC session-2) – Ferrite ring, High Pass, Low Pass, Band Pass Notch.• Poor immunity of affected device – Age, construction and use of equipment..• Proximity for affected item. – Coupling / Connections, Location.• Good Quality Coax – Quality connectors, soldered correctly and water tight.
  • 60. RF Earths ‫تأرٌض التردد الرادٌوي‬ “Mains Earth” ‫• التستخدم أرضً القدرة‬– Provide a separate earth point consisting of several copper rods in the ground and a thick copper wire to the equipment– Earth outer of coax cable as it enters any building.– Do not use water / gas pipes as they may not be truly earthed. -‫الدكتور المهندس محمد منذر القادري‬ munthear@gmail.com
  • 61. EMC ‫ و‬RFI ‫ و‬EMI ‫ما هو‬ Electromagnetic Interference (EMI) ً‫• التداخل الكهرامغناطٌس‬ – Any electromagnetic disturbance that interrupts, obstructs, or otherwise degrades or limits the effective performance of electronics/electrical equipment Radio Frequency Interference (RFI) ‫• التداخل الرادٌوي‬ – In general, extraneous energy, from natural or man-made sources, that impedes the reception of desired signals.Electromagnetic Compatibility (EMC) ‫• المالئمة الكهرامغناطٌسٌة‬ – A device is compatible with its electromagnetic (EM) environment and it does not emit levels of EM energy that cause electromagnetic interference (EMI) in other devices in the vicinity.
  • 62. EMI ‫مسببات‬ ‫المنابع‬ • Signal / Power energy in EM fields ‫– حقول كهرامغناطٌسً لخطوط القدرة‬Reflections from un-terminated transmission lines ‫– إنعكاس من تهاٌات خطوط إرسال‬ Electrostatic Discharges (ESD) ً‫– تفرٌغ كهراستاتٌك‬ ‫• التربط‬ Inductive / Capacitive coupling ً‫ترابط سعوي أو تحرٌض‬ – Common impedance coupling ‫ترابط بممانعة مشتركة‬ – Radiated electromagnetic fields ‫حقل كهرامغناطٌسً مشع‬ – ‫المستقبالت‬ • Unnecessarily high bandwidth ‫– عرض مجال واسع غٌر مرغوب‬ Low noise margins ‫– هامش ضجٌج منخفض‬
  • 63. ‫تقنٌات تخفٌض ‪EMI‬‬ ‫• تخمٌد منابع اإلشعاع‬ ‫موافقة خطوط اإلرسال‬ ‫–‬ ‫تخمٌد عناصر اإلشارة الرادٌوٌة الغٌر ضروري‬ ‫–‬ ‫تخفٌض مستوٌات الجهد والتٌار‬ ‫–‬‫مرشح مسالم على خطوط التغذٌة وعلى خطوط اإلشارة وعلى نبضات النزامن‬ ‫–‬ ‫• تخفٌض الترابط‬ ‫– توضع للعناصر وتوزٌع مسار الخطوط.‬ ‫– التحجٌب.‬ ‫– تأرٌض .‬ ‫الدكتور المهندس محمد منذر القادري-‬ ‫‪munthear@gmail.com‬‬
  • 64. ‫كٌف تعمل المرشحات على تخفٌض ‪EMI‬‬ ‫1‪V‬‬‫‪-1/1V‬‬ ‫‪Int Z‬‬ ‫1‪R‬‬ ‫05‬ ‫001‬ ‫ٌخمد مرشح التمرٌر المنخفض‬‫‪1mHz‬‬ ‫1‪C‬‬ ‫توافقٌات اإلشارة التً هً أعلى من‬ ‫‪TVS‬‬ ‫2‪C‬‬ ‫القطع )‪ (fc‬من أجل اإلختبار نختار‬ ‫‪TVS‬‬ ‫‪20pf‬‬ ‫‪20pf‬‬ ‫‪50 Load‬‬ ‫1‪ D‬و2‪ D‬من نوع دٌود ‪ TV‬ذو‬ ‫سعة وصلة ‪ ,20pF‬سوف ‪TVS‬‬ ‫تحمً من الحالة العابرة وتخمد‬ ‫اإلشارات الغٌر مرغوبة التً فوق تردد‬ ‫القطع‬ ‫الدكتور المهندس محمد منذر القادري-‬ ‫‪munthear@gmail.com‬‬
  • 65. ‫المرشح بوجود تحرٌضٌات طفٌلٌة‬ ‫1‪R‬‬ ‫001‬‫1‪+ Vs‬‬ ‫1‪C‬‬ ‫2‪C‬‬ ‫‪15pF‬‬ ‫‪15pF‬‬ ‫‪RL‬‬ ‫‪2.5V‬‬ ‫05‬‫-‬ ‫‪TVS‬‬ ‫2‪D‬‬ ‫50.‬ ‫50.‬ ‫‪TVS‬‬ ‫1‪L‬‬ ‫1‪D‬‬ ‫2‪L‬‬ ‫المكثفبث 1‪ C‬و2‪ C‬هي مكثفبث الىصلت الذيىداث ‪L1 , TVS‬‬ ‫و 2‪ L‬هي ححشيضيبث وبشئت مه حىصيالث الذاسة المطبىعت ‪. PCB‬‬ ‫المششح سىف يخمذ اإلشبساث الخي فىق حشدد المطع‬ ‫والذيىداث ‪ TVS‬سىف ححمي مه الىبضبث اإلبشيت الىبجمت مه الحبلت العببشة.‬
  • 66. ‫‪EMIF6-100LFC‬‬ ‫مثال‬ ‫إن ‪ EMIF6-100FC‬هى عببسة عه مششح ‪ EMI‬رو 6‬ ‫خطىط مع حمبيت مه الحبالث العببشة ضمه ششيحت واحذة‬
  • 67. ESD ‫المناعة ضد تفرٌغ الشحنة الساكنة‬• EN61000-4-2• Performance Criteria B• ESD events create high-speed transients that can: • Permanently damage ICs • Cause false resets or other spurious reactions • The performance criteria is B - so some degradation in performance is permitted during the test but the device MUST recover without user intervention.• ESD events caused by people discharging directly to the product or to nearby objects
  • 68. ‫توضع عناصر دارة صحٌح‬ ‫حافظ على جعل مسارات نبضات التزامن أقصر ما ٌمكن.‬ ‫‪‬‬ ‫حاول إبعاد مسارات نبضات التزامن بعٌدة ما ٌكمن عن حواف البطاقة اإللكترونٌة ‪.PCB‬‬ ‫‪‬‬ ‫دعم الدارة بمكثفات إزالة الترابط الرادٌوي وخصوصا على الدارات المتكاملة التً تعمل على‬ ‫‪‬‬ ‫التقطٌع وحاول وصلها أقرب ماٌمكن من أرجل .‬‫إن مكثفات إزالة الترابط فعالة فقط فً الترددات حتى ‪ ,100MHz‬فً الترددات األعلى من ذلك ٌتم‬ ‫‪‬‬ ‫تحقٌق إزالة الترابط بجعل وحدات التغذٌة أقرب ما ٌكون ومن خالل صفائح معدنٌة مؤرضة.‬ ‫الخطوط الحاملة لنبضات التزامن ٌجب وصل نهاٌاتها بمقومات عندما طولها ثالثة أضعاف زمن‬ ‫‪‬‬ ‫صعودها لحماٌتها من الطنٌن على خطوطهاألن ممانعة المسار ال تساوي المصدر مقسومة على‬ ‫الحمل.‬ ‫.‪tr = rise time in nS‬‬ ‫‪‬‬
  • 69. ‫توضع عناصر دارة صحٌح‬ Provide filtering on all interface ports (including AC & DC power ) RF caps to a “clean” ground (typically chassis), common mode chokes or ferrite beads make ideal circuit elements Include the filter components on ALL signal lines, including ground (especially where the ground is a digital signal ground)
  • 70. I/O Interfaces ‫التداخل بٌن الخرج والدخل‬ If possible, use PCB connectors with metal back shells as these can prevent high frequency signals radiated from the board from coupling onto the signal lines after the filter Shields ideally terminate 360 to the enclosure (NOT to digital ground). Shielded cables should have the shield terminated to the enclosure at the “noisy” end(s) - single ended grounding at rf does not work Never use pigtails to terminate shields - at best they make a shielded cable ineffective, at worst they can increase emissions.  XLR cables are not designed for effective use of the shields - if you cannot terminate the shield directly to chassis (because of low frequency ground loops) tie to chassis using ceramic capacitors (alternatively create a capacitor on the PCB)
  • 71. ‫الحلول الوقائٌة‬• ‫ الحصانة من اإلشعاع‬Radiated Immunity – Solve problems in a similar manner to radiated emissions – Restrict bandwidths – Add common mode filtering to audio inputs – Pay particular attention to high-gain stages - make sure they are provided with adequate rf decoupling• ‫ الحالة العابرة السرٌعة‬Fast Transients – Transzorbs on I/O lines, filtering, enclosure design all have an effect• ‫ إنبعاث الجهد‬Surge – Power supply design could incorporate MoVs line-to-line (line-to- ground typically prohibited by Safety standard) – AC line filters can reduce surge effects.
  • 72. ‫فلتر ‪EMI‬‬ ‫مثال:‬‫الشبكة‬ ‫الجهاز‬‫الكهربائٌة‬
  • 73. ‫مبهي الخىافميبث ؟‬ ‫+‬ ‫=‬ ‫)‪sin(5x‬‬‫)‪f(x) = sin(x‬‬ ‫= )‪f(x‬‬ ‫5‬ ‫)‪f(x) = sin(x) + sin(5x‬‬ ‫5‬ ‫الدكتور المهندس محمد منذر القادري-‬ ‫‪munthear@gmail.com‬‬
  • 74. ‫التشوه التوافقً‬ ‫التشوه التوافقً هو تشوه فً شكل الموجةالجٌبٌة . ٌحدث بسبب مرور تٌارات أحمال‬ ‫غٌر جٌبٌة فً ممانعة مشتركة فً نظام التوزٌع الذي بدوره ٌؤدي إلى خلق جهد غٌر‬ ‫جٌبً على خطوط التوزٌع.‬‫إن وحدات التغذٌة وأنظمة قٌادة المحركات التً تعتمد أنصاف النواقل وتٌارات مغنطة‬ ‫المحوالت جمٌعها تسبب تشوهات توفقٌة.‬‫تشوهات الجهد هذه قد تؤذي أو تخل فً أداء العدٌد من األجهزة المصولة على خطوط‬ ‫الشبكة المشوهة.‬ ‫الدكتور المهندس محمد منذر القادري-‬ ‫‪munthear@gmail.com‬‬
  • 75. ‫اآلثار الضارة للتشوه التوافقً‬‫• ضجٌج سمعً وإهتزاز مٌكانٌكً فً التجهٌزات الكهرومغناطٌسٌة كالمحوالت والمحركات و لوحات‬ ‫الحماٌة (القواطع).‬ ‫• إرتفاع الحرارة فً المحوالت والمولدات والكبالت ومكثفات التعوٌض.‬ ‫• سوء أداء بعض تجهٌزات التحكم اإللكترونٌة الحساسة.‬ ‫• فتح قواطع الحماٌة بشكل غٌر مبرر.‬ ‫• إرتجاف اإلضاءة وشاشات التلفزة والحواسٌب.‬ ‫• تشوه الصوت فً األنظمة الصوتٌة.‬ ‫• إنخفاض عامل اإلستطاعة الغٌر مفسر.‬ ‫• تحمٌل الزائد للناقل الحٌادي خصوصا عند وجود التوافقٌة الثالثة.‬ ‫الدكتور المهندس محمد منذر القادري-‬ ‫‪munthear@gmail.com‬‬
  • 76. ‫مصادر التوافقٌات & اإلرتعاش‬ ‫• العناصر الفٌرومغناطٌسٌة‬ ‫– المحوالت(اإلشباع , الالخطٌة).‬ ‫• عناصر القوس الكهربائً‬ ‫– مصابٌح الفلورٌسانت.‬ ‫– أجهزة اللحام بالقوس الكهربائً.‬ ‫– أفران القوس الكهربائً.‬ ‫• العناصر اإللكترونٌة المفتاحٌة‬ ‫الدكتور المهندس محمد منذر القادري-‬ ‫‪munthear@gmail.com‬‬
  • 77. Conquering Harmonic Resonance can be accomplished by:(1) adding or subtracting capacitance from the system to move theparallel resonance frequency to one that is not deleterious;(2) adding tuned harmonic suppression reactors in series with thecapacitor to prevent resonance; (3) altering the size of non-lineardevices. It is important that the tuned frequency, for the 5th harmonic,be at approximately the 4.7th harmonic to account for tolerance inmanufacturing and to remove the largest offending portion of the 5thharmonic. Parallel resonance will occur around the 4th harmonic, at amuch lower amplitude and in an area that does no harm to thesystem or capacitor. Tuning lower than 282 Hz is not efficient inremoving large portions of the offending harmonic -‫الدكتور المهندس محمد منذر القادري‬ munthear@gmail.com
  • 78. ‫تطبٌق تصحٌح عامل القدرة فً بٌئة مشوه توافقٌا‬
  • 79. where: h = harmonic orderKVAsc : available short circuit at point of capacitor bank installationKVAR =capacitor bank size -‫الدكتور المهندس محمد منذر القادري‬ munthear@gmail.com
  • 80. ‫دارة إزالة الرنٌن‬
  • 81. ‫منظمات زاوٌة الطور‬ ‫مثال: مخفتات اإلضاءة‬ ‫•‬ ‫‪lamp dimmer circuit‬‬ ‫تعلٌقات:‬ ‫•‬ ‫– ٌمكن تخفٌض تشوهات التٌار باستخدام ملف خانق مناسب‬‫– إن ‪THD‬و ‪ EMI‬المشع ٌكون بأقل قٌمته عند زاوٌة قدح °0 و °081 (صفر أو كامل التوتر)‬ ‫– إن ‪THD‬و ‪ EMI‬المشع ٌكون بأعلى قٌمته عند زاوٌة قدح °09 (نصف التوتر)‬
  • 82. ‫أشكبل أمىاج مخفج اإلضبءة‬
  • 83. ‫طيف مىجت الخيبس لمخفج اإلضبءة‬• High frequency components which lead to EMI are reduced by the choke.
  • 84. ‫المقومات وحٌدة الطور‬ ‫مثال: وحدات تغذٌة الحواسب, شواحن البطارٌات‬ Typical computer power supply front-end• The rectifier conducts only when the line voltage magnitude exceeds the capacitor voltage.• The capacitor gets charged by drawing current at the peak of the voltage cycle and gets discharges slowly into the switching regulator between the voltage peaks.• Thus the circuit draws short pulses of current during line voltage peaks.
  • 85. ‫التٌار المستجر من وحدة تغذٌة الحاسب‬
  • 86. ‫تٌار الحٌادي فً جسر تقوٌم ثالثً الطور‬ ‫الدكتور المهندس محمد منذر القادري-‬ ‫‪munthear@gmail.com‬‬
  • 87. Sequence Classification of Harmonics• In AC systems, the current and voltage waveforms have rotational symmetry. – even harmonics will not be present.• Power system harmonics are hence predominantly the odd, i.e 3rd, 5th, 7th, etc.
  • 88. ‫مقوم ثالثً الطور‬ Six-pulse Rectifier• Used in motor drives, traction, electrochemical plants, etc.• The high inductance in the dc side causes the dc current, Id to be essentially constant.
  • 89. ‫ مقوم ثالثً الطور‬Six-pulse Rectifier• The Fourier series for the line current for a diode rectifier is: 2 3  1 1 1 1 ia ( t)   Id   sin t  sin5 t  sin 7 t  sin 11 t  sin 13 t  ... 5 7 11 13 • For symmetrical ideal triggering, only harmonics of the order 6n±1 are present in the AC side currents.• The presence of source reactance and commutation effects lead to smoother current waveforms. -‫الدكتور المهندس محمد منذر القادري‬ munthear@gmail.com
  • 90. Supply voltage and current waveforms for three-phase bridge with highly inductive load
  • 91. Twelve-pulse Rectifier (cont.)• Used in high power motor drives, traction, hvdc converters, etc.• The Fourier series for the line current for a twelve-pulse diode rectifier is: 2 3  1 1  ia (t )  I d sin t  sin 11t  sin 13t  ...•  For symmetrical ideal triggering, only harmonics of the 13 12n±1 are   11 order present in the AC side currents. Supply voltage and current waveforms for twelve pulse bridge with highly inductive load
  • 92. ‫مبدالت التردد ‪Cycloconverters‬‬ ‫- ٌستخدم فً قٌادة المطاحن الكبٌرة فً صتاعة اإلسمنت وصناعة التعدٌن.‬ ‫- التوافقٌات المتولدة عنه هً :‬ ‫‪ cycloconverter‬حشدد الخشج لمبذل الخشدد =‪fo‬‬ ‫‪f h   pm  1 f‬‬ ‫‪‬‬ ‫0 ‪6nf‬‬ ‫; …,3,2,1=‪m‬‬ ‫…,2,1,0=‪n‬‬ ‫- طيف الخىفميبث يخغيش كلمب حغيش حشدد الخشج‬‫‪Typical input current harmonics of a six-pules cycloconverter with 5-Hz output frequency‬‬
  • 93. Integral-cycle Controllers or Pulse Burst Modulation (PBM) • This technique is used in applications such as heating, ovens, furnaces, etc. • Subharmonics are predominant. DC component can also be present. • High frequency harmonics above 200 Hz are practically absent.Pulse-burst-modulation power conditioning .Current wave: n=6; g=4/6Harmonic spectrum for g6/8. Currents generated by a typical PBM system. 
  • 94. A Demonstration That a Balanced 3-Phase Load Can Result In Neutral Current
  • 95. ‫الخىافميبث والمحىالث‬ ‫إرتفاع حراري للمحول وعطب العزل وذلك ألسباب عدة:‬ ‫زٌادة تأثٌر الظاهرة القشرٌة ‪ skin‬وظاهرة التجاور‪proximity‬‬ ‫دوران التوافقٌات فً الملف اإلبتدائً ‪. circulating‬‬ ‫تزٌد من ضٌاعات اإلبطاء ‪hysteresis‬‬ ‫تزٌد من ضٌاعات التٌارات اإلعصارٌة ‪eddy‬‬ ‫تٌار مستمر فً الملف اإلبتدائً ‪DC‬‬‫‪AFC‬‬ ‫‪AFC‬‬ ‫الدكتور المهندس محمد منذر القادري-‬ ‫‪munthear@gmail.com‬‬
  • 96. ‫الخىافميبث والمحىالث‬ Many transformers are rated by “K factor” which simply describes their ability to withstand harmonics. Transformers may also be derated to compensate for the additional heating caused by harmonics. Improved transformer designs have also been developed, with oversizedAFC AFC neutral busses, special cores, and specially designed coils. -‫الدكتور المهندس محمد منذر القادري‬ munthear@gmail.com
  • 97. ‫تأثٌر التوافقٌات على المحوالت‬ ‫ضٌاعات المحول الناتجة عن التوافقٌة الثالثة ‪TRIP‬‬ ‫•تقسم ضٌاعات المحول إلى ضٌاع الملفات وضٌاع النواة الحدٌدٌة‬ ‫• ضٌاع النواة تلقى إهتمام أقل ألنها ناتجة من السٌالة المولدة فً النواة من قبل الجهد المستمر‬ ‫• ضٌاع الملفات ٌزداد مع إزدٌااد ‪ I2R‬والضٌاعات الشاردة‬ ‫تأثٌر التوافقٌة الثالثة:‬ ‫• إجهادات مفرطة ناجمة عن الحرارة‬ ‫•إنهٌار العازلٌة‬ ‫•مردود تشغٌلً منخفض‬ ‫•زمن حٌاة قصٌر‬ ‫•ضجٌج صوتً‬ ‫الدكتور المهندس محمد منذر القادري-‬ ‫‪munthear@gmail.com‬‬
  • 98. ‫الخىافميبث ومكثفبث حصحيح المذسة‬ ‫مكثفات تصحٌح عامل القدرة قد تسبب طنٌن تسلسلً أو طنٌن‬ ‫تفرعً فً نظم القدرة.‬‫إذا تولدت توافقٌات تقع ضمن تردد طنٌن النظام , فً هذه الحالة‬ ‫سوف تضخم التوافقٌات‬
  • 99. ‫الخىافميبث ومكثفبث حصحيح المذسة‬ :‫مثال‬ Assume a 1500 kVA supply xfmr, 1500 kVA with a 5.75% impedance. 5.75% 600 kVAC Also assume 600 kVA of power correction capacitors on the system :‫ٌعرف تردد الطنٌنً التوافقً بالعالقة‬ kVAsc 1500 / 0.0575 = 6.6 hr = = kVAC 600
  • 100. ‫الحلول القدٌمة فً معالجة التوافقٌات‬ ‫‪Leo Craig‬‬ ‫1-وضع عامل أمان كبٌر عند حساب منابع الطاقة والكبالت والقواطع وهوحل مكلف جدا‬ ‫وبطبٌعة الحال ال ٌنفً وجود التوافقٌات على الشبكة.‬ ‫2- وضع محوالت بتوصٌالت مختلفة للحد من حركة التوافقٌات الثالثة ومضاعفاتها (‬ ‫التوافقٌة التاسعة ) وهو للحد من آثار التوافقٌة الثالثة لحماٌة كابل الحٌادي. وٌبقى حال‬ ‫جزئٌا مكلفا.‬ ‫وهً خاصة لتخمٌد التوافقٌة )‪ -36 pulse Bridge‬استخدام جسور خاصة تدعى (‬ ‫‪d,y‬الخامسة والسابعة . وطبعا لكونها محوالت صرفة (ذات لف مختلف لمفات الثانوي‬ ‫)متوضعة تسلسلٌا بٌن المنبع والحمل فٌها فهً مكلفة للغاٌة وتعتبر حال جزئٌا.‬‫4- دارات الطنٌن المولفة ( الفالتر الطنٌنٌة ) والتً تتألف من ملف ومكثف موصولٌن بشكل‬ ‫دارة طنٌن تعٌٌر على التردد المرغوب التخلص منه بحٌث تمرر هذا التردد دون غٌره إلى‬ ‫الخط الحٌادي أو األرضً . وكسابقتها هً حل مكلف وجزئً.‬ ‫5- ملف تسلسلً بٌن المنبع والحمل تكون ممانعته عالٌة بالنسبة للترددات األكبر من التردد‬‫) بحٌث تخفض مجموع التوافقٌات الكلً . وهً تعتبر حال جٌدا للتوافقٌات ‪50hz‬األساسً (‬ ‫الكبٌرة ولكنها اقل فعالٌة بالنسبة للتوافقٌات الصغٌرة الهامة فهً كغٌرها من الحللول تعتبر‬ ‫حال جزئٌا.‬
  • 101. ‫التوصٌات العملٌة للتعامل مع مشكلة التوافقٌات‬Identify the required PCC and apply techniques that are most cost effective for that location. Add a line reactor (or DC link choke if possible) to any un-buffered 6 pulse drives. Never use power factor correction capacitors at the input (or output) terminals of a drive. Active filters are most cost effective on larger multi-drive systems to correct for both displacement and distortionpower factor. For an even number of equally sized drives, consider a Pseudo 12 pulse solution by placing half of the load on aphase shifting delta wye transformer. Design the system to Isolate linear and non-linear loads and create two systems with 5% and 10% voltage limitsrespectively. If passive filters are used on generator power, select a passive filter with an LC dropout contactor terminal block. Take the time to understand the benefits and drawbacks of each type of mitigation solution to assure you meetthe requirements of the applicationand that you can live with any negative effects created by the chosen harmonic solution. Consider an active front end if the application requires regenerative operation and harmonic compliance. Perform a preliminary computer analysis and explore the effects of using various compliance methods.
  • 102. ‫كٌف نخفض التٌار التوافقً‬‫• خانق ترابط مستمر داخل نظام القٌادة ‪DC link choke within the drive‬‬ ‫• مفاعل خط ‪line reactor‬‬ ‫• مرشح مسالم ‪passive filter‬‬ ‫• مر شح فعال ‪active filter‬‬ ‫• تعدد األطوار ‪multi-pulse‬‬ ‫• مبدل مقوم فعال ‪active rectifier / converter‬‬ ‫الدكتور المهندس محمد منذر القادري-‬ ‫‪munthear@gmail.com‬‬
  • 103. ‫أنواع المرشحات‬ ‫المرشحات المسالمة ‪Passive filters‬‬ ‫•‬ ‫تؤمن مسار ذو ممانعة منخفضة إلى األرض عند تردد الرنٌن‬ ‫–‬ ‫تستخدم المكثفات كمرشحات فعالة.‬ ‫–‬ ‫تستخدم عناصر ‪ RLC‬مولفة .‬ ‫–‬ ‫إقتصادٌة.‬ ‫–‬ ‫المرشحات الفعالة ‪Active filters‬‬ ‫•‬ ‫معوض ستاتٌكً لإلستطاعة الردٌة.‬ ‫–‬‫تحقن تٌارات توافقٌة ( أو توترات) معاكسة بالطور للتوافقٌة الموجودة‬ ‫–‬ ‫تستخدم عناصر مثل مفاتٌح أنصاف النواقل ومضخمات.‬ ‫–‬ ‫غالٌة الثمن.‬ ‫–‬
  • 104. ‫‪ Passive Filters‬المرشحات المسالمة‬ ‫• النمط ذو الطنٌن التسلسلً ٌؤمن ممانعة منخفضة عند تردد الطنٌن‬ ‫• النمط ذو طنٌن التوازي ٌؤمن ممانعة عالٌة عند تردد‬
  • 105. Capacitor as a Filter ‫المكثف كمرشح‬ ‫• المكثف التفرعً هو أبسط شكل للمرشح المسالم‬ ‫إقتصادي‬ - (Q) ‫– أٌضا ٌؤمن تعوٌض قدرة ردٌة‬• delines for sizing capacitive filters – resonance between capacitor and circuit inductive reactance should not occur exactly at an integer multiple of fundamental frequency. – sensitivity of resonant point to drift in capacitor value should be investigated, – voltage and var support provided should not be excessive, – IEEE Standard 18 should be consulted for sizing and placement of capacitor.
  • 106. ‫مرشح توافقٌات مسالم‬
  • 107. ‫معالجة مسالمة ‪ Passive‬لتخفٌض تٌار الحٌادي‬
  • 108. ‫مرشح تٌار الحٌادي‬Neutral Current Filter (Blockade)
  • 109. ‫تٌار الخط وتٌار الحٌادي وأطٌافهما بدون مرشح‬Line Current & Neutral Current and Spectrum Without the Blockade
  • 110. Line Current & Neutral Current With the Blockade
  • 111. ‫)‪ (NFC‬مرشح تٌار الحٌادي‬
  • 112. ‫المخطط المبسط لمرشح تٌار حٌادي فعال‬
  • 113. ‫نتائج اإلختبار لمرشح تٌار حٌادي فعال‬
  • 114. ‫نتائج إختبار مرشح تٌار حٌادي فعال‬
  • 115. ‫توزع المرشحات على الشبكة‬
  • 116. Motor Derating vs. Harmenic Voltage Distortion This chart requires a calculation for the Harmonic Voltage Factor or HVF based on weighted individual harmonic component levels. Since the motor impedance is lower for the lower harmonic components, they will cause more heating and thus carry more weight. To determine the motor de-rating factor, the following formula should be used. for values of n from 0 to infinity.
  • 117. Six pulse buffered vs. un-buffered drives
  • 118. Six pulse buffered vs. un-buffered drives
  • 119. Six pulse buffered vs. un-buffered drives
  • 120. ‫المرشحات المسالمة‬
  • 121. ‫المرشحات العرٌضة المجال‬
  • 122. ‫مرشح توافقٌات فعال‬
  • 123. ‫المرشحات الفعالة‬
  • 124. ‫المرشح الفعال نمط الجهد ونمط التٌار‬ ‫.‪Voltage type (left) and current-type active filters‬‬ ‫• مرشح فعال منبع تٌار‬ ‫• مرشح فعال منبع جهد‬‫– ملف,)‪(current source‬‬ ‫– مكثف,)‪(dc source‬‬ ‫– معرج منبع تٌار.)‪(CSI‬‬ ‫– معرج منبع جهد.)‪(VSI‬‬
  • 125. ً‫مبدأ التعوٌض الفعال التفرع‬Shunt Active Compensation Principle IS IF IL
  • 126. ً‫ تفرع‬PWM ‫فلتر فعال‬ Shunt PWM Active Filters IS IL IL IF + IFSource C Load = IS Filter
  • 127. ‫مبدأ التعوٌض الفعال التسلسلً‬
  • 128. ‫تكنولوجٌا المرشحات الفعالة‬‫• تعتبر المرشحات الفعالة ‪ Active filters‬مكٌفات قدرة فعالة ‪active power line‬‬ ‫.‪conditioners‬‬ ‫المرشحات الفعالة أٌضا تصنف إعتمادا على طرٌقة التصحٌح‬ ‫•‬ ‫- تصحٌح فً المجال الزمنً‬ ‫- تصحٌح فً المجال الترددي‬
  • 129. ‫منابع الجهد‬
  • 130. ‫‪AFE System‬‬ ‫مرشح فً المقدمة فعال‬
  • 131. ‫مدخل فعال‬
  • 132. ‫فعال من جهة المدخل‬ ‫‪Active Front End‬‬
  • 133. Active Front End Rectifier ‫مقوم فعال فً المقدمة‬
  • 134. Recommendations Practices to Aid in Harmonic Compliance• Identify the required PCC And apply techniques most cost effective for that location.• Add a line reactor (or DC link choke if possible) to any un-buffered 6 pulse drives.• Use Active Filters on multi-drive systems to correct displacement / distortion.• For an even number of equally sized drives, consider a Pseudo 12 pulse solution by placing half ofthe load on a phase shifting delta wye transformer.• Design the system to Isolate linear and non-linear loads and create two systems with 5% and 10%voltage limits. -‫الدكتور المهندس محمد منذر القادري‬ munthear@gmail.com
  • 135. Recommendations Practices to Aid in Harmonic Compliance • For passive filters on generator power, select a filter with an LC dropout contactor terminal block. Limit leading power factor. • Take time to understand the benefits and drawbacks of each type of mitigation solution to assure you meet the requirements of the application and that you can live with any negative effects created by the chosen harmonic solution. • Consider an active front end if the application requires regenerative operation and harmonic compliance. • Perform a preliminary computer analysis and explore the effects of using various compliance methods. • Never use power factor correction capacitors at the input (or output) of a drive.
  • 136. ‫الكلفت والىثىليت‬ COST & RELIABILITY
  • 137. ‫أنواع األحمال فً الشبكة الكهربائٌة‬
  • 138. ‫ - الحذود المىصى بهب‬IEEE 519 The Institute of Electrical and Electronics Engineers (IEEE) has set recommended limits on both current and voltage distortion in IEEE 519-1992. THD (voltage) ‫نوع التطبٌق‬ 3% Special Hospitals and Airports 5% General Commercial Industrial 10% Dedicated Non-lineal load systemcareful review of the IEEE-519-1992 document reveals three levels ofcompliance with regard to voltage distortion. These levels are set at anddefined as:
  • 139. ‫915 ‪ - IEEE‬الحذود المىصى بهب للخشىهبث‬‫تشوه التٌار التوافقً األعظمً كنسبة من تٌار الحمل‬ ‫رقم التوافقٌة الفردٌة‬ ‫‪Isc/IL‬‬ ‫11<‬ ‫71<‪11<h‬‬ ‫32<‪17<h‬‬ ‫53<‪23<h‬‬ ‫‪TDD‬‬ ‫02<‬ ‫0.4‬ ‫0.2‬ ‫5.1‬ ‫6.0‬ ‫0.5‬ ‫05-02‬ ‫0.7‬ ‫5.3‬ ‫5.2‬ ‫0.1‬ ‫0.8‬ ‫001-05‬ ‫0.01‬ ‫5.4‬ ‫0.4‬ ‫5.1‬ ‫0.21‬‫0001-001‬ ‫0.21‬ ‫5.5‬ ‫0.5‬ ‫0.2‬ ‫0.51‬ ‫0001>‬ ‫0.51‬ ‫0.7‬ ‫0.6‬ ‫5.2‬ ‫0.02‬ ‫‪ : Isc‬تٌار قصر الدارة األعظمً عند نقطة الربط المشتركة ‪(PCC Point of Common Coupling‬‬ ‫تٌار الحمل المطلوب األعظمً عند نقطة ‪PCC‬‬ ‫‪: IL‬‬
  • 140. ‫حخميذ الخىافميبث ‪Attenuation of Harmonics‬‬‫المفاعلة التحرٌضٌة‬ ‫طرٌقة العمل : إضافة مفاعلة خط أو محول عزل لتخمٌد التوافقٌات‬ ‫منخفض الكلفة‬ ‫الفوائد:‬ ‫تقانة بسٌطة‬ ‫االهتمام: ٌخدم فً تقدٌم تخفٌض فً توافقٌات المرتبة العلٌا. وله تأثٌر قلٌل على‬ ‫التوافقٌات الخامسة والسابعة‬ ‫بسبب ترافق ذلك مع هبوط فً الجهد. ٌوجد حدود فً إضافة هذه المفاعالت‬
  • 141. ‫حخميذ الخىافميبث ‪Attenuation of Harmonics‬‬ ‫المرشحات المسالمة‬ ‫ٌؤمن ممر ممانعة منخفضة بالنسبة للترددات التوافقٌة الى األرض‬ ‫طرٌقة العمل:‬‫ٌمكن أن تولف على تردد بٌن التوافقٌٌن الشائعٌن بحث ٌخدم فً تخمٌد الترددٌن‬ ‫الفوائد:‬ ‫تولٌف الفالتر تحتاج إهتمام مركز من قبل الفنٌٌن‬ ‫االهتمام :‬ ‫تختلف الفالتر بحجومها وال ٌمكن تحدٌد مقاٌٌس لها‬ ‫تبدي حساسٌة عالٌة ألي تغٌٌر فً مواصفات النظام‬ ‫الدكتور المهندس محمد منذر القادري-‬ ‫‪munthear@gmail.com‬‬
  • 142. ‫‪Attenuation of Harmonics‬‬ ‫حخميذ الخىافميبث‬ ‫المرشحات الفعالة‬‫طرٌقة العمل: ٌحقن توافقٌات مساوٌة ومعاكسة إلى نظام القدرة لحذف تلك التوافقٌات المولدة من أجهزة‬ ‫أخرى‬ ‫الفوائد: ٌضمن تخفٌض فعال للتوافقٌات إلى مستوٌات منخفضة مطلوبة‬ ‫االهتمام : ٌتطلب إنفرتر أداء عالً لحقن التوافقٌات وهذا مكلف‬ ‫ترانستورات القدرة المستخدمة تتعرض إلى ظروف التً ٌخضع لها الخط.وبذلك نواجه مشكلة الوثوقٌة‬ ‫الدكتور المهندس محمد منذر القادري-‬ ‫‪munthear@gmail.com‬‬
  • 143. Attenuation of Harmonics ‫حخميذ الخىافميبث‬ ‫مقومات 21 نبضة‬‫:طرٌقة العمل‬ Two separate rectifier bridges supply a single DC bus. The two bridges are fed from phase- shifted supplies.‫:الفوائد‬ Very effective in the elimination of 5th and 7th harmonics. Stops harmonics at the source. Insensitive to future system changes.Concerns: May not meet the IEEE standards in every case. Does little to attenuate the 11th and 13th harmonics.
  • 144. ‫حخميذ الخىافميبث ‪Attenuation of Harmonics‬‬ ‫مقومات 81 نبضة‬‫طرٌقة العمل: محول إزاحة الطور المتكامل ومقوم الدخل الذي ٌستجر فً الغالب موجة جٌبٌة نقٌة‬ ‫من المنبع‬ ‫ٌلبً المعٌار ‪ IEEE‬فً جمٌع الحاالت‬ ‫الفوائد:‬ ‫ٌخمد جمٌع التوافقٌات حتى التوافقٌة 53‬ ‫ٌوقف التوافقٌات عند المنبع‬ ‫غٌر حساس لتغٌر مواصفات النظام‬ ‫االهتمام: ٌمكن أن ٌكون غالً الثمن عند استطاعات منخفضة‬
  • 145. ً‫ ستاتٌك‬Var ‫معوض إستطاعة ردٌة‬• Consists of electronically switched capacitor and/or inductor.• Some SVC technologies – Thyristor Controlled Reactor (TCR) with fixed capacitor (FC) – TCR with thyristor switched capacitor (TSC).• The Adaptive Var Compensator (AVC), developed at the University of Washington, is essentially a bank of TSCs.
  • 146. FACTS and Custom Power Devices• The other families of power electronic devices, very closely related to the active filters, are – Flexible AC Transmission System (FACTS) devices, – Custom Power Devices.• FACTS devices are intended for [4] – greater control of power transmission, – maximize utilization of existing transmission lines, – reduction of generation reserve margin, – prevention of cascading outages, – damping of power system oscillations.
  • 147. Static Condenser (STATCOM) ً‫المكثف الستاتٌك‬ Figure 22: Functional block diagram of a STATCON.• FACTS and Custom Power Device – reactive power compensation, – voltage regulation (by reactive power compensation), – harmonic current compensation.• Behaves as a voltage source connected in shunt to the power system through an inductor.
  • 148. ‫معوض الجهد الدٌنامٌكً )‪(DVR‬‬‫‪Dynamic Voltage Restorer‬‬ ‫• مناسب ألجهزة المستهلكٌن‬ ‫– تنظٌم جهد بطرٌقة التعوٌض التسلسً‬ ‫– تعوٌض توافقٌات جهد الخط‬‫ٌتصرف كمنبع جهد موصول مع خط القدرة‬ ‫•‬
  • 149. ‫معوضات القدرة المتكٌفة‬ ً‫• إزالة الترابط الردي والتعوٌض التوافق‬ ‫• ترتب المبدالت بحٌث ٌكون‬– slow switching reactive converter bears most of the stress– fast switching harmonic converter handles lower voltages and currents. -‫الدكتور المهندس محمد منذر القادري‬ munthear@gmail.com
  • 150. ً‫المعوض التفرع‬ Shunt Compensator Implementation IS IL A B Source C Load IH LH S ensing HP C Filter LQ & H IQ Control P W M inverter - phase A G ate s ignals C Stepped-w ave inverter Q -reactive compensator
  • 151. ً‫نتائج محاكاة المعوض التفرع‬Compensation of Rectifier Load
  • 152. ‫معوض القدرة الردٌة المتكٌف )‪(AVC‬‬‫‪The Adaptive Var Compensator‬‬ ‫إن ‪ AVC‬الٌولد توافقٌات أو أي حالة عابرة‬ ‫•‬ ‫ٌتم التعوٌض خالل الدورة‬ ‫•‬ ‫– التحكم بمعامل القدرة‬ ‫– التحكم بالتوتر‬ ‫– التحكم بإرتعاش التوتر‬ ‫الدكتور المهندس محمد منذر القادري-‬ ‫‪munthear@gmail.com‬‬
  • 153. ‫)‪(AVC‬‬ ‫معوض القدرة الردٌة المتكٌف‬‫)‪The Adaptive Var Compensator (AVC‬‬ ‫.‪AVC is a bank of electronically switched capacitors in a binary ratio‬‬ ‫بشكل أساسً هً بنك من المكثفات المقطعة‬ ‫•‬ ‫نسب المكثفات وفق الوزن الثنائً.)4:2:1(‬ ‫•‬ ‫ٌتم وصل وفصل الثاٌرستورات عند مرور التٌار والجهد بالصفر‬ ‫•‬
  • 154. ‫)‪ (SSB‬قواطع أنصاف النواقل‬ ‫• عناصر قدرة إلكترونٌة مخصصة :‬ ‫– إلزالة األعطال لحظٌا‬ ‫– لألعادة الوصل فً جزء من الدورة.‬ ‫– تغلق عند مرور التٌار التوتر بالصغر‬ ‫الدكتور المهندس محمد منذر القادري-‬ ‫‪munthear@gmail.com‬‬
  • 155. ‫معالجة مشاكل القدرة الكربائٌة‬‫مشاكل القدرة‬ Standby Power System Power Conditioner TVSS Automatic Voltage UPS (online) Dual Generator CVT Stabiliser (AVS) Conversion ً‫مولد قدرة احتٌاط‬ ‫مثبت توتر‬ ً‫مثبت جهد آل‬ ‫وحدة تغذٌة عدٌمة اإلنقطاع‬mains failure‫إنهٌار التوتر‬      ‫إنخفاض‬sage /Brownouts     Surges‫إندفاع التوتر‬     Spikes / Transients‫حاالت عابرة وجهود إبرٌة‬     High Frequency Noiseً‫ضجٌج تردد عال‬     Frequency Variation‫تغٌرات فً التردد‬     
  • 156. Prevention ‫المنع والوقاٌة‬¥ Check that the electrical contractor is reputable, and practices proper grounding and wiringtechniques. The electrical installation should be tested with instruments to determine complianceto codes and equipment requirements. Have all wiring inspected.¥ Electrically separate highly sensitive loads from other loads. This may involve using separatebuses, or separate distribution transformers. The Electrical Safety Code generally does not allowseparate AC services to be used in a facility.¥ Ensure that overvoltage protection exists at the powerline entrance to the building and at othersusceptible points.¥ Ensure that all equipment is CSA certified for safety reasons. Before purchasing mitigatingequipment, ensure that all distribution and grounding problems have been identified andcorrected. Then identify any problems that require mitigating equipment.¥ When purchasing electrical products, ensure that they will effectively perform the functions thatare required, and cause minimal degradation of the power system. It is a good idea to request ademonstration of the equipment within the plant, when possible, especially for mitigatingequipment.¥ Following installation of mitigating equipment, verify that the problem is solved.¥ Always identify any equipment sensitivity requirements, such as sensitivity to voltagefluctuations, in specifications.¥ Consider the interaction between mitigating equipment and the load. For instance, if themitigating equipment has a high impedance, and the load has high inrush current (due, perhaps,to the starting of large motors), a voltage sag could result.
  • 157. ¥ The noise suppression capabilities of some products may be specified in terms of peak attenuation, whichmay not be appropriate for some applications. In addition, it is important to know the conditions under which theattenuation was measured.¥ The purchaser should check if quoted equipment capabilities apply to units operating at no load, partial loador full load.¥ All electrical equipment should be properly sized. Products may be sized by power, in Volt Amps (VA), or bymaximum current rating in amps. To determine proper sizing, the following steps should be taken:Ð Determine the load operating voltage, current, and/or VA from the nameplate rating.Ð Sum all individual VA ratings of the loads.Ð To obtain an estimate of the power consumed by the load, which is the real power in Watts, calculate: Watts= VA x Power Factor.Ð Many nameplate ratings assume a power factor of unity. If this is not a good assumption, factor this in.Ð Some units are rated in Primary Power ratings. If this is the case then the sum of all secondary loads willhave to be divided by the efficiency of the unit in order to obtain the Primary Power rating.It is especially important to obtain the power requirements for sensitive loads from the manufacturer. Refer toFederal Information Processing Standard (FIPS) Publication 94 for a checklist of items to match automatic dataprocessing systems to power source characteristics and grounding requirements.¥ Ensure that all components of an interconnected data processing system share the same grounding systemand that this point is tested both initially as well as routinely thereafter to ensure quality level not to exceed aspecified maximum impedance.¥ For the purposes of signal grounding, never assume that two physically separated points of a groundsystem will be at the same potential. Use isolation techniques or current transmitters for physically separatedequipment.
  • 158. ¥ Keep the signal ground separate from the power ground except for one common point for the whole system.¥ If significant changes have been made in an electrical system, and a low voltage condition exists, notify theutility so that the tap setting on the electrical transformer can be checked.¥ Proper installation of electrical equipment is very important and yet often overlooked. For example, manyferroresonant transformers and power conditioners are improperly installed due to incorrectly sized primaryconductors or breakers.¥ Reduce the number of disturbance sources.¥ Maintain a malfunction log.¥ Customers should be aware of the level of harmonics they are producing. If a customer is exceeding theacceptable limits of the distribution system, they may be required to shut down their facility.¥ To minimize problems related to voltage sags:Ð Use reduced voltage starters on motors.Ð Use closed (not open) transition starters on motors. The open ones mitigate sags but create transients.Ð If installing an isolation transformer, ensure that the ground on the secondary side is properly connected; this isoften neglected. In addition, check that the connections on the primary side are tight, otherwise a voltage on thesecondary side may be induced, which will damage the equipment.Ð Above all, know and understand the technology of mitigating equipment before applying it.
  • 159. Troubleshooting ‫تقصً الخلل‬1. Define and acknowledge the problem: Ð type of disturbance, frequency of occurrence magnitude Ð determine which power conductor, hot neutral or safety ground, has a problem; this is critical, since some mitigation techniques only address problems with a specific conductor. For safety ground problems, for instance, the source of the problem must be fixed: no mitigating equipment will provide a solution. Ð consider power quality of neighbouring facilities.2. Check wiring and grounding: Ð loose connections, proper grounding techniques, etc. Ð important since many power quality problems are attributable to these factors3. Analyze the disturbance if applicable:4. If required, identify the technology that will mitigate the problem Ð check compatibility with existing electrical system, for example, determine the ride-through capabilities and sensitivities of existing computer systems Ð check possible problems with existing mitigating equipment Ð consider various techniques to alleviate the symptoms (suppress disturbance at source, make receptor insensitive to disturbance, or minimize transmission through coupling channel).5. Check that proposed solution actually works, and follow-up.
  • 160. ‫المعاٌٌر‬ ANSI/IEEE C62.41 - Location and wave shapes ANSI/IEEE C62.45 - Testing guide UL 1449 - TVSS Safety and Performance UL 1283 - Noise Filtering for TVSSNEW - National Electric Code 285
  • 161. Heres where youll find information about all the IEEE working groups. In general, you can find the Minutes of the last meeting foreach group; try sending an e-mail to the Chairman of that meeting if you need more information or a password. Information isgenerally free.•IEEE SCC-22: Power Quality Standards Coordinating Committee•IEEE 1159:Monitoring Electric Power Quality•IEEE 1159.1: Guide For Recorder and Data Acquisition Requirements•IEEE 1159.2: Power Quality Event Characterization•IEEE 1159.3: Data File Format for Power Quality Data Interchange•IEEE P1564:Voltage Sag Indices•IEEE 1346:Power System Compatibility with Process Equipment IEEE ‫معاٌٌرجودة القدرة‬•IEEE P1100: Power and Grounding Electronic Equipment (Emerald Book)•IEEE 1433: Power Quality Definitions•IEEE P1453: Voltage flicker•IEEE 519: Harmonic Control in Electrical Power Systems•IEEE Harmonics Working Group•Single-phase Harmonics Task Force•IEEE P519A Guide for Applying Harmonic Limits on Power Systems•Interharmonics Task Force•Harmonics Modeling and Simulation Task Force•Probabilistic Aspects of Harmonics Task Force•Surge Protective Devices CommitteeSeventeen sub-committee links can be found at the "Sub-committee pages" link...•IEEE P446: Emergency and standby power•IEEE P1409: Distribution Custom Power•IEEE P1547: Distributed Resources and Electric Power Systems Interconnection
  • 162. ‫المعاٌٌر الدولٌة الخاصة بمشاكل التغذٌة‬GRID & Distribution Codes Stipulates max / min values of voltage, frequency etc.BS EN 61000-4-7 (G5/4) Harmonics limits and regulationsBS EN 50160 Details typical disturbances found on the system.BS EN 61000-4-15 Flicker measurement limits and methodsBS EN 61000-4-30 Class A & B for monitoring compliancy -‫الدكتور المهندس محمد منذر القادري‬ munthear@gmail.com
  • 163. UPS ‫المعاٌٌر الهندسٌة الخاصة بنظام‬BS EN 62040: UPS ‫المعٌار الصناعً الخاص بأنظمة القدرة عدٌمة اإلنقطاع‬ • BS EN 62040-1-1:2003 (UPS). General and safety requirements for UPS used in operator access areas • BS EN 62040-1-2:2003 General and safety requirements for UPS used in restricted access locations • BS EN 62040-3:2001 Method of specifying the performance and test requirements
  • 164. Standards ‫المعاٌٌر الهندسٌة‬BS EN 62040 replaces the EN50091 standard.EN50091-1: Uninterruptible Power supply systems; general provisions of safetyEN50091-1-1: Uninterruptible Power supply systems; general provisions of safety used in areas accessible to operatorsEN60950 : ITE Information technology equipment safetyEN50091-2: Uninterruptible Power supply systems (UPS) electromagnetic compatibility provisionsEN50081-2: Electromagnetic compatibility (immunity)EN61000-4-2: Immunity: Electro Static Discharge (ESD)EN61000-4-3: Immunity: Electromagnetic FieldsEN61000-4-4: Immunity: Transient over voltages (BURST)EN61000-4-5: Immunity: Current surges (Surges)EN61000-4-11: Low frequency DisturbancesEN50141: Induced radio interferenceEN55022: Radio frequency disturbanceENV50091-3: UPS performance and test provisionsIEC146 : semiconductor electronic convertersIEC529 : degree of protection of casingsEuropean directives73/23: Low Voltage Directive enforcing CE marking89/336: electromagnetic compatibility directive enforcing CE marking
  • 165. G5/4 ‫التوصٌات الهندسٌة‬Planning levels for Harmonic Voltage Distortion and the connection of non-linearequipment to transmission systems and distribution networks in the United KingdomUPS will put Harmonics back on to the mains6 Pulse Rectifier typical THD of 20-30%12 Pulse rectifier typical THD less than 8%.Filters are required to give a THD less than 5%.Active or Passive.G5/4 States-If load draws more than 16A / phase an assessment should be made.If in Doubt - Ask the UPS Manufacturer.Remember the Building should comply with the standard not just the UPS -‫الدكتور المهندس محمد منذر القادري‬ munthear@gmail.com