The document summarizes the current tariff metering system at Hub Power Station and identifies issues. It discusses replacing the aging energy meters and outstation system to address reliability problems. The proposed solution involves installing intelligent digital meters and upgrading the outstation system to improve flexibility and synchronization. Key benefits of the new system include reading instant parameters, automatic time synchronization, and reduced number of meters needed.
This document discusses the calculation of ampere turns for the air gap and teeth in a DC machine. It covers several key points:
1. The effective area of the air gap is calculated using the field form factor, which accounts for variations in air gap length across the pole pitch.
2. The reluctance of an air gap is increased in a slotted armature due to the additional length of the air gap from slots and fringing effects around the tooth edges.
3. The exact calculation of ampere turns for teeth is difficult due to varying flux density along tapered teeth and lower actual flux passing through teeth compared to air gap flux. Simpson's rule and flux density at 1/3rd section methods
The document discusses the Nyquist stability criterion for analyzing the stability of sampled-data control systems. It begins by defining the Nyquist criterion and contour, and how they can be used to determine the number of closed-loop poles outside the unit circle (Z). It then provides an example showing how to apply the Nyquist criterion by plotting the loop gain and counting encirclements of the critical point. The document also discusses modifications to the Nyquist contour when open-loop poles are on the unit circle and defines the Nyquist criterion theorem.
Factors to be considered while selecting CTParth Patel
The document discusses key factors to consider when selecting current transformers (CTs). It covers:
- CT functions such as supplying protective relays with proportional currents and isolating measuring devices from high voltages.
- Principles such as magnetic flux inducing proportional secondary currents and high current transformation ratios.
- Types including bar, wound, and window types based on construction and measuring vs protective functions.
- Additional factors like accuracy class, knee-point voltage, burden, short-time current rating, and accuracy limit factor which influence performance during faults. Proper consideration of these factors is important for specifying CTs suited for an application's requirements.
The document describes the operation of a single phase semi-converter circuit with an R-L load. It has two SCRs and two diodes arranged in a bridge configuration, which allows current to flow in only one direction, making it a single quadrant converter. The operation involves four modes - in modes 1 and 3 current flows from the supply to the load through one of the SCRs, storing energy in the inductive load. In modes 2 and 4, freewheeling occurs through the diodes as the supply voltage changes polarity, maintaining current flow with the stored energy in the inductor.
This document discusses various semiconductor switching devices including SCRs, triacs, diacs, GTOs, LASCRs, and UJTs. It provides details on their construction, operation, applications, and key specifications. The SCR is described as a thyristor that conducts in one direction and remains latched on once triggered by a gate signal. Commutation circuits are needed to turn off an SCR. The triac can conduct in both directions like a diac and is triggered by a gate or breakover voltage.
This document discusses translational and rotational mechanical systems. It begins by defining variables for translational systems like displacement, velocity, acceleration, force, work, and power. It then discusses element laws for translational systems including viscous friction and stiffness elements. The document also introduces rotational systems and defines variables like angular displacement, velocity, acceleration, and torque. It discusses element laws for rotational systems including moment of inertia, viscous friction, and rotational stiffness. Finally, it covers interconnection laws for both translational and rotational systems and provides an example of obtaining the system model for a rotational system.
3 phase half wave controlled converter with r Loadmechatronics jf
This document discusses three-phase converters that convert AC power to DC power for loads. It specifically describes three-phase half-wave controlled rectifiers, which are made up of three single-phase half-wave converters connected together. It provides the equation to calculate the average DC output voltage of a three-phase half-wave converter and discusses that the thyristor conducts from 30 degrees to 180 degrees for a resistive load. The document concludes by describing a problem to calculate firing angle, average/RMS load current, and efficiency for a 3-phase converter operating from a 230V 50Hz supply with a 10 ohm resistive load and 50% of maximum output voltage required.
The document summarizes the current tariff metering system at Hub Power Station and identifies issues. It discusses replacing the aging energy meters and outstation system to address reliability problems. The proposed solution involves installing intelligent digital meters and upgrading the outstation system to improve flexibility and synchronization. Key benefits of the new system include reading instant parameters, automatic time synchronization, and reduced number of meters needed.
This document discusses the calculation of ampere turns for the air gap and teeth in a DC machine. It covers several key points:
1. The effective area of the air gap is calculated using the field form factor, which accounts for variations in air gap length across the pole pitch.
2. The reluctance of an air gap is increased in a slotted armature due to the additional length of the air gap from slots and fringing effects around the tooth edges.
3. The exact calculation of ampere turns for teeth is difficult due to varying flux density along tapered teeth and lower actual flux passing through teeth compared to air gap flux. Simpson's rule and flux density at 1/3rd section methods
The document discusses the Nyquist stability criterion for analyzing the stability of sampled-data control systems. It begins by defining the Nyquist criterion and contour, and how they can be used to determine the number of closed-loop poles outside the unit circle (Z). It then provides an example showing how to apply the Nyquist criterion by plotting the loop gain and counting encirclements of the critical point. The document also discusses modifications to the Nyquist contour when open-loop poles are on the unit circle and defines the Nyquist criterion theorem.
Factors to be considered while selecting CTParth Patel
The document discusses key factors to consider when selecting current transformers (CTs). It covers:
- CT functions such as supplying protective relays with proportional currents and isolating measuring devices from high voltages.
- Principles such as magnetic flux inducing proportional secondary currents and high current transformation ratios.
- Types including bar, wound, and window types based on construction and measuring vs protective functions.
- Additional factors like accuracy class, knee-point voltage, burden, short-time current rating, and accuracy limit factor which influence performance during faults. Proper consideration of these factors is important for specifying CTs suited for an application's requirements.
The document describes the operation of a single phase semi-converter circuit with an R-L load. It has two SCRs and two diodes arranged in a bridge configuration, which allows current to flow in only one direction, making it a single quadrant converter. The operation involves four modes - in modes 1 and 3 current flows from the supply to the load through one of the SCRs, storing energy in the inductive load. In modes 2 and 4, freewheeling occurs through the diodes as the supply voltage changes polarity, maintaining current flow with the stored energy in the inductor.
This document discusses various semiconductor switching devices including SCRs, triacs, diacs, GTOs, LASCRs, and UJTs. It provides details on their construction, operation, applications, and key specifications. The SCR is described as a thyristor that conducts in one direction and remains latched on once triggered by a gate signal. Commutation circuits are needed to turn off an SCR. The triac can conduct in both directions like a diac and is triggered by a gate or breakover voltage.
This document discusses translational and rotational mechanical systems. It begins by defining variables for translational systems like displacement, velocity, acceleration, force, work, and power. It then discusses element laws for translational systems including viscous friction and stiffness elements. The document also introduces rotational systems and defines variables like angular displacement, velocity, acceleration, and torque. It discusses element laws for rotational systems including moment of inertia, viscous friction, and rotational stiffness. Finally, it covers interconnection laws for both translational and rotational systems and provides an example of obtaining the system model for a rotational system.
3 phase half wave controlled converter with r Loadmechatronics jf
This document discusses three-phase converters that convert AC power to DC power for loads. It specifically describes three-phase half-wave controlled rectifiers, which are made up of three single-phase half-wave converters connected together. It provides the equation to calculate the average DC output voltage of a three-phase half-wave converter and discusses that the thyristor conducts from 30 degrees to 180 degrees for a resistive load. The document concludes by describing a problem to calculate firing angle, average/RMS load current, and efficiency for a 3-phase converter operating from a 230V 50Hz supply with a 10 ohm resistive load and 50% of maximum output voltage required.
This Presentation provides information about generator protection. All types of protection system which is used for generator are included in this presentation
The document discusses current transformers, which are used to measure electric current. They reduce high currents to safer, measurable levels by converting the primary current into a smaller secondary current. A current transformer functions by inducing a current in its secondary winding through the alternating magnetic field produced in its core by the primary current. It maintains an accurate ratio between the primary and secondary currents over a defined range.
A transformer consists of two coils wound around an iron core. Changing current in the primary coil induces a changing magnetic field that induces an alternating voltage in the secondary coil. This allows a transformer to change AC electric power to a different voltage level through electromagnetic induction without changing frequency. The transformer transfers power between circuits by mutual induction of the two coils linked by the core.
1. The document discusses symmetrical components, which allow representation of unbalanced three-phase quantities as the sum of three balanced components.
2. It introduces the positive, negative, and zero sequence components and the transformation matrix used to relate the symmetrical components to the original unbalanced quantities.
3. Symmetrical components are useful for simplifying analysis of unbalanced conditions like single line-to-ground faults in power systems. Sequence impedances can be used to model devices and transmission lines.
The document describes the design of a 250V, 2.565A single-phase AC inductor. It involves calculating the required inductance, selecting a suitable core, determining the number of turns, calculating losses, and ensuring design constraints are met. The key steps are:
1) Calculating inductance and selecting a core that meets the area product requirement
2) Determining the number of turns needed to achieve the required inductance
3) Ensuring operating flux density and losses meet specifications by calculating copper, core, and gap losses.
The document discusses three-phase induction motors. It covers the motor's construction, basic concepts, equivalent circuit model, power and torque characteristics, and speed control. The key learning objectives are understanding the motor's construction, slip concept, equivalent circuit model, torque-speed curve variations, and speed control techniques. The motor has a stationary stator and a rotating squirrel cage or wound rotor. Voltage induced in the rotor from the rotating stator magnetic field causes current flow and torque production. The motor runs at sub-synchronous speed due to slip between the rotor and field speeds.
Power System Dynamics and Control Presentation on Unit 3Chaitra Panat
In this presentation we see the concept of power system stability with their classification, concept of power system stabilizer and types then basic concept of control signals in Power system stabilizers, its structure and tuning, field implementation and operating Experiences, Advantages, disadvantages, applications, future scope and conclusion
It is based on current transformer description
It's working and applications are present in it ,it also includes videos of it's windings and it's inrush ability of transformer, and also about instrument transformer and it's working with applications.Current transformers are used-in measuring high currents and connected with it in parallel to it
1) An LQR controller with feedforward control and steady state error tracking was designed and simulated to control an inverted pendulum system.
2) The LQR controller stabilized the unstable system and achieved good performance for the pendulum angle and cart position with minimal overshoot and steady state error.
3) Simulation results demonstrated the robustness of the designed controller under system uncertainties, showing improved performance over existing H-infinity control methods.
1) The document describes the equivalent circuit model and power equations of a synchronous motor. It discusses how changes in shaft load, field excitation, and armature current affect the power angle, armature current, and power factor.
2) Increasing shaft load causes the power angle to increase and leads to a decrease in power factor. Increasing field excitation causes the power angle to decrease and can change the power factor from lagging to leading.
3) The document contains diagrams of the phasor relationships and how they change under different operating conditions, including under, normal, and over excitation levels.
3 phase Transmission Line fault detector edit 1-3.pptxKrishna2017
This document presents a project on an automatic tripping mechanism for a three-phase power supply system to prevent damage from faults. The system can detect line-to-ground, line-to-line, and other faults and automatically disconnect power. It uses an Arduino Uno microcontroller along with relays, sensors and other components to sense fault types, locations and temporarily or permanently trip the supply. The system provides safety benefits and can help reduce losses by quickly detecting and isolating faults on transmission lines, substations and industrial applications.
Electrical Power Systems Synchronous GeneratorMubarek Kurt
Here are the steps to solve this problem:
a) Given: Generator is 6 pole, 50 Hz
Using the synchronous speed formula: nm = 120f/P
nm = 120*50/6 = 1000 RPM
b) Terminal voltage at different power factors:
1) Given load: Ia = 60 A, PF = 0.8 lagging
Using phasor diagram: Vt = Ea - IaXs
Ea = Vt + IaXs = 480 + 60*1 = 540 V
Vt = 540*cos(cos-1(0.8)) = 480 V
2) PF = 1.0
Vt = Ea = 540 V
3) PF
Current transformers and potential transformers are both instrument transformers but have key differences in how they operate. A current transformer converts a high value current into a lower value that can be easily measured by instruments. It has a primary winding connected in series with the line. A potential transformer converts a high voltage into a lower voltage. It has a primary winding connected in parallel with the line. Some main differences are that current transformers measure current while potential transformers measure voltage, and their windings and core materials are constructed differently to handle current or voltage inputs.
3 PHASE INVERTER WITH SPEED CONTROL FOR ELECTRIC CARSMATHEW JOSEPH
The document describes a 3-phase inverter with speed control that can be used to power electric cars. It consists of a 4x4 matrix keyboard, microcontroller, PWM module, IGBT inverter circuit, battery, and 3-phase induction motor. The microcontroller converts the input speed value to frequency control signals, the PWM module generates gate pulses for the IGBT inverter, which converts DC power from the battery to 3-phase AC to run the motor at the set speed. This provides an efficient way to control speed and replace costly BLDC motors in electric cars.
The document describes a single phase transformer. A transformer transfers electrical energy from one circuit to another through mutual induction of two coils linked by a common magnetic flux, allowing voltages to be stepped up or down. It does this without moving parts, making it highly efficient and easy to maintain compared to other electrical machines. A transformer allows high voltages to be used for power transmission and distribution via the electric grid, improving efficiency.
Power quality improvement using upqc with soft computing method: Fuzzy logicSakti Prasanna Muduli
Now a days problems regarding power quality is more in large inter connected power systems. There are many method to mitigate these problems but using the latest most efficient compensation method is some what impressive. Here is the brief explanations regarding UPQC using soft computing method(fuzzy logic). This was my academic project along with my friends.
EMF EQUATION OF TRANSFORMER,TRANSFORMATION RATIO OF TRANSFORMER|DAY 3|BASIC E...Prasant Kumar
#EMF_equation_transformer
#Transformation_Ratio of transformer
#Basic electrical engineering
#Derivation of transformer emf equation
#How to calculate transformer emf equation
#Topic - ELECTRICAL TRANSFORMER
~ Link of all sessions are.
DAY 1 (Need/Definition)
https://youtu.be/BvaykFJ_NoE
DAY 2 (Working principle and Construction)
https://youtu.be/06rgxocihaM
DAY 3 (EMF equation and Turns Ratio)
https://youtu.be/g7e5xBPmv3Y
DAY 4 (Classification of Transformer)
https://youtu.be/6NP5L4MlvY4
DAY 5 ( Ideal and practical transformer on no load)
(Equivalent Transformer)
https://youtu.be/6LCLQC1p3lg
The forward converter uses a transformer to step up or down an input dc voltage and provide isolation for the load. It operates in two modes: when the switch is on, the input voltage is applied to the primary winding and power is transferred to the secondary winding and load; when the switch is off, the secondary inductor maintains current through a freewheeling diode. Key aspects of design include transformer turn ratio selection, inductor and capacitor sizing, and duty cycle adjustment for output voltage control. Benefits include better transformer utilization, filtered output, input-output isolation, and higher efficiency compared to flyback converters for power levels of 100-200 watts.
This Presentation provides information about generator protection. All types of protection system which is used for generator are included in this presentation
The document discusses current transformers, which are used to measure electric current. They reduce high currents to safer, measurable levels by converting the primary current into a smaller secondary current. A current transformer functions by inducing a current in its secondary winding through the alternating magnetic field produced in its core by the primary current. It maintains an accurate ratio between the primary and secondary currents over a defined range.
A transformer consists of two coils wound around an iron core. Changing current in the primary coil induces a changing magnetic field that induces an alternating voltage in the secondary coil. This allows a transformer to change AC electric power to a different voltage level through electromagnetic induction without changing frequency. The transformer transfers power between circuits by mutual induction of the two coils linked by the core.
1. The document discusses symmetrical components, which allow representation of unbalanced three-phase quantities as the sum of three balanced components.
2. It introduces the positive, negative, and zero sequence components and the transformation matrix used to relate the symmetrical components to the original unbalanced quantities.
3. Symmetrical components are useful for simplifying analysis of unbalanced conditions like single line-to-ground faults in power systems. Sequence impedances can be used to model devices and transmission lines.
The document describes the design of a 250V, 2.565A single-phase AC inductor. It involves calculating the required inductance, selecting a suitable core, determining the number of turns, calculating losses, and ensuring design constraints are met. The key steps are:
1) Calculating inductance and selecting a core that meets the area product requirement
2) Determining the number of turns needed to achieve the required inductance
3) Ensuring operating flux density and losses meet specifications by calculating copper, core, and gap losses.
The document discusses three-phase induction motors. It covers the motor's construction, basic concepts, equivalent circuit model, power and torque characteristics, and speed control. The key learning objectives are understanding the motor's construction, slip concept, equivalent circuit model, torque-speed curve variations, and speed control techniques. The motor has a stationary stator and a rotating squirrel cage or wound rotor. Voltage induced in the rotor from the rotating stator magnetic field causes current flow and torque production. The motor runs at sub-synchronous speed due to slip between the rotor and field speeds.
Power System Dynamics and Control Presentation on Unit 3Chaitra Panat
In this presentation we see the concept of power system stability with their classification, concept of power system stabilizer and types then basic concept of control signals in Power system stabilizers, its structure and tuning, field implementation and operating Experiences, Advantages, disadvantages, applications, future scope and conclusion
It is based on current transformer description
It's working and applications are present in it ,it also includes videos of it's windings and it's inrush ability of transformer, and also about instrument transformer and it's working with applications.Current transformers are used-in measuring high currents and connected with it in parallel to it
1) An LQR controller with feedforward control and steady state error tracking was designed and simulated to control an inverted pendulum system.
2) The LQR controller stabilized the unstable system and achieved good performance for the pendulum angle and cart position with minimal overshoot and steady state error.
3) Simulation results demonstrated the robustness of the designed controller under system uncertainties, showing improved performance over existing H-infinity control methods.
1) The document describes the equivalent circuit model and power equations of a synchronous motor. It discusses how changes in shaft load, field excitation, and armature current affect the power angle, armature current, and power factor.
2) Increasing shaft load causes the power angle to increase and leads to a decrease in power factor. Increasing field excitation causes the power angle to decrease and can change the power factor from lagging to leading.
3) The document contains diagrams of the phasor relationships and how they change under different operating conditions, including under, normal, and over excitation levels.
3 phase Transmission Line fault detector edit 1-3.pptxKrishna2017
This document presents a project on an automatic tripping mechanism for a three-phase power supply system to prevent damage from faults. The system can detect line-to-ground, line-to-line, and other faults and automatically disconnect power. It uses an Arduino Uno microcontroller along with relays, sensors and other components to sense fault types, locations and temporarily or permanently trip the supply. The system provides safety benefits and can help reduce losses by quickly detecting and isolating faults on transmission lines, substations and industrial applications.
Electrical Power Systems Synchronous GeneratorMubarek Kurt
Here are the steps to solve this problem:
a) Given: Generator is 6 pole, 50 Hz
Using the synchronous speed formula: nm = 120f/P
nm = 120*50/6 = 1000 RPM
b) Terminal voltage at different power factors:
1) Given load: Ia = 60 A, PF = 0.8 lagging
Using phasor diagram: Vt = Ea - IaXs
Ea = Vt + IaXs = 480 + 60*1 = 540 V
Vt = 540*cos(cos-1(0.8)) = 480 V
2) PF = 1.0
Vt = Ea = 540 V
3) PF
Current transformers and potential transformers are both instrument transformers but have key differences in how they operate. A current transformer converts a high value current into a lower value that can be easily measured by instruments. It has a primary winding connected in series with the line. A potential transformer converts a high voltage into a lower voltage. It has a primary winding connected in parallel with the line. Some main differences are that current transformers measure current while potential transformers measure voltage, and their windings and core materials are constructed differently to handle current or voltage inputs.
3 PHASE INVERTER WITH SPEED CONTROL FOR ELECTRIC CARSMATHEW JOSEPH
The document describes a 3-phase inverter with speed control that can be used to power electric cars. It consists of a 4x4 matrix keyboard, microcontroller, PWM module, IGBT inverter circuit, battery, and 3-phase induction motor. The microcontroller converts the input speed value to frequency control signals, the PWM module generates gate pulses for the IGBT inverter, which converts DC power from the battery to 3-phase AC to run the motor at the set speed. This provides an efficient way to control speed and replace costly BLDC motors in electric cars.
The document describes a single phase transformer. A transformer transfers electrical energy from one circuit to another through mutual induction of two coils linked by a common magnetic flux, allowing voltages to be stepped up or down. It does this without moving parts, making it highly efficient and easy to maintain compared to other electrical machines. A transformer allows high voltages to be used for power transmission and distribution via the electric grid, improving efficiency.
Power quality improvement using upqc with soft computing method: Fuzzy logicSakti Prasanna Muduli
Now a days problems regarding power quality is more in large inter connected power systems. There are many method to mitigate these problems but using the latest most efficient compensation method is some what impressive. Here is the brief explanations regarding UPQC using soft computing method(fuzzy logic). This was my academic project along with my friends.
EMF EQUATION OF TRANSFORMER,TRANSFORMATION RATIO OF TRANSFORMER|DAY 3|BASIC E...Prasant Kumar
#EMF_equation_transformer
#Transformation_Ratio of transformer
#Basic electrical engineering
#Derivation of transformer emf equation
#How to calculate transformer emf equation
#Topic - ELECTRICAL TRANSFORMER
~ Link of all sessions are.
DAY 1 (Need/Definition)
https://youtu.be/BvaykFJ_NoE
DAY 2 (Working principle and Construction)
https://youtu.be/06rgxocihaM
DAY 3 (EMF equation and Turns Ratio)
https://youtu.be/g7e5xBPmv3Y
DAY 4 (Classification of Transformer)
https://youtu.be/6NP5L4MlvY4
DAY 5 ( Ideal and practical transformer on no load)
(Equivalent Transformer)
https://youtu.be/6LCLQC1p3lg
The forward converter uses a transformer to step up or down an input dc voltage and provide isolation for the load. It operates in two modes: when the switch is on, the input voltage is applied to the primary winding and power is transferred to the secondary winding and load; when the switch is off, the secondary inductor maintains current through a freewheeling diode. Key aspects of design include transformer turn ratio selection, inductor and capacitor sizing, and duty cycle adjustment for output voltage control. Benefits include better transformer utilization, filtered output, input-output isolation, and higher efficiency compared to flyback converters for power levels of 100-200 watts.
1. Xudoyberdiyev Kamoliddin
MUHAMMAD AL-
XORAZMIY NOMIDAGI
Qarshi fiali Toshkent Axborot
Texnologiyalari Universiteti
Elektronika va elektronika asoslari fanidan
MUSTAQIL
ISHI
Tayyorladi:Xudoyberdiyev K.
Qabul qildi: Rustamova M.
Qarshi 2020
2. Xudoyberdiyev Kamoliddin
Mavzu: Aktiv tok transformatori sxemasi.
REJA:
1. Aktiv tokТransformatorlarning vazifasi
2.Тransformatorning ishlash prinsipi
3.Тransformatorlarning tuzilishi
4. Avtotransformatorlar
3. Xudoyberdiyev Kamoliddin
TRANSFORMAТORLAR
Тransformatorlarning vazifasi
Тransformator elektrdan foydalanishda asosiy uskuna hisoblanadi. U past kuchlanishdagi
elektrni yuqori kuchlanishga yoki yuqori kuchlanishdagi elektrni past kuchlanishga aylantirib
beradi. Тransformator qo‘zg‘almas tuzilma hisoblanadi. Iste’molchilar elektr manbayidan uzoq
bo‘lganligi tufayli, elektr stansiyada ishlab chiqilgan elektr energiyani ularga yetkazib berishi
kerak. Bu vazifani transformatorlar va elektr uzatish liniyalari bajaradi. Elektr energiyani
ming kilometrgacha uzatishga to‘g‘ri keladi. Generatorlar 10 ming va undan oshiq kuchlanishda
soatiga milliongacha kilovatt soat elektr energiyasini ishlab chiqarsa, ming kilometrgacha
uzatish uchun transformator uni 10 kVdan 500 kV gacha aylantirib beradi va uzatish
liniyalari bu kuchlanishda elektr energiyani uzoq masofalarga yetkazib beradi. Iste’molchilar
joylashgan yerda bu kuchlanishni yana 10 kV li kuchlanishga aylantirish vazifasini
transformator bajaradi. Agarda generatorlar ishlab chiqargan elektr energiyani 10 kV da
uzatilganda, u holda simlarning qalinligi kamida o‘n santimetrgacha bo‘lishi kerak. Bu simlarni
ko‘tarib turish uchun juda kuchli qurilmalar va ko‘p miqdorda mis yoki alumin simlar kerak
bo‘lar edi. Тransformatorlar kuchlanishni 35; 110; 220; 330; 500; 750 kilovoltlarga
aylantirib berishi mumkin. Elektr energiyadan foydalanadigan joylarda transformatorlar
yordamida kuchlanishlarni 220 va 380 V ga aylantiriladi. Тransformatorlar hamma sohalarda
ishlatiladi. Ularning juda ko‘p turlari bor.
Тransformatorlarning tuzilishi
Тransformator po‘lat induktiv o‘tkazgich, ikki yoki bir necha o‘zaro induktiv aloqada bo‘lgan
o‘ramlardan iborat. Magnit o‘tkazuvchi po‘lat o‘ramlar orasidagi elektromagnit aloqani
kuchaytirish uchun kerak. Тransformator bir va uch fazali bo‘ladi. 1.51-rasmda uch fazali
transformatorning magnit o‘tkazuvchisi ko‘rsatilgan.
Bunda temir yupqa plastinka tayoqchalar (1), ularga yuqorida (2) va pastda (3) o‘ramlar
joylashtirilgan. Girdob toklariga elektr energiyaning ko‘p sarf bo‘lmasligi uchun magnit
4. Xudoyberdiyev Kamoliddin
o‘tkazgichlar qalinligi 0,35 dan 0,5 mm gacha bo‘lgan elektrotexnikada ishlatiladigan temir
tunukalardan tayyorlanadi. Тunukalarni bir-biridan lok, yupqa qog‘oz yoki metall zaki
(okalina) bilan izolatsiyalanadi.
Тransformatorlar ikki turga bo‘linadi: 1) yupqa plastinkalardan iborat tayoqchali; 2) bronli.
Yupqa plastinkali temir tunukalardan yasalgan tayoqchalarga izolatsiyali sim o‘ramlar
kiydiriladi. Bronli transformatorlarda o‘ramlarning bir qismini magnit o‘tkazgich o‘rab
olgan. Тransformator magnit o‘tkazgichning gorizontal qismidagi o‘ramlarni qurshab turgan
qism yuqori va pastki bo‘yinturuqlar (yarmolar) deyiladi. Katta va o‘rta quvvatli
transformatorlar tunuka po‘latlardan tayyorlanadi. Bu transformator o‘ramlarini sovitish uchun
juda qulay. Тransformatorlarda magnit qarshiligini kamaytirish uchun plastinkalar ulanishini har
xil joyda qilinadi. Kichkina transformatorda plastinkalarni Ш shaklida tayyorlanadi. 1.52-
rasmda po‘lat plastinkalarni yig‘ish sxemasi ko‘rsatilgan.
Тransformatorni tunuka idishga (bakka) joylashtirib, ichiga transformator yog‘i quyiladi. Bu
yog‘ sovitish uchun xizmat qiladi. Bron turidagi transformator yog‘siz tayyorlanganligi uchun
quruq transformator deyiladi.
Тransformatorning ishlash prinsipi
1.53-rasmda ko‘rsatilgan magnit o‘tkazgich po‘latga (1) sim (2) o‘ramlar o‘ralgan.
Тransformator ikki o‘ramli bo‘lsa, bir fazali, agarda uch o‘ramli bo‘lsa uch fazali bo‘ladi.
Birinchi o‘ramiga U1 kuchlanish manbadan ulanadi. Buni transformatorning birinchi o‘rami deb,
uning o‘ramlarini w1 deyiladi. Ikkinchi o‘ramni w2 ikkinchi o‘ram deb aytiladi. Unda hosil
bo‘lgan kuchlanishni E2 deyiladi. O‘ramlarning uchlarini A va a, oxirlarini X va x deyiladi.
O‘zgaruvchan kuchlanish U1 ta’sirida birinchi o‘ramning o‘ramlaridan o‘zgaruvchan tok I oqib
o‘tib, o‘zgaruvchan magnit yurgazuvchi kuch i w1 hosil qiladi, bu esa magnit
o‘tkazuvchipo‘lat temirdan kesib o‘tuvchi asosiy o‘zgaruvchan magnit oqimi F ni hosil qiladi.
Katta magnit o‘tkazuvchanlik qobiliyatiga ega bo‘lgan magnit o‘tkazuvchini qo‘llash o‘ramlar
orasidagi o‘zaro elektromagnit aloqasidagi magnit oqimini oshirishga imkoniyat yaratadi.
Magnit oqimi F birinchi o‘ramni ikkinchi o‘ram bilan ulab, ularni birlashtiradi.
Birinchi o‘ramning sinusoidal kuchlanishi sinusoidal magnit oqimini hosil qiladi:
5. Xudoyberdiyev Kamoliddin
bu yerda: F – magnit oqimi; Fm – birinchi o‘ramdagi elektr yurituvchi kuchning
amplitudasi (EYK); sinωt – tezlik burchagi. Magnit oqimi birinchi o‘ramda o‘zinduksiya elektr
yurituvchi kuchini induksiyalaydi. Bu hosil qilingan EYK o‘ramlarning o‘ram soniga va magnit
oqimining tezligiga proporsional:
bu yerda: E1m = ωM1Fm – birinchi o‘ramdagi elektr yurituvchi kuch (EYK) tebranishlari
(amplitudasi). Magnit oqimi ikkinchi o‘ramda EYK hosil qiladi. Bu quyidagicha ifodalanadi:
Тransformatorning ikkinchi o‘ramidagi EYK fazasi birinchi o‘ramdagi EYK fazasiga o‘xshab
magnit oqimidan 2π burchakka orqada qoladi, chunki bu ikkala EYK shu magnit oqimi
bilan induksiyalanadi.
EYK chastotasi bir xil bo‘lganligi va bir xil magnit oqimi bilan induksiyalanganligi uchun
birinchi o‘ramdagi EYK ikkinchi o‘ramning EYK dan farq qiladi, chunki birinchi o‘ramning
o‘ram soni M1 ikkinchi o‘ram soni M2 dan farq qiladi. O‘ram soni qancha ko‘p bo‘lsa, EYK
shuncha ko‘p bo‘ladi. Birinchi o‘ram EYK ning ikkinchi o‘ram EYK ga nisbati
transformatorning koeffitsiyenti deb ataladi:
Тransformatorning M2 o‘rami ko‘p bo‘lib, M1 o‘rami kam bo‘lsa, kuchlanishni oshiruvchi
transformator deyiladi, agarda M2 o‘rami kam bo‘lib, M1 o‘rami ko‘p bo‘lsa, kuchlanishni
kamaytiruvchi transformator deb aytiladi. Тransformatorlar bir fazali va uch fazali bo‘ladi.
Uch fazali transformator
Uch fazali tokni transformatsiya qilish uchun bir fazali transformatorlarni qo‘llash
mumkin. 1.54-rasmda transformator guruhlarini ulash sxemasi keltirilgan. Ularning
o‘ramlarini yulduzcha yoki uchburchak shaklida ulash mumkin. Amalda uch fazali
transformatorlar qo‘llaniladi. Uch fazali transformatorlarning yuqori kuchlanish tomonidagi
o‘ramlarning uchlarini A, B, S bilan, oxirlarini X, Y, Z bilan belgilanadi. Ikkinchi
o‘ramlarning uchlari a, в, s bilan, oxirlari esa x, y, z bilan belgilanadi. Тransformatorlarda,
asosan, uchburchak va yulduzchali ulanish usullari qo‘llaniladi. Uch fazali transformatorlarning
birinchi va ikkinchi o‘ramlari yulduzcha shaklida ulanishi eng arzon va sodda hisoblanadi,
chunki ularning har bir o‘rami va izolatsiyasi (neytrali yerga ulanganda) faqat fazali
kuchlanishga va lineyniy tokka hisoblangan bo‘ladi. Тransformatorlarning pastki kuchlanishi
6. Xudoyberdiyev Kamoliddin
tomonida iste’molchilarga neytral simi kerak bo‘lmasa, u holda yulduzcha-uchburchak
ulanishdagi katta quvvatli transformatorlar ishlatiladi. Тransformatorlarning lineyniy kuchlanishi
nisbati uning o‘ramlarining ulanish turiga bog‘liq.
Avtotransformatorlar
1.56-rasmda avtotransformatorlarning prinsiрial sxemasi keltirilgan. Avtotransformatorlarda
pastki kuchlanishning o‘ramlari yuqori kuchlanish o‘ramlarning qismi bo‘ladi.
Avtotransformatorlarda elektr energiya elektromagnit yo‘li bilan uzatishdan tashqari,
o‘ramlarning bir-biriga ulanganligi orqali ham uzatiladi. Avtotransformatorda kuchlanish va
tok kuchlarining o‘zaro bog‘lanishi odatdagi transformatorlarnikiga o‘xshash:
Avtotransformatorlar hamma sohalarda ishlatiladi.
Тransformatorlarda quvvatning yo‘qolishi va foydali ish koeffitsiyenti
7. Xudoyberdiyev Kamoliddin
Тransformatorga ulangan quvvat:
P1 = U1 I1 cos ϕ1 .
Тransformator tayyorlagan va iste’molchilarga berayotgan quvvat:
P2 = U2 I2 cos ϕ2 .
Ularning ayirmasi P1 – P2 quvvatning yo‘qolishi bo‘ladi. Katta quvvatli transformatorlarda
quvvatning yo‘qolishi 1—5 % bo‘ladi. Тransformatorning foydali ish koeffitsiyenti:
1.57-rasmda transformator foydali ish koeffitsiyentining transformator yuklanish
koeffitsiyentiga bog‘liqligi ko‘rsatilgan. Kichik quvvatli transformatorlarda me’yorli foydali
ish koeffitsiyenti 70 dan 90 % gacha bo‘lishi mumkin. 1.58-rasmda transformatorning tashqi
tavsifi keltirilgan.
8. Xudoyberdiyev Kamoliddin
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лива в народном хозяйстве. Т., «Узбекистон», 1974.
3. К.Адылов. Использование электроэнергии в сельском
хозяйстве Узбекистана. Т., «Узбекистон», 1974.
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маторами на напряжение 35/10/6/0,4 и 110/10/6 кв. Журнал
«Промышленная энергетика», М., № 9, 1963.
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това. Тексты лекций по социально-экономическим факто-
рам безопасности жизнедеятельности. Т., «Узбекистон», 1992.
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Бюллетень научно-технической информации института НТИ.
Журнал «Новая техника», №10, 1962.
