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# Tariff & power factor

## on Jul 13, 2011

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## Tariff & power factorPresentation Transcript

• Unit 1: Tariff & Power Factor Correction
• Understand tariff and power factor correction
• Understand the tariffs for consumers
• Understand the methods to improve power factor
• Understand tariff & power factor correction
• The use of tariff & power factor
• Tariff : to determine payment for electricity used by consumers
• Power factor : determine the value of power and efficiency
• Definition of tariff & power factor
• Tariff : electricity payment scale charged by supplier (TNB)
• Power factor :
• Ratio between real power (watt) and apparent power (VA)
• Cosine angle that separate watt and volt-ampere
• Understand tariff & power factor correction
• Perbelanjaan bagi mengeluarkan tenaga elektrik :
• Kos tetap
• Perbelanjaan asas yg perlu dikeluarkan oleh pembekal
• Pembinaan penjana, penghantaran dan pengagihan, gaji pekerja, insurans dll.
• Kos berubah
• Perbelanjaan yg kadarnya bergantung kpd jumlah tenaga yg dikeluarkan
• Kos-kos tambahan unit bahan api dan air, penggantian alat-alat loji dll
• Understand tariffs for consumers
• Three types of common tariffs
• 1) Flat rate ( Kadar sama rata/sekata)
• Devide rate into 2 parts – lamps & power
• Need 2 units of kilowatt hour meter
• More usage, more you pay
• Understand tariffs for consumers
• Three types of common tariffs
• 1) Flat rate ( Kadar sama rata/sekata)
• How this tariff is used
• Only for small industries
• Calculation
• Lamps = 100 units x RM0.20
• = RM 20.00
• Power = 200 units x RM0.25
• = RM 50.00
• Total = RM 70.00
• Tariffs for consumers
• Three types of common tariffs
• 2) Two parts rate (kadar dua bahagian) :
• Directly devided into 2 parts
• Use only 1 kilowatt hour meter
• 1 st part : maximum demand payment (base on consumer’s need)
• 2 nd part : used power units in a month
• Tariffs for consumers
• Three types of common tariffs
• 2) Two parts rate (kadar dua bahagian) :
• How this tariff is used
• For big factories/industries
• Calculation
• Max. demand = 4kW x RM12.00
• = RM 48.00
• Units used = 200 units x RM0.07
• = RM 14.00
• Total = RM 62.00
• Tariffs for consumers
• Three types of common tariffs
• 3) Block rate
• Devide into 3 payment scale:
• 1 st scale: if more than some units (eg. 100 units)
• 2 nd scale: balance of 1 st scale, if more than some units (eg. 50 units)
• 3 rd scale: balance of 2 nd scale, if more
• Use only 1 units of kilowatt hour meter
• Tariffs for consumers
• Three types of common tariffs
• 3) Block rate
• How this tariff is used
• Housing area
• Calculation
• 1st 100 units = 100 x RM0.20 = RM 25.00
• 2nd 50 units = 50 x RM0.20 = RM 10.00
• Balance 150 units = 100 x RM0.20 = RM 34.50
• Total = RM 69.50
• Methods to improve power factor
• Various methods to improve power factor
• Phase (Pemaju fasa)
• Mesin khas yg disambungkan secara selari dgn motor/alat yg boleh merendahkan faktor kuasa
• Dihidupkan/dimatikan bersama-sama dgn motor/alat
• Synchronous motor (Motor segerak)
• Saiz besar
• Dipasang selari dgn palang bas bekalan
• motor boleh berfungsi seperti biasa semasa pembaikan faktor dibuat
• Capacitor (Pemuat)
• Komponen paling murah dan mudah digunakan, tidak memerlukan kawasan yg besar, kenaikan suhunya rendah dan kehilangan kuasanya boleh diabaikan
• Dipasangkan selari dgn peralatan
• Methods to improve power factor
• Disadvantages for low power factor
• Perbelanjaan utk membekalkan tenaga elektrik adalah lebih besar kerana voltan perlu dinaikkan utk mendapat kuasa yg sama dgn tenaga elektrik yg dikeluarkan pada faktor kuasa yg tinggi. Ini melibatkan peralatan seperti penjana, pengubah, sius peralatan dll.
• Jika voltan sukar dinaikkan, maka arus perlu dinaikkan bagi memperolehi kuasa yg serupa dgn kuasa ketika faktor kuasa tinggi. Saiz kabel dan kadar arus alat perlu ditukar dan mengakibatkan perbelanjaan yg lebih. Kehilangan kuprum (I 2 R) dan susut voltan pada kabel (IR) akan bertambah.
• Seterusnya kecekapan alat akan berkurang.
• Methods to improve power factor
• How to calculate power factor correction
• Seorang pengguna kuasa menggunakan permintaan maksima sebanyak 250kW utk tempoh setahun. Tarif yg ditawarkan ialah RM140 setiap kW permintaan maksima setahun, tambah RM0.20 bagi setiap unit. Unit yg digunakan sebanyak 350000 pada faktor kuasa satu. Kira kos utk tempoh setahun dan harga purata per unit.
• Penyelesaian:
• Kos setahun = RM (140x250) + (350000x0.20)
• = RM (35000) + (70000)
• = RM 105000
• Harga purata per unit = 105000 / 350000
• = RM 0.30
• Methods to improve power factor
• How to calculate power factor correction
• Pengguna yg sama juga mempunyai faktor kuasa 0.6 menyusul. Tarif yg dikenakan ialah RM 140.00 bagi setiap kVA permintaan maksima dalam setahun, tambah RM0.20 bagi setiap unit. Kira kos utk tempoh setahun dan harga purata per unit.
• Penyelesaian:
• kVA permintaan maksima = kW / faktor kuasa
• = 250 / 0.6
• = 416.66 kVA
• Kos setahun = RM (140x416.66) + (350000x0.20)
• = RM (58332.40 + 70000)
• = RM 128332.40
• Harga purata per unit = 128332.40 / 350000
• = RM 0.36