Switching Transient Reduction of Shunt Capacitor Bank for Power Quality Improvement
Moe Kay Thi Khaing
#Department of Electrical Power Engineering, West Yangon Technological University, Myanmar
Adding shunt capacitors to existing power system distribution for large industrial loads provides well known benefits for power quality, including power factor correction, voltage level and increase of active power transfer capacity. This study determines the size of capacitor banks to maintain an acceptable power factor after capacitor bank installation. Switching of shunt capacitor produce inrush current that can cause failure of adjustable speed drive, other process equipment shutdown and problems with sensitive equipment. Switching transient analysis is studied as the capacitor switching transient can be very damaged and costly problems where the transient voltage on the power system change from the steady-state value. In order to take appropriate pre-cautions in real system, it is necessary and advantage to analyze and determine the worst case switching transient before the actual switching take place. Both single bank switching transient and bank-to-bank switching transient are studied to design transient reduction method. The pre-insertion resistor method and zero-crossing switch for shunt capacitor switching which reduce the transient voltage are also investigated. The modeling and transient simulation are carried out by using MATLAB software.
- Shunt capacitor, switching transient, power quality improvement, pre-insertion resistor, zero-crossing switch