Voltage Sag Assessment Based on the Interval Characteristic of Customer Satisfaction

An analytical voltage sag assessment method is proposed considering the interval characteristic of customer satisfaction degree. Based on the relationship between fault line length and voltage amplitude, the critical fault position can be determined by iterative algorithm and the customer un-satisfaction area in the power supply system is determined also. Due to the interval characteristic of customer satisfaction degree, the frequency of voltage sags at given buss can be assessed by the un-satisfaction area. The proposed method has been applied to a five-buss system and IEEE 30-buss RTS and compared with existing methods. The results show that the new method is credible and correct and with practical foreground.