Voltage dip in the distribution network is caused by disturbance at different voltage levels and experienced by low voltage customers are established. Voltage dips are those disturbances which damage the power quality of the distribution network and causing heavy economic damage to the customers. This chapter investigates procedures of mitigating the voltage dip by reducing the number of faults due to short circuits, lowering the fault clearing time, and changing the power system design and DSTATCOM Compensator with DG and dynamic voltage restorer.
TopIntroduction
Voltage dip is the unexpected reduction of the root mean square (RMS) voltage, and the cause of voltage dip in power system distribution is due to short circuit, overload or starting of motors. According to the IEEE the variation of the voltage sags is between the ranges of 10% to 90% i.e. 0.1 pu to 0.9 pu of the nominal voltage followed by the recovery within a short time 10 ms to 60 sec. It starts when voltage sags occur to low voltage than threshold voltage (Vthr) usually 0.9 pu voltage dip and temporary interruption of power are possibly the main power quality problems affecting the end user or customers. These actions are mostly allied with a disturbance anywhere on the power system source. If the disturbances are faced by the end users than these disturbances will be exist. Voltage dip is the most common meanwhile they can be interconnected with the end users. Even the voltage dip is 4 to 5 cycles, it affects the sensitive distribution materials to drop out fuses (Alhelou et al., 2019; Makdisie et al., 2018; Alhelou et al., 2018; Alhelou et al., 2016; Haes Alhelou et al., 2019; Njenda et al., 2018).
There are various causes for power quality problems, which affect the distribution network. These are temporary faults; transient, harmonic distortion, notch voltage, flicker, voltage swells and voltage sages. Sensitive electronic materials, series and nonlinear loads including accuracy industrial procedures are unfavorably affected by power quality problems and results in momentary losses, damaged equipment and product quality degradation (Brumsickle, et al. 2001).
According to IEEE standard 1159-1995, the voltage dip variation is between 0.9 pu to 0.1 pu for the duration of 50.5 cycles, which is smaller than a minute. Generally facing due to the disturbance of distribution and transmission networks and it is the most dangerous to the power quality problems (Brumsickle, et al. 2001; Khan et al., 2019; Khan et al., 2018; Khan et al., 2017; Banteywalu et al., 2019; Anteneh et al., 2019; Molla et al., 2019, Molla et al., 2018, Jariso et al. 2018).