Self zero sequence component control of dynamic voltage restorer in systems with different neutral point grounded modes

The dynamic voltage restorer (DVR) has become popular as a cost effective solution for the protection of sensitive loads from voltage problems such as sags. There are many investigations on DVR dealing with the unbalanced operation situations, however, few found in the area relating to DVR self zero sequence component control in power grid with different neutral point grounded modes. In fact, incorrect control strategy of zero sequence will lead DVR to instability in a special system condition. This paper studies the generating mechanism of self zero sequence component in systems with different neutral point grounded modes and presents effective control strategy to get rid of its influence. Simulations are carried out to verify the validity of proposed self zero sequence component control strategy