A study on new connection types of the main circuits for low voltage dynamic reactive power compensation device and its synchronous trigger circuits

The research of reactive power compensation is of great theoretical significance and practical value to maintain the voltage stability and improve the quality of the electric power. The operation modes of the low-voltage dynamic reactive power compensation devices are flexible and variable, therefore how to choose the circuit structure and control method is the key to improve their performances. In this paper, some kinds of possible connection types and their characteristics are discussed in detail. A more stable and reliable double Y-type circuit is presented in this paper, which could eliminate the switched impulsion caused by the neutral current. To overcome the disadvantages of conventional Δ- type circuits, a more economical Δtype circuit controlled by two thyristors is also presented. Based on the analysis of compensation theorem of thyristor-switched capacitor banks and connection types of the corresponding main circuit, the transient-free technical conditions of switching capacitor banks are presented in this paper. The synchronous trigger circuit that adapts to the above circuits is also designed. This provides a scheme for the practical application of switching capacitor banks in low-voltage dynamic reactive power compensation devices.