Research On The Experiment Of Distribution Static Synchronous Compensator

This dissertation is within the research field of power quality control, which has drawn lots of concerns and is one of the most important and hot areas in electrical engineering. For traditional indirect current control strategy, the DSTATCOM operates as a voltage source. Therefore, the impedance for negative sequence component is very small. Thus, a small amount of negative sequence voltage could result high current, even leading to overcurrent or shuting down of the DSTATCOM.The research in this dissertation deals with the solutions to the problems of the distribution static synchronous compensator (DSTATCOM) used in industry field. The objective is to find proper control strategies and systematic design method for DSTATCOM under unbalanced voltage condition, furthermore to extend the compensation functions of the DSTATCOM, which will lay a foundation for promoting its practical use as soon as possible. If the DSTATCOM can operate properly in unbalanced voltage condition, and furthermore mitigate the negative sequence component impact on the load, the functions of the DSTATCOM could be extended and its compensating capability is fully utilized. In order to mitigate the unbalanced voltages at the Point of Common Coupling (PCC), a fundamental negative sequence voltage controlled voltage source strategy for DSTATCOM compensating voltage unbalance is proposed. With this control strategy, the PCC negative voltage can be mitigated efficiently and the positive current can be also controlled through regulating the DSTATCOM fundamental positive voltage. Thus, the compensation ability of DSTATCOM is increased without deteriorating the voltage unbalance compensation performance.According to strategy stated above, a hardware platform based on DSP2407 is carried out and the±10kvar DSTATCOM experimental system is designed. The results show that the proposed DSTATCOM has satisfactory performance under unbalanced voltage condition.