Study On The Parameters Design And Inverse System Control Method Of DSTATCOM

Dynamic reactive power compensation is a main measure of reducing network dissipation and improving power quality. DSTATCOM, as dynamic reactive power compensation equipment, can rapidly and continuously compensate reactive power of the load, and has a characteristic that rated compensation current is not related with the network voltage. So DSTATCOM is the developing trend of reactive power compensator. The control technology and the parameter design method of low-voltage DSTATCOM was researched based on the Voltage Source Inverter and PWM control technology.The state-of-art of STATCOM was summarized in this paper, and the operating principle and steady-state characteristics of DSTATCOM is analyzed. Based on the equivalent circuit, dynamic model of DSTATCOM is established, and two basic control modes were analyzed. Then, the indirect current control mode with single of regulating control angle is selected in this paper.The simulation model of DSTATCOM system is established, and the hybrid control strategy of inverse system and PI control is researched through simulation. After considering the realizing limitations, zero-order inverse system was used. Against the strong nonlinear characteristics of DSTATCOM, the correction technology of sectionalizing linearization was used from measured characteristics, and dynamic and static performances of the system were improved. The effect of filter inductance on the compensator structure, compensation capacity, the amount of harmonic, power loss and anti-interference ability was comprehensively analyzed, and the selection range of filter inductance is recommended.An experimental system of ±5kvar/380V DSTATCOM was developed, and the control system of DSTATCOM was designed based on DSP and the performances of DSTATCOM is tested completely. The experimental results indicate that the control strategy and design method used in this paper is effective and feasible, and the design of main circuit, control system and protection system is rational and correct.