Theory And Applied Research Of Nove Modular SVC

In this paper,the advantages and disadvantages of traditional reactive power compensator are introduced and compared.In order to reduce the harmonic current component which the SVC injects into system,a new topology and operating principle is proposed in this paper.Based on modular design,groups of low TCR reactive power modules connect to power system with Y/Y/Δtransformer.It injects little harmonic current component into system,and needn't additional filter. Because of modular design,it is easy to expend system capacity and redundancy design.There is only one group TCR works at phase control state and others in switching state at high volume compensation.According to the reactive power compensation capacity of the SVC,we can determine work status of each module,then use of closed-loop voltage control strategy to minimum the voltage fluctuation of PCC.This paper discusses the difference of two instantaneous reactive power detection algorithm and studies the advantages and disadvantages in the reactive power measurement precision and dynamic performance.The design of digital low-pass filter is to be an important part.Using second-order Butterworth low-pass filter,which with good frequency response and filtering effects,can easy to software programming.The experimental results verify the correctness of this method.The general control platform based on FPGA and the driver protective circuit of thyristor is designed.In order to verify the correct of control algorithm,the main circuit of novel SVC is achieved at RTDS and the trigger angle is generated by FPGA.When the RTDS connects with the control platform,the thyristor can be controlled by FPGA but not by RTDS internal pulse.The result of RTDS is showed that novel SVC has good dynamic response speed and steady-state accuracy.Finally,the three-phase 2kvar 12 pulse TCR experimental platform is designed. Steady-state and dynamic results verify the theoretical analysis correctly.Using Topas2000 power quality analyzer,the loss test results of single-phase TCR is given, to be its power loss of about 3 percent.