Study On Control Strategy Of TSVG Based On Voltage Stability Analysis

With the scale expansion of industrial production in China, more and more power electronic equipments are put into use, which makes the power quality issues become more prominent. In this paper the TSVG device is proposed to solve the low power factor and harmonic problem in the plastics processing industry when injection molding machine works. The voltage stability at the Point of Common Coupling is analyzed when the TSVG works to ensure the safe and stable operation of the system. The TSF channel parameters optimization based on Particle Swarm Optimization is proposed, which improves the efficiency and stability of system. It provides a new method for solving the relevant issues.Firstly, the working principle and circuit structure of Static Var Generator and Thyristor Switch Filter in TSVG are introduced. The transient analysis of the TSF is carried out, the zero-voltage triggering of thyristor is determined. The control scheme for SVG with voltage topology is selected, and the output current control scheme of SVG adopts direct-current control. In the current detection step, the detection scheme of reactive power and harmonic current based on instantaneous reactive power theory is adopted, which ensures the rapidity and accuracy of detection. And the coordinated control strategy is used for TSVG.Secondly, in order to ensure the stability of PCC voltage, the system with TSVG is analyzed in detail, the mathematical model of system is also analyzed. The voltage outer loop and current inner loop control are used in the PCC voltage controller, and the inner loop adopts the current feed-forward decoupled mode. The strategy can effectively control the AC side voltage and DC bus capacitor voltage. In order to improve the control performance of the voltage controller for the different voltage faults of PCC, the voltage controller is improved. To improve the reactive compensation and harmonic suppression effect of TSF, this paper presents a multi-objective channel setting method with PSO. And the mistuning analysis is carried out to ensure the stable operation of system.Finally, the simulation model of TSVG system is built in the MATLAB simulation environment. And the field test data of voltage and current is used in the simulation to simulate the practical situation of locale. The system can effectively compensate the reactive power and suppress the harmonic. The TSVG hardware platform is built in the laboratory environment. The experimental results show that the TSVG can effectively complete the expected target, improve the system power quality.