Voltage compensation and fault current limiting hybrid system and control method thereof

Abstract

The invention discloses a voltage compensation and fault current limiting hybrid system and a control method thereof. The hybrid system control method comprises three parts of direct current voltage stabilization module control, voltage compensation module control and fault current limiting module control. The direct current voltage stabilization module control uses SVPWM control to provide an active power energy exchange channel for a direct current side. The voltage compensation module control uses wide area prediction change PI control, and carries out precise tracking compensation on voltage fluctuations of a power grid. According to the control method provided by the invention, real-time voltage compensation can be effectively realized; short-circuit current can be timely limited; and the reliability and the safety of power supply of the power grid are improved.

Description

technical field [0001] The invention relates to a hybrid system of voltage compensation and fault current limiting and a control method thereof. Background technique [0002] With the continuous development and progress of society, people pay more and more attention to power quality. The frequent occurrence of short-circuit faults, excessive short-circuit current will damage the grid equipment, and may cause damage to user electrical equipment; voltage swell, sag and imbalance will cause losses to some sensitive users, and in severe cases will cause huge economic losses. Although there are many current limiting and voltage compensation devices, most products still have many shortcomings: [0003] 1. The traditional series current-limiting reactance has been connected in series in the line for a long time, and the loss on it is very large under normal conditions of the power grid; [0004] 2. Common control methods for voltage compensation devices include PI control and hy...

AI Technical Summary

Problems solved by technology

[0003] 1. The traditional series current-limiting reactance has been connected in series in the line for a long time, and the loss on it is very large under normal conditions of the power grid;

[0004] 2. Common control methods for voltage compensation devices include PI control and hysteresis control, etc.; when PI control is used, the control accuracy is poor and PI parameters are difficult to adjust; when hysteresis control is used, the setting of the loop width has a greater impact on the system, and the loop width Hours have high requirements on the frequency of the switching tube, and the ring width is too large to accurately meet the compensation requirements;

[0005] 3. The DC side voltage stabilizing device often uses traditional PI control, deadbeat control, etc.; when the AC side voltage fluctuates when using these control methods, the DC voltage stabilization value will change significantly, which cannot be used for common The voltage compensation device on the DC side provides energy

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