基于闭环控制的两相电源直流输电系统线路稳态电压协控方法

Coordinated Control Method for Line Steady-state Voltage of Two-phase Source DC Transmission System Based on Closed-loop Control

直流电压会影响分解开关控制、直流保护等过程,导致电压波动幅度较大,系统线路稳定性较差。采用闭环控制方法控制两相电源直流输电系统线路稳态电压,通过占空比函数计算占空比,根据脉宽调制占空比信号和三角载波,获取驱动三相脉宽调制整流器和三桥臂逆变器脉宽调制开关信号;采用开关信号调节交流侧电流值,通过调节电流控制电压。实验分析发现,该方法能够有效抑制两相电源直流输电系统线路稳态电压波动,提升两相电源直流输电系统响应性能,端口电压波动幅度较小,输电效率最高为99.83%。

DC voltage will affect processes such as decomposition switch control and DC protection,resulting in a large range of voltage fluctuations and a poor stability of system line.In this paper,the closed-loop control method is used to control the line steady-state voltage of a two-phase power supply DC transmission system.The duty ratio is calculated by the duty ratio function.According to the PWM duty cycle signal and triangular carrier signal,the PWM switch signal that drives a three-phase PWM rectifier and a three-bridge-arm inverter is obtained.The switch signal is used to adjust the AC current value,and the voltage is controlled by adjusting the current value.Through experimental analysis,it is found that this method can suppress the line steady-state voltage fluctuations of two-phase power supply DC power transmission system and improve its response performance.Under the control of the proposed method,the port voltage fluctuation range is small,and the maximum transmission efficiency is 99.83%.