适用于电压源型高压直流输电的控制策略

将电压源型高压直流输电(VSC-HVDC)两端节点等效为两个有源节点,推导得到VSC-HVDC两端等效节点注入电流的表达式,从而可以方便地通过修改系统导纳矩阵,得到含VSC-HVDC系统的数学模型。在该模型的基础上,考虑VSC内部电流环和系统控制要求,提出了一种新的VSC-HVDC控制策略。以一个含VSC HVDC的6机电力系统为例,仿真表明,采用该控制策略,在系统发生大扰动后,VSC HVDC不仅能够迅速恢复正常运行,而且对系统电压和频率稳定没有太大影响。

A Novel Control Strategy for Voltage Sourced Converters Based HVDC

The injection current expressions of voltage sourced converters (VSC) based HVDC (VSC-HVDC) are derived, in which two terminals of VSC-HVDC are regarded as active nodes, thus the equivalent mathematical models for a multi-machine system with VSC-HVDC can be conveniently obtained by revising the system admittance matrix. With the inner current loop and system control requirements taken into account, a novel control strategy for VSC-HVDC is proposed based on the model obtained. As an example, a six-machine power system with VSC-HVDC is simulated. The simulation results demonstrate that the VSC-HVDC using the proposed control strategy can quickly recover from system fault without negative influences on the frequency and voltage stability of the AC system.