基于VSC的DCIPC阻尼系统功率振荡及限制短路电流研究

Power oscillation damping and short circuit current limiting by VSC-based DCIPC

根据相间功率控制器(IPC)和电压源型变换器(VSC)的基本原理、工作特性,将二者结合构成移相环节连续可调的动态可控相间功率控制器(DCIPC)。通过参考电压值对VSC进行调节,进而改变电感和电容支路的注入电压,达到快速连续地改变IPC各支路移相角的目的。分析移相角控制对带DCIPC联络线传输功率的调节作用,以发电机角速度变化作为反馈控制信号设定VSC产生的移相电压,从而实现抑制功率振荡的功能。该控制器电感支路由晶闸管控制电抗器(TCR)代替,电容支路由晶闸管控制串联电容器(TCSC)容性微调模式构成,分析TCR支路感抗和TCSC支路容抗对短路电流的限制作用,以晶闸管触发角作为控制信号设定DCIPC的等值参数,从而实现限制短路电流的功能。以经带DCIPC联络线相连的两机系统为例,验证了所提方法的有效性。

A DCIPC （Dynamic Controlled Interphase Power Controller） with continuously adjustable phaseshifting section is constructed by integrating IPC（Interphase Power Controller） with VSC（Voltage Source Converter） according to their basic principle and characteristics. In order to quickly and continuously change the phase-shifting angle of each branch of the IPC,the injecting voltages of inductor and capacitor branches are modified by adjusting the VSC via the in regulating the transferring power of tie line with reference voltage. The function of angle shifting control DCIPC is analyzed and the angular velocity variation of generator is taken as the feedback control signal to set the phase-shifting voltage generated by the VSC for the power oscillation damping. Its inductor branch is a TCR（Thyristor Controlled Reactor） and its capacitor branch is a TCSC（Thyristor Controlled Series Capacitor） with slightly adjustable capacitance. The function of TCR branch inductive reactance and TCSC branch capacitive reactance in limiting the short circuit current is analyzed and the firing angle of thyristor is taken as the control signal to set the equivalent parameters of DCIPC for the short circuit current limiting. A two-machine system connected by the tie line with DCIPC is taken as an example to verify the effectiveness of the proposed method.