利用柔性功率调节器提高电力系统稳定性

多功能柔性功率调节器(FPC)是一个大容量低速飞轮储能系统,也是一种新型FACTS装置。它由双馈电机(DFIG)和作为交流励磁电源的电压源型双PWM变换器组成。类似于超导磁储能(SMES),FPC具有独立的有功和无功调节能力,能提高电力系统稳定和改善电能质量。与SMES相比,FPC易于开发和运行,成本也低。为了提高FPC的控制性能,提出了一种改进型定子磁链定向控制策略。该策略对于电网电压波动具有较好的鲁棒性,且易于实现。针对一个包含FPC的双机无穷大母线系统进行仿真,证明该改进型控制策略具有良好的动态特性,电力系统的稳定性得到明显改善。

Power System Stability Enhancement by the Flexible Power Conditioner

The multi-functional flexible power conditioner (FPC),which is a large-capacity low-speed flywheel energy storage system,is a novel FACTS device.It consists of a doubly fed induction generator(DFIG)and a voltage-source pulse width modulation(PWM)rectifier-inverter used,as an AC exciter.Similar to that of the superconducting magnetic energy storage (SMES),the FPC can realize an independent active and reactive power control,so it can be used to improve the stability of power system as well as the quality of power supply. Additional advantage of the FPC over the SMES based device is that it is easy to develop and operate.Therefore,the cost will be greatly reduced.In order to increase performance of the proposed device,an improved stator flux linkage orientated control strategy is proposed.This strategy is robust for the grid voltage fluctuation and easy to realize.Simulation results of applying the proposed device in a two-machine and an infinite bus system show that the proposed control provides excellent dynamic characteristics,and the power system stability is enhanced evidently.