风电场中级联STATCOM直流侧电压控制方法

DC Capacitor Voltage Balancing Control for Cascade STATCOM in Wind Farm

由于风能具有随机性和间歇性等特点,风电场中级联STATCOM各模块直流侧电压波动更为明显。建立风电场中级联STATCOM的数学模型,分析其在四象限下的控制特性,提出有功功率均等分配来控制其各模块直流侧电压的平衡方法,通过控制其交流侧吸收的有功功率来控制其直流侧电压的大小。利用分层协调控制实现级联STATCOM的有功、无功调节,上层通过解耦实现总体控制,下层通过模块控制器实现有功功率均等分配控制。仿真和实验结果表明,该方法可以有效地稳定风电场中级联STATCOM直流侧电压,具有较高的工程实用价值。

As wind energy has the characteristics of randomness and intermittent, the fluctuations of each module DC voltage of cascade STATCOM is more obvious. This paper setted up the mathematical model of cascade STATCOM in wind farm; analyzed the control characteristics in the fourth quadrant,and proposed the method of active power equal distribution to control the voltage of each module DC side to be balancing, which could control the AC side＇s input active power to control the DC side＇s voltage. By using hierarchical coordinated control strategy to regulate active power and reactive power of cascade STATCOM. In the upper, it could realize the whole control by decoupling ; in the lower, it could realize the equal distribution of active power by using the module controller. Simulation and experimental results show that this method can effectively stabilize the DC side＇s voltage of the cascade STATCOM.