配电网静止同步补偿器的非线性控制方法

Nonlinear control method of DSTATCOM

通过对系统电路结构的分析获得了多变量、强耦合、非线性的系统模型。提出一种配电网静止同步补偿器(DSTATCOM)的非线性控制方法,不仅实现了交流侧瞬时电压与交流侧瞬时电流之间强耦合关系的消除,而且解决了直流侧电压因其非线性特性而存在难以快速稳定的问题,并保证了DSTATCOM交流侧瞬时电流和直流侧瞬时电压均能稳态无差地跟踪各自的期望值信号;基于瞬时无功功率的定义获得了无功电流在dq坐标系下的期望值信号。实验结果表明,DSTATCOM采用所提非线性控制方法后,配电网公共连接点电压和DSTATCOM直流侧电压均能及时、有效地调整到其期望值。

The system model with multiple variables,strong coupling and nonlinearity is established by system circuit analysis and a nonlinear control method is presented for STATCOM,which eliminates the strong coupling of instantaneous voltage and instantaneous current at its AC side,quickly makes its DC-side voltage stable,and tracks without error the expected steady-state signals of AC-side current and DC-side voltage.The expected reactive current of DSTATCOM in dq coordinates is obtained based on the definition of instantaneous reactive power.Experimental results show that,with the proposed nonlinear control method,the PCC voltages of grid and the DC-side voltage of DSTATCOM can be effectively regulated to their expected values in time.