考虑直流调制的交直流系统中长期电压稳定协调控制

Coordinated Control for Middle-long-term Voltage Stability of AC/DC Power System Considering DC Modulation

综合考虑直流系统整流侧和逆变侧控制量的调制,协调交流系统和直流系统各控制量,提出了一种考虑直流调制的交直流系统中长期电压稳定协调控制方法。首先,推导出换流母线电压对整流侧和逆变侧换流器传输功率的灵敏度解析表达式,并基于轨迹灵敏度建立以节点电压轨迹偏差和控制代价最小为综合目标的模型预测控制优化模型。然后,根据对系统控制轨迹的预测,进行交直流系统控制数量自适应调整和控制地点优选,以提高模型预测控制的效率,协调交直流系统各控制量进行电压滚动优化控制。最后,对交直流混联系统进行仿真,结果表明针对不同的故障场景,所提控制方法均能有效调制直流系统传输功率和熄弧角,全面协调交直流系统的各种控制手段,提高系统中长期电压稳定性。

Based on the modulation of control variables on both rectification and inverter sides and the coordination of control variables in AC/DC power system,a coordinated control method is proposed for middle-long-term voltage stability of AC/DC power systems considering the DC modulation.Firstly,analytical sensitivity expression of transmission power of converter bus voltage to converters on the rectifier side and the inverter side is deduced.Based on the trajectory sensitivity,an optimization model of model predictive control(MPC)is established with the objective of minimizing both the deviation of voltage trajectories and the control cost.Then,to improve the efficiency of MPC and coordinate control variables of AC/DC power system for voltage rolling optimization control,the number and the location of AC and DC control measures are optimally determined by system predictive trajectory.Finally,multiple AC/DC power system is simulated.The results show that the proposed method can effectively modulate the transmission power and extinction angle of DC system according to different fault scenarios and comprehensively coordinate various control measures of AC system,which improves the middle-long-term voltage stability.