改善交直流输电系统故障恢复特性的直流功率能量面积补偿方法

Energy Area Compensation Method of DC Power for Improving Recovery Characteristic of AC/DC Transmission System

交直流输电系统面临的突出问题之一是故障后与交流系统相适应的直流控制问题。以改善交流系统故障后的频率和电压恢复特性为目的,提出了直流功率的能量面积补偿方法。该方法能基于换流站本地数据准确计算出在线调整系统减速面积的直流功率补偿量和持续时间,在整流侧交流系统严重故障后抑制振荡过程,加速系统恢复;对于逆变侧交流故障,能改善系统频率和电压的恢复特性,避免连续换相失败的发生。建立交直流混联系统电磁暂态仿真模型进行仿真验证,仿真结果验证了所提出控制方法的可行性和有效性。

DC power control for AC systems after fault is one of the key problems for AC/DC transmission systems. Aiming at improving the recovery characteristics of frequency and AC voltage for an AC system after fault, we put for- ward an energy area compensation method of DC power. The method obtains DC power order and duration time accurately based on local measurements to regulate retardation area online. With this method, oscillation of AC system can be suppressed after AC faults at the rectifier side. Moreover, it can prevent continuous commutation failure by im- proving frequency and AC voltage recovery after faults at the inverter side. Meanwhile, using the proposed method, we made a simulation on an electromagnetic transient simulation model, and the results proved the effectiveness of the method.