一种基于级联延迟信号消去锁相环的高压直流输电同步触发控制

现有同步触发控制在交流故障下无法精确产生触发脉冲,这将增大逆变器发生后续换相失败的风险。为此,该文通过建立小信号模型对同步触发控制系统进行详细分析,提出一种改进同步触发控制方法。该方法采用级联延迟信号消去锁相环快速跟踪换相电压相位,并根据交流故障快速检测改进触发方式,使得实际触发角快速准确地跟随触发角指令,有利于高压直流控制系统的精准调节。最后,利用CIGREHVDC标准测试模型对改进同步触发控制进行测试。仿真测试结果表明,该改进同步触发控制能够有效降低逆变器发生后续换相失败的概率,显著提升高压直流输电系统在故障后的恢复性能。

A Firing Control of HVDC Based on Cascaded Delayed Signal Cancellation Phase Locked Loop

The existing firing control cannot generate the firing pulses accurately under AC faults, which will increase the risk of subsequent commutation failure of LCC-HVDC system. Therefore, the firing control system was analyzed in detail by establishing a small signal model, and an improved firing control method was proposed. In this method, the phase of commutation voltage is tracked quickly by the CDSC-PLL, and improve the trigger mode according to the rapid detection of AC faults. In this way, the actual firing angle can change quickly and accurately according to the firing angle order, which is more conducive to the precise regulation of the HVDC control system. Finally, the improved firing control was tested in the CIGRE HVDC benchmark model. The simulation results show that it can effectively reduce the probability of subsequent commutation failure and improve the recovery performance of HVDC system.