厦门柔性直流输电工程换流阀充电触发无源逆变试验研究

为了确保厦门柔性直流输电工程核心设备——换流阀的安全,有必要在换流阀带进线开关首次解锁前先确认换流阀触发相序的正确性。根据厦门柔性直流输电工程真双极的接线方式,提出了换流阀充电触发无源逆变试验方案。首先对换流阀进行不控充电,并将未试验极控制系统电压作为试验极控制系统锁相和控制用电压,然后断开试验极交流进线开关,为了防止阀子模块因低电压导致旁路过多,极控制系统在收到开关返回节点信号后自动解锁换流阀200 ms完成无源逆变。现场试验结果表明了该方案的可行性和有效性,证明了极控制保护系统、阀基控制系统和换流阀之间工作的正确性,确保了换流阀的安全,并依据试验结果提出了控制系统延时的确定方法及补偿方法。该方案的提出也为其他类似工程提供了有益的借鉴。

Research on the Converter Valves Charging and Triggering Passive Inversion Test of Xiamen Flexible DC Transmission Project

In order to ensure the safety of Xiamen flexible DC project converter valves, it is necessary to confirm the correctness of the triggering phase sequence of converter valves before the first time deblock of converter valves with line breaker. According to the real bipolar connection mode of Xiamen flexible DC project, the test scheme of converter valves charging and triggering passive inversion is proposed. Firstly, the converter valves are charged without control and the voltage of unworking pole control system is used as the voltage of working pole control system for phase-locking and control. Then, the line breaker is disconnected, and in order to prevent excessive bypassing of valve submodules under low voltage, the pole control and protection system deblocks converter valves automatically for 200 ms to complete the passive inversion after the breaker returns to the node. The field test result verifies the feasibility and effectiveness of the scheme, and proves the correctness of the working among pole control and protection system, valve basic controller and converter valves, and the safety of converter valves is assured. According to the test results, the method for determining the time delay of the control system and the corresponding compensation method are put forward. The scheme can also provide a useful reference for other similar projects.