基于模拟退火算法的特高压直流VDCOL控制环节优化方法

Optimization for VDCOL of high-voltage DC transmission system based on simulated annealing algorithm

高压直流传输系统受端交流电网日趋复杂,在逆变站所配置的传统低压限流单元(voltage dependent current order limiter,VDCOL)的控制特征已难以适应现代电力系统的调控方式,为此,提出基于模拟退火算法的特高压直流VDCOL控制环节优化方法。首先,基于高压直流传输系统逆变站的稳态模型和常规VDCOL控制环节的响应特性,分析逆变站与直流受端交流系统的功率交互特性,推导直流电流指令值与逆变站无功消耗的关系;其次,设计高压直流传输系统典型故障集合,提出基于模拟退火算法的VDCOL控制环节U-I特性曲线多拐点参数的优化方案;最后,采用MATLAB与PSCAD/EMTDC联合仿真的方法得到所提改进的VDCOL控制环节U-I特性曲线。通过与常规VDCOL控制环节的仿真对比分析可知,所提方法更加符合系统暂态无功的实际需求,可有效抑制直流连续换相失败的发生。

As the AC grid at the receiving end of high-voltage direct current(HVDC)transmission systems becomes increasingly complex,the control characteristics of traditional voltage-dependent current order limiter(VDCOL)units configured at inverter stations have become difficult to adapt to the regulation of modern power systems.To address this issue,an optimization method for the VDCOL control segment of HVDC based on simulated annealing algorithm is proposed.Firstly,based on the steady-state model of the inverter station of the HVDC transmission system and the response characteristics of the conventional VDCOL control segment,the power interaction characteristics between the inverter station and the AC system at the receiving end are analyzed,and the relationship between the DC current command value and the reactive power consumption of the inverter station is derived.Secondly,a typical fault set for HVDC transmission systems is designed,and an optimization scheme for the multi-inflection point parameters of the U-I characteristic curve of the VDCOL control segment based on simulated annealing algorithm is proposed.Finally,the improved U-I characteristic curve of the VDCOL control segment is obtained using a joint simulation method combining MATLAB and PSCAD/EMTDC.Through comparative simulation analysis with the conventional VDCOL control segment,it can be seen that the proposed method better meets the actual demand for system transient reactive power and can effectively suppress the occurrence of continuous commutation failures in the HVDC transmission system.