基于参数自适应调节的虚拟同步发电机暂态响应优化控制

Optimal Control of Transient Response of Virtual Synchronous Generator Based on Adaptive Parameter Adjustment

虚拟同步发电机(virtual synchronous generator,VSG)因能模拟同步发电机的运行机制,受到新能源发电领域的广泛关注。针对分布式能源出力变化引起系统频率和功率波动甚至越限的问题,该文在分析暂态过程中各物理量变化情况的基础上,充分利用VSG虚拟惯量和阻尼系数灵活可调的优势,建立了以暂态响应时间最短为目标,以频率及其变化率不超过设定值为约束并考虑系统平衡点边界条件的优化模型。进一步,提出了该模型的求解方法并据此设计了虚拟惯量和阻尼系数的自适应调节策略,并分析其稳定性。该策略可有效抑制暂态过程VSG频率和功率的波动,且能显著缩短暂态响应时间。仿真结果验证了所提控制策略的正确性和有效性。

The virtual synchronous generator（VSG） has attracted wide attention in the field of new energy power generation since it can mimic the mechanism of synchronous generator. However, frequency and active power may fluctuate severely and even exceed their limitation if distributed energy varies seriously. To solve this problem, this paper first investigated the change of physical variables in transient process, and then established the optimal model by taking full advantage of the flexible adjustability of virtual inertia and damped coefficient of VSG. The model aims at minimizing transient response time, with limitation of frequency amplitude and change rate being constraint and system new equilibrium point being boundary condition. In addition, the adaptive adjustment strategy of virtual inertia and damped coefficient was proposed according to the solution of the model, and its stability was analyzed. The strategy can inhibit fluctuation of frequency and active power, and shorten the time of transient response efficiently. The simulation results verify the correctness and effectiveness of the proposed control strategy.