交直流子网双边惯量约束下互联变流器动态功率控制策略

Dynamic Power Control Strategy for Interlinking Converter Under Bilateral Inertia Constraints in AC/DC Subgrid

随着虚拟同步发电机技术的广泛应用,混合微电网(HMG)的交直流子网均具有惯量。当惯量特性不同的交直流子网经互联变流器(ILC)互联运行时,子网的动态特性会通过ILC耦合,因此建立了含交直流子网双边惯量的HMG小信号模型,分析了子网双边惯量对HMG动态性能和稳定性的影响规律。针对交直流子网互联后功率振荡和变化率越界等问题,提出一种考虑双边惯量约束的ILC动态功率控制策略;并以HMG动态性能、系统稳定性和功率传输极限为约束条件,优化设计了动态功率控制器的参数。基于StarSim半实物仿真平台搭建了HMG系统,在多种工况下验证了所提出的动态功率控制策略和参数设计方案的有效性和适应性。

With the extensive application of virtual synchronous generator technology, both AC and DC subgrids of the hybrid microgrid(HMG) have the inertia. When the AC and DC subgrids with different inertia characteristics are interconnected by an interlinking converter(ILC), the dynamic characteristics of the subgrids are coupled by ILC. Therefore, this paper establishes a small-signal model of HMG with the inertia of both AC and DC subgrids, and analyzes the influence law of bilateral inertia of subgrids on the dynamic performance and stability of HMG. Aiming at the problems of power oscillation and the overshoot of change rate after the interconnection of AC and DC subgrids, a dynamic power control strategy of ILC considering bilateral inertia constraints is proposed. Taking the dynamic performance, system stability and power transmission limit of HMG as constraints,the parameters of the proposed dynamic power controller are designed and optimized. An HMG system built on StarSim semiphysical simulation platform verifies the effectiveness and adaptability of the proposed dynamic power control strategy and parameter design scheme under various operation conditions.