基于多目标离散粒子群算法的电容隔直装置优化配置

Optimal Configuration of Capacitor Blocking Devices Based on Multi-Objective Discrete PSO

电容隔直装置可能造成区域电网内变压器中性点直流电流增大。该文提出了一种多目标离散粒子群优化算法,从全局角度对电容隔直装置进行了优化配置。首先分析了高压直流输电系统入地电流引起的交流系统中直流电流的流通路径,并搭建了等效场路耦合模型,可采用有限元法求解。其次建立以各变压器中性点直流电流不超限值为约束条件,以电容隔直装置投入数量和电网内变压器中性点直流电流绝对含量总和最小为优化目标的电容隔直装置优化模型。最后,通过引入变异环节及粒子更新策略,求解多目标优化问题的Pareto最优前沿,获得了优化函数对应的最优解,可确定隔直装置配置的最佳方案。

Capacitor blocking devices may cause increase of DC current through neutral point of transformers in regional network.A multi-objective discrete particle swarm optimization(PSO)algorithm is proposed to optimize allocation of capacitor blocking devices from a global perspective.Firstly,the flowing path of the DC current caused by HVDC transmission system earth-return current is analyzed and an equivalent field-circuit coupling model is established,which can be solved with finite-element method.Then,a multi-objective optimization model is established to ensure safe margin values of neural DC current in transformers in AC network,where the least quantity of devices and minimum absolute sum of the neutral DC current are the objective functions.Finally,combined with particle updating strategy,PSO algorithm is applied to solve the objective functions and optimal Pareto front is found.Accordingly,optimal configuration of capacitor blocking devices is obtained.Taking an actual power grid close to an UHVDC grounding electrode as example,the results verifies effectiveness and superiority of the proposed algorithm.