基于参数权重的虚拟同步机同调等值算法

Homology Equivalence Algorithm of Virtual Synchronous Machine Based on Parameter Weight

摘要

针对传统同调分析方法在处理多逆变器参数耦合问题时存在显著不足, 难以满足大规模电力系统降阶建模对精度与效率的双重要求的局限性, 提出一种基于参数权重的虚拟同步机(VSG: Virtual Synchronous Generator)同调等值算法。首先, 在强电网假设下, 通过解耦分析逆变器输出功率动态特性, 建立虚拟转子运动方程与参数间的数学模型, 明确转动惯量(J)、阻尼系数(D)及线路电抗(X)对虚拟转子角的差异化作用机理。其次, 引入偏导数积分法量化各参数在暂态过程中对转子角轨迹的影响权重, 突破传统K-means聚类算法仅依赖欧氏距离的局限, 提出基于参数权重的加权聚类策略, 显著提升同调群划分的物理意义与准确性。同时, 结合有功功率守恒原则, 推导无功功率聚合算法, 构建兼顾有功-无功动态特性的等值模型。为验证算法有效性, 在PLECS仿真平台搭建含10台异构VSG的并联系统, 设置电阻接地、切机故障等多扰动场景进行测试。结果表明, 在不同扰动工况下, 所提算法可精准识别同调逆变器群组, 其划分结果与转子角轨迹的时域仿真高度吻合。等值模型的有功功率最大误差小于1.5%, 无功功率误差低于2.8%, 验证了算法的工程适用性。其为高比例新能源电力系统的动态稳定分析与高效仿真提供了理论依据和技术支撑。

Abstract

The extensive integration of distributed generation complicates power system operation, challenging the computational efficiency and scalability of existing analytical tools. To address this, efficient reduced-order modeling techniques must be developed for representing multi-inverter networks. A promising approach involves coherency-based aggregation to create simplified dynamic models for large-scale distributed generation systems with heterogeneous inverters. Simple and efficient, conventional methods retain network nonlinearities, limiting accuracy in dynamic analyses under disturbances. And prior coherency analyses often overlook virtual EMFs (Electromotive Forces) and parameter coupling effects among inverters. To resolve these limitations, a parameter weight-based coherency equivalence method for VSGs (Virtual Synchronous Generators) is proposed. First, through small-signal analysis, the voltage-current dual-loop control of inverters is shown to exert minimal influence on virtual rotor motion, enabling the derivation of a virtual synchronous generator excitation model grounded in physical principles. This achieves precise coherency identification under small perturbations while clarifying the parametric influence mechanisms. Subsequently, virtual rotor motion equations are utilized to quantitatively analyze parameter impacts (e.g., moment of inertia J, damping coefficient D, and line reactance X), with results assigned as parameter weights to establish a weighted coherency algorithm. This algorithm enables rapid and accurate identification of coherent inverter clusters, followed by an aggregation algorithm that integrates active power conservation and reactive power dynamic equivalence. The correctness and effectiveness of the proposed coherency and aggregation methods are validated via PLECS simulations.

关键词

同调等值算法 / 参数权重 / 加权聚类 / 虚拟同步机 / 动态聚合

Key words

coherency equivalence algorithm / parameter weight / weighted clustering / virtual synchronous generator(VSG) / dynamic aggregation

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基金资助

鲁软科技公司智慧能源分公司2025年度虚拟同步发电机(VSG)控制技术使用基金资助项目(SGSDLRZNMYJS2600277)