基于电压灵敏度的交直流系统源网协调电压优化控制

Sensitivity-based Optimal Source-Grid Coordinated Voltage Control in AC/DC Hybrid System

随着特高压直流输电在远距离、大容量功率传输方面的广泛应用,当前电网发展成为交-直流深度耦合的复杂系统,给系统电压安全控制带来了严峻挑战。基于交直流系统的电压灵敏度,计及直流系统整流侧及逆变侧换流器控制量调制,提出了交直流系统源网协调的在线电压优化控制方法,构建了以综合控制代价及电压控制偏差最小为目标的线性约束二次优化模型,能够快速求解交直流系统源网控制量的控制参考值,进行在线电压幅值偏差校正。通过对直流系统整流侧、逆变侧换流器的控制量进行优化,直流系统可充分参与交直流电网电压稳定控制。交直流混联系统的仿真结果表明了所提优化控制方法能有效协调交直流系统控制量,保证电压运行在安全范围之内。

With the widespread application of HVDC power transmission as a key channel for long-distance,large-capacity power transmission,the current grid has become a complex system with deep AC-DC coupling,posing serious challenges to voltage control problems. Based on the voltage sensitivity in the AC/DC system,considering control quantity modulation of rectifier side and inverter side converter of DC system, an optimal coordinated voltage control(CVC) method is proposed incorporating the controls of HVDC rectifier and inverter converters. In this optimal method,a linearly constrained quadratic programming(LCQP) model with the minimization of the control costs and the voltage control deviation as objective function is constructed to coordinate the control variables of AC/DC system for voltage magnitude correction. By optimizing the control variables of converter and inverter converters of HVDC systems,the potential of HVDC system participating in voltage control is developed. The simulation results of the AC/DC hybrid system show that the proposed control method can effectively coordinate the AC/DC system control variables to ensure the voltage operating within a safe range.