基于模型预测控制的全功率变速抽水蓄能与SVG功率协调控制

Coordinated Power Control of Variable Speed Pumped Storage Unit with Full-size Converter and SVG Based on Model Predictive Control

摘要:

全功率变速抽水蓄能机组（FSC-VSPSU）通过背靠背变流器接入电网，具有功率快速可调、有功无功独立解耦的优点，在近年来得到了广泛关注。由于新能源场站具有波动性，通常配置静止无功发生器（SVG）来维持系统电压稳定。针对SVG易出现容量不足的状况，研究FSC-VSPSU与SVG功率协调控制。分析了FSC-VSPSU与SVG无功调节特性，提出了基于模型预测控制的功率协调控制策略。采用模型预测控制协调响应时间不同的FSC-VSPSU与SVG，通过电压灵敏度计算无功和电压的关系，建立以并网点电压、FSC-VSPSU电压偏差最小以及SVG无功储备最大为目标的模型预测控制（MPC）问题数学模型，求解得到FSC-VSPSU与SVG功率参考值。通过仿真验证了所提模型预测控制的可行性以及其相较于下垂控制的优越性。

Abstract:

The variable speed pumped storage unit with full-size converter (FSC-VSPSU) is connected to power grid through back-to-back converters, which has the advantages of fast power adjustment and independent decoupling of active and reactive power, so it has attracted wide attention in recent years. Due to the volatility of new energy station, it is usually equipped with static var generator (SVG) to maintain the stability of system voltage, but SVG is also prone to insufficient capacity. Aiming at this situation, the coordinated power control of FSC-VSPSU and SVG is studied, the reactive power regulation characteristics of FSC-VSPSU and SVG are analyzed, and a coordinated power control strategy based on model predictive control (MPC) is proposed. Model predictive control is used to coordinate FSC-VSPSU and SVG with different response times, and the relationship between reactive power and voltage is calculated by voltage sensitivity. A mathematical model of MPC problem is established with the goal of minimum voltage deviation of FSC-VSPSU and point of common coupling, and maximum SVG reserve,and then the power reference values of FSC-VSPSU and SVG are solved. The feasibility of the proposed model predictive control and its superiority over droop control are verified by the simulation.