直流配电网分布式光伏并网功率控制策略研究

Research on Distributed Photovoltaic Grid-connected Power Control Strategy of Direct Current Distribution Network

直流配电网具有线路损耗低、可控性高、适应新能源接入等优点,分布式光伏直接接入直流配电网可以省去大量的DC/AC环节,结构简单且效率更高,与传统的交流输电相比还具有输电损耗低、可控性高等优势,成为未来配电网的发展趋势之一。但与传统的交流配电网不同,直流配电网没有频率和无功功率,电压的稳定性成为衡量直流系统是否可以稳定运行的唯一指标。这里以含分布式光伏和储能系统的直流配电网为研究对象,首先研究了主、从换流站的控制策略,分析研究以交流主网作为功率平衡节点和以储能为功率平衡节点的控制策略及其切换。最后通过建立的仿真模型,验证了该策略的有效性和可行性。

The direct current distribution network has the advantages of low line loss,high controllability,and adaptability to new energy access.Distributed direct access to the direct current distribution network can save a large number of DC/AC links,and the structure is simple and efficient.Compared with the traditional alternating current transmission,it has the advantages of low transmission loss and high controllability,and it will become one of the development trends of the distribution network in the future.However,unlike the traditional alternating current distribution network,the direct current distribution network has no frequency and reactive power,and the stability of the voltage is the only indicator to measure whether the direct current system can operate stably.The direct current distribution network with distributed photovoltaic and energy storage systems is taken as the research object.Firstly,the control strategies of the main and slave converter stations are studied.The alternating current main network is analyzed as the power balance node and the energy storage is considered as the power balance node of the control strategy and its switching.Finally,the effectiveness and feasibility of the strategy are verified by the established simulation model.