Research On Three-level Energy-fed Power Electronic Load And Energy-saving Loss Simulation Simulation Platform

With the development of energy Internet, in addition to conventional distribution network electrical eq uipment, a variety of smart grid devices have emerged, such as power electronic transformers, energy router. Before the electrical devices are applied to the power grid, it is necessary to carry out a long run test with load. Because of low energy consumption, power electronic load s has gradually become a hot research topic and be used to test electrical devices. The existing power electronic load is divided into AC and DC type, and all of them have two- level topology structure. In this paper, a multi- function and multi- usage three level power electronic load(PEL) with energy feedback is proposed. Such PEL has multi- function and multi- usage, it can not only simulate various types of AC and DC load, but also can charge the battery as DC power supply. Therefore the device utilization rate of PEL is improved, and the application of the PEL proposed in this paper is wider than the existing PEL. The main research contents are as follows:Firstly, a structure of three level power electronic loads based on the diode clamped three level converters has been presented, and the dynamic characteristics of the energy flow balance and power flow of the PEL has been analyzed.Secondly, a new multi- function and multi- usage power electronic load based on three- level converter has been proposed, and the work principle and implementation method of three- level PEL has been analysed in detail. According to the performance requirement of PEL, the PEL is designed in different operation mode. In accordance with the different operation modes of the PEL, the corresponding mathematics model of main circuit is established, and the controller of each module of the PEL is designed, including AC load, DC load, constant voltage charging, constant current charging.Then, establishes the simulation system of the three level power electronic load with the EMTDC/PSCAD, and carries out the simulation experiment under various test conditions. The simulation result verifies the feasibility and effectiveness of the topology and control strategy proposed in this paper.Finally, establishes the Energy Saving and Loss Reduction Technology Laboratory based on PEL. It can simulate the dynamic operation of the really mid-low distribution network, and evaluates the real-time energy efficiency of various AC or DC electrical devices.