Research On Field Interoperability Testing Device Of Electric Vehicle Charging System

Because of its advantages of fast charging speed,DC charging pile gradually plays a greater role in the field of public charging.DC charging pile adopts high voltage and large current charging mode.Therefore,with the rapid development of DC charging pile,the safety and reliability of DC charging pile cannot be ignored.In order to standardize the working process of DC charging piles,the state has successively launched the relevant standards on communication protocol,interoperability test and communication consistency test of DC charging piles.Whether the communication process and charging control process of the charging piles meet the relevant national standards requires that the DC charging piles be tested at the factory by the manufacturer of the DC charging piles or by a third-party testing organization The test results show that the traditional manual test or traditional test method can not meet the test requirements of DC charging pile because of many test items.Therefore,it is necessary to develop a set of universal and efficient interoperability testing equipment for DC charging piles.This paper analyzes the working principle of DC charging pile,DC charging process and communication message interaction process to complete the overall design of DC charging interoperability test system.The main principle of the interoperability test system of DC charging pile is to build the actual model of electric vehicle at the output end of DC charging pile,simulate and realize the BMS function and power battery function of electric vehicle.In the real power output process of DC charging pile,collect the key parameters of different stages of DC charging pile,and inject the fault of DC charging pile before and during charging To simulate different fault states and check whether the charging control and message interaction of DC charging pile meet the test requirements.The hardware part of the test system is built with the measurement and control module as the core.The measurement and control module is the bridge between the upper computer test software and the DC charging pile and the power battery simulation module.It mainly completes the DC charging pile parameter acquisition,control guide circuit simulation,control guide circuit fault injection,power battery voltage simulation module control,resistance load control and other functions.The software part of the test system is based on the NI LabVIEW application developmentenvironment.The test software mainly consists of two parts: the front panel human-computer interface and the back panel program block diagram.The main human-computer interface and program block diagram of the test software are introduced in detail.Finally,the test environment of a DC charging pile is built,and the software function and hardware design of the test system are tested to ensure the reliability and stability of the system.