Research And Implementation Of Portable High-precision DC Charging Pile Measurement And Verification System

In recent years,energy shortage and pollution have become more and more serious,countries have begun to vigorously develop the new energy vehicle industry,and they have focused on the construction of charging infrastructure based on DC charging piles.For the various stages of type testing,factory inspection,installation inspection,and periodic inspection of the charging pile,it is necessary to strictly follow the corresponding metrological verification specifications.At present,there are many brands and models of charging piles in the market,and non-standard agreement and inaccurate measurement are very common.In addition,for the development of the charging pile measurement verification system,the traditional manual testing or semi-automatic testing technology is used to develop,its performance and testing efficiency are extremely low,which cannot meet the actual production needs.To solve the above problems,through the in-depth study of relevant national standards,this paper designs an automatic test system suitable for metrological verification tasks such as operating error,indication error,payment amount error,and clock indication error of DC charging pile.Design requirements such as high precision,high performance,and portability.The main research contents are as follows:1.System overall plan design: In this part,through the study of relevant test standards,the task and principle of measurement verification are defined,the overall scheme and technical indicators of the test system are formulated,also the innovation and design advantages of the system are described.2.Design of electric vehicle function simulation device: The device is used to simulate the charging condition and build a perfect test environment,which is the basis of the charging pile test.The overall device includes DC charging interface control simulator,which is used to realize charging control guidance circuit and provide parameter acquisition interface;on-board BMS communication simulator,which is used to start charging communication process and feedback communication failure;on-board battery voltage simulator,which is used to simulate the initial voltage of on-board battery;high-power modular load,which is used to consume charging energy.3.High-precision metering module design: The acquisition of high-precision DC power parameters is the premise of accurate measurement and test.Firstly,according to the principle and calculation method of DC power measurement,this paper builds a synchronous acquisition circuit to realize the signal sampling of charging voltage,auxiliary voltage,acquisition point 1 voltage and charging ambient temperature;then,it formulates a digital processing scheme to realize the data analysis,power calculation and power integration calculation of the sampling signal;finally,it encapsulates the software function interface for the secondary development.After verification,the high-precision metering module can realize the DC measurement range of 1000 V and 300 A,and the power metering accuracy reaches 0.1 level.4.Design of automatic test software system: As the control center and interactive interface of the entire DC charging pile measurement verification system,the automatic test software is the core of realizing the test logic task.This part proposes the overall design scheme based on the MVC-three-tier architecture from the perspective of software design architecture and design patterns by analyzing test requirements and related technical principles and formulates detailed implementation strategies for each functional module.After simulation testing and field verification,the measurement verification system designed in this paper meets the measurement accuracy and functional integrity of the DC charging pile and has extremely high practical value,which is convenient for market promotion.