Direct current charging pile test method, device and equipment based on sweep frequency calibration shunt

Abstract

The invention discloses a direct current charging pile test method, device and equipment based on a sweep frequency calibration shunt. The test method comprises the following steps: collecting currentand voltage signals output by a direct current charging pile when an electric vehicle is charged, arranging a shunt in an output loop of the direct current charging pile to collect the current signal, calibrating the resistance value of the shunt in real time by using a sweep frequency method real-time calibration circuit, and collecting the voltage signal by using a divider resistance network; carrying out analog-to-digital conversion on the collected current and voltage signals to obtain secondary direct-current voltage Uv output by the direct-current charging pile and direct-current voltage Ui of the shunt; calculating real-time direct current active power output by the direct current charging pile by utilizing the acquired Uv and Ui and the calibrated resistance value of the shunt; collecting the pulse number of an electric energy meter in the detected charging pile; and calculating an active electric energy error of the DC charging pile according to the real-time DC active powerand the pulse number of the electric energy meter in the detected charging pile. The active electric energy error of the charging pile can be monitored, and fairness and justice of metering and billing of the charging pile of a charging pile operation company are ensured.

Description

technical field [0001] The invention relates to a DC charging pile testing method, device and equipment for calibrating the resistance value of a shunt based on a frequency sweep method, and belongs to the technical field of electric vehicle charging. Background technique [0002] Electric vehicle charging piles, like fuel dispensers, are measuring instruments used for trade settlement, and the accuracy of their measurement (billing) directly affects the economic interests of both parties to the trade. It is of great significance to carry out the legal management of measurement of electric vehicle charging piles, strengthen the measurement and supervision of charging piles, ensure the accuracy and reliability of the electric energy value of charging piles, and maintain the fairness and justice of electric energy trade settlement. [0003] As of May 2020, the cumulative number of charging infrastructure in the country is about 1.29 million units. Among them, the member units ...

AI Technical Summary

Problems solved by technology

[0005] However, the DC charging pile calibrator generally adopts the principle of direct sampling, and is generally equipped with AC and DC zero-flux current transformers and DC voltage transformers. Among them, the AC-DC zero-flux current sensor is expensive (LEM company 250A is about 5,000 yuan a piece) , can also be configured with 0.01 level 250A standard resistance (the price is more expensive), the accuracy of the active energy of the calibrator depends on the expensive DC current sensor

In addition, the existing non-vehicle DC charging pile active energy error verification equipment is not only too large, inconvenient to transport, but also expensive

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