Electric vehicle off-board direct-current charger direct-current electric energy meter on-line verification system and method

Abstract

The invention discloses an electric vehicle off-board direct-current charger direct-current electric energy meter on-line verification system and method. The system is composed of a charging module, aload module, a measurement verification module, an industrial personal computer and related programs. By means of a virtual battery management system and a real-time pulse comparison method, direct-current charger direct-current electric energy meter on-line verification can be realized when the load module is charged; on the basis of requirements, the virtual battery management system sets different power battery types and parameters, configures charging parameters, acts on the load module, and provides corresponding loads for online verification; during a charging process, a data acquisition unit acquires detected pulses outputted by a tested direct-current electric energy meter and standard electric energy pulses outputted by a standard direct-current electric energy meter; and the number of the standard electric energy pulses is compared with the number of the detected direct-current electric energy pulses, so that the direct-current electric energy meter of a direct-current charger can be verified. With the system and method of the invention adopted, real-time online verification can be performed on the direct-current electric energy meter of an on-site off-board direct-current charger, and safe and accurate on-line verification of electric energy measurement can be realized.

Description

technical field [0001] The invention belongs to the technical field of DC watt-hour meter verification, and in particular relates to an on-line verification system and method for a DC watt-hour meter of an off-vehicle DC charger for an electric vehicle. Background technique [0002] As an important part of the national new energy strategy, the electric vehicle industry is in a stage of rapid development. According to the characteristics of on-board batteries used in electric vehicles, on-board batteries used in large and medium-sized electric vehicles are generally charged by DC. The voltage / current of the DC charger when charging the battery is: (400-800)V / (0-500)A, the existing DC electric energy meter can no longer meet this demand, so some domestic electric energy meter manufacturers have developed A new type of DC watt-hour meter for measuring the electric energy of off-vehicle DC chargers. Due to the high rated current and rated voltage of this type of electric energ...

AI Technical Summary

Problems solved by technology

The voltage / current of the DC charger when charging the battery is: (400-800)V / (0-500)A, the existing DC electric energy meter can no longer meet this demand, so some domestic electric energy meter manufacturers have developed A new type of DC energy meter for energy measurement of off-vehicle DC chargers

Due to the high rated current and rated voltage of this type of electric energy meter, and the large range of current changes, the existing measurement and verification devices cannot effectively verify this type of electric energy meter. Therefore, it is necessary to study on-line verification for DC electric energy meters of electric vehicle chargers. System and method to achieve safe and accurate on-line verification of the checked DC electric energy meter

[0003] For the DC watt-hour meter of the non-vehicle DC charger of electric vehicles, the general verification method is to use the real-time pulse comparison method to verify the meter device: as disclosed in the Chinese invention patent "A Verification Device and Method for DC Electric Energy Meter" (Application No.: 201010565330.7) It includes human-computer interaction interface, main control module, voltage and current power amplifier module and measurement module, electric energy calculation module, standard pulse output interface and detected pulse input interface. The electric energy calculation module calculates and converts according to the measurement results of the voltage and current measurement module The electric energy calculation module converts the electric energy input of the electric energy meter under inspection according to the pulse input of the electric energy meter under inspection, and compares it with the electric energy of the verification device to calculate the electric energy measurement error of the electric energy meter under inspection , and its disadvantages are: due to the high rated current value and rated voltage value of the DC electric energy meter, large dynamic range and high frequency response performance requirements, the device and method have poor adaptability to the verification of the DC electric energy meter of the charger, and are not suitable for electric energy meters. The verification of the dynamic range and frequency response and other performances cannot meet the requirements of the national verification regulations

[0004] The Chinese invention patent "A DC Electric Energy Meter Verification System for Electric Vehicle Charging Pile" (Application No.: 201510843965.1) discloses a DC electric energy meter verification system for electric vehicle charging piles, including a computer controller, an integrated meter source device and multiple For the DC electric energy meter to be tested, the computer controller is connected to the meter source integration device through the communication bus, and the computer controller sends the verification task to the meter source integration device through the communication bus, and the meter source integration device The task is to verify the energy errors of multiple DC electric energy meters under inspection at the same time. The disadvantage is that the verification of electric energy meters by this system and verification method can only be carried out under laboratory conditions, while the field conditions are more complicated.

Obviously, the measurement accuracy of the energy meter in different environments should be verified, especially its reading and display are related to billing. Since the energy meter works under field conditions, this involves the online verification of the energy meter

[0005] On the other hand, in the prior art, for the verification of the DC watt-hour meter, a relatively high-power DC power supply is used to input the voltage and current values ​​required for the verification of the watt-hour meter to be tested, and the output terminal of the watt-hour meter to be tested is connected to the standard load. Therefore, this method consumes a lot of power during the verification

[0006] Aiming at the problem that the current DC electric energy meter verification device cannot perform real-time online verification, this invention proposes an online direct current electric energy meter verification system and method based on a virtual battery management system and a real-time pulse comparison method, which is not found in existing patents or related technical documents. See the report

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