Basic Knowledge of EV Charger Metering

What Is EV Charger Metering?

EV charger metering refers to the energy metering of electric vehicle charging stations (EVSE) during the charging process, which ensures the accuracy and reliability of energy metering data. As an important component of EV charger metering, the electric vehicle charging pile must be installed with an energy meter that meets national metering standards. Usually, an AC or DC electric vehicle charging meter is set up inside the EV charging pile. It monitors and measures the energy & power consumption of each charging gun in real-time. Take a dual-gun EV charger as an example, it may install one dual-channel energy meter or two electric meters.

How Does EV charging Metering Work?

In the electric vehicle charging system, the EV charging pile communicates with the vehicle battery management system (BMS) to convert the three-phase AC input power into the DC power required by the BMS. A DC energy meter is connected to the output side of the DC bus to measure the output power. The charging management controller reads the power data of the DC energy meter and controls the DC charging output. The electric meter for EV charger can be configured with a shunt or a Hall sensor to measure the charging power.

The DC energy meter can be connected to the main control of the EV charging pile by RS485 communication. The main control can read the meter information and monitor the charging status according to user needs. The DC energy meter charging detection software can intuitively display electric vehicles’ voltage, current, power, and power during fast charging at DC charging stations, which is convenient for querying various data and viewing abnormal situation records.

EV Charging Metering Standards

EV charging metering should comply with relevant national and regional measurement standards to ensure the accuracy and reliability of measurement data. At present, the internationally used EV charging metering standards include:

IEC 61850-2010: substation automation systems communication protocols

IEC 62196: plugs and socket outlets for EV charging

German Eichrecht: applies to electricity meters on EV charging stations

In addition, the accuracy standards for the electric vehicle charging meter vary from country to country. The EV charging metering accuracy standard refers to the accuracy requirements that EV charging piles should meet when measuring electricity. Here are some common standards in the following:

1. China’s national standard “Technical Specifications for Measurement of Electric Vehicle Charging Facilities” (GB/T 18487.12015) stipulates that the measurement accuracy of EV charging piles should meet the following requirements:
DC power meter accuracy: 0.2%;
AC power meter accuracy: 0.2%.

2. The US national standard “Charging Measurement Standard” (SAE J17722019) stipulates that the measurement accuracy of charging piles should meet the following requirements:
DC power meter accuracy: 0.1%;
AC power meter accuracy: 0.2%.

3. The European standard “Electric Vehicle Charging Equipment Measurement and Test Specification” (IEC 618511:2017) stipulates that the measurement accuracy of charging piles should meet the following requirements:
DC power meter accuracy: +0.5%:
AC power meter accuracy: 1%

It should be noted that the standards of different countries and regions may differ, and the specific requirements should be based on the relevant local standards.

Blue Jay Energy Metering for Electric Vehicle (EV) Charging Stations

Blue Jay offers a variety of solutions on the EV metering side with varying degrees of measurement depending on your energy management needs. For example, if you need EV metering in a dual-gun EV charger, we can offer you a dual-channel DC energy meter to measure energy in the dual-gun EV charger separately. This solution can replace two DC energy meters for EV charger metering. Thus, you can save much costs.