JJG 1192-2023Calibrator of Off-board Chargers for Electric Vehicles (English PDF)

4.6 Clock time error

The absolute error of the clock time is better than ±1 s.

5.1 Appearance and power inspection

The calibrator shall display the following information:

- Product name and model;

- Manufacturer and exit-factory number;

- Pulse constant C (imp/kWh);

- Level of accuracy;

- Measuring range.

After the calibrator is powered on, the functions and software control shall be normal.

5.2 AC withstanding voltage

The calibrator powered by AC is in the non-working state; the power switch is placed in the ON position; the voltage of AC 1.5 kV is applied between the input terminal of the power supply and the casing, for a duration of 1 min. There shall be no spark discharge or breakdown.

All the lines, whose reference voltage exceeds 40 V, are connected together as one point;

the other point is the grounded. The test voltage is applied between these two points, which shall be able to withstand the AC 3 kV withstanding voltage test for 1 minute.

There shall be no spark discharge or breakdown during the test.

time is not less than 5 s.

2) Watt-second method

Use the measurement standard to measure the set constant power. Use the standard timer to measure the time, which is required for the calibrator to accumulate the electric energy value. This time is multiplied by the constant power to obtain the measure electric energy, which is then compared with the accumulative electric energy of the calibrator, to determine the relative error of the calibrator's electric energy.

When the calibrator is verified by the watt-second method, the time measurement error (%) of the standard time measuring device shall not be greater than 1/20 of the accuracy level of the calibrator. When counting and reading the time, the standard time meter shall have enough readings, so that the reading error of 1 word due to the change of the last digit does not exceed

1/10 of the accuracy level of the calibrator.

c) Cumulative power error

At 500 V and Imax, the calibrator runs synchronously with the current line of the measurement standard in series and the voltage line in parallel. The cumulative electric energy value shall meet the requirements of 4.1. Calculate the relative error gamma', according to formula (3).

6.3.2.4 Limit operating error

Carry out verification, according to the test load point, which is specified in Table 10.

The verification is according to 6.3.2.3.

6.3.2.5 Energy measurement repeatability

Under repeatability conditions, conduct no less than 5 electric energy error determinations, according to the provisions in Table 3. Calculate the standard deviation

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