Measurement device for measuring a current calibration coefficient

1. A measurement device for measuring a current calibration coefficient, comprising a host computer and a current source;

wherein the host computer is configured to:

control, when ambient temperature of a current detection device is at a preset temperature within an operation temperature range of a shunt of the current detection device, the current source to output a current with a preset current value to the current detection device, wherein the current detection device is used for performing a detection of a current in a current circuit requiring current detection;

receive a calibrated current value sent by the current detection device, wherein the calibrated current value is determined according to a detected current value corresponding to the preset current value detected by the current detection device and a predetermined current calibration coefficient, wherein the predetermined current calibration coefficient is sent to the current detection device by the host computer;

calculate a measurement error of the current detection device according to the preset current value and the calibrated current value; and

determine, when the measurement error is less than a preset current error, the predetermined current calibration coefficient as a current calibration coefficient of the current detection device.

2. The measurement device according to claim 1 , wherein

the host computer is further configured to:

acquire the predetermined current calibration coefficient, wherein the predetermined current calibration coefficient comprises a current calibration coefficient at a temperature T1 and a current calibration coefficient at a temperature T2, wherein the T1 is a reference temperature of a resistance-temperature characteristic curve of the shunt of the current detection device, and the T2 is any one temperature other than the T1 within the operation temperature range of the shunt;

wherein the predetermined current calibration coefficient is acquired by:

controlling the current source to output a first current with a first specified current value to the current detection device when ambient temperature of the current detection device is at the T1;

calculating, according to the first specified current value and a first detected current value detected by the current detection device, a current calibration coefficient at the T1, and

determining, according to the current calibration coefficient at the T1 and the resistance-temperature characteristic curve of the shunt of the current detection device, a current calibration coefficient at the T2.

3. The measurement device according to claim 2 , wherein the host computer is configured to:

control the current source to sequentially output currents with n different first specified current values at the T1;

acquire n first detected current values corresponding to the n different first specified current values, wherein n≥2; and

calculate the current calibration coefficient at the T1 according to the n different first specified current values and the n first detected current value.

4. The measurement device according to claim 3 , wherein

the host computer is configured to calculate, according to the n different first specified current values and the n first detected current values, the current calibration coefficient at the T1 by a least-square linear fitting method, and wherein the current calibration coefficient comprises a linear calibration coefficient and a constant calibration coefficient.

5. The measurement device according to claim 2 , wherein

the host computer is further configured to:

control the current source to output the current with a second specified current value when the ambient temperature of the current detection device is at the T 2 ;

acquire a second detected current value at the T2 detected by the current detection device;

calculate a first actual resistance value R 1 of the shunt at the T 1 according to the first specified current value, the first detected current value at the T 1 and a nominal resistance value of the shunt;

calculate a second actual resistance value R 2 of the shunt at the T 2 according to the second specified current value, a second detected current value at the T 2 and the nominal resistance value of the shunt;

calculate, a resistance-temperature coefficient of the shunt at the T 2 according to the R 1 and R 2 , and

determine the resistance-temperature characteristic curve of the shunt based on the resistance-temperature coefficient at the T 2 and a resistance-temperature coefficient at the T 1 , wherein the resistance-temperature coefficient at the T1 is zero.

6. The measurement device according to claim 5 , wherein

the host computer is configured to:

determine, a third actual resistance value R 3 of the shunt at the T 2 according to the T 2 and the resistance-temperature characteristic curve, and

calculate the current calibration coefficient at the T 2 according to the R 3 and the current calibration coefficient at the T 1 by a formula:

A 3 =A 1 *R 3 /R 1 ,B 3 =B 1

where A 1 is a linear calibration coefficient at the T 1 , A 3 is a linear calibration coefficient at the T 2 , B 1 is a constant calibration coefficient at the T 1 , and B 3 is a constant calibration coefficient at the T 2 .

7. The measurement device according to claim 2 , wherein

the host computer is further configured to

control the current source to output a first actual current value corresponding to the first specified current value; and

calculate, according to the first detected current value and the first actual current value corresponding to the first specified current value, the current calibration coefficient at the T 1 of the current detection device.