高压用电则还应选用电压互感器。应根据计算负荷选配互感器，比如100千瓦，计算电流为100/0.38/1.732=152A，则可选择200/5的电流互感器，计算电流应在选用的额定电流的三分之二左右较好。
Voltage transformer should also be used in high voltage power supply. Transformers, such as 100 kW, 100/0.38/1.732=152A, should be selected according to the calculated load. Current transformers of 200/5 can be selected. The calculated current should be about two-thirds of the rated current selected.
低压电流互感器的变比一般有：20、30、40、50、75、100、150、200、250、300、400、500、600、750、1000、1250/5A,
The conversion ratios of low voltage current transformers are generally 20, 30, 40, 50, 75, 100, 150, 200, 250, 300, 400, 500, 600, 750, 1000, 1250/5A.
这只是大致的，具体情况具体分析。
This is only a general, specific analysis of the specific situation.
根据你当前回路的电流选互感器，电度表接互感器，
Select the transformer according to the current in your current loop, and connect the meter to the transformer.
1.计算回路的额定电流
1. Calculate the rated current of the circuit
2.额定电流乘4/3，得互感器一次电流的最小值。
2. The minimum primary current of transformer can be obtained by multiplying the rated current by 4/3.
3.按产品目录，选取比步骤2略大的一次电流值的互感器即可
3. According to the product catalogue, select the transformer whose primary current value is slightly larger than step 2.
计量用互感器最好将满量程测量在三分之二处即可
Transformers for metrology are best measured at two-thirds of the full range.