电动汽车绝缘电阻计算方法的对比研究

Comparative Study on Methods of Calculating Insulation Resistance of Electric Vehicles

在详细研究国内外有关电动汽车安全标准的基础上,重新推导了各标准中绝缘电阻的计算公式,并从理论上对各种计算方法进行了对比研究。结果表明,由于假设与实际测量值之间的差异,现有标准中的计算方法在实际测量中均存在一定的缺陷,计算结果与实际值存在一定的差异。只有在测量值与假设完全相符的情况下,GB/T 18384.1—2001中附录A的计算方法才会与GB/T 31498—2015及GB/T 18384.1—2015中计算方法的结果相等,并等于电动汽车的实际绝缘电阻值;一般情况下GB/T 18384.1—2001中标准计算方法的计算结果与实际值相差甚远,只有在极端假设成立的情况下,计算结果才会与GB/T 18384.1—2001中附录A的计算结果相等。最后通过大量试验数据的对比,验证了上述结论的正确性,为电动汽车绝缘电阻的计算提供了参考。

Based on the detailed study of the electric vehicle safety standards at home and abroad, the formulas for calculating insulation resistance were derived and various calculation methods were compared theoretically. The results show that due to the difference between the assumed and the actual measured values,the standard calculation methods have certain shortcomings in the actual measurement,leading to the difference between the calculated and the actual value. Only if the measured values are exactly the same as the assumed ones,the methods in the regulation GB/T 31498-2015,GB/T 18384.1-2015 and appendix A of GB/T 18384.1-2001 are equivalent,and give identical result which is equal to the actual insulation resistance. In general,the result calculated by the standard calculation method in the GB/T 18384.1-2001 is far from the actual value. Only if the extreme assumptions are satisfied,the result calculated by using the method in the appendix A of GB/T 18384.1-2001 will be accurate. At last,the correctness of the conclusions above was verified by a large number of experimental data. The paper provides a reference for the calculation of insulation resistance.