Parameter selection method and apparatus, and storage medium for insulation detection circuit

A parameter selection apparatus for an insulation detection circuit, wherein the insulation detection circuit comprises a signal generation module, a voltage division module, an isolation module, a first sampling point, a second sampling point and a processor, the isolation module comprises a first end configured to be connected to a positive electrode of a power battery under test and a second end connected to the second sampling point and is configured to isolate a voltage signal of the power battery under test, the signal generation module is connected to the first sampling point and configured to inject an AC signal to the power battery under test and provide the first sampling point with a first sampled signal of a predetermined frequency, the voltage division module comprises a first end connected to the first sampling point and a second end connected to the second sampling point and is configured to provide the second sampling point with a second sampled signal, and the processor is configured to calculate an insulation resistance of the power battery under test according to the first sampled signal and the second sampled signal, and the parameter selection apparatus comprises:

• a processor;
• and
• a memory configured to store instructions executable by the processor,
• wherein the processor is configured to:
• determine an allowable injection frequency range of the AC signal according to a predetermined resistance range of an insulation resistance of the power battery under test and a predetermined resistance calculation cycle of the insulation resistance;
• obtain a maximum frequency among a lowest frequency of an output signal of the signal generation module, a frequency corresponding to a predetermined minimum signal injection cycle, and a frequency corresponding to a predetermined minimum resistance calculation cycle;
• determine whether the maximum frequency is within the allowable injection frequency range;
• and
• select the maximum frequency as an output frequency of the AC signal output by the signal generation module when the maximum frequency is within the allowable injection frequency range,
• wherein the processor is further configured to determine the allowable injection frequency range of the AC signal by:
• determining a maximum injection frequency of the allowable injection frequency range according to the predetermined resistance range, a predetermined sampling precision and a predetermined sampling resolution of the voltage signal between the isolation module and the voltage division module;
• and
• determining a minimum injection frequency of the allowable injection frequency range according to the predetermined resistance calculation cycle.