Insulation detection device and method for energy storage system

An insulation detection device for an energy storage system, comprising:

• a positive switching device, a negative switching device, a sampling unit, a reference voltage terminal and a processor, wherein:
• a positive electrode of an energy storage device is connected to a first end of the positive switching device, a negative electrode of the energy storage device is connected to a first end of the negative switching device, a second end of the positive switching device and a second end of the negative switching device are respectively connected to a first end of the sampling unit, and a second end of the sampling unit is connected to the reference voltage terminal;
• the sampling unit is configured to collect a positive sampled signal on the energy storage device when the positive switching device and the negative switching device are in a first switching state, and to collect a negative sampled signal on the energy storage device when the positive switching device and the negative switching device are in a second switching state;
• and
• the processor is connected to a third end of the sampling unit, and configured to determine a positive insulation resistance value and a negative insulation resistance value of the energy storage device according to the positive sampled signal and the negative sampled signal.