Energy storage system and insulation detection method therefor

1. An insulation detection method of an energy storage system, comprising:

turning on a main positive relay and a main negative relay in a high voltage safety box of each electric cabinet in the energy storage system;

controlling an insulation detection board in a main control cabinet of the energy storage system to:

perform insulation detection on the energy storage system at a main power management system in the main control cabinet, and

report an insulation detection result at the main power management system to a power conversion system configured to convert a direct-current voltage from the electric cabinet into an alternating-current voltage;

controlling, in response to that the insulation detection result at the main power management system indicates no fault and no instruction of starting insulation detection at the power conversion system is received, the insulation detection board to continue performing the insulation detection on the energy storage system at the main power management system; and

instructing, in response to that the insulation detection result at the main power management system indicates an insulation fault, a battery management system of each electric cabinet to control the main positive relay and the main negative relay in the high voltage safety box to turn off.

2. The insulation detection method according to claim 1 , wherein the controlling the insulation detection board to perform insulation detection on the energy storage system at the main power management system comprises:

changing an on/off state of an insulation detection circuit by controlling status of a control switch in the insulation detection circuit in response to that a sampling voltage applied by the battery management system of the electric cabinet to the insulation detection circuit in the high voltage safety box is a high voltage;

controlling, in different on/off states of the insulation detection circuit, a high voltage sampling chip of the insulation detection circuit to sample a plurality of voltages U c applied to an insulation-to-earth value R p of the main positive relay and a plurality of voltages U a applied to an insulation-to-earth value R n of the main negative relay;

performing calculation to obtain the insulation-to-earth value R p of the main positive relay and the insulation-to-earth value R n of the main negative relay by using an insulation sampling formula based on the plurality of voltages U c and U a sampled; and

determining, according to the insulation-to-earth value R p of the main positive relay and/or the insulation-to-earth value R n of the main negative relay, whether insulation performance of the electric cabinet meets insulation requirements.

3. The insulation detection method according to claim 2 , wherein that the insulation detection result at the main power management system indicates no fault means that the insulation performance of the energy storage system fully meets the insulation requirements.

4. The insulation detection method according to claim 1 , wherein after the controlling the insulation detection board to perform insulation detection on the energy storage system at the main power management system, and to report the insulation detection result at the main power management system to the power conversion system, the method further comprises:

controlling, in response to that the insulation detection result at the main power management system indicates no fault and an instruction of starting insulation detection at the power conversion system is received, the insulation detection board to stop performing the insulation detection on the energy storage system at the main power management system.

5. The insulation detection method according to claim 1 , further comprising:

receiving an insulation detection result fed back by the power conversion system; and

instructing, in response to that the insulation detection result at the power conversion system indicates an insulation fault, the battery management system of each electric cabinet to control the main positive relay and the main negative relay in the high voltage safety box to turn off.

6. An energy storage system, comprising: a power conversion system, a main control cabinet, and a plurality of electric cabinets electrically connected to each other, wherein the main control cabinet comprises a main power management system and an insulation detection board, each electric cabinet comprises a high voltage safety box, and the high voltage safety box comprises a main positive relay and a main negative relay; wherein the main power management system is configured to

control, after turning on the main positive relay and the main negative relay in the high voltage safety box of each electric cabinet, the insulation detection board to:

perform insulation detection on the energy storage system at the main power management system, and

report an insulation detection result at the main power management system to the power conversion system configured to convert a direct-current voltage from the electric cabinets into an alternating-current voltage;

control, in response to that the insulation detection result at the main power management system indicates no fault and no instruction of starting insulation detection at the power conversion system is received, the insulation detection board to continue performing the insulation detection on the energy storage system at the main power management system; and

instruct, in response to that the insulation detection result at the main power management system indicates an insulation fault, a battery management system of each electric cabinet to control the main positive relay and the main negative relay in the high voltage safety box to turn off.

7. The energy storage system according to claim 6 , wherein the main power management system is further configured to:

change an on/off state of an insulation detection circuit by controlling status of a switch in the insulation detection circuit in response to that a sampling voltage applied by the battery management system of the electric cabinet to the insulation detection circuit in the high voltage safety box is a high voltage;

control, in different on/off states of the insulation detection circuit, a high voltage sampling chip of the insulation detection circuit to sample a plurality of voltages U c applied to an insulation-to-earth value R p of the main positive relay and a plurality of voltages U a applied to an insulation-to-earth value R n of the main negative relay;

perform calculation to obtain the insulation-to-earth value R p of the main positive relay and the insulation-to-earth value R n of the main negative relay by using an insulation sampling formula based on the plurality of voltages U c and U a sampled; and

determine, according to the insulation-to-earth value R p of the main positive relay and/or the insulation-to-earth value R n of the main negative relay, whether insulation performance of the electric cabinet meets insulation requirements.

8. The energy storage system according to claim 7 , wherein that the insulation detection result at the main power management system indicates no fault means that the insulation performance of the energy storage system fully meets the insulation requirements.

9. The energy storage system according to claim 6 , wherein the main power management system is further configured to control, in response to that the insulation detection result at the main power management system indicates no fault and an instruction of starting insulation detection at the power conversion system is received, the insulation detection board to stop performing the insulation detection on the energy storage system at the main power management system.

10. The energy storage system according to claim 6 , wherein the main power management system is further configured to:

receive an insulation detection result fed back by the power conversion system; and

instruct, in response to that the insulation detection result at the power conversion system indicates an insulation fault, the battery management system of each electric cabinet to control the main positive relay and the main negative relay in the high voltage safety box to turn off.

11. An insulation detection method of an energy storage system, comprising:

turning on a main positive relay and a main negative relay in a high voltage safety box of each electric cabinet in the energy storage system;

controlling an insulation detection board in a main control cabinet of the energy storage system to:

perform insulation detection on the energy storage system at a main power management system in the main control cabinet, comprising:

changing an on/off state of an insulation detection circuit by controlling status of a control switch in the insulation detection circuit in a case response to that a sampling voltage applied by the battery management system of the electric cabinet to the insulation detection circuit in the high voltage safety box is a high voltage;

controlling, in different on/off states of the insulation detection circuit, a high voltage sampling chip of the insulation detection circuit to sample a plurality of voltages U c applied to an insulation-to-earth value R p of the main positive relay and a plurality of voltages U a applied to an insulation-to-earth value R n of the main negative relay;

performing calculation to obtain the insulation-to-earth value R p of the main positive relay and the insulation-to-earth value R n of the main negative relay by using an insulation sampling formula based on the plurality of voltages U c and U a sampled; and

determining, according to the insulation-to-earth value R p of the main positive relay and/or the insulation-to-earth value R n of the main negative relay, whether insulation performance of the electric cabinet meets insulation requirements; and

report an insulation detection result at the main power management system to a power conversion system;

controlling, in response to that the insulation detection result at the main power management system indicates no fault and no instruction of starting insulation detection at the power conversion system is received, the insulation detection board to continue performing the insulation detection on the energy storage system at the main power management system; and

instructing, in response to that the insulation detection result at the main power management system indicates an insulation fault, a battery management system of each electric cabinet to control the main positive relay and the main negative relay in the high voltage safety box to turn off.