Control method and apparatus for power supply system, and power supply system

A control apparatus for a power supply system, wherein:

• the power supply system comprises a first power supply device and a second power supply device, the first power supply device being connected to a first energy storage apparatus, and the first power supply device and the second power supply device being connected to a coupling point;
• and
• wherein the control apparatus comprises:
• an obtaining module configured to obtain a current State of Charge (SOC) and current charging/discharging power of the first energy storage apparatus connected to the first power supply device;
• and
• a processing module configured to execute a target control policy in response to the current SOC exceeding a target SOC range or the current charging/discharging power exceeding a target power range, wherein the executing the target control policy comprises:
• controlling a frequency of the first power supply device;
• or
• controlling a contactor connected to the second power supply device to be disconnected, to disconnect the second power supply device from the coupling point;
• wherein the processing module is configured to execute the target control policy in response to the current SOC exceeding the target SOC range, wherein the processing module being configured to execute the target control policy in response to the current SOC exceeding the target SOC range comprises the processing module being configured to:
• determine a frequency adjustment amount based on the current SOC;
• and
• adjust the frequency of the first power supply device based on the frequency adjustment amount;
• wherein the processing module being configured to adjust the frequency of the first power supply device based on the frequency adjustment amount comprises the processing module being configured to:
• raise the frequency of the first power supply device based on the frequency adjustment amount in response to the current SOC being greater than an upper limit of the target SOC range, to cause the second power supply device to automatically operate in a derated mode, wherein the second power supply device is configured to automatically stop operating in response to the frequency of the first power supply device exceeding an over-frequency protection threshold;
• wherein the processing module being configured to adjust the frequency of the first power supply device based on the frequency adjustment amount further comprises the processing module being configured to:
• reduce the frequency of the first power supply device based on the frequency adjustment amount in response to the current SOC being smaller than a lower limit of the target SOC range, to cause the second power supply device to automatically increase output power, wherein the second power supply device is configured to automatically stop operating in response to the frequency of the first power supply device being smaller than an under-frequency protection threshold.