Power systems and control methods to address peak loading

A power system, comprising:

• a bus;
• a main power supply system connected to the bus and configured as a voltage source with a droop function;
• a rechargeable energy storage system connected to the bus and configured as a voltage source with a droop function, the rechargeable energy storage system including a rechargeable energy storage element and a converter connected between the rechargeable energy storage element and the bus;
• and
• a control circuit configured to:
• monitor a voltage of the bus;
• and
• control the converter to either charge or discharge the rechargeable energy storage element based on the voltage of the bus, wherein the control circuit is configured to adjust a zero-current voltage setpoint of the converter upward and downward to regulate a state of charge (SOC) of the rechargeable energy storage element.

A power system, comprising:

• a main power supply system having an output characteristic of a voltage source with a droop function;
• a bus configured to connect to a load;
• a rechargeable energy storage system connected to the bus having an output characteristic of a voltage source with a droop function;
• and
• a control circuit configured to:
• monitor a voltage of the bus;
• and
• control the rechargeable energy storage system to either charge or discharge to or from the bus based on the voltage of the bus, wherein the output characteristic of the main power supply system and the output characteristic of the rechargeable energy storage system enable the main power supply system and the rechargeable energy storage system to regulate the voltage of the bus independent of one another, wherein the control circuit is configured to adjust a zero-current voltage setpoint of a converter in the rechargeable energy storage system upward and downward to regulate a state of charge (SOC) of a rechargeable energy storage element in the rechargeable energy storage system.