Aircraft thermal management system for an energy storage system

A thermal management system for an energy storage system for an aircraft, the thermal management system comprising:

• a pump to circulate a thermal management fluid through at least part of the thermal management system and an energy storage device of the aircraft;
• a power controller configured to control voltage output and current output of a power converter of the aircraft, the power converter configured to convert a voltage level of power received from the energy storage device, wherein the power converter is thermally managed by the thermal management fluid circulated by the pump;
• a pump controller configured to directly control, responsive to signals received from the power controller, a variable pumping capacity of the pump;
• and
• a sensor in communication with the power controller, the sensor sensing at least one of pressure and temperature of the thermal management fluid at the energy storage device;
• wherein, to control the variable pumping capacity of the pump, the power controller is configured to:
• determine, based at least in part from data received via the sensor, a target pumping capacity of the pump;
• control the pump to operate at the target pumping capacity;
• determine whether a pump control failure condition of the power controller has occurred in which the signals from the power controller do not reach the pump controller such that the power controller is unable to control the pump to operate at an arbitrary target pumping capacity;
• and
• responsive to determining that the pump control failure condition has occurred, increase the variable pumping capacity of the pump to a maximum pumping capacity.