Three-Phase Electronic Control Unit for Enclosure Air Conditioners

A thermal management system for an enclosure containing electrical components, the thermal management system comprising:

• a cooling unit mounted on the enclosure such that the cooling unit cools an interior space of the enclosure, the cooling unit having an impeller and a compressor;
• and
• a control unit in electrical communication with the cooling unit and with a power supply that generates three-phase alternating-current (“AC”) input power at an input voltage, the input power comprising a first phase, a second phase, and a third phase, the control unit comprising:
• a rectification circuit configured to receive the input power and rectify the input power to output a direct current (“DC”) output power having a rectified DC voltage;
• a phase detection circuit coupled to the rectification circuit and configured to output a plurality of phase sequence signals indicating an order of the first, second, and third phases, the plurality of phase sequence signals including a first phase signal representing the first phase, a second phase signal representing the second phase, and a third phase signal representing the third phase;
• a phase correction circuit comprising a first relay configured to receive the second phase and the third phase of the input power, and a second relay configured to receive the second phase and the third phase of the input power, the first and second relays being selectively activated to output a corrected second phase and a corrected third phase, the control unit providing to the cooling unit a corrected input power comprising the first phase, the corrected second phase, and the corrected third phase;
• and
• a microcontroller coupled to the phase detection circuit, the phase correction circuit, and the rectification circuit, the microcontroller configured to:
• receive the first phase signal, the second phase signal, and the third phase signal;
• and
• activate one of the first relay and the second relay based on the first phase signal, the second phase signal, and the third phase signal.