| CPC F04D 27/0223 (2013.01) [F04D 27/001 (2013.01); F04D 27/0261 (2013.01)] | 14 Claims |

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1. A vapor cycle cooling system, the system using a circulating fluid and comprising a recirculation valve (RCV), a condenser, an expansion valve, an evaporator, a compressor motor, a compressor coupled to the motor, an electronic control unit (ECU), and a plurality of pressure, temperature and motor sensors, the ECU configured to control the compressor motor by receiving a commanded speed, and controlling current to the motor or torque generated by the motor, the ECU further configured to perform a method of controlling compressor surge comprising:
determining a parameter of motor operation;
obtaining a circulating fluid parameter upstream of the compressor,
obtaining a circulating fluid parameter downstream of the compressor,
obtaining mass flow of the circulating fluid through the compressor;
evaluating a likelihood of compressor surge by:
a) analyzing variance or oscillation of the parameter of motor operation to identify compressor surge; and
b) analyzing the circulating fluid parameter upstream of the compressor, the circulating fluid parameter downstream of the compressor, and the mass flow of the circulating fluid through the compressor, using a compressor map, to identify potential surge conditions; and:
if compressor surge is identified at a), derating compressor speed to reduce compressor speed below the commanded compressor speed; or
if potential surge conditions are identified at b), actuating the RCV to mitigate potential surge.
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