To provide a refrigerator driving system, an air conditioning system, and its control system allowing efficient response also when load on a refrigerator largely varies.

The refrigerator driving system comprises a compression refrigerator 1, a power generation / motor 2 for rotating and driving the compression refrigerator and having a power generation function, a first clutch 3 for connecting or disconnecting a driving force from the power generation / motor to the compression refrigerator, an engine 8 for rotating and driving the power generation / motor, and a second clutch 9 for connecting or disconnecting a driving force from the engine to the power generation / motor.