Cooling system for a multistage electric motor

A submersible pump comprising:

• a first pump;
• and
• a multistage electric motor operatively connected to the first pump comprising:
• a plurality of motor stages connected in series, each motor stage comprising a stator, and a rotor;
• a plurality of cooling fluid paths, each cooling fluid path forming a recirculating loop independent of the other cooling fluid paths, each cooling fluid path in communication with the stator of one of the motor stages;
• and
• a cooling fluid flowing through each cooling fluid path, the cooling fluid removing heat from the stator of each motor stage.

A method of cooling a multistage electric motor comprising:

• providing a multistage electric motor comprising:
• a plurality of motor stages connected in series, each motor stage comprising a stator, and a rotor;
• a plurality of cooling fluid paths, each cooling fluid path forming a recirculating loop independent of the other cooling fluid paths, each cooling fluid path in communication with the stator of one of the motor stages;
• and
• a cooling fluid flowing through each cooling fluid path;
• circulating the cooling fluid in the cooling fluid path;
• and
• reducing the temperature of the stator of each motor stage independent of any other motor stage, the temperature being reduced by the cooling fluid.