A control algorithm for a simple flywheel energy storage system to be used in space applications

Flywheels have been under consideration to be used for energy storage purposes in space applications to replace electrochemical batteries. An electrical machine is used as a motor to store kinetic energy when the solar energy is available, and then the stored energy is converted back to electrical energy by running the machine as a generator when the solar energy is no longer available. A control algorithm for these systems is proposed in this paper. The proposed method uses a current reference rather than a speed reference in the motor mode. A method is also suggested to properly determine the current reference to overcome the losses and to create constant acceleration. The proposed algorithm is tested on an experimental set-up and the results are given.