A genetic algorithm-based current control of high-speed brushless direct current motor can be used in flywheel energy storage system for satellites

The satellite orbital path around the earth consists of two regions as dark and bright. The required energy is provided by the mechanical energy storage unit when operating in the dark region. Brushless dc motors (BLDC) are widely used in the FESS due to the low weight, high power density, high efficiency, high reliability, and high speed. Some mechanical resonances is occurred due to physical features of the mechanical parts of flywheel energy storage unit. Ripples are occurred in the current of the brushless direct current motor during the acceleration of the flywheel occurred in mechanical resonances. These currents ripples should be avoided because they cause the increase of the cost of solar panels. Therefore, current reference method is preferred in order to eliminate the ripple in motor current. In this thesis, a flywheel energy storage system has been designed consists of a high speed BLDC, a variable frequency motor drive, a flywheel, a coupling between motor and flywheel, a high speed bearing, a vacuum chamber. The PI parameters have been determined by using genetic algorithm to obtain optimum performance for current control. An effective current reference method has been proposed in order to pass the region of the mechanical resonances by adequate current increasing in a short time. In addition, mechanic resonance region has been determined by using mechanical model of flywheel energy storage.