Research On Flywheel Energy Storage System

In the 21st century, mankind are facing a great challenge which is the development of economic and social sustainable, and environment and energy issue has become the world's most important issue. How to make more effective utilization of existing energy resources has been a cause of growing concerns. At the same time, new types of energy sources are developing. Energy storage is an important way of the efficient use of energy. Flywheel energy storage Technology has a lot of advantages, such as high-energy per unit, high-efficiency, pollution-free, wide range of application, noise-free, long-life, simple maintenance, capable of continuous working, capable of modular design and manufacturing, etc. Therefore it has a wide application prospect. In recent years, with the development of modern motor/generator technology, power electronics technology, new material technology, the magnetic suspension technology and control technology, it is possible to realize the development and application of this new energy storage technology. Based on this, this thesis will expand the study of energy conversion tache, which is the key tache of flywheel energy storage.Under the condition of Searching a large number of studies on the basis of both at home and abroad,on the application background of electric vehicles and uninterruptible, this thesis design an medium-sized flywheel battery power control system. According to the demand of the driving motor, this thesis chooses a three-phase squirrel-cage induction motor as motor/generator. This type of motors not only has the advantages of large capacity and easy for high-speed operation, but doesn't need position detector when controlling its speed.Energy conversion is an important aspect of controller, the application of an advanced voltage space vector control and vector control technology in controller. In the charging process, the usage of speed and current double closed-loop, voltage space vector modulation; while in the discharge process, the use of voltage and current double closed loop, sine wave modulation (SPWM). In the charging process, deviation between the given speed and feedback speed accomplish the input of adjustment ring, which after PI calculating is a output torque given current, achieve speed tracking links; In the discharge process, deviation between the given voltage and feedback voltage accomplish the input of adjustment ring, which after PI calculating is a output torque given current, achieve DC voltage tracking links.This control system guarantees the stability rapidity accuracy of charging. The load motor consume flywheel release energy and avoid the DC bus voltage to pump, so as to achieve its objective of feedback control. The experiment results show that this method is easy to control and convenient debugging, and the control effects are excellent.Finally test the system from MATLAB simulation. The experimental results indicate that under the two different work modules, i.e. real-time control and energy feedback, the model system could achieve excellent static and dynamic performance. It has high power transformation efficiency, which achieves the anticipated design effect.