Control strategy of MW flywheel energy storage system based on a six-phase permanent magnet synchronous motor

Abstract

The implementation of the “dual carbon” goal, nationally in China, has accelerated the profound transformation of the energy industry, and the development and utilization of large-scale clean energy has become a basic global consensus. However, clean energy is having trouble meeting the needs of rigid energy demands due to its randomness, intermittency, and unpredictability, so energy storage is currently being considered to solve this incompatibility. The flywheel energy storage system (FESS) cooperates with clean energy power generation to form “new energy + energy storage”, which will occupy an important position among new energy storage methods. This study analyzes the basic requirements of wind power frequency modulation, establishes the basic model of the flywheel energy storage system, adopts a six-phase permanent magnet synchronous motor as the system driver, designs an eleven-stage pulse width modulation control method, and proposes a power and current double-closed loop. The control strategy is used to test and simulate the machine-side converter that has been built. The results show that the proposed control strategy is reasonable and effective. By introducing a six-phase permanent magnet synchronous motor into FESS, the system could output higher power under the condition of low voltage and the noise and vibration of the motor are optimized during operation. Most importantly, the stability of the FESS is guaranteed in actual operation.

Keywords

• Flywheel energy storage
• Six-phase PMSM
• Pulsed-width modulation
• Control strategy
• Frequency modulation