The Development of Power Amplifier for the High-Power Magnetic Suspension Bearing Blower

Abstract

The blower with Active Magnetic Bearing (AMB) has the advantage of high speed, high reliability, small size, good adaptability. Power amplifier is an important part of the magnetic bearing system, directly determines the magnetic bearing system performance. The three-level PWM signal generation algorithm is analyses in this paper, and the IR2113 gate driven circuits with a negative bias is designed, and build a three-level magnetic bearing power amplifier. The gate driven signal of circuit is test, and entire power amplifier tracking step signal and sinusoidal signal also be test, the test results indicate that the three-level power amplifier meet the design requirements. At last, the power amplifier application on the blowers with AMB successful. Introduction Active Magnetic Bearings (AMB) using electromagnetic force to suspend rotor, with no friction loss, no lubrication, high-speed, non-polluting characteristics.The blower with AMB has the advantage of high speed, high reliability, small size, good adaptability Power amplifier is an important part of the overall magnetic bearing system, directly determines the magnetic bearing system performance . Depending on the realization of the principle, magnetic bearings power amplifier divided into linear power amplifier and switching power amplifier. With respect to the linear power amplifier, switching power amplifier has the advantage of low power consumption and high conversion efficiency; occupy a dominant position in large power amplifiers. Switching power amplifier can be divided into two-level amplifier switching amplifier and three-level switching amplifier depending on the switching signal. In two-level switching amplifier, the magnitude of current ripple is related to the DC voltage. Increases the DC voltage to improve the dynamic characteristics of the system, it will increase the electromagnetic coil current ripple at the same time. The current ripple of three-level switching power amplifier is not only smaller than the two-level power amplifier, but also nothing affected by the DC voltage , and therefore more suitable for high-power active magnetic bearings. In this paper, using FPGA chip to generate three-level switching signals, half-bridge circuit using IGBT modules and IGBT gate drive circuit is designed based on the drive requirements. The Three-level PWM Signal Generation Algorithm: D2 L Drive circuit FPGA Current sensor feedback AD circuit A D1 Vref S1 S2 I Reference signal Q1