Topology and control of high frequency resonant inverter systems.

摘要

High frequency AC (HFAC) power distribution architecture has recently attracted a lot of attention from both industry and academy. However, it is challenging to design high performance topology and control for the high frequency resonant inverters with wide load change and unknown impedance. Furthermore, the current sharing and circulating current minimization issue is very difficult to address in a HFAC system with multiple modules in parallel. This thesis investigates topology and control issues for high frequency resonant inverters as building blocks for HFAC power distribution architectures.;The current sharing problem is addressed for multiple modules in parallel. Two approaches to current sharing control are proposed, the scalar approach and phasor approach. In one scalar approach, the magnitude of the current of each inverter is controlled with a new phase shift modulation to minimize the current distribution error, owing to its feature that the phase angle of the inverter output voltage is independent of the voltage feedback control and current sharing control. In another scalar approach, the phase angle of the inverter output voltage is controlled with a pulse phase modulation (PPM). The circulating current can be reduced by changing the voltage phase angles of the individual inverters. A new current decomposition method is proposed, where the module currents of individual inverters are decomposed into active current and reactive current respectively in an orthogonal frame. Based on this concept, a phasor current sharing control is proposed. The circulating current is minimized by both active current sharing control and reactive current minimization control. The performance is verified with both simulations and experiments.;A single-stage resonant inverter and a two-stage resonant inverter are proposed for system level, medium to large power applications, and onboard low to medium power distribution architectures, respectively. Both resonant inverters are analyzed, simulated and experimentally verified. The uncertainty models for the inverters are derived and the robust controllers are designed with consideration of the uncertainties of component tolerance, input voltage variation, and the HFAC bus, to which multiple loads are connected.