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In this article, the advanced angle control (AAC) for the active rectifier (AR) is proposed to improve the output power of doubly salient electromagnetic generator systems. The AAC AR is an optimization by turning on the switches in advance with an angle based on the angular position control (APC) and pulsewidth modulation (PWM) ARs. The operation principle of the AAC in ARs is different from that in the inverters. The phase inductance variation is analyzed. The inductance flat top at load condition is utilized to accelerate the commutation process and enlarge the phase current. The unified analysis is proposed by summarizing the four states of the conduction modes in the AR. The analysis of the proposed AAC strategies, the conventional APC, and PWM strategies are unified. The output power of AAC APC ARs is significantly improved compared with that of the conventional AR. The copper loss, iron loss, and torque ripple are reduced. The AAC strategies are compared with conventional strategies. The optimized performances of AAC strategies are verified by finite-element analysis and experimental results. [ABSTRACT FROM AUTHOR]

Due to its high power density, the fractional slot concentrated winding permanent magnet synchronous machine (PMSM) is a competitive candidate for the aircraft starter generator (SG) system. However, the short circuit (SC) fault, especially the turn-to-turn SC fault, is the obstruct crux in aviation applications. The turn-to-turn SC current can be restricted to a permissible level with higher reactance and the current injection mitigation method. However, higher self-inductance always leads to lower power density. So far, there have been no numerical criteria for the tradeoff between the two characteristics in machine design. In this article, an analytical model based on flux distribution is used to estimate the SC current. The effectiveness of the d-axis current injection mitigation method is numerically analyzed in the series and parallel connected windings individually. The requirement for PMSMs to survive the turn-to-turn SC fault is derived. The mathematical analysis is verified by finite-element analysis and experiments on a 12-slot, 10-pole PMSM. This article provides theoretical support for designing high-performance permanent magnet starter generator (PMSG) with SC current mitigation ability for the aviation power system. [ABSTRACT FROM AUTHOR]