A control scheme to maximize output power of a synchronous alternator in a vehicle electrical power generation system

The paper presents a new control scheme to maximize the output of the alternator in a vehicle electrical power generation system. This control scheme maximizes the output power by using a controllable rectifier to optimize the operating conditions of the alternator. The controllable rectifier is synchronized with the alternator based on the zero crossing information of the third harmonic voltage. The output power is controlled by shifting the phase voltage with respect to the third harmonic voltage. The optimal value of this phase shift (for maximum output) is determined experimentally for different operating conditions. The output power is maximized by optimizing the phase shift. The only required information for the control is the zero crossing of the third harmonic voltage and phase voltage, which is easy to collect. Therefore, the cost to implement the control scheme is low. A proof of concept system has been built and tested in the laboratory. With the same alternator, the control scheme can increase the output of the alternator at engine idle speed and high ambient temperature by 43% compared with a conventional system with a diode rectifier.