Abstract

In electric vehicles and plug-in hybrid electric vehicles, the utility grid charges the vehicle battery through a battery charger. Different solutions have been proposed to reduce the size and cost of the charger. One solution to achieve this is to include the devices used in the traction circuit in the charger circuit; this is called an integrated motor drive and battery charger. A split-phase PM motor, a motor with double set of windings, gives the opportunity to implement different winding configurations to keep the motor at stand-still when it is connected to the grid. The motor will act as inductors in the charging process. This is an advantageous chance in order to use the motor in an integrated battery charger. In the current thesis, a non-isolated battery charger based on some of these special configurations is tested. Two different PM motors are utilized in proposed chargers. Different windings configurations have been practically tested. The main challenge is to keep the motor in stand-still during charge operation. Practical results show that with proposed schemes, the motors are in stand-still. A National Instrument CompactRIO system is used to perform the control of the integrated charger in the practical implementation. A brief explanation of the practical setup and a user guide for running the experimental system is included as well. Ingeniería Industrial

Abstract

Pulse width modulation (PWM) technology is widely used in traction converters for high-speed railways. The harmonic distribution caused by PWM is quite extensive, and increases the possibility of grid–train coupling resonance in the traction power supply system (TPSS). This paper first analyzes the mechanism of resonance, when the characteristic harmonic frequency of a four-quadrant converter (4QC) current that injects into the traction grid matches the resonant frequency of the traction grid, which may result in resonance in the system. To suppress resonance, this paper adopts specific harmonic elimination–pulse width modulation (SHE-PWM) technology combined with a transient direct current control strategy to eliminate the harmonics in the resonant frequency, which may suppress the grid–train coupling resonance. Due to the fact that the SHE-PWM process with multiple switching angles contains complex transcendental equations, the initial value is difficult to provide, and is difficult to solve using ordinary iterative algorithms. In this paper, an active-set secondary optimization method is used to solve the equation. The algorithm has the benefits of low dependence on initial values, fast convergence and high solution accuracy. Finally, the feasibility of the resonant suppression algorithm is verified by means of Matlab simulation. Document type: Article