A. Mohammadi; M.A. Shamsi Nejad
Abstract
This paper investigates a fundamental issue in AC-DC rectifiers that are specifically used as charger for electric vehicle (EV), i.e. the total harmonic distortion (THD) of input current waveforms. Firstly, the topology of two-stage charger along with the corresponding control scheme is reviewed. Then, ...
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This paper investigates a fundamental issue in AC-DC rectifiers that are specifically used as charger for electric vehicle (EV), i.e. the total harmonic distortion (THD) of input current waveforms. Firstly, the topology of two-stage charger along with the corresponding control scheme is reviewed. Then, the research gap namely high harmonic distortion of input current is identified and analyzed. A revision of the conventional control method with the aid of virtual resistant is proposed and investigated from the circuit perspectives. Finally, simulation results are delivered to validate the analysis and the reduction of THD in the input current waveform. this is proposed method, the steady state is studied.
Energy Management
H. Moayedirad; M. A. Shamsi Nejad
Abstract
A dual stator winding squirrel-cage induction motor (DSWIM) is a brushless single-frame induction motor that contains a stator with two isolated three-phase windings wound with dissimilar numbers of poles. Each stator winding is fed by an independent three-phase inverter. The appropriate efficiency of ...
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A dual stator winding squirrel-cage induction motor (DSWIM) is a brushless single-frame induction motor that contains a stator with two isolated three-phase windings wound with dissimilar numbers of poles. Each stator winding is fed by an independent three-phase inverter. The appropriate efficiency of this motor is obtained when the ratio of two frequencies feeding the machine is equal to the ratio of the number of poles. In the vector control method at low speeds, flux is difficult to estimate because the voltage drop on the stator resistance is comparable with the input stator voltage, disturbing the performance of the motor drive. To solve the abovementioned problem, researchers have benefited from the free capacity of the two windings of the stator. This makes the motor deviate from its standard operating mode at low speeds. The main purpose of this paper is reducing the power losses of the inverter unit in the DSWIM drive at low speeds via the proposed control method and a five-leg inverter. This paper deals with two topics: 1. Using the idea of rotor flux compensation at low speeds, the motor works in its standard operating mode. Therefore, the power losses of the utilized power electronic converters are also reduced to a considerable extent; and 2. Reduction in capital cost can be achieved by utilizing a five-leg power electronic converter. The proposed methods are simulated in MATLAB/Simulink software, and the results of simulation confirm the assumptions.
Power Electronic
M. Heidari; M. A. Shams Nejad; M. Monfared
Abstract
Because of installation for local consumers and since it is free of all contaminations, connecting photovoltaic cells to the grid via single-phase inverter is significantly on the rise. In this paper, a new simple current control is proposed for a single-phase grid-connected voltage source inverter. ...
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Because of installation for local consumers and since it is free of all contaminations, connecting photovoltaic cells to the grid via single-phase inverter is significantly on the rise. In this paper, a new simple current control is proposed for a single-phase grid-connected voltage source inverter. Using the PQ theory and modelling a single-phase system as an unbalanced three-phase system, a method is provided for reference current generation. In the proposed method, it is not necessary to generate a fictitious phase for the current signal. Also, the removal of adjusting filter parameters which were used to generate fictitious current signal increases the simplicity of the control system and reduces computational efforts, especially in the presence of distortion in the current. The simulation results confirm that the proposed method provides a precise and fast current control with minimum harmonic distortions.
