Abstract

Abstract: This paper introduce a novel sensorless control for the Brushless DC motor drive by phase voltage method for minimizing the torque and current ripple in high speed, high power applications. The commutation signals for the six switch inverter are generated from the phase voltage. In each phase commutation two switches conduct corresponding to the truth table logic. Delay occurring in speed is compensated by the phase voltage deviation. Selection of commutation logic in a parallel mode improves the efficiency of system by reducing the operation delay. Compared with the existing traditional control torque and current ripple of BLDC motor can be significantly reduced by using this proposed method.

Keywords: BLDC motor, Current ripple, Commutation, Phase voltage, Sensorless control.

Abstract: It is essential to extract the maximum available power from solar system since the energy efficiency of solar cell is about 13%-17% only. There must be converter for efficient electrical tracking. It is achieved by impedance matching between load and solar module. There may be multiple peaks under varying illumination and under partial shading of individual modules. In these case we have to track global maximum power point (GMPP) apart from local maximum power point (LMPP). The conventional techniques either cause energy wastage due to unwanted full PV curve sweeping or complex due to photo sensor and error in calculation. So a new algorithm based on modification of conventional P&O algorithm to track GMPP is trying to establish

Keywords: Maximum power point tracking (MPPT), multiple maxima, partial shading, photovoltaic (PV), Local Maximum Power Point, Global Maximum Power Point.

Abstract: From the economic perspective, densely populated areas can generate great amounts of electric power by installing PV panels on its rooftops and it can be fed in to the grid. In this paper describes a grid tied micro inverter for photovoltaic applications. The system consists of a Cuk converter connected with a full-bridge current source inverter. The connection of micro inverter systems to the grid can raise several challenges, as the islanding detection and extracting maximum available power from PV module. In this sense, if the system is unable to detect the islanding situation, it may cause power quality degradation, electrical safety threats to maintenance crews, and damage to the devices that connected at the same power grid .In order to maximize the power extraction  from the photovoltaic module it is mandatory, to make use of a MPPT algorithm

Keywords: photovoltaic, Distributed Generation Systems (DGS)

Abstract: The minimization of speed ripple of the permanent magnet synchronous motors (PMSM) in low speed range becomes a major problem while applying the PMSM to refrigerant system. In conventional methods, an iterative learning controller is applied in conjunction with the conventional proportional integral (PI) speed controller to minimize the speed ripple. In this paper a frequency variable resonance controller is applied with the conventional proportional integral speed controller as a PI-RES controller, which provides the reference torque current. The main reference current generated by the PI controller together with the compensation torque current generated by the resonant controller is used to minimize speed ripple. The proposed method is verified through simulation results.

Keywords: Permanent Magnet Synchronous Motor, PI-RES controller, Field Oriented Control

Abstract: A Two inductor boost converter (TIBC) for photovoltaic applications is proposed in this paper. The proposed converter provides better solutions to renewable energy sources. The proposed system is mainly based on a current resonant converter which is also known as TIBC. The classic topology of the TIBC features is increased voltage gain and reduced current ripple. The proposed system is efficient and low cost. The analysis of TIBC with PV array has been simulated using MATLAB Simulink. In this paper, it is further modified with snubber along with hysteresis controller to improve its efficiency. The converter is designed to drive three phase induction motor directly from PV energy. For tracking maximum available solar power, maximum power point tracking hill climb algorithm is used. The use of a three-phase induction motor presents a better solution to the commercial dc motor water pumping system. The development is oriented to achieve a more efficient, reliable, maintenance-free, and cheaper solution than the standard ones that use dc motors or low-voltage synchronous motors.

Keywords: Induction motor, dc-dc power conversion, dc-ac power conversion, solar power generation.

Abstract: In the conventional air conditioning system, induction motors are used for driving the compressor. The main problem of AC(Alternating current) supply while using an inductive load is low power factor, presence of plentiful harmonics at the ac input side and it requires high starting current. Here the induction motor is replaced with an SRM (Switched reluctance motor), and thus the system can be used for low power solar applications. The efficiency of a switched reluctance motor is more compared to a conventional induction motor. In air conditioning system, using inverter technology as drive circuit for induction motor, DC is obtained at the second stage of the inverter circuit. This DC supply can be used to drive the Switched reluctance motor and thus the cost of additional drive circuit can be compensated. SRM has relatively high starting torque compared to induction motor with minimum starting current, which makes it more suitable for air conditioning system, which further enhances the power quality for the power distribution system. Further, the SRM can be used in places where DC grid exists, i.e. in a train. Conventionally, induction motors are used in a train to drive its air conditioning system. And the DC supply is inverted and fed to the induction motor. Replacing induction motor with Switched reluctance motor in air conditioning system of train will improve the overall efficiency of the system and thus reduce the running cost. Life expectancy of a SRM is comparable to that of an induction motor. So, SRM can be used in place of induction motor in these applications.

Keywords: air conditioners, induction motors, switched reluctance motor, perturb and observe