Performance Comparison of Grid Connected Small Wind Energy Conversion Systems

Abstract

A small scale Wind Energy Conversion System (WECS) has tremendous diversity of use and operating conditions, and consequently is evolving rapidly along with the large scale WECS for generation of electricity in either on grid or off grid applications. In recent years, the grid connected Small Wind Turbine (SWT) industry is primarily dominated by the Permanent Magnet Generators (PMGs) based topology. The Power Conditioning Systems (PCS) for grid connection of the PMG based topology requires a rectifier, boost converter and a grid-tie inverter. However, a small wind turbine may be based on Wound Rotor Induction Generators (WRIGs). The WRIG based topology can employ a rectifier, a chopper and an external resistor in the rotor side while the stator is directly connected to the grid. These two topologies have diverse losses that fluctuate with the wind speed. This paper presents a comparative study of a PMG and WRIG based topologies for SWT systems. The study employs numerical simulation to investigate the conversion losses for both topologies. It is demonstrated that a WRIG based topology offers less losses than a PMG based topology. The comparison is further enhanced by investigating the annual energy capture, annual energy loss and efficiency for the wind speed data and Weibull distribution of three different locations of Newfoundland, Canada. The study shows that a WRIG based topology is an optimum alternative in terms of performance characteristics within a slip variation of 15%.

Speed sensor‐less maximum power point tracking and constant output power operation of wind‐driven wound rotor induction generators

“…Squirrel-cage induction generators have been popularly used for small and medium capacity in WECSs [1,2]. The slip ring induction machine based generators are now becoming popular for large capacity wind energy systems in the MW range and they feed power to the grid at constant frequency and voltage of the grid [3][4][5][6][7][8][9][10][11][12][13][14][15][16]. The major advantage of these generators is that the control is exercised on the rotor side with reduced rating for power electronic converters.…”

“…This paper aims at developing suitable controller for achieving the MPPT or constant output power mode operations of variable speed wind turbine systems employing WRIG. It is to be noted that in all the existing schemes for the rotor resistance control of WRIGs [7][8][9][10][11][12][13][14], a fixed external resistor is connected with chopper circuit. However, in this proposed system, for effective utilisation of wind energy, the rotor power has been planned to be used for space heating and battery charging application.…”

Efficiency Comparison of Power Electronic Converters Used in Grid-Connected Permanent-Magnet Wind Energy Conversion System Based on Semiconductors Power Losses

“…It is well understood that the modulation algorithm is always unique for a specific conventional PWM converter regardless of DC-AC or AC-DC operation mode, the model of conduction and switching losses is also unique to a specific conventional PWM converter as far as the conditions of physical devices keep unchanged. In view of these the PWM rectifier results (35) and (36) for the conduction, P cc1,d-R BBC and switching loss, P cc1,i-R BBC of the anti parallel diode respectively. In addition, (37) and (38) presents the conduction, P ss1,d-R BBC and switching, P ss1,i-R BBC loss of the IGBT respectively [36].…”

Modeling and Simulation of Grid Connected Permanent Magnet Generator (PMG)-based Small Wind Energy Conversion Systems

“…To achieve these criteria, active stall, passive stall, or pitch control can be applied [2], however, dependence on the airfoil design and system complexity are the major obstacle of such controls. In contrast, furling control is promising and has received a tremendous concentration in the small wind turbine area [3,4]. Nevertheless, to track the maximum power as well as maintain the flow of maximum power to the grid is also an essence of an entire control strategy for a feasible variable speed operation.…”