Wind Energy Conversion System Applications Research Articles

An improved model predictive control of back-to-back three-level NPC converters with virtual space vectors for high power PMSG-based wind energy conversion systems

In this study, an improved virtual space vector (VSV)-based two-stage model predictive control (MPC) scheme is presented for neutral point clamped (NPC) converters in high power-rated permanent magnet synchronous generator (PMSG)-based wind energy conversion system applications. The presented MPC scheme utilizes the VSVs and involves two-stage prediction for effectively reducing computation complexity. In stage-I prediction, a virtual space vector is identified based on the optimum cost function. Then, a set of sub-sector vectors are placed in stage II prediction based on the capacitor voltage levels. From this, the cost function predicts the optimum switching state. At the same time, the conditional selection of small voltage vectors in stage II prediction eliminates the neutral point voltage balancing constraint. Finally, the presented method is verified by the simulation of the back-to-back NPC converter of a high-power-rated PMSG-based wind energy conversion system. Further, the adaptability of the presented scheme for maximum power point tracking, reactive power control, and dc-link voltage control is also verified by simulation.

PMSG Wind Energy Conversion Systems ZSI

Abstract: Recently Permanent Magnet Synchronous Generator are mostly used in the Wind Energy Conversion System applications This work is clearly deal with the study of Wind Energy Conversion System WECS by way of Permanent Magnet Synchronous Generator PMSG with Z Source Inverters. The PMSGs and wind turbines are gradually entered in the field of power generation huge wind farms are used at constant voltage and frequency to increase capacity power supply Particularly Permanent Magnet Synchronous Generators is used in this machinery due to special characteristics such as low weight volume and high. PMSG never required the power supply at the starting time of power production PMSGs run at synchronous speed. These type of inverter are classified has Z-Source Inverter ZSI, Quasi Z Source Inverter QZSI, Trans Z Source Trans ZSI and Cascaded Multi Cell Z Source Inverter CMCTZSI etc. This inverter is operated such as shoot through state and on shoot through state previously to convert DC supply to AC supply where the DC supply side have been boosted up to required AC supply level are executed. The above mention shoot through state is not applicable to implementing in the conventional Voltage Source Inverter VSI and Current Source Inverter CSI. The PMSG and types of Z Source inverter systems are simulated in MATLAB Simulation platform.

Cascaded Multilevel Rectifiers for Open-End Winding PMSM

This article proposes three-phase cascaded multilevel rectifiers for wind energy conversion system applications. These configurations operate as machine-side converters and play an essential role in the integration of wind power generation units. The proposed rectifiers are connected to a permanent magnet synchronous machine by an open-end winding arrangement, making the ac–dc conversion of the power delivered with high-power factor operation. Their structures are composed of a combination of a converter based on Vienna rectifiers and one H-bridge per phase with a floating capacitor. Compared with the conventional configurations, the proposed ones provide sinusoidal currents with lower harmonic distortion using, proportionally, a fewer number of controlled switches. Furthermore, they can operate with a lower switch blocking voltage. These features make them attractive options for industrial applications due to their good performance, providing an interesting cost–benefit. The system model, pulsewidth modulation technique, capacitor voltage balancing, and control strategy are detailed. Computer simulations and experimental tests are provided in order to validate their feasibility.

Vienna Rectifiers for WECS Applications With Open-End Winding PMSM

This article proposes three-phase configurations for wind energy conversion system applications. The proposed topologies are based on Vienna rectifiers and they have a reduced number of controlled switches, which may allow reducing size and costs. Despite they can work with other arrangements, the proposed structures operate at an open-end winding configuration in this article, providing some benefits over the traditional ones. Compared to the conventional topology, the proposed ones provide a better power quality employing, proportionally, a fewer number of controlled switches, offering a higher levels-per-switch ratio. Moreover, they can also operate at a lower switch blocking voltage. These features offer an interesting cost–benefit and make them attractive options to industry applications. The system model, modulation technique, and control strategy are discussed. Simulation and experimental results are provided in order to validate their performance and feasibility.

On Reducing the Shaft Torque Ripple of Small-to-Medium-Scale Wind Energy Conversion Systems Using Multi-Pulse Autotransformer Rectifier

In a small-to-medium-scale wind energy conversion system (WECS), diode rectifiers rather than pulse-width modulated (PWM) rectifiers are widely adopted due to the features of high reliability and low cost. However, large current harmonics are induced in the generator phase current by commutations of diode rectifier, eventually causing large torque ripple on the drive-train of the WECS and making it more likely to be fatigue breakdown. In this paper, a 12-pulse autotransformer rectifier unit (ATRU) with reduced volume and weight is proposed for WECS application. By analyzing the characteristics of the input current and output voltage of the ATRU within the entire operation range of WECS, the method to properly design its parameters is proposed. A 1.2 kW direct-drive WECS demonstration platform using ATRU is built in the lab. A modified sensorless overall power control strategy is adopted to control the WECS. Experimental tests are carried out and the results not only validate the feasibility of implementing ATRU in WECS applications, but also prove its high torque ripple reduction ability.

Techno-economic Feasibility Analysis of Stand-alone Renewable Energy Systems (PV/bat, Wind/bat and Hybrid PV/wind/bat) in Kerman, Iran

This article presents a feasibility analysis of renewable energy systems for supplying the electrical load requirements of a typical community (50 rural households) in a remote location in Kerman, Iran. The renewable energy systems (photovoltaic/battery [PV/bat], wind/battery [wind/bat] and hybrid photovoltaic/wind/battery [PV/wind/bat]) considered in the analysis were comprised of different combinations of PV modules and wind energy conversion systems (WECS) supplemented with battery storage. The assessment criterion for the analysis was total net present cost of each system configuration. The National Renewable Energy Laboratory's Hybrid Optimization Model for Electric Renewable software was utilized as the assessment tool for the present study. The results showed that because of the scatter in the distribution of wind speed (sudden decreases in the wind speeds) in Kerman, the application of WECS results in an increase in the number of wind turbines, the required capacity of battery storages and, consequently, the total net present cost of the wind/bat and hybrid (PV/wind/bat) renewable energy systems. For this reason, the PV/bat system was recommended for supplying the electrical load requirements of the present study.

Autonomous wind energy conversion system with a simple controller for maximum-power transfer

The paper describes a small autonomous wind energy conversion system that has been designed and implemented as a prototype unit for the demonstration of wind-electricity generation. A simple, closed-loop control system assures maximum-power transfer by the aid of a lookup table which relates the electrical power output of the system to the shaft speed. The lookup table is deduced from the turbine and generator data and corrected by field tests. A directly-coupled, wound-rotating field synchronous generator is used for energy conversion. The generator speed in this system is variable while the terminal voltage is substantially constant. The terminal voltage is kept under control by varying the field current to meet various load and battery conditions. In the paper a new criterion for determining optimum dimensions of a generator for wind energy conversion system applications is introduced. This criterion envisages a maximisation of the energy output for the chosen wind regime while keeping the generator cost at a minimum. To obtain the optimum solution of the cost minimisation problem, the constrained optimisation problem is first converted to the unconstrained form by using the external penalty approach and then solved using the Devidon-Fletcher-Powel method. Results of the optimisation are presented and evaluated in the paper.