Wind energy conversion systems
Wind turbine development has become an attractive research topic in renewable energy resources in recent years. Wind energy conversion systems (WECSs) have been intensively developed to contribute the “green energy” demand up 20% by 2030. Clearly, energy specialists and policy makers have realized the potential importance of wind energy resource in common energy crisis in the world nowadays. For technical aspects, many of opportunities being pursued through advanced control techniques are utilized to achieve higher contribution of wind energy.
This writing briefly summarizes important characteristics of WECSs based on a DFIG and PMSG, which are widely used in research topics as well as commercial markets.
Wind turbine is a device that converts mechanical energy from wind into electrical energy to be used in stand-alone grid or to be connected with the grid. A typical wind turbine consists of necessary components, illustrated in the following figure
There are two basic configurations in WECSs, depending on the electrical machine type.
1- Fixed-speed WECSs
This wind power system operates at a constant rotor speed regardless of the wind speed variations. The rotor speed is controlled according to the grid frequency. The electrical machine equipped with such wind turbines is squirrel-cage induction generator. Sometimes a permanent-magnetic synchronous generator can be used. Fixed-speed WECSs have advantage of being simple, robust, and reliable with a low-cost generator and easy control. However, such wind power systems also have drawbacks due to limited control when wind speed changes continuously.
2- Variable-speed WECS
Comparing with fixed-speed wind turbines, variable-speed WECSs based on a doubly-fed induction generator (DFIG) offer a number of merits such as simple control, four-quadrant active and reactive power regulation, and low cost converter. With a DFIG-based wind system, the stator side is directly connected to the grid, whereas the rotor side is connected to a back-to-back voltage source inverter. The stator outputs power into the grid. The rotor is capable of delivering or absorbing power to/from the grid, depending on the rotor speed.
With a PMSG-based wind system, the generator output voltage and frequency are proportional to the rotor speed and the current is proportional to the torque on the shaft. The output is rectified and fed through a buck-boost regulator to an inverter which generates the required fixed amplitude and frequency AC voltage.
Reference source: http://www.mpoweruk.com
19/04/2010 – Posted by tungvp | Wind energy
- van systems
- plans of conversion of van
- various components of wind energy conversion systems
- windpower a handbook on wind energy conversion systems
- grid integration of wind energy conversion systems
- Facts about wind turbines – Renewable Energy Sources
Wind turbine and wind power Wind turbine rotors can be divided according to several basic principles: – by wind action – returned to the position and axis of rotation – the speed of rotation. According to the action of wind, wind turbine rotors can be: 1. Rotor with resistant action are based on the
- Wind Farm Using Doubly-Fed Induction Generators
Wind Farm Using Doubly-Fed Induction Generators On this page… Description of the Wind Farm Turbine Response to a Change in Wind Speed Simulation of a Voltage Sag on the 120 kV System Simulation of a Fault on the 25 kV System Description of the Wind Farm The example described in this section
- Vertical Axis Wind Generator (GLJV
1. 11 years experience in this line, reliable engineer experts team 2. CE certificate offered. 3. High net power output than others. To prove this, customers can make real spot test on the generators test stand. Also, we can offer measurement power curve for your reference. 4. Our generator can work for more than 20
- Grid Integration of Wind Energy Conversion Systems
Grid Integration of Wind Energy Conversion Systems-Second Edition Siegfried Heier, Rachel Waddington (Translated by) Wind energy is a reliable, natural and renewable electrical power supply. The high installed capacity of today’s wind turbines and decreasing plant costs have shown that wind power can be competitive with conventional, more heavily polluting, fuels in the long
- The real truth about windmills
The real truth about windmills Prof. Howard HaydenBrookesNews.Com Monday 01 September 2003 The US government has spent hundreds of million of dollars on wind energy but most US wind farms use turbines purchased from Danish companies. Its our way of subsidizing a poor little anti-nuclear country whose economy is