Introduction to wind power generation system
Composition of wind power generation system
Wind Turbines
Fan controller
Wind Turbine Dummy Load
Power distribution device
Energy storage device: generally a valve-regulated lead-acid battery
communication device
Voltage conversion device: only used when supplying communication equipment with different voltages at the same time
Wind Turbine – Principle
Wind power generators are mainly composed of wind energy collection devices, transmission mechanisms and generators. Wind energy collection devices and transmission mechanisms are different due to different power generation capacities. The capacity of wind power generators for communication in my country is small machines, and conventional paddle-type wind wheels are mostly used. As a wind energy collection device, the generator is fixed on the same shaft, thereby omitting the transmission mechanism, and the rotation of the paddle-type wind wheel has three types: resistance type, lift type, and resistance-lift combination type.
The power generation of wind turbines is affected by climate conditions. Only when the wind force is greater than the starting wind speed of the wind turbine can it rotate to generate electricity. In order to make full use of the wind force, when the wind direction changes, the wind wheel must also be adjusted to face the wind. Tail adjustment, medium and large wind turbines mostly use auxiliary wind wheel adjustment
When the wind turbine is running at a speed greater than the starting wind speed, within a certain wind speed range, the greater the wind speed, the more electricity will be generated. Overspeed causes damage, and the wind wheel generally has a speed regulating device. There are two types of speed control systems:
One is that the pitch of the blades is fixed. When the wind speed increases, the wind rotor is rotated around the vertical axis through auxiliary wings or tilt-hinged empennages and other aerodynamic mechanisms to deviate from the wind direction and reduce the windward side to achieve the purpose of speed regulation.
One is that the pitch of the blades can be changed. When the wind speed changes, the aerodynamic pressure or the centrifugal force caused by the rotation of the wind wheel is used to change the pitch to realize speed regulation. When the wind speed exceeds the limit value, the wind turbine can realize “folding tail” protection, so that the wind The plane of the wheel is parallel to the wind direction, and the power generation is stopped
Wind power generators for communication usually use brushless three-phase permanent magnet AC generators (some also use permanent magnet DC generators), and the windings are fixed on independent stators made of non-ferromagnetic composite materials. Magnets do not lock into a running wind turbine, eliminating iron losses and enabling wind turbines to operate at maximum efficiency at common low wind speeds
Wind Turbine – Classification
Communication bureaus (stations) generally use small horizontal-axis three-phase AC wind turbines and their supporting fan dummy loads, as well as rectification, control, and power distribution equipment.
According to different power generation capacity, it is divided into large (above 50kW), medium (10-50kW), small (1-10kW) and micro (below 1kW).
According to the form of the fan, it can be divided into three types: vertical axis type, horizontal axis type (common) and free type (small capacity).
According to the rated power of the generator, it can be divided into AC and DC. AC can be divided into single-phase and three-phase. Three-phase AC wind turbines are more common.
Wind turbine – wind turbine controller
The fan controller consists of two parts: finisher and controller.
The rectifier uses the principle of semiconductor rectification to convert the alternating current generated by the wind turbine into direct current when the communication equipment needs it.
The controller adopts a single-chip microcomputer to receive the command signal sent by the main control machine, and controls the wind power generator.
Control the wind power generator to switch on or off the power supply to the communication equipment. When the power supply is removed, the dummy load of the wind turbine should be turned on in advance to ensure that the wind turbine can avoid running in an open circuit state and cause a runaway.
Wind turbine – fan dummy load
The dummy load of the wind turbine is a resistance box. Using the principle of heat generated by the current through the resistance and the method of heat dissipation, the excess electric energy generated by the wind turbine is converted into heat energy and dissipated into the air, so as to ensure that the wind turbine is always running under load. state.
Fan dummy load is a special device produced according to the requirements of wind turbines, and its voltage, power and service life are all matched with wind turbines. Due to the continuous heat dissipation during work, both safety and ventilation are considered.
