Research on Small Wind Power Lifting Wind Turbine
The lifting efficiency of the wind power lifting wind turbine is more than twice that of the mechanical water lifting wind turbine, the amount of maintenance of the system is very small, the freedom of installation position between the wind turbine and the water pump is large, and there is a very wide use of the wind energy for water lifting. Prospects. In the countries of the world today, more and more wind power lifting wind turbines have replaced mechanical water lifting wind turbines, which are widely used in farmland irrigation, household water use, and livestock drinking water. In the wind power water collection system, the power generated by the wind turbine is variable frequency, so the motor-driven water pump unit runs at a variable speed. To increase the efficiency of the system, wind turbines must operate stably at a wide range of wind speeds (especially at high wind speeds). The electric controller is connected between the wind turbine generator and the pump load, and the compensation capacitance and unloading load are connected in parallel dynamically. The parameters (voltage, frequency, voltage-frequency ratio) are properly selected for cutting in and out, and the efficiency of the wind power lifting wind turbine can be Significantly improved.
2 Conditions for stable operation of small-scale wind power lifting systems To maintain stable operation, the following power and torque balance equations must be satisfied.
It is the electromagnetic torque of the motor; Tz is the load torque of the pump; Toi is the loss torque of the generator; TO2 is the loss torque of the pump.
3 Parameters analysis of small-scale wind power water collection system According to the system's power balance equation and torque balance equation, the influence of wind speed and generator terminal voltage and frequency on system operation can be analyzed.
With the addition of speed v, the generator's output voltage U or current I increases rapidly. In order to keep the generator from overheating, I should not exceed the rated current of the generator for a long time. When the wind speed increases, it is hoped that the generator terminal voltage will increase.
The load current If or the generator internal resistance rF increases and decreases. To maintain the voltage-to-frequency ratio, the generator's current and temperature rise should not exceed the rated value. In the system, the appropriate compensation capacitance and unloading load are dynamically connected in parallel to limit the current and temperature rise of the generator. Maintaining the pressure-frequency ratio of the wind power pumping system around the rated voltage-frequency ratio (220/50 = 4.4), the system operates most stable and the water lifting efficiency is high. Under normal circumstances, the system's pressure-frequency ratio should not be less than 3. 5 Small Wind Power Water Pumping System Example 51 System Configuration The 10kW FS7-PDM3 wind turbine produced by Xiangtan Boli Wind Power Co., Ltd. is a typical small-scale wind power water pumping system.
In the test project, with a 15-pole, 90m head deep well pump, the motor power is 5. 6kW, the pump power is 3. Fixed compensation capacitance Ci = 55F, dynamic input capacitance C2 = 75MF, dynamic input unloading load R2 (1kW220V). Controller monitoring system frequency, terminal voltage, voltage-frequency ratio, parameter settings are as follows: 1 low cut-out frequency (for the wind power frequency is too low, the controller cuts off the wind turbine power supply to the motor of a pump unit) 30Hz.2 low cut-in frequency (Minimum wind power frequency that the controller allows the wind turbine to start supplying power to the motor-pump unit): 40Hz. High cut-out frequency (The controller cuts off the wind power supplied by the wind turbine to a motor pump unit due to the high wind power frequency): 90Hz. High reset frequency (after the wind power frequency exceeds the high cut-out frequency, the controller recovers the wind power frequency that the wind turbine must reach to supply a motor water pump unit) 70Hz.5Q2 closing frequency: 50Hz; cut out pressure ratio: 3.1. 2 test Results In the field test, the system's on-line rate, outflow rate, power, and pressure-frequency ratio were tested. System online means that the system continuously raises water. It is an online rate curve. The on-line rate of the wind speed from 6 to 15 m/s is very high and the system runs stably. Is the flow rate curve, the wind speed from 4 ~ 13. 5m / s flow rate with the wind speed and synchronization faster, the maximum of 11.8m3 / h, the system of high water efficiency. It is the power curve. The wind speed increases from 4 to 13.5m/s with the wind speed and the unloading resistor with a maximum of 11kW.3kW absorbs excess energy. It is a pressure-frequency ratio curve, wind speed from 6~11m/s, voltage/frequency ratio is above 4.3 (close to rated voltage/frequency ratio of 4.4), especially when high pressure (v is 11~15m/s). Increase the motor to provide enough torque at high speed to ensure that the system can operate stably over a wide range of wind speeds.
6 Concluding remarks The small-scale wind power water-lifting wind turbine has high efficiency, the system structure is simple and flexible to install, the maintenance amount is extremely small, and the reliability is high. Today in the world, it is an advanced wind pumping system. In the vast northwest region of China, where there is arid and rainy weather, many villages have not yet been energized, and people’s living conditions are very difficult. However, the region’s wind resources are very rich. The use of small-scale wind-powered water extraction wind turbines to extract groundwater for production and life can improve their quality of life, in line with the country’s strategic decision to develop the Great North West. Therefore, the small-scale wind-powered water-lifting wind turbine has a very broad prospect of popularization and application in China.
Strain Gauges,Accuracy Load Cell,Parallel Grid Strain Gauge,Pressure Sensor Use Gauges
Zhejiang Nanhua Electronic Technology Co., Ltd , https://www.nhloadcells.com