Control method for steplessly adjusting operation of high power water pump or fan

Abstract

The invention discloses a control method for steplessly adjusting operation of a high power water pump or a fan. A controller controls a frequency converter, and the frequency converter controls a motor; and controlled working modes are manually or automatically switched according to values of the power of the motor and the power of the frequency converter. According to the control method disclosed by the invention, the frequency converter with the capacity which is 1 / 2 of the capacity of the motor is adopted to control the motor of the pump or the fan to be started, so as to realize stepless control over the rated flow of about 0 to 80 percent, and the full-load operation requirement under a special condition is met. The low capacity frequency converter controls the high power motor, thus reducing the surplus of use of the frequency converter, saving energy and decreasing the equipment investment; impact on a power grid is reduced; meanwhile, the impact influence on a water pump impeller, a pump shaft and a bearing can be reduced to the maximum extent, the service lives of equipment and valves are prolonged, and the maintenance cost of equipment pipes is saved; by stepless adjustment of the water amount and the air volume, production operation parameters can be precisely controlled, and the engineering requirement can be met; and multiple interfaces can be connected with a computer and a network to realize intelligent control.

Description

technical field [0001] The invention relates to a control method for steplessly adjusting the operation of a water pump or fan, in particular to a control method for steplessly adjusting the operation of a high-power water pump or fan. Background technique [0002] Existing motor equipment such as water pumps and fans adjust the flow mainly by adjusting the baffles or valves at the inlet and outlet, and then control the water flow and air flow. The control accuracy is not high, which also leads to the current design. The capacity is much higher than the actual needs, and there is a phenomenon of large horses and small carts, resulting in a lot of waste of electric energy; when mechanically adjusting the flow of fans and water pumps, the existing technology is manual adjustment of mechanical baffles or valves, and construction adjustments are frequent , Roughly, the pump is prone to cavitation; and frequent adjustment of mechanical valves is easy to accelerate the damage of v...

AI Technical Summary

Problems solved by technology

[0002] Existing motor equipment such as water pumps and fans adjust the flow mainly by adjusting the baffles or valves at the inlet and outlet, and then control the water flow and air flow. The control accuracy is not high, which also leads to the current design. The capacity is much higher than the actual needs, and there is a phenomenon of large horses and small carts, resulting in a lot of waste of electric energy; when mechanically adjusting the flow of fans and water pumps, the existing technology is manual adjustment of mechanical baffles or valves, and construction adjustments are frequent , Roughly, the pump is prone to cavitation; and frequent adjustment of mechanical valves is easy to accelerate the damage of vulnerable parts such as water pump impellers, bearings, pump shafts, and pipeline valves

Although the above problems can be well solved by using frequency converter control, the required frequency converter capacity is relatively large, and the one-time investment is large, especially the maximum capacity of the low-voltage frequency converter series produced by the manufacturer is limited, which cannot meet the requirements of high-power motors.

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