Pumping method and device adopting alternating current power supply to driving permanent magnet motor submersible pump

Abstract

The invention discloses a water pumping method and a device for a submersible pump driven by an AC power supply. According to the current magnetic field polarity position of the motor rotor and the positive and negative polarities of the AC power supply, whether the positive and negative half cycles of the AC power supply are controlled The conduction and half-circle leading-edge conduction phases match the polarity of the magnetic field generated by the stator of the motor with the polarity of the rotor magnetic field, and improve the non-directional start and operation of the motor to directional start and operation. Including setting the rotor magnetic field polarity position detection circuit, AC power supply positive / negative polarity detection circuit, signal processing circuit, thyristor and motor drive circuit, by matching the power supply polarity signal and the rotor magnetic field polarity signal, and meeting the conditions The matching result is output and triggers the thyristor, so that the stator winding, rotor and impeller of the AC drive motor rotate in a specific direction, so as to be suitable for further modification of the structure of the submersible pump, and obtain a pumping method and its device with better efficiency.

Description

technical field [0001] The invention belongs to a submersible pump, and relates to a submersible pump driven by a single-phase AC two-pole permanent magnet synchronous motor, and the improvement of its motor driving mode and structure. More specifically, based on the current magnetic field polarity position of the motor rotor and the positive and negative polarities of the AC power supply, by controlling whether the positive and negative half cycles of the AC power supply are turned on and the phase of the leading edge of the half cycle, the polarity of the magnetic field generated by the motor stator is consistent with the current polarity of the AC power supply. The polarity matching of the rotor magnetic field improves the non-directional start and operation of the motor to directional start and operation, so as to be suitable for the further modification of the structure of the submersible pump, and obtains a submersible pump pumping method and its device. Background tech...

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Problems solved by technology

[0002] At present, the submersible pumps driven by single-phase AC two-pole permanent magnet synchronous motors appearing on the market are composed of permanent magnet rotors and simple stators, which have the advantages of simple manufacturing process and low cost. Due to the influence of the magnetic polarity position of the rotor at startup, the polarity of the input drive power, the motion inertia of the rotor and impeller and the water body in the pump room, when the stator winding is directly driven by the AC power supply, the rotor starts and runs with rotation. The disadvantage that the direction cannot be determined makes the method of pumping water and the design of the pump room must be suitable for or meet the left-right symmetrical structure, the blades of the impeller must be made into straight and symmetrical radial blades, and the water outlet must also be along the radial center of the pump room The left and right symmetrical settings, therefore, have brought bad phenomena such as low working efficiency of the whole machine and poor start-up performance.

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