Brushless DC (Direct Current) motor with brushless AC (Alternating Current) composite excitation

Abstract

The invention discloses a brushless DC (Direct Current) motor with brushless AC (Alternating Current) composite excitation. When a stator excitation winding end adopts an AC variable frequency excitation winding, high excitation efficiency and wide excitation range at a low rotating speed are achieved; a rotor power excitation unit performs composite power excitation by using a DC winding and a permanent magnet; a stator power winding can perform excitation square wave electricity generation by adopting a three-phase or multi-phase winding; the motor running power density is great, and the running range is wide, so that brushless DC motor with the brushless AC composite excitation can be used for power generation running and electric running. The brushless DC motor with the brushless AC composite excitation comprises a stator excitation winding, a motor rotor and a stator power winding; the motor rotor comprises a rotor excitation winding, a rotary rectifier and the rotor power excitation unit; the rotor power excitation unit comprises the DC winding and the permanent magnet; the DC winding is wound on the permanent magnet, and the DC winding and the permanent magnet perform composite excitation.

Description

technical field [0001] The invention belongs to the technical field of brushless DC motors for AC power generation, in particular to a brushless AC compound excitation brushless DC motor. Background technique [0002] For more than a century, motors, including generators and motors, have been used as electromechanical energy conversion devices, and their applications have spread throughout various fields of the national economy and people's daily lives. The main types of motors are DC motors, synchronous motors and asynchronous motors and three. [0003] Disadvantages of DC motors: the structure is relatively complex, which increases the manufacturing cost; sparks are generated during commutation, which limits the scope of use; disadvantages of synchronous motors: the maximum torque is limited by the demagnetization of permanent magnets, poor shock resistance, limited high speed, low power Small, expensive and difficult to start. Disadvantages of asynchronous motors: compl...

AI Technical Summary

Problems solved by technology

[0003] Disadvantages of DC motors: the structure is relatively complex, which increases the manufacturing cost; sparks are generated during commutation, which limits the scope of use; disadvantages of synchronous motors: the maximum torque is limited by the demagnetization of permanent magnets, poor shock resistance, limited high speed, low power Small, costly and difficult to start

Disadvantages of asynchronous motors: complex drive circuits lead to high system costs, low motor efficiency and power density

[0005] Disadvantages of brushless DC motor: high price, high controller requirements, easy to form resonance

Disadvantages of brushless double-fed motors: the system model of brushless double-fed motors is complex; the hard mechanical characteristics of synchronous motors cannot always be maintained when the load changes greatly; the excitation current is large, the operating power and efficiency are low; the excitation loss is high and the stability is poor , poor reliability

Disadvantages of brushless excitation synchronous motor: DC excitation winding on the excitation side of brushless excitation synchronous motor, the excitation efficiency is reduced at low speed, the excitation is easy to fail, and the power density is low

It solves the problem of complex brush structure of ordinary brushed DC motors, low power density of brushless DC motors, brushless doubly-fed motors, permanent magnet synchronous motors and asynchronous motors

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