Synchronous motor excitation system

Abstract

The invention relates to an excitation system, in particular to a synchronous motor excitation system which comprises a controller and an exciter; the exciter is coaxially connected with a synchronous motor; the controller adjusts three-phase voltage input into the exciter; the exciter comprises an exciter stator core, an exciter rotor core, an exciter stator winding and an exciter rotor winding; the exciter stator winding is arranged on the exciter stator core; the exciter rotor winding is arranged on the exciter rotor core; the exciter rotor core and the synchronous motor are coaxially connected through a shaft; an air gap is formed between the exciter stator winding and the exciter rotor winding;three-phase current or direct current can be introduced into an exciter; and the frequency and amplitude of an excitation voltage can be flexibly controlled through the controller, so that the excitation voltage can be matched with the synchronous motor rotor to the maximum extent, the synchronous motor can achieve excitation within the full-speed range, torque output of the synchronous motor is guaranteed in a low-speed section, and field weakening control over the synchronous motor rotor is achieved in the high-speed section.

Description

technical field [0001] The invention relates to an excitation system, in particular to an excitation system of a synchronous motor. Background technique [0002] Synchronous motors have the advantages of high efficiency and adjustable magnetic field, and have great application prospects in the field of new energy vehicles, but they require carbon brush components, which reduces the reliability of the motor. The excitation voltage of the traditional motor brushless excitation system changes with the speed, and it cannot maintain stable excitation when the motor speed changes. [0003] The structure of the traditional synchronous motor brushless excitation system is similar to that of a DC motor. The stator of the excitation system is equipped with a fixed coil to generate a magnetic field. The rotor coil of the excitation system cuts the magnetic field lines of this magnetic field when it rotates, and it will be at the output port of the rotor. The AC induced voltage is gene...

AI Technical Summary

Problems solved by technology

Therefore, the excitation voltage increases with the increase of the motor speed, so this structure can only be used in fields such as generators with relatively fixed speed and relatively simple working conditions

However, in the working area where the motor speed is low, due to insufficient motor speed, the excitation voltage drops, and the motor cannot be fully excited, resulting in insufficient motor output torque.

In the high-speed region, the excitation voltage is too high, resulting in over-excitation of the motor and increased loss

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