Voltage regulation method applicable to frequency conversion alternating-current generator

Abstract

The invention discloses a voltage regulation method applicable to a frequency conversion alternating-current generator, and belongs to the technical field of three-level type frequency conversion alternating-current generators. According to the voltage regulation method, a one-level DC-DC converter is additionally arranged between a permanent magnet pilot exciter and an alternating-current exciter, the input-output characteristic curve of the DC-DC converter is designed, and when the voltage of the no-load end of the generator is a reference voltage at any rotating speed of the generator, the duty ratio of an excitation main power tube is constant. Meanwhile, open-loop gain of a forward path of a voltage regulation system can not be affected by the rotating speed of the generator.

Description

technical field [0001] The invention discloses a voltage regulation method suitable for a variable frequency alternator, and belongs to the technical field of a three-stage variable frequency alternator. Background technique [0002] The generator voltage regulator is a device that keeps the effective value of the generator output voltage constant. It is an important part of aircraft, ships and vehicles, and has always been valued by the production department. The control block diagram of most constant frequency generator voltage regulator systems is as follows: figure 1 . G 1 (s) is the voltage loop PID adjustment module, G 2 (s) is the PID adjustment module of the current loop, G PWM (s) is the generation module of PWM wave duty cycle D, V f (s) is the excitation voltage of the AC exciter, G gen (s) is the transfer function of the two-stage generator, G f (s) is the transfer function of the excitation winding, G uporf (s) is the transfer function of the voltage det...

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Problems solved by technology

Therefore, there are two extreme situations in the case of frequency conversion: ①The open-loop gain of the forward channel of the system is very small at the lowest speed, and the stability of the system is very high at this time, but the dynamic performance of the voltage regulation system is particularly poor, and the steady-state error is relatively large; ② At the highest speed, the open-loop gain of the system's forward channel is very large. At this time, the stability of the system is particularly poor, and the voltage at the generator terminal will oscillate very violently, and even cannot be stabilized.

[0006] According to the two essential differences analyzed above, if it is applied in variable frequency alternator figure 1 The voltage regulator with the structure shown in will bring two problems: ① The duty ratio D of the excitation main power tube may not be enough at the lowest speed, and the duty cycle of the excitation main power tube is particularly small at the highest speed. Causes the output of the system to be particularly sensitive to interfering signals

②In the entire speed range, the voltage regulator can only have good control performance at certain speeds, and the control performance at other speeds will become worse, or even unstable

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