Dynamic Adjustment Method of Excitation Input Voltage of Aeronautical Three-Stage Variable Frequency Alternator

Abstract

The invention discloses an excitation input voltage dynamic adjustment method for an aerial three-level variable-frequency alternator, and belongs to the technical field of digital voltage adjustment.According to the technical scheme, a three-phase PWM controllable rectifying circuit is adopted for adjusting excitation input voltage, and during adjustment, a method for changing a voltage reference valve in real time according to rotation speed is created. When the excitation input voltage dynamic adjustment method is applied to the aerial three-level variable-frequency alternator, the excitation input voltage can be dynamically adjusted according to the current rotation speed. Especially under high rotation speed, by adopting the technical method for lowering the excitation input voltage,the requirements of a power pipe for switching characteristics are reduced. In a digital voltage adjustment technique of the aerial three-level variable-frequency alternator, the excitation input voltage is dynamically adjusted, and the overshoot phenomenon of unloaded transient voltage can be effectively alleviated when a motor runs at full rotation speed.

Description

technical field [0001] The invention relates to a method for dynamically adjusting the excitation input voltage of an aviation three-stage variable-frequency alternator, which belongs to the technical field of digital voltage regulation. Background technique [0002] For aircraft systems, the power system is responsible for the power supply function of the entire aircraft. There are two methods of voltage regulation in the aircraft power system: analog voltage regulation and digital voltage regulation. The analog voltage regulator has the inherent shortcomings of analog circuits, such as the difficulty in adjusting parameters, and it is not easy to obtain circuit parameters that are used in various states. In recent years, digital control technology has developed rapidly, and it is an inevitable trend to realize digital control of aircraft generators. [0003] The principle of the so-called digital voltage regulator is that after the output voltage of the generator passes ...

AI Technical Summary

Problems solved by technology

Therefore, when the motor is running at high speed, the voltage of the permanent magnet machine will be too high, and the control algorithm of the digital voltage regulator will generate a PWM wave with a duty cycle that is too small, that is, the duty cycle of the drive signal of the power tube that controls the excitation switch is too high. Small (generally less than 3%), it will lead to severe heat generation of power tubes, excessive loss, higher failure rate, lower efficiency, shorter life span, and even failure to complete effective switching actions within one cycle

At present, most aviation variable frequency AC power generation systems do not adopt any adjustment control strategy for the rectified voltage of the permanent magnet machine (that is, the excitation input voltage), such as figure 2 The structure of the three-phase uncontrolled rectification circuit shown

Therefore, there is a technical problem that the excitation input voltage cannot be dynamically adjusted in the prior art

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