Synchronous sampling method for effective value of aviation wide variable-frequency power supply signal

Abstract

The invention discloses a synchronous sampling method for an effective value of an aviation wide variable-frequency power supply signal. According to the method, synchronous sampling is realized by adopting a half-cycle fixed sampling point number; the line voltage of the permanent magnet auxiliary exciter is shaped into square wave signals with the same frequency, and the time of the positive half period and the time of the negative half period of the signals are calculated through the two DSP capturing units respectively; wherein the time interval of the sampling points is changed accordingto the signal frequency of the latest half cycle, the sampling points of the half cycle are adopted to calculate the effective value, and the effective value is recalculated once every time a new point is acquired. According to the method, adverse effects caused by synchronous sampling delay under a wide frequency conversion condition are reduced; the method has few steps, can effectively deal with the conditions of rapid frequency change of the aviation wide variable frequency generator and frequency change during loading and unloading of the aviation RAT three-level generator, greatly improves the rapidity and accuracy of sampling, and improves the dynamic performance of a power generation system.

Description

technical field [0001] The invention relates to a method for synchronously sampling effective values ​​of aviation wide-frequency variable-frequency power supply signals, and belongs to the digital technical field of aviation variable-frequency power generation systems. Background technique [0002] The frequency conversion power system has the advantages of simple structure, light weight, small size and high efficiency. It has gradually replaced the variable speed constant frequency power generation system and become the development direction of large aviation power systems in the future. At present, the advanced multi-electric aircraft Boeing 787 and Airbus A380 are both Three-stage generator power generation system with variable speed and frequency conversion. The stable frequency range of the variable frequency AC power supply is 360-800Hz. Compared with the constant frequency AC voltage regulation system and the high and low voltage DC voltage regulation system, the sam...

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Problems solved by technology

The stable frequency range of the variable frequency AC power supply is 360~800Hz. Compared with the constant frequency AC voltage regulation system and the high and low voltage DC voltage regulation system, the sampling of the variable frequency AC signal is more difficult.

[0003] When sampling the 50Hz AC of the traditional power system or the 400Hz AC of the aircraft power supply system, due to the small frequency fluctuation, the sampling period can be determined, and then compensated by subsequent algorithms such as quasi-synchronous sampling, or by selecting the appropriate initial sampling point position , and carry out whole-cycle sampling to ensure the accuracy of sampling, and the wide frequency range of the aviation variable-speed variable-frequency power supply is 360-800Hz, and the emergency-use aviation RAT three-stage motor and APU auxiliary power motor will also have frequency fluctuations when the load changes changes, traditional sampling and compensation methods are difficult to achieve satisfactory results

When faced with the 200Hz / s fast frequency conversion required by the national military standard and the loading and unloading of the above-mentioned aviation motors, if the cycle time determined in the previous cycle is used to perform the whole cycle sampling of the next cycle, not only the sampling accuracy cannot be effectively improved, but also It will cause adverse effects on system control due to poor real-time performance

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