An asynchronous sampling method for three-stage brushless synchronous variable frequency AC power generation system

Abstract

The embodiment of the invention discloses an asynchronous sampling method for a three-stage brushless synchronous motor frequency conversion AC power generation system, which relates to the technical field of aircraft wide frequency conversion AC digital sampling, and can improve the accuracy and timeliness of voltage effective value collection. The invention includes: using FPGA to measure the frequency of the three-phase AC voltage signal output by PMG, and indirectly deriving the voltage frequency output by the main motor; controlling the AD7656 to synchronously collect the three-phase voltage output by the main motor through FPGA; according to the output voltage of the main motor Signal frequency f and sampling frequency f s , to determine the number of sampling points N of DSP; DSP according to the sampling frequency f s , read N data from the FPGA through the interrupt service program; after the compensation process, obtain the effective value of the voltage; input the effective value into the voltage regulation module, and use the voltage regulation module to output the PWM signal. The invention is suitable for improving the accuracy and rapidity of digital sampling and effective value calculation of an aircraft frequency conversion AC power generation system, thereby improving voltage regulation precision and dynamic performance.

Description

technical field [0001] The invention relates to the technical field of variable-frequency AC digital sampling of a three-stage brushless synchronous motor, in particular to an asynchronous sampling method for a three-stage brushless synchronous variable-frequency AC power generation system. Background technique [0002] The aircraft frequency conversion AC power generation system is widely used in the most advanced multi-electric large passenger aircraft such as A380, A350 and B787 due to its simple structure, safety and reliability, high power density, and easy start-up power generation. The C919 airliner also adopts the architecture of the frequency conversion AC power generation system. The frequency conversion AC power generation system has become an important development direction for future multi-electric aircraft, especially large passenger aircraft and large transport aircraft. The voltage frequency of the aircraft frequency conversion AC power system is generally be...

AI Technical Summary

Problems solved by technology

Therefore, it is necessary to accurately collect and calculate the effective value of the three-phase voltage signal within the full speed range. The traditional method of fixed frequency and fixed number of sampling points is difficult to accurately collect and calculate the effective value of the sinusoidal periodic signal under wide frequency conversion. Therefore, it is necessary to study the asynchronous sampling device suitable for aircraft frequency conversion AC power generation system and its digital sampling and effective value algorithm to improve the accuracy and real-time performance of effective value calculation

[0004] In the patent "An Error Correction-Based Calculation Method for the RMS of Aviation Wide-Variable Power Supply Signal" (CN108761353A), the patent only uses DSP, and the actual error compensation needs to obtain a lot of data through simulation, which requires a large amount of DSP space, and it is difficult to obtain accurate error compensation data

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