飞机交流供电特性测试的高精度校准源设计

High precision calibration source design for aircraft AC power supply testing

飞机供电系统的发展,给飞机交流供电特性参数测试系统校准提出了更高的要求,为解决现有通用校准仪器在校准测试系统时校准过程复杂、效率低等问题,提出了一种三相变频校准源设计方案。基于直接数字波形合成(DDWS)可产生正弦、调制、瞬变、畸变等信号,并对信号的频率、幅值、相位差、波峰系数等进行调整。主要采用双波形查找表动态切换方法实现电压瞬变、时钟捷变方法实现频率瞬变和采用梯形波实现波峰系数调整的设计方案。通过实验测试,信号发生装置产生的各种信号具有高精度高稳定性,频率误差≤0. 02%,电压误差≤0. 1%,波峰系数误差≤0. 01。

With the development of aircraft power supply system,higher requirements are put forward for the calibration of aircraft AC power supply characteristic parameter testing system. In order to solve the problem of complex calibration process and low efficiency in calibration test system,a three-phase variable frequency AC calibration source design is proposed. Based on direct digital waveform synthesis( DDWS),it can generate sine,modulation,transient,distortion and other signals,it can also adjust the signal frequency,amplitude,phase difference and crest factor. In this paper,the design of dynamic switching method of dual waveform look-up table is adopted to realize the voltage transient,frequency transient is implemented using clock agility,and trapezoidal wave is used to change the crest factor. The experiment shows that the signal generated by the calibration source has the characteristics of high precision and high stability. The frequency error is less than 0. 02%,the voltage error is less than 0. 1% and the crest factor error is less than 0. 01.