摘要
在继电保护测试仪的电压电流功放中,通常采用"数字基准源+模拟SPWM"的方案,数字基准源为功放提供了高精度的基准信号,保证了功放输出的低THD要求。基于MC56F8013的平台,设计了输出频率10Hz^1kHz的数字基准源,其幅值频率可调。同时,为了进一步采用数字化技术,提供高可靠的数字功放,还初步设计了数字SPWM宽变频功放。最后给出数字基准源部分实验结果,证明了设计方案的有效性,基准源输出THD不超过0.25%;另外将数字SPWM与模拟SPWM功放进行对比实验,分析给出数字功放较难实现低THD的原因。
In relay protection testing apparatus, the scheme of ＂Digital Reference Source and Analog SPWM＂ is widely used, in which the Digital Reference Source provides high-precision sine signal to satisfy the demand of low THD. The reference source was designed based on MC56F8013 which varies from 10Hz to lkHz. To use the digital technology more, the Digital-SPWM power amplifier was designed. In the end, the experiment result of Digital Reference Source was given, showing that the THD is below 0.25%. Besides, the Digital and Analog SPWM was compared by experiment with analysing the reason of the high THD of Digital- SPWM power amplifier.
出处
《电源学报》
2012年第4期13-18,共6页
Journal of Power Supply
基金
国家自然科学基金资助项目(51077069)
关键词
功放
数字基准源
数字SPWM
power amplifier
digital reference source
digital SPWM
