CAJ | 학술논문

提出一种基于 sigma-delta 模拟数字转换器(ADC)设计的解决方案。该方案主要包括提高 sigma-delta ADC 中比较器的反馈电压精确度和 sigma-delta ADC 的转换精确度来提高电能计量的精确度。实际应用中，电能计量芯片包括2路以上的 sigma-delta ADC转换通道，一部分通路用于实现固定幅度的电压模数转换，因而电压数字量的 SQNR 为一定值，另外的通路则实现用户用电产生电流的模数转换，因而电流数字量的 SQNR 随用户用电量而变，通过将电压数字量与电流数字量相乘，即得到用户所用电量及相应的有效值。经验证，当反馈电压存在 x%的偏差时，会使电能计量和有效值计量分别产生2x%和 x%的偏差。当电流通道 SQNR(信号至量化噪声比)低于30 dB时，会使电能计量产生0.5%的误差，电流通道有效值计量误差大于0.4%。
제출일충기우 sigma-delta 모의수자전환기(ADC)설계적해결방안。해방안주요포괄제고 sigma-delta ADC 중비교기적반궤전압정학도화 sigma-delta ADC 적전환정학도래제고전능계량적정학도。실제응용중，전능계량심편포괄2로이상적 sigma-delta ADC전환통도，일부분통로용우실현고정폭도적전압모수전환，인이전압수자량적 SQNR 위일정치，령외적통로칙실현용호용전산생전류적모수전환，인이전류수자량적 SQNR 수용호용전량이변，통과장전압수자량여전류수자량상승，즉득도용호소용전량급상응적유효치。경험증，당반궤전압존재 x%적편차시，회사전능계량화유효치계량분별산생2x%화 x%적편차。당전류통도 SQNR(신호지양화조성비)저우30 dB시，회사전능계양산생0.5%적오차，전류통도유효치계량오차대우0.4%。
The design of the power metering system is described. Both theoretical analysis and simulations are made to examine the influence of the sigma-delta Analog to Digital Converter(ADC) on this system. It points out that the reference voltage in sigma-delta ADC is a key factor in power metering system. As an offset of x% in sigma-delta ADC, reference voltage results in a 2x% bias in power measurement and x% in RMS(Root Mean Square) measurement. In addition, the resolution of sigma-delta ADC also affects the performance of the system. This is especially true in current RMS calculation channel because this channel adopts the current input, whose SQNR(Signal-to-Quantization-Noise Ratio) is low when the current is small.