A 100-ppm Integrated TDM-Based Single-Phase Wattmeter for Smart Grid

In this brief, the Time-Division Multiplier (TDM)based electronic wattmeter has be integrated for the first time. To integrate the wattmeter and properly select parameters for its circuit, this brief provides the modeling of TDM and the theoretical analysis of three types of errors, which improved the TDM theory. Based on these analysis, the considerations for designing the circuits of the modules of TDM are provided. Besides, the analysis using root locus theory for notch filter design are also provided, which simplified the initialization and determination of the design parameters. The wattmeter circuits, whose maximum input voltage and current amplitudes are +/- 15 V and +/- 2.5 mA respectively, is integrated into a chip manufactured by a 0.35-mu m high-voltage semiconductor process and occupying area of 1.6 x 2.5 mm(2). And the precision of this integrated wattmeter is sub-100 ppm, represented by relative systematic error.