High Accuracy Split-Phase CT Fuel Gauge Reference Design with Independent ADC

qwqwqw2088 · Published on 2019-11-20 08:49

High Accuracy Split-Phase CT Fuel Gauge Reference Design with Independent ADC [Copy link]

This reference design implements Class 0.1 split-phase energy metering using high-performance, multi-channel analog-to-digital converters (ADCs). Independent ADCs sample the output of current transformers (CTs) at 8kHz to measure current and voltage in each branch of the main AC source. The reference design achieves high accuracy over a wide input current range (0.05–100 amps) and supports high sampling frequencies when necessary to enable advanced power quality features such as independent harmonic analysis. Using independent ADCs to sample the CT outputs gives designers more flexibility in selecting a metering microcontroller compared to integrated SoCs and application-specific specialty products. This reference design uses a SimpleLink ARM Cortex-M4 host microcontroller to calculate energy metering parameters.

Electricity meter with split-phase measurement, meeting ANSI C12.20 Class 0.1 active energy accuracy requirements with 10000:1 input range
Active and reactive energy and power, root mean square (RMS) current and voltage, power factor, and line frequency calculations
Isolated RS-232 and RS-485 with 5kV RMS isolation
Communication module expansion with current limiting and overvoltage and undervoltage protection
Tested over 50mA to 100A input range
Tested complete reference design with hardware files and design guide