The voltage and current of any line in a circuit depends on the phase to which it is connected. This is the basis of the metering equation Watts equals 0.5 volts times (amps of phase A minus amps of phase B) plus the difference in voltage between phase wires.
This is why most of the electricity meters on the market are still analog. They are extremely accurate, and are a great choice for most applications.
Single Phase Analog Power
Single phase power is a good choice for many applications because it requires less equipment, fewer transformers and lower energy bills.
It also gives more stable power, so that a power surge won’t cause damage to appliances.
It can be used with a variety of devices, including electric motors and transformers. It can even be used with an electrical switch to measure the amount of electricity flowing through a single-phase power distribution system.
Unlike three-phase power, which is typically delivered to large industrial users and multifamily dwellings, single-phase power does not require local transformers. Instead, it delivers low voltages to the customer, which can be safer and easier to measure.
This type of power can be measured using the MAXQ3180 multifunction, polyphase analog front-end device. Whether the load is a simple resistive or capacitive load, the device can measure and calculate a variety of metering and power-quality parameters.
Single-phase operation of the MAXQ3180 is simple and requires no special software configuration. In fact, the unused channels in a phase A measurement can be disabled to improve performance and eliminate unnecessary calculations.
The metering and power-quality measurement process for a single-phase application starts with accurate measurement of the mains frequency. Next, a 90deg phase shift is applied to the voltage samples. The shifted samples are stored in 48-bit registers for further processing.
The accumulated results are processed for apparent power, frequency and power factor. During this process, the AFEENRDYFG metering interrupt flag is asserted high to signal completion of the foreground measurements.