For a domestic or small commercial environment, single-phase electricity meters are generally required to cut down costs of a three-phase distribution network. This article presents some ready-to-use single-phase meter reference designs involving many advanced features like high accuracy, tamper detection for continued operation during power failure, LCD display for accurate calibration and connectivity with RS-232, I2C and USB. Take a look!
- Single Phase E-Meter for Low Cost and Power Needs based on PIC18F87J72: Here is a smart single-phase meter reference design that meets the cost and power requirements of a single-phase system. To cut down cost, the design uses a shunt for the current sensor in place of expensive current transformers. The design uses a PIC18F87J72 MCU with Analog Front End to drive the LCD and calculate the parameters like active/ reactive powers, RMS currents and voltages, forward/reverse energies, and more. To meet accuracy requirements, a Microchip’s energy meter software is provided to quickly calibrate and monitor the meter with the help of MCU. Click here to download the reference design.
- Single-Phase E-Meter for Residential Metering with I2C: The following reference design is a cost-optimised, high-performance single-phase meter for residential metering with two wire installations. It can be used in smartgrid applications by connecting to Zigbee network using the I2C interface. The design features a Kinetis MK30X256 ARM MCU for active and reactive power measurements that are displayed on a built-in LCD. The design includes cost-effective voltage sensing using an inexpensive resistor divider. The system can switch to low-power mode with the help of an in-built RTC operated by a 3V battery. The BOM of the system is kept low. Click here for detailed reference design.
- Low-cost Single-Phase E-Meter with Tamper Detection: This is a simple and low-cost single-phase meter reference design that calculates active and reactive energy in both phase and neutral channels using a 32-bit MCU. A shunt resistor is used as a transducer for phase current sensing and a current transformer is used for neutral current sensing. The design includes tamper detection and can detect neutral missing with a current transformer and can log power-failure event with a built-in RTC. The Kinetis 32-bit ARM MCU with AFEs implements Discrete Fourier transformation (DFT) for accurate measurements. Click here to know more about the reference design.