Three smart meter ICs from STMicroelectronics allow accurate measurements down to extremely low power levels. Meters featuring ST’s STPM32, STPM33, and STPM34 ICs will help utilities minimise revenue losses and ensure consistent billing for even the most frugal customers.
Although existing meters are accurate at current levels typically down to 50 mA, errors at lower currents can bring about, in today’s low-standby era, up to megawatt-hours of lost billings across a large customer base. The STPM3 devices prevent such losses by keeping the meter accuracy down to just a few milliamps, comparable to the current drawn by an LED television in standby.
The STPM32, STPM33, and STPM34 perform power-quality calculations on-chip, including RMS voltage and current measurement, apparent-energy computation, and under-voltage/over-voltage detection. These features can help offload the meter’s host processor, simplifying software.
Neutral-phase tamper detection in the STPM33 and STPM34 helps further simplify the design and enhance system security. The STPM34 also can calculate apparent power in single- and multi-phase systems.