A three-phase power meter needs to deal with more current and voltage information compared to a single-phase power meter and requires analog input for a maximum of seven channels and high processing capacity for power calculation. Further, the smart power meter needs to meet the security requirements of the Device Language Message Specification (DLMS) international standard.

Renesas offers microcontrollers (MCUs) for three-phase power meters equipped with optimum analog input structure and calculation support functions.

The 32-bit CPU RX21A microcontroller is equipped with an up to 7-channel 24-bit Delta-Sigma A/D converter, AES encryption engine and 1.56 DMIPS/MHz processing performance suitable for high-end three-phase power meters.

The 16-bit CPU RL78/I1C microcontroller is equipped with an up to 4-channel 24-bit Delta-Sigma A/D converter, a phase adjustment function, a high pass filter, and a 32-bit multiply-accumulator, making it suitable for low-end three-phase power meters. In addition, it is equipped with an encryption/decryption processing hardware engine that supports AES encryption GCM mode to support DLMS standard security requirements.

The three-phase 4-wire power meter can be supported by linking a 4-channel Delta-Sigma A/D converter and a 3-channel sequential A/D converter with the event link controller.

Three-Phase Power Meter