Voltage Waveform Transient Identification for Autonomous Load Coordination

Abstract

Significant electrical loads such as HVAC systems can be made “aware” of the operation of other loads nearby in the electric grid. Local examination of the utility voltage waveform can provide this awareness without the need for a dedicated communication network. This is particularly true in low-inertia microgrids and “soft” sections of a utility network. This paper presents techniques for extracting frequency and voltage harmonic transients corresponding to individual load events. With data collected from a microgrid energized by diesel generators, we demonstrate the ability to identify the operation of HVAC units and generator dispatch events from their transient effects on the voltage using a cross-correlation based scoring algorithm. Ultimately, incorporating such awareness into load controllers allows loads to autonomously meet system-level objectives in addition to their individual requirements. For example, HVAC units could maintain occupant comfort while also reducing the utility's peak aggregate electrical demand by consuming electricity on a schedule interleaved with the operation of other nearby HVAC units.

Keywords

• Microgrids
• smartgrids
• autonomous systems
• monitoring
• load management
• current-voltage characteristics