Networked control of single-phase induction motor air conditioners for constrained power systems

Split-Type Air Conditioners (ACs) are extensively used in households, commercial organizations and industrial setups. The duty-cycle based hysteretic control is inefficient and requires high power provisioning of full startup current for the compressor at each turn-on. This is especially demanding in constrained power systems with weak grids where people are dependent on backup generators and UPS for power needs during load-shedding. Some work has been done on optimizing energy consumption of Split-type ACs based on DC Compressors e.g. permanent magnet brushless DC motors (PMBLDCM) and three-phase induction machines but limited work has been done on operational optimization and energy efficiency of Split-type ACs based on single phase permanent split capacitor induction motors (SPPSCIM). This paper presents a networked Variable Frequency Drive (VFD) for these ACs to optimize operation, enhance energy efficiency and increase load drive capability of constrained energy systems. The network mode of operation allows existing installed base of standalone units to be integrated with central control infrastructure in an organization through Building Management Systems (BMS). The drive is designed, and tested on a 2.3kW Mitsubishi Electric Split-type air conditioner with SPPSCIM. The results of implemented VFD with networked control over Wi-Fi are presented to validate the effectiveness of the speed drive and the enhanced capability enabled by networked operation.