Optimal Energy Efficiency Evaluation in Induction Machines Driven by Adjustable Speed Drives under EN 50598–2 and IEC 61800-9-1 Standards

The European Commission has defined a sustainable energy industry as a core 2030 strategy: cut CO
₂
emissions by 40% throughout Europe. Energy-saving adjustable speed drive (ASD) solutions play a key role in this effort. As the regulatory requirements continue to grow, it is imperative to have common quantifiable standards. Therefore, a systematic approach is proposed in the European EN 50598-2 and International IEC 61800-9-1 standards in order to determine and verify the efficiency of the complete drive module (CDM) and the power drive system (PDS). As compared with the benchmarked linear Volts/Hz profile, three types of energy saving algorithms representing industry practices including scalar quadratic Volts/Hz control, flux optimization, and scalar energy optimizing Volts/Hz algorithm are presented for quantifying their performances. In variable torque (VT) applications, due to its low computational burden, stable operation, insensitivity and demonstrated energy saving effectiveness, the efficiency optimizing Volts/Hz control method is selected for developing evaluation procedures under EN 50598-2 and IEC 61800-9-1 Standards. Experimental tests with a 400V, 50Hz, 7.6A ASD and a 4.6kW, 380V, 50Hz IM system are conducted for quantifying the losses and energy efficiency applying the efficiency optimizing Volts/Hz strategy. The methodology and evaluation procedures presented in this paper provide reference value and clarity for practicing engineers.