This paper presents a novel approach to the establishment of the operational boundary for synchronous motors in variable speed drives. This is based on the strategy of keeping the motor total power loss constant at its rated value with rated output power. Subject to hot spot risks, this is likely to ensure the thermal robustness of the motor at any operating point, independent of motor current and power limits. The proposed strategy of control adjusts the net air-gap flux to achieve the desired speed and maintain the motor total loss within the rated value. The motor operational boundary for a typical motor, under the proposed control strategy, is established and compared with the corresponding boundary under conventional VIF control. Higher torques, output powers and efficiencies are achieved. Furthermore the operational speed range can be extended above base speed, compared with the more limited range with conventional V/F control. Efficiency maximization at different values of part load is also investigated by controlling the net air-gap flux. A significant reduction in power loss is obtained, achieving worthwhile significant energy savings. The theoretical analysis is derived based on an equivalent circuit model. Saturation, armature reaction and variation of iron losses are taken into consideration. Experimental verification at some of the theoretical results is obtained.
Ghoneem, G. A. (2002). Performance Maximization of Variable Frequency Synchronous Motor Drive Based on Power Loss Control. ERJ. Engineering Research Journal, 25(3), 219-232. doi: 10.21608/erjm.2002.70906
MLA
G. A. Ghoneem. "Performance Maximization of Variable Frequency Synchronous Motor Drive Based on Power Loss Control". ERJ. Engineering Research Journal, 25, 3, 2002, 219-232. doi: 10.21608/erjm.2002.70906
HARVARD
Ghoneem, G. A. (2002). 'Performance Maximization of Variable Frequency Synchronous Motor Drive Based on Power Loss Control', ERJ. Engineering Research Journal, 25(3), pp. 219-232. doi: 10.21608/erjm.2002.70906
VANCOUVER
Ghoneem, G. A. Performance Maximization of Variable Frequency Synchronous Motor Drive Based on Power Loss Control. ERJ. Engineering Research Journal, 2002; 25(3): 219-232. doi: 10.21608/erjm.2002.70906