Loss and Efficiency Comparison of Mover PM and Stator PM Linear-Rotary Generators for Wind-Wave Combined Energy Conversion System

This paper studies the loss and efficiency of two permanent magnet linear-rotary generators (PMLRGs) for wind-wave combined energy conversion systems. One of the two PMLRGs is a mover PM machine (MPMLRG), and the other one is a stator PM machine (SPMLRG). Their structure is introduced first. The loss and efficiency calculation equations of PMLRGs are given. Then the loss and efficiency results of both LRGs under different operation conditions are obtained and compared through finite element analysis. The related loss comparison includes the iron loss comparison, eddy current loss comparison of PM, and copper loss comparison. In addition, some tests are conducted on an established platform with an MPMLRG prototype to verify the analysis results. The load voltage and phase current waveforms are recorded, and the output power and copper loss of the prototype are calculated and compared finally.