Design Principle for Linear Electrical Machines to Minimize Power Loss in Periodic Motions

Recent progress on performance and control of linear engine generator

“…In Otto von Guericke University Magdeburg, the combination of 5-poles and 6-slots was implemented, and an equal length stator and mover flat-type LG was proposed (see Figure 17). 116 Based on FEM results, a low mover mass and high efficiency can be achieved. Using a similar length structure, the end effect caused by the finite length of the mover/stator produced the thrust fluctuation and inductance variation, affecting the operation’s stability and maximum efficiency.…”

“…Similarly, Benecke, Gerlach, and Leidhold proposed an approach for minimising power loss to achieve high efficiency under acceleration and deceleration conditions. 116 An analytical losses model was developed based on the unique periodic trajectory. The iron and copper loss were evaluated, and the total loss was minimised.…”

“…The optimisation algorithm is presented in Figure 18. 116 Using the tracked trajectory, such as a sinusoidal function in optimisation studies, the researchers noticed the large generating-braking forces at dead centres, which indicates LGs must resist rapidly rising cylinder pressure in FP-LEG application. In Wang et al 101 a comprehensive methodology of a generating-braking modulation method was proposed to achieve the best transient efficiency distribution and the optimal energy conversion efficiency.…”

“…Optimisation algorithm with drive system simulation. 116 stators at the dead centres are used as the magnetic springs (high system stiffness) to improve the stiffness for high oscillation frequency.…”

“…Figure 17. A LG in in Otto von Guericke University Magdeburg: (a) simulated section of the flat-type linear machine and (b) concept drawing for the construction of LG 116. …”