An improved series equivalent circuit of a single-sided linear induction motor

Abstract

The derivation of the equivalent circuit for a singlesided linear induction motor (SLIM) is not straightforward. Especially if it includes longitudinal end effects from the cutopen primary magnetic path, transverse edge effects from the differing widths between the primary lamination and secondary sheet, and half filled primary slots. This paper proposes an improved series equivalent circuit for this machine. The longitudinal end effects are estimated using three different impedances representing the normal, forwards and backwards flux density waves in the air-gap. The transverse edge effects accounted for with a correction coefficient K t and an air-gap flux density correction coefficient K b . Using the series circuit, the performance of the SLIM was assessed in a similar manner to a rotating induction machine. A 4 kW SLIM prototype was tested which validated the simulation technique.

An Improved Equivalent Circuit Model of a Single-Sided Linear Induction Motor

“…The flux density b y includes three parts: b 0 , b 1 and b 2 [22,[28][29][30][31][32]. b 0 is the normal traveling wave which moves forward in a similar manner to the fundamental flux density wave in a rotating induction machine (RIM).…”

“…The fundamental elements such as excitation current, electric field intensity and flux density are assumed to be sinusoidal shown below. From [27,32], the entrance and exit-wave elements, such as b 1 (x,t), b 2 (x,t), e 1 (x,t), e 2 (x,t), have similar forms. In order to simplify the derivation procedure, we can use the following equations to represent the current, air-gap flux density and electric fields: (16) where P is the factual number of pole pairs.…”

“…The half-filled slots at the ends of the machine are accounted for by use of the half-filled slot correction coefficient K p . These coefficients lead to small corrections in the fundamental and longitudinal end-effect impedances which make the performance analysis more accurate [27,32]. Because the derivation procedures are interminable, we could summarize their brief expressions here.…”

A new method to reduce end effect of linear induction motor

“…The distribution regularity of air-gap magnetic flux density along the x axis in an LIM is illustrated as Fig. 1 [12][13][14][15]. The thrust of the LIM, F x , is…”

Analysis and measure of novel stereo-garage driven by linear induction motor

“…Regarding LIMs, the thrust force and normal force under constant voltage excitation or constant current excitation are investigated by adopting the analytical electromagnetic field solution [4]- [7]. The biggest disadvantage is the calculation accuracy that is affected by many simplifications used for solving the complex mathematical operation.…”