FE-Aided Synchronization Analysis of Line-Start Synchronous Reluctance Motors

Abstract

Since line-start synchronous permanent magnet motors (LSPMs) entered the market, they have attracted research interest toward counterpart induction motors of low power-ratings. This paper reports an investigation of line-start synchronous reluctance motors (LS-SynRMs). LS-SynRMs has not been investigated as much as LSPMs have. A motor needs to maximize rotor saliency to achieve high efficiency and a high power-factor. This results in complicated rotor geometry because the rotor cage and multiple flux barriers share the same rotor space. This paper provides an approximate method based on steady state torque analysis by which to estimate the critical inertia of a LS-SynRM. A finite element analysis (FEA)-aided analytical approach to the approximation of steady state torque is proposed to replace the more typical approach based on equivalent circuit parameters. The critical inertia resulting from the proposed method is compared to the results obtained using the FEA.

Line-Start Synchronous Reluctance Motor With V-Shaped Rotor Laminations

“…The relation between the three-phase variables associated with the stator windings and the rotor arbitrary frame are well presented in [23]. Figure 12 illustrates the steady state d-and q-axis equivalent circuital models of the LS-SynRM [24]. The voltage equations that describe the electrical characteristic of the LS-SynRM in rotating arbitrary reference frame are stated by [24]- [26]:…”

“…Figure 12 illustrates the steady state d-and q-axis equivalent circuital models of the LS-SynRM [24]. The voltage equations that describe the electrical characteristic of the LS-SynRM in rotating arbitrary reference frame are stated by [24]- [26]:…”

“…The Electromagnetic torque developed at asynchronous speed by the SynRM with cage rotor is stated by [24], [26]:…”

“…This torque pulsates at twice the slip frequency during starting phase of the motor [4], [30]. Its magnitude 𝑇 𝑟𝑒𝑙 depends on the difference between the d-axis and q-axis magnetizing inductances as expressed in (15) [24]. On the other hand the asynchronous torque 𝑇 𝑎𝑠𝑦 is generally expressed as in ( 16) [24].…”