Analysis of starting and synchronization process for line start IPM motors
This paper presents an improved analytical method for determining the synchronizing capability of a line start interior permanent magnet (IPM) synchronous motor. Approximate solution techniques based on average torque analysis for determining the critical slip and maximum inertia are also presented. A dynamic d-q axis model of the motor is developed to investigate the run-up response as well as synchronization capability of line start IPM synchronous motors. The start-up and synchronization performances of a 1hp 208V 4-pole line start IPM motor for various loads have been obtained using MATLAB. Experimental investigations have been also carried out for the same 1 hp IPM motor and test results are presented to support simulation results.
Pull-in criterion for reluctance motors
The behaviour of reluctance machines during synchronisation and attempted synchronisation is carefully examined. Critical modes of synchronisation are identified, and, based on these, a pull-in criterion is developed. This enables the possible combinations of inertia and load torque that any given motor can synchronise to be simply and reliably predicted. Evaluation of the criterion can be carried out manually, making it entirely suitable for routine design purposes. The accuracy of the criterion is established by comparison with a wide range of transient solutions.
Influence of Space Harmonics on Starting Performance of a Single-Phase Line Start Permanent-Magnet Motor
In this paper, we investigate the effects of space harmonics of single-phase line start permanent-magnet (LSPM) motors on starting performance. We construct an equivalent electric circuit considering the harmonics for the analysis, in which the magnetostatic field computation is coupled with finite-element modeling. We analyze the starting characteristics by circuit simulation and show that the results compare well with those of time-step finite-element analysis and of experiments.