Direct-Phase Variables Performance Analysis of Concentrated Winding Permanent Magnet Synchronous Generator with Capacitive Assistance

Аннотация

The dynamic and transient performance analysis of a three-phase interior rotor concentrated winding permanent magnet synchronous generator (CW-IPMSG) with was presented. In this paper. The study was done in direct-phase variables concentering only the fundamental magneto-motive force (MMF). The machine’s inductance was determined using winding function theory (WFT). The derived inductance was used to determine performance characteristics of the machine’s variables such as phase current, load current and electromagnetic torque. The study was validated in MATLAB/Simulink to observe the performance of the characteristics of the generator. The study was carried out at no-load condition, under load perturb, as well as increase and decrease of capacitor. It was observed that the permanent magnet synchronous generator had slightly better output performance with capacitor assistance. Keywords: Concentrated Winding; Direct-Phase Variables.; Inductance, Permanent Magnet; Winding Function Theory. Introduction: Most electric machines have distributed winding (DW). Distributed windings were preferred over The American Journal of Engineering and Technology 102 https://www.theamericanjournals.com/index.php/tajet the concentrated winding (CW) because the distributed the minimum capacitance requirements was also winding gives a sinusoidal uniform MMF [1-3]. proposed, and experiments were carried out to verify the analytical results. After that, attention was paid on In recent years electric machines with concentrated the capability of self-excitation in reluctance generator windings have become a competitive alternative to with different residual magnetisms in the rotor. machines with distributed windings for certain Different levels of residual rotor magnetism are applications. Machine with concentrated winding is achieved by different magnetizing DC currents. An easier and cheaper to manufacture because of the short indicative value of phase current was defined to ends winding feature. It has higher power density and determine the self-excitation, and the required good fault tolerance capabilities especially the minimum residual rotor magnetism for self-excitation in fractional-slot concentrated winding machine. Again, the reluctance generator connected with different machine with CW has higher slot fill factor and good capacitances was discussed. At last, the capability of efficiency compared to distributed winding permanent self-excitation in reluctance generators by connecting magnet (PM) machine [4]. A concentrated winding is charged capacitors was investigated. preferred for a cost-effective application which requires higher power density. Reference [9] presented a performance comparison of an interior mounted permanent magnet synchronous The benefits of concentrated windings and dual- generator (IPMSG) with a synchronous reluctance windings together have not been taken advantage of in generator with the same size for a wind application. It the synchronous reluctance motor. Previous researches was found that using the same geometrical dimensions, carried out on the synchronous reluctance motor a SynRG can convert 74 % of the power that an IPMSG considered the stator of the machine as having only can convert, while it has 80% of the IPMSG weight. distributed, or having distributed dual stator winding. Moreover, it is found that the efficiency for the IMPSG is 99 % at rated power compared to 98.7 % for the SynRG. Performance characteristic of permanent magnet synchronous motor (PMGM) with CW and DW was Reference [10] in their work, investigated the capability carried out. The study compared the performance of the of simple salient-pole rotor synchronous reluctance two arrangements using certain rotor parameters such generators at a 5 MW power level. Different salient pole as back EMF, resistance, efficiency, output torque etc rotor profiles are considered in the finite element design with two identical rotor dimensions. Parasitic optimization of the generator. It was found that with the characteristics such as cogging torque, torque pulsation, simple salient pole rotor, similar torque density and unbalanced magnetic force, mechanical vibration and efficiency are obtained as in published equivalent acoustic noise are always of significant concern during distributed flux barrier rotor reluctance synchronous the machine design. The parasitic effects could be generators. Also, potentially more harmful in CW PMSM since there are additional space harmonic contents in the stator MMF Reference [11] presented a performance comparison of distribution of the machine [5]. a 5MW interior permanent magnet synchronous generator (IPMSG) with a 5 MW PMa-SynRG with the The synchronous reluctance generator with transversely same stator, to be used for a wind energy application. It limited rotor has been studied. It was reported that the was found that PMa-SynRG has lower rotor weight as generator is more robust, and has relatively lower