The effect of the three level neutral point clamped (NPC) inverter on the core loss of a synchronous reluctance machine (SynRM)

The effects of the three level inverter on the core losses of a SynRM are investigated particularly at the stator yoke and tooth. A comparative study on the effects of space vector pulse width modulated (SV-PWM) two and three level inverter on the iron/core loss are analyzed. A SynRM stator made of silicon steel, M36, 0.35 mm thickness is used. The machine was driven from a two and three level inverters and the current waveforms where used in the finite element model so as to capture the flux densities. The SynRM stator was then excited by these flux density waveforms obtained from the FE model. Tests were conducted at 30 Hz, 60 Hz and 180 Hz and there was an approximate 6 % reduction in core losses at 180 Hz under a three level inverter drive. The reduction in core losses were significant on the stator tooth than on the stator yoke. The use of a three level inverter will reduce the burden of the cooling system on the machine.

[1]  N. Takahashi,et al.  Behavior of Minor Loop and Iron Loss Under Constant Voltage Type PWM Inverter Excitation , 2012, IEEE Transactions on Magnetics.

[2]  Gyu-Hyeong Cho,et al.  DSP based space vector PWM for three-level inverter with DC-link voltage balancing , 1991, Proceedings IECON '91: 1991 International Conference on Industrial Electronics, Control and Instrumentation.

[3]  Francesco Profumo,et al.  Energetic behavior of soft magnetic materials fed by inverter supply , 1992, Conference Record of the 1992 IEEE Industry Applications Society Annual Meeting.

[4]  Paolo Ferraris,et al.  Induction motor iron losses measurement with a static converter supply using a slotless rotor test bench , 1994 .

[5]  Nabeel A. O. Demerdash,et al.  Simulation of inverter-fed induction motor drives with pulse-width modulation by a time-stepping coupled finite element-flux linkage-based state space model , 1999 .

[6]  Francesco Profumo,et al.  Iron losses in magnetic materials with six-step and PWM inverter supply (induction motors) , 1991 .

[7]  Jie Zhang.  High performance control of a three-level IGBT inverter fed AC drive , 1995, IAS '95. Conference Record of the 1995 IEEE Industry Applications Conference Thirtieth IAS Annual Meeting.

[8]  Frede Blaabjerg,et al.  Thermal optimised modulation methods of three-level neutral-point-clamped inverter for 10 MW wind turbines under low-voltage ride through , 2012 .

[9]  Michele Pastorelli,et al.  ABOUT THE POSSIBILITY OF DEFINING A STANDARD METHOD FOR IRON LOSS MEASUREMENT IN SOFT MAGNETIC MATERIALS WITH INVERTER SUPPLY , 1996 .

[10]  M. Pastorelli,et al.  About The Choice of The Reference Magnetic Quantity in Presence of Non Sinusoidal Waverforms , 1997, 1997 IEEE International Magnetics Conference (INTERMAG'97).

[11]  Naoyuki Kurita,et al.  Loss Estimation Method for Three-Phase AC Reactors of Two Types of Structures Using Amorphous Wound Cores in 400-kVA UPS , 2014, IEEE Transactions on Power Electronics.

[12]  P. Pillay,et al.  Lamination core losses in motors with nonsinusoidal excitation with particular reference to PWM and SRM excitation waveforms , 2005, IEEE Transactions on Energy Conversion.

[13]  Pragasen Pillay,et al.  Three level NPC inverter DC capacitor sizing for a synchronous reluctance machine drive , 2014, 2014 IEEE Energy Conversion Congress and Exposition (ECCE).

[14]  Marian P. Kazmierkowski,et al.  Control of Three-Level PWM Converter Applied to Variable-Speed-Type Turbines , 2009, IEEE Transactions on Industrial Electronics.

[15]  A.M. Hava,et al.  A novel neutral point potential stabilization technique using the information of output current polarities and voltage vector , 2001, Conference Record of the 2001 IEEE Industry Applications Conference. 36th IAS Annual Meeting (Cat. No.01CH37248).

[16]  Andrea Cavagnino,et al.  Predicting iron losses in soft magnetic materials with arbitrary voltage supply: an engineering approach , 2003 .

[17]  M. Pastorelli,et al.  Induction and synchronous reluctance motors comparison , 2008, 2008 34th Annual Conference of IEEE Industrial Electronics.

[18]  Don-Ha Hwang,et al.  Loss distribution of three-phase induction motor fed by pulsewidth-modulated inverter , 2004 .

[19]  Ruifang Liu,et al.  Modeling of Eddy-Current Loss of Electrical Machines and Transformers Operated by Pulsewidth-Modulated Inverters , 2008, IEEE Transactions on Magnetics.