Detailed Design Procedures for PMSG Direct-Driven by Wind Turbines

  • Ahmed HebalaEmail author
  • Walid A. M. Ghoneim
  • Hamdy A. Ashour
Original Article


This paper is committed to show a well-ordered system used to design a permanent magnet synchronous generator (PMSG). The fundamental focus of this work is the generators which are in gearless configuration, and in the fragmentary or couple of kilowatts power range. A straight lumped-component based model is introduced, which is utilized for fundamental investigation and design. Later, a proposed comprehensive design strategy—stated with conditions, tables, design limits and practical recommendations—are presented in full details. Likewise, a flowchart is created to be later used as a Matlab M-File code for PMSG design. The outlined strategies are then authenticated through three case studies while being compared to the result from Finite Element Method (FEM) of Maxwell package. The three case studies are firstly, comparing the effectiveness of the procedures with a PMSG presented in literature. Secondly compared to a generator from the market. And finally using the procedure to implement a 1 kw prototype generator and validate the results with it. Such comparisons have validated the proposed procedures as a contributed step-by-step simple and reliable design tool for such cluster of PMSGs.


Finite element methods Design methodology Wind energy Permanent magnet generators 

List of Symbols

\(H_{m} , H_{s} , H_{g}\)

Flux intensity in magnet, steel, airgap (At/m)

\(L_{m} , L_{s} , L_{g}\)

Mean length of magnet, steel, airgap (m)

\(B_{m} , B_{s} , B_{g} B_{tooth} ,\), \(B_{core }\)

Flux density of magnet, steel, airgap, tooth, core (T)


Flux in core (Weber)

\(\mu_{0} ,\mu_{m} , \mu_{s}\)

Permeability of air, magnet, steel (H/m)

\(A_{m} , A_{s} , A_{g}\)

Area of magnet, steel, airgap (m2)

\(R_{outer} , R_{inner}\)

Outer radius, inner radius (m)

P, S, Q

Number of poles, slots, phases

\(f_{rated} , n_{rated} ,\)\(T_{rated} , P_{rated}\), \(\omega_{m\_rated}\)

Rated: frequency, speed, torque, output power, radial speed (Hz, rpm, Nm, Watt, rad/s)

SRo, SRi, RRo, RRi

Stator outer, inner radius, rotor outer, inner radius (m)

Lstk, \(lg\), \(lm\), dc

Length of stack, airgap width, magnet thickness, stator and rotor back iron (m)

Ds, ts, \(\tau_{s}\), bs0, bs1, bs2

Slot depth, teeth width, slot pitch, slot opening, slot upper, lower width (m)


Coil span (in slots)

\(N_{c} ,\)\(N_{s}\), ncpp, \(N_{tc}\), \(\hat{N}_{a}\)

Number of Coils, series coils, coils per phase, turns per coil, effective number of turns

\(V_{\varphi ,rated, } ,I_{\varphi }\), \(V_{no\_load }\)

Rated phase voltage, phase current, no-load phase voltage (V, A, V)

\(Z_{\phi } , R_{\phi } , XL_{\phi }\)

Phase impedance, resistance, reluctance (Ω)

\(Z_{\phi } , R_{\phi } , XL_{\phi }\)

Phase impedance, resistance, reluctance (Ω)

\(L_{\phi } ,Li_{g} , Li_{i1}\)

Inductance of phase, airgap, slot leakage (H)

\(kw\), PF, \(P_{a}\)

Winding factor, power factor, parallel paths

\(C_{csa}\),\(J_{s,copper }\), DW

Turn cross section area, copper ampacity (m2, A/m2), turn diameter (m)

\(\rho\), \(\rho_{cu}\), \(\rho_{stator}\), \(\rho_{rotor}\), \(\rho_{pm}\)

Density of copper, stator, rotor, PM (kg/m3)


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Copyright information

© The Korean Institute of Electrical Engineers 2019

Authors and Affiliations

  • Ahmed Hebala
    • 1
    Email author
  • Walid A. M. Ghoneim
    • 1
  • Hamdy A. Ashour
    • 1
  1. 1.Arab Academy for Science and Technology and Maritime TransportAlexandriaEgypt

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