Appendix

A. Parameters of the Simulation Models

Table 9.A.1

Parameters of the Simplified Model (Turbine and Generator)

ParameterValue
Density area, ρ (kg/m)1.225
Nominal mechanical power, Pm,n (MW)5
Radius of the turbine, R (m)63
Nominal wind speed, vn (m/s)12
Gain of the multiplier, G97
Inertia of the turbine, Jt (kg/m)35.44 × 106
Inertia of the generator, Jg (kg/m)534.116
Shaft spring constant, K (N/m/rad)867.64 × 106
Shaft mutual damping, D (N/m/s/rad)6.217 × 106
Hydraulic time constant, τH (s)0.05

Table 9.A.2

Parameters of the Detailed Model

ParametersSCIG 2 kWSCIG 149.2 kWDFIG 1.5 MW
Grid
Effective voltage, Vs (V)380460610
Frequency, fs (Hz)505050
Transformer
Leakage resistance, Rf (Ω)3.40.13
The leakage inductance, Lf (mH)3.322.5
Turbine
Density area, ρ (kg/m2)1.2251.2251.225
Nominal mechanical power, Pm,n (kW)2.68149.21.5
Radius of the turbine, R (m)1.410.535
Nominal wind speed, vn (m/s)121211
Gain of the multiplier, G2.44531217.180675
SCIG and DFIG
Nominal frequency, fg,n (Hz)505050
Stator resistance, Rs (mΩ)485014.8512
Stator leakage inductance, Lls (mH)160.302713.7
Rotor resistance, Rr (mΩ)38059.29521
Rotor leakage inductance, Llr (mH)160.302713.7
Cyclic mutual inductance, Lm (mH)25810.4613.5
Inertia, J  (kg/m2)0.0313.11000
Viscous friction coefficient , f (Nm s/rad)0.001140.080.0024
Number of pole pairs, p222
Table Continued

image

ParametersSCIG 2 kWSCIG 149.2 kWDFIG 1.5 MW
DTC-SVM
Flux hysteresis band, Δφimage±0.01 Wb
Torque hysteresis band, ΔTemimage±0.5 Nm
SVM switching frequency (Hz)20002000

image

Table 9.A.3

Parameters of the PI Controllers

ParametersSCIG 2 kWSCIG 149.2 kW
DTC-SVPWM Control Block
Proportional gain of speed controller, Kp130
Integral gain of the speed controller, Ki15.872200
Proportional gain of torque controller, Kpt21.5
Integral gain of torque controller, Kit150100
Proportional gain of flux controller, Kpf200250
Integral gain of flux controller, Kif12004000
DC-Side Control Block
Proportional gain of DC voltage controller, Kpdc22
Integral gain of DC voltage controller, Kpdc2533.33
Source-Side Control Block
Proportional gain of current controller, Kpc66
Integral gain of current controller, Kic45004.50

image

Table 9.A.4

Parameters of the PI Controllers of the IFOC Blocks

IFOC Control Block
Regulator ParametersSCIG 2 kW
Proportional gain of current controller, Kpc1
Integral gain of current controller, Kic15.872

image

B. Influence of Order 3 Harmonic on the Behavior of the SVPWM

In three phase, harmonics can be reduced without reducing the amplitude of the output voltage because the harmonic of order 3 or a multiple of 3 are eliminated from output voltages. A harmonic of order 3 can be added to a sinusoid of frequency f to form the reference waveform. This harmonic appears in the three fictitious voltages Vao, Vb0, and Vc0with respect to the fictitious midpoint 0, but does not appear in the phase output voltages Van, Vbn, and Vcn and line-to-line output voltages Vab, Vbc, and Vca.
The addition of harmonic of order 3 increases the maximum amplitude of the fundamental in the output voltages.
With reference to Fig. 9.B.1, the reference voltage is composed of two sinusoids: one for the fundamental and the other for the harmonic of order 3.
The new reference signal for the PWM is:

(VaVo)w=U2(MIsin(ωt)+ksin(3ωt))

image (9.B.1)

This is called suboptimal control.
The maximum value of MI occurs for k=1/33image and is found as:

MImax=23

image (9.B.2)

image
Figure 9.B.1 Suboptimal SVPWM. (A) Triangular carrier Vt(t) and reference (Va  Vo)w. (B) Control pulse for phase i(where i = a, b, c).
Therefore, with suboptimal control, the maximum amplitude of the fundamental output voltage V1 corresponding to MImax is:

V1,MImax=2/3Vdc

image (9.B.3)

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