Electrical Machine Drives Control An Introduction by Pyrhonen, Juha; Hrabovcova, Valeria; Semken, R. Scott | 9781119260455 | 1119260450 | Holooly

Electrical Machines

Electrical Machine Drives Control An Introduction

28 SOLVED PROBLEMS

Question: 8.1

Tuning the control of an electrically excited synchronous machine ...

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(derived by Dr.Pasi Peltoniemi, LUT, 2015) This ex...

Question: 11.1

Check whether a totally enclosed fan cooled (TEFC) motor, with S1 compliant motor power that is exceeded by 30%, can be applied to S3-25% duty in 10-minute cycles. The power factor at 130% is cosφ=0.87 and cosφ=0.85 at rated power. The effect of changing efficiency can be ignored. ...

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If the time constant of the subject machine is lon...

Question: 10.5

Derive(10.37). idref=ψsmaxref/√2La ...

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Differentiating the torque equation

T_{e} ...

Question: 11.4

Determine how DFIM behaviour changes as rotor voltage is reduced or increased by 1% unit from the no-load slip value of 0.25 pu. The per-unit rotor resistance is Rr=0.01, and the leakage inductance is Lrσ=0.1. ...

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The base slip and rotor voltage at DFIM no-load ar...

Question: 11.3

Show that fast changes are dictated by the effect of leakage in ductances. ...

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In the machine to be investigated, assume that Ls=...

Question: 11.2

Derive angular speed ωψrT of the rotor-flux-linkage reference frame Equation (11.51) using Equation (11.42). ...

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The equation for angular speed from Equation (11.4...

Question: 10.4

Figure10.8 shows power factor versus load angle for a SynRM motor drive at rated voltage and speed and saliency ratios of 5, 10, and 50. Check the operating point power factor versus load angle for the saliency ratio of 50 with Lq=0.2 pu at the rated voltage, current, and frequency. ...

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The RMS load angle Equation(10.1) can be written i...

Question: 10.3

Calculate power factor versus current angle for saliency ratios between 5 and 50 and Lq=0.2 at rated voltage, current, and frequency. Calculate the current angle at which the power factor reaches its maximum value and the maximum power factor at that current angle. ...

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Equation(10.26) is the basis for the power factor ...

Question: 10.2

Calculate the per-unit electromagnetic torque versus load angle for a saliency ratio between 5 and 50. Lq=0.27 at rated voltage and frequency. ...

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Equation (10.15) can be rearranged in terms of pe...

Question: 10.1

Draw a space-vector diagram of a SynRM, which has the following per unit parameters. Lmd=3, Lmq=0.2, Lsσ=0.1, us=1, is=1, ωs=1, ψs=1, ψmd=0.95, ψmq=0.18, and ψsσ=0.1. Calculate cosφ, Ld/Lq, the electric current components, load angle, current angle, and pu electromagnetic torque and power. ...

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The SynRM space-vector diagram was shown in Figure...

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