EE463-Static Power Conversion-I

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# EE-463 STATIC POWER CONVERSION-I

# 3-Phase Controlled Rectifiers

## Ozan Keysan

## [keysan.me](http://keysan.me)

### Office: C-113 <span class="meta">•</span> Tel: 210 7586

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# Review
## N-Phase Half Wave Rectifier

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# Review

## 3-Phase Half Wave Diode Rectifier

<img src="./images/ee463/3ph_half_bridge_voltage.png" alt="Drawing" style="width: 600px;"/>
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# Review

## 3-Phase Half Wave Diode Rectifier Average Voltage?
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## \\(V\_{dc}= \dfrac{3\sqrt{6}}{2 \pi} V\_{ph,rms}\\)

###or

## \\(V\_{dc}= \dfrac{3\sqrt{2}}{2 \pi} V\_{ll,rms}\\)
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# Half-bridge Thyristor Rectifier

<img src="http://www.nainasemi.com/img/power-modules4.jpg" alt="Drawing" style="width: 700px;"/>
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# Half-bridge Thyristor Rectifier

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# Half-bridge Thyristor Rectifier

## Average Voltage?
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## \\(V\_{dc(\alpha)}= \dfrac{3\sqrt{6}}{2 \pi} V\_{ph,rms} cos (\alpha)\\)

###or

## \\(V\_{dc(\alpha)}= \dfrac{3\sqrt{2}}{2 \pi} V\_{ll,rms} cos (\alpha)\\)

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# Full-bridge Thyristor Rectifier

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# Full-bridge Thyristor Rectifier

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## Diode Rectifier (or \\(\alpha=0\\))

<img src="https://upload.wikimedia.org/wikipedia/commons/2/2e/3_phase_rectification_2.svg" alt="Drawing" style="width: 350px;"/>
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# Full-bridge Thyristor Rectifier

### Remember output voltage follows line to line voltages!

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# Full-bridge Thyristor Rectifier

### Remember output voltage follows line to line voltages!

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# Full-bridge Thyristor Rectifier

## Non-zero firing angle
--

<img src="./images/ee463/3phase_full.png" alt="Drawing" style="width: 700px;"/>
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# Full-bridge Thyristor Rectifier

## Non-zero firing angle
--

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# Output Voltage vs. Firing Angle
--

<img src="./images/ee462/3phase_thyristor_0.png" alt="Drawing" style="width: 800px;"/>
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# Output Voltage vs. Firing Angle

<img src="./images/ee462/3phase_thyristor_30.png" alt="Drawing" style="width: 800px;"/>
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# Output Voltage vs. Firing Angle

<img src="./images/ee462/3phase_thyristor_60.png" alt="Drawing" style="width: 800px;"/>
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# Output Voltage vs. Firing Angle

<img src="./images/ee462/3phase_thyristor_90.png" alt="Drawing" style="width: 800px;"/>
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# Output Voltage vs. Firing Angle

<img src="./images/ee462/3phase_thyristor_120.png" alt="Drawing" style="width: 800px;"/>
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# Output Voltage vs. Firing Angle

<img src="./images/ee462/3phase_thyristor_150.png" alt="Drawing" style="width: 800px;"/>
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# Output Voltage vs. Firing Angle

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# Full-bridge Thyristor Rectifier

## Average output voltage?

<img src="./images/ee463/3ph_thyristor_nonzero2.png" alt="Drawing" style="width: 800px;"/>
--

### \\(V\_{d(\alpha)}= \dfrac{3\sqrt{2}}{\pi} V\_{ll,rms} cos (\alpha)\\)

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# Full-bridge Thyristor Rectifier

## What about the current?
--

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## Current Waveform: No triple harmonics
#### Comparison: <a href="https://www.google.com.tr/?gfe_rd=cr&ei=XqrmWLLjEc-z8weYuJvgDA&gws_rd=ssl#q=sin(x)%2Bsin(3x)/3%2Bsin(5x)/5%2Bsin(7x)/7%2Bsin(9x)/9%2Bsin(11x)/11%2Bsin(13x)/13%2Bsin(15x)/15%2Bsin(17x)/17">Single Phase</a>, <a href="https://www.google.com.tr/?gfe_rd=cr&ei=warmWK-gCM-z8weYuJvgDA&gws_rd=ssl#q=sin(x)-sin(5x)/5-sin(7x)/7%2Bsin(11x)/11%2Bsin(13x)/13-sin(17x)/17-sin(19x)/19">Three Phase</a>
--

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## Current Waveform:

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# Full-bridge Thyristor Rectifier

## Current Waveform: 
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## Fundamental RMS:  \\(I_{s1}=\frac{\sqrt{6}}{\pi}= 0.78 I_d\\)
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## Total RMS:  \\(I_{s}=\sqrt{\frac{2}{3}} I_d = 0.816 I_d\\)

## THD= 31.08 %

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# Effect of Ls (Commutation)
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# Effect of Ls (Commutation)

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# Commutation: \\(\alpha =0 \\), \\(L\_s =0 \\)

<img src="https://upload.wikimedia.org/wikipedia/commons/9/91/Bridge_rectifier_at_alpha%3D0_u%3D0.png" style="width: 700px;"/>
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# Commutation: \\(\alpha =0 \\), \\(L\_s > 0 \\)

<img src="https://upload.wikimedia.org/wikipedia/commons/1/18/Bridge_rectifier_at_alpha%3D0_u%3D20.png" style="width: 700px;"/>
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# Commutation: \\(\alpha =20 \\), \\(L\_s > 0 \\)

<img src="https://upload.wikimedia.org/wikipedia/commons/7/7c/Bridge_rectifier_at_alpha%3D20_u%3D20.png" style="width: 700px;"/>
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# Commutation: \\(\alpha =40 \\), \\(L\_s > 0 \\)

<img src="https://upload.wikimedia.org/wikipedia/commons/6/6d/Bridge_rectifier_at_alpha%3D40_u%3D20.png" alt="Drawing" style="width: 700px;"/>
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# Effect of Ls (Commutation)

<img src="./images/ee463/3ph_thyristor_commutation.png" alt="Drawing" style="width: 800px;"/>
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# Effect of Ls (Commutation)
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### \\(A_u = \omega Ls Id\\)  (repeats itself every \\(\pi/3\\))
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### \\(V\_{d(\alpha)}= \dfrac{3\sqrt{2}}{\pi} V\_{ll,rms} cos (\alpha) - \dfrac{ 3 \omega Ls Id}{\pi}\\)

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# Effect of Ls (Commutation)
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### Introduces a voltage drop on the rectified side

- ### Single Phase: \\(\dfrac{2\omega L_s}{\pi}I_a\\)
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- ### Three Phase: \\(\dfrac{3\omega L_s}{\pi}I_a\\)
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- ### Resultant voltage in a 3-ph rectifier:

### \\(V\_{d\alpha}= \dfrac{3\sqrt{2}}{\pi}V\_{l-l} cos (\alpha) - \dfrac{3\omega L_s}{\pi}I_a \\)

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# Inverter Mode of Operation

## Two Quadrant Operation

### Two quadrant operation with source side voltage (i.e. DC motor)
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## How can you obtain four-quadrant operation?
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## Use two separate converters

### Ref: Mohan Chapter 13 DC Motor Drives
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## How can you obtain four-quadrant operation?

## Use two separate converters

### Ref: Mohan Chapter 13 DC Motor Drives

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## You can download this presentation from: [keysan.me/ee463](http://keysan.me/ee463)