EE463-Static Power Conversion-I

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# EE-463 STATIC POWER CONVERSION-I

# 3-Phase Diode Rectifiers

## Ozan Keysan

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

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

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## 3-Phase Half Wave Rectifier
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### N-Phase Generalized Form
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## 3-Phase Half Wave Rectifier

## Voltage Waveforms

<img src="./images/ee463/3ph_half_bridge_voltage.png" alt="Drawing" style="width: 600px;"/>
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## 3-Phase Half Wave Rectifier

## [Try Yourself](./interactive/three_phase_rectifier_explorer.html)
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## 3-Phase Half Wave Rectifier

## Average Voltage?

## \\(V\_{dc}= \dfrac{3\sqrt{6}}{2 \pi} V\_{rms}\\)

### = 270 V for a 400V grid

### Comparison with the single phase rectifier?

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## 3-Phase Half Wave Rectifier

## Disadvantages:

- ### All current passes through the neutral line

- ### DC current in transformer windings

- ### A ripple of 163 V at 150 Hz

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## 3-Phase Full Wave (Bridge) Rectifier
## also called 6-pulse rectifier

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## 3-Phase Full Wave (Bridge) Rectifier
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## 3-Phase Full Wave (Bridge) Rectifier

### Ignore Ls and redraw
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## 3-Phase Full Wave (Bridge) Rectifier

### Can you draw the voltage and current waveforms?
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<img src="./images/ee463/3ph_diode_voltage.png" alt="Drawing" style="width: 800px;"/>
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## 3-Phase Full Wave (Bridge) Rectifier

### Can you draw the voltage and current waveforms?

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## 3-Phase Full Wave (Bridge) Rectifier

## Average voltage?
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: Twice the half-wave rectifier value

## \\(V\_{dc}= \dfrac{3\sqrt{6}}{ \pi} V\_{ph}\\)

### or
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## \\(V\_{dc}= \dfrac{3\sqrt{2}}{ \pi} V\_{l-l} = 1.35 V\_{l-l}\\)

### =540 Vdc for a 400 V grid

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## 3-Phase Full Wave (Bridge) Rectifier

### Output voltage waveforms

## [Try Yourself](./interactive/three_phase_rectifier_explorer.html)
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<img src="./images/ee463/3ph_diode_current.png" alt="Drawing" style="width: 800px;"/>
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## What about the current waveforms?

### What are the differences wrt single phase?
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### No 3rd order harmonics!
### Phase currents cancel each other, zero neutral line current.

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# Comparison of Rectifiers

| Type                | Vout | \\(\Delta\\)Vout | \\(f\_{ripple}\\) |
|:---------------------:|:------:|:---------:|:---------:|
| **Single Phase**        | \\(\;\dfrac{2\sqrt{2}}{\pi}V\_{ph}\\) = 207 V    |  \\(\;\sqrt{2} V\_{ph} = 325 V\\)       |      100 Hz           |
| **3-phase Half-wave** |  \\(\;\dfrac{3\sqrt{2}}{2\pi}V\_{l-l}\\) = 270 V |   \\(\;\dfrac{\sqrt{2}}{2} V\_{ph} = 162.5 V\\)    |  150 Hz  |
| **3-phase Full Bridge** |  \\(\;\dfrac{3\sqrt{2}}{\pi}V\_{l-l}\\) = 540 V  |  \\(\;( 1-\frac{\sqrt{3}}{2}) \sqrt{2}V\_{l-l} = 75.8 V\\)  |  300 Hz  |
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# Commutation in 3-Phase Rectifiers

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# Commutation in 3-Phase Rectifiers
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## [Try Yourself](./interactive/three_phase_rectifier_explorer.html)
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# Commutation in 3-Phase Rectifiers
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## [Try Yourself](./interactive/three_phase_rectifier_explorer.html)
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### Average Voltage

## Without Commutation

### \\(V\_{dc}= \dfrac{3\sqrt{2}}{ \pi} V\_{l-l} = 1.35 V\_{l-l}\\)
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## With Commutation

### \\(V\_{dc}= \dfrac{3\sqrt{2}}{ \pi} V\_{l-l} - \dfrac{3}{\pi}\omega L_s I_d\\)

### [More info](http://www.ehu.eus/electronica-industrial/ElectronicaIndustrial_Automatica/apuntes/overlap1.pdf)

### [Try simulation with commutation](./interactive/three_phase_rectifier_explorer.html?Ls=2&Id=40)

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