EE362-Electromechanical Energy Conversion-II

class: center, middle

# EE-362 ELECTROMECHANICAL ENERGY CONVERSION-II

# Synchronous Machines

## Ozan Keysan

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

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

---

# Full Equivalent Circuit with Field Circuit

<img src="./images/synch_full_circuit.png" alt="Drawing" style="width: 800px;"/>

---
# Lagging Power Factor (no field control)

<img src="./images/sync_lagging_pf.png" alt="Drawing" style="width: 450px;"/>

### As load increases, \\(V_t\\) considereably decreases: [Animation](https://andymikeknight.github.io/machines/synchronous/sg_standalone.html)

#### Assumptions: Speed constant, \\(I_f\\) constant
---
# Unity Power Factor (no field control)

<img src="./images/sync_unity_pf.png" alt="Drawing" style="width: 600px;"/>

### As load increases, \\(V_t\\) slightly decreases: [Animation](https://andymikeknight.github.io/machines/synchronous/sg_standalone.html)

#### Assumptions: Speed constant, \\(I_f\\) constant
---
# Leading Power Factor (no field control)

<img src="./images/sync_leading_pf.png" alt="Drawing" style="width: 550px;"/>

### As load increases, \\(V_t\\) slightly increases: [Animation](https://andymikeknight.github.io/machines/synchronous/sg_standalone.html)

#### Assumptions: Speed constant, \\(I_f\\) constant
---
## Standalone Operation of a Synchronous Generator
--

## Two Independent Control Loops

## As electrical load increases, we should increase the mechanical input power: To keep the speed constant

## As current increases, we should control the field current (for constant terminal voltage)

---
# Parallel Operation Synchronous Generators
--

<img src="https://andymikeknight.github.io/machines/images/synch/parallel_gens.gif" alt="Drawing" style="width: 700px;"/>
---

# Parallel Operation Synchronous Generators

<img src="http://ndstudies.gov/energy/level2/files/level2/img/module04/iStock_000000730824Medium_hoover_dam_turbines-optimized.jpg" alt="Drawing" style="width:700px;"/>

---
# Conditions for Closing the Switch?

<img src="./images/synch_parallel.png" alt="Drawing" style="width: 600px;"/>

---
# Conditions for Closing the Switch?
--

- ## Equal Terminal Voltage
--

- ## Equal Frequency
--

- ## Co-Phasal (Zero phase angle difference)
--

- ## Same Phase Sequence
--

# Can you propose a very simple method to check all these?
---
# Synchronizing Lamps

<img src="https://2.bp.blogspot.com/-jYu7UJqhZEs/UVsJeEb2IdI/AAAAAAAADrE/4iLAs9ubjvg/s1600/Capture.PNG" alt="Drawing" style="width: 800px;"/>
--

### Industrial Method: [Synchronoscope](https://youtu.be/FI_07YVS3tY?t=34s), [Sync to Grid](https://www.youtube.com/watch?v=sgBzQaH5pWY)
---
## Grid Synchronization

<iframe width="600" height="400" src="https://www.youtube.com/embed/xGQxSJmadm0" frameborder="0" allowfullscreen></iframe>

#### [Synchronization at Sarıyar Hydro Electric Power Station](https://www.icloud.com/photos/#06dxESFkrO-GPCg3Ae12OM-9g)

#### [Photos](https://www.icloud.com/photos/#06fK-zftt65rIN_ndNEPPcovQ), [Photos](https://www.icloud.com/photos/#0a0MwnEqaPSANIphFfM6na50Q), [Photos](https://www.icloud.com/photos/#066IGyElPdVmM1KrhrQLjyL1Q)
---
# Grid Synchronization

<iframe width="600" height="400" src="https://www.youtube.com/embed/sgBzQaH5pWY" frameborder="0" allowfullscreen></iframe>

---
## Synchronous Generator Connected to Infinite Bus

# Infinite Bus ??

<img src="https://www.megabus.co.za/wp-content/uploads/2017/02/a107ddc47fadb1bfd370c093607f7b6b.jpg" alt="Drawing" style="width: 700px;"/>

---
# Infinite Bus:

<img src="https://www.researchgate.net/profile/Abdul_Hameed_Kalifullah/publication/236009431/figure/fig1/AS:363465500839938@1463668336782/Single-Machine-connected-to-infinite-bus-system.png" alt="Drawing" style="width: 600px;"/>

## An electric source so large that voltage and frequency assumed to be constant independent of power flow

---
## Synchronous Generator Connected to Infinite Bus

<img src="https://www.eeeguide.com/wp-content/uploads/2016/01/Synchronous-Machine-on-Infinite-Bus-Bars-002.jpg" alt="Drawing" style="width: 700px;"/>

## Constant Terminal Voltage and Speed

---
## Synchronous Generator Connected to Infinite Bus

<img src="https://andymikeknight.github.io/machines/images/synch/inf_bus_vf.gif" alt="Drawing" style="width: 700px;"/>

## Constant Terminal Voltage and Speed

---
## Synchronous Generator Connected to Infinite Bus

# \\(\vec{E\_f} = \vec{V\_t} \pm (R\_a + j X\_s)\vec{I\_a}\\)

## \\(+\\): Generating

## \\(-\\): Motoring

## \\(V\_t\\): Constant (Infinite Bus)

---
## Synchronous Generator Connected to Infinite Bus

## Neglect \\(R\_a\\) for simplicity

## Constant Terminal Voltage

## Let's Have a Look at the Phasor Diagram
---
# Constant Excitation, Variable Load (Circle Diagram)

## \\(I_f\\) constant, \\(E_f\\) magnitude constant
--

## \\(\vec{E\_f} = \vec{V\_t} + j X\_s\vec{I\_a}\\)
--

## \\(\vec{I\_a} = \dfrac{\vec{E\_f}-\vec{V\_t}}{jX\_s} \\)
--

## [Animation](https://andymikeknight.github.io/machines/synchronous/sg_p_infinite_bus.html)
---
# Constant Power, Changing Excitation
--

# Power = 
--
 \\(P = 3 V\_t I\_a cos (\theta)\\) 
--
 
## \\(P\\)  constant, \\(V\_t\\) constant
--

## \\(I\_a cos (\theta)\\) constant!
--

## From geometry: \\(E\_f sin (\delta) = X\_s I\_a cos (\theta)\\)  = Constant
--

## [Animation](https://andymikeknight.github.io/machines/synchronous/sg_p_infinite_bus.html)

---
# Power of a Synchronous Machine
--

## We already showed: \\(E\_f sin (\delta) = X\_s I\_a cos (\theta)\\)

### Note: We neglected \\(R\_a\\)
--

## Write Power equation in terms of \\(E\_f\\)
--

# \\(P = 3 V\_t  I\_a cos (\theta) \\)
---

# Power of a Synchronous Machine

## We already showed: \\(E\_f sin (\delta) = X\_s I\_a cos (\theta)\\)

### Note: We neglected \\(R\_a\\)

## Write Power equation in terms of \\(E\_f\\)

# \\(P = \dfrac{3 V\_t E\_f sin(\delta)}{X\_s}\\)
---

# Power of a Synchronous Machine

# \\(P = \dfrac{3 V\_t E\_f sin(\delta)}{X\_s}\\)
--

## What about Torque?
--

### Neglect losses (core, copper etc)

# \\(P = T \omega\_s\\)
---

# Torque of a Synchronous Machine

# \\(T = \dfrac{P}{\omega\_s }\\)

# \\(T = \dfrac{3 V\_t E\_f sin(\delta)}{X\_s \omega\_s }\\)
---
# Torque of a Synchronous Machine

## Remember the previous weeks:
--

## \\(T = T\_{max} sin (\delta)\\)
--

## \\(T\_{max} = \dfrac{3 V\_t E\_f}{X\_s \omega\_s }\\)
---

# Torque of a Synchronous Machine

## \\(T\_{max} = \dfrac{3 V\_t E\_f}{X\_s \omega\_s }\\)

<img src="http://i.stack.imgur.com/DmWrO.png" alt="Drawing" style="width: 450px;"/>

---
# Generalized Power Transfer in AC Systems

## \\(P = \dfrac{3 V\_t E\_f sin(\delta)}{X\_s}\\)

<img src="./images/ee362/ac_transmission.png" alt="Drawing" style="width: 500px;"/>

---
# Generalized Power Transfer in AC Systems

## In Transmission Systems

<img src="https://www.ssen-transmission.co.uk/globalassets/projects/bdsamplepictures-040-2.jpg" alt="Drawing" style="width: 600px;"/>
---
# Generalized Power Transfer in AC Systems

## In Wireless Communication

<img src="http://cdn4.explainthatstuff.com/how-antennas-work.png" alt="Drawing" style="width: 600px;"/>
---
# Generalized Power Transfer in AC Systems

## In Wave Energy Converters

<img src="https://www.emec.org.uk/wp-content/uploads/2012/04/8T1Y3729-2.jpg" alt="Drawing" style="width: 850px;"/>

#### [Pelamis WEC Operation](https://www.youtube.com/watch?v=JYzocwUfpNg), [Full Story](https://www.youtube.com/watch?v=ziLtIbwFXB8)

---
# Power Flow

# DC Systems:

## Power flows from high potential to low potential

--

# AC Systems:

## Power flows from leading voltage source to lagging voltage source (sign of load angle, \\(\delta\\) determines the direction of power flow)

---

## You can download this presentation from: [keysan.me/ee362](http://keysan.me/ee362)