Date post: | 07-Aug-2018 |
Category: |
Documents |
Upload: | tapas-chaudhuri |
View: | 219 times |
Download: | 0 times |
of 15
8/20/2019 GOVERNOR Basics
1/37
Governor Control Systems, Inc.
Knowledge. Experience. People
Prime Movers and Governors Basics
8/20/2019 GOVERNOR Basics
2/37
Slide 2
Agenda
Introduction to Prime Movers
Gas Turbines
Steam Turbines
Natural Gas Engines
Diesel Engines
Governor Basics
8/20/2019 GOVERNOR Basics
3/37
Slide 3
Introduction to Prime Movers
8/20/2019 GOVERNOR Basics
4/37
Slide 4
Prime Mover Introduction
Prime Mover Definition: An initial source of motive
power (as a waterwheel, turbine, or engine) designed
to receive and modify force and motion as supplied
by some natural source and apply them to drive
machinery.
Before we can understand what a governor is or how
a governor works, here is a quick introduction of the
prime movers that use governors.
8/20/2019 GOVERNOR Basics
5/37
Slide 7
Example of Hydro Turbine
8/20/2019 GOVERNOR Basics
6/37
Slide 8
Example of Hydro Turbine
Hydro-electricity begins with a water source, which all or part is
diverted through a powerhouse. This creates energy.
The water flows down the penstock through the wicket gates.
The governor controls the amount of water to the turbine
blades, causing the rotation of the turbine which drives the load
or generator.
The distance the water falls (head) and the volume of the water
source is directly related to the generating capacity.
The water then leaves the powerhouse in a swirling motion,
called tail water, and continues down river.
8/20/2019 GOVERNOR Basics
7/37Slide 9
Example of a Steam Turbine
Boiler
Three Phase
Power
Condenser
8/20/2019 GOVERNOR Basics
8/37Slide 10
Example of a Steam Turbine
High pressure steam flows from the boiler at approximately 600
psi and 850 degrees Fahrenheit to the steam chest and onto the“Nozzles” or “First Stage”. The control system governs theamount of this steam flow.
Nozzles then direct the steam flow to the rotating blades or“Buckets”. Between each rotating “Stage” is a fixed nozzle
which directs the expanding steam to the next row of blades.Exhaust steam, reduced in pressure and temperature to about35 psi and 340 degrees Fahrenheit is condensed back to waterand returned to the boiler.
There are many other types of steam turbines; Extraction,
Double Extraction, Backpressure...
8/20/2019 GOVERNOR Basics
9/37Slide 11
Example of a Gas Turbine
Compressor
Section
Air Intake
Combustion
Section
Power
Turbine
SectionExhaust
A simple gas turbine is comprised of three main sections
Air is drawn in the front of the turbine and compressed. The compressed air is then mixed with
fuel, and burned. The control system governs the amount of fuel being burned.
The resulting hot gas expands and is forced through the power turbine creating horsepoweror work.
The power turbine section is connected to the load.
There are many other types of gas turbines; Aero Derivative, 2-Shaft, 3-Shaft ...
8/20/2019 GOVERNOR Basics
10/37Slide 12
Example of a Natural Gas Engine
Natural gas can be a single gas or a mixture of methane, ethane,
propane, or other type of gases.
Natural gas is brought in through a fuel mixer (carburetor) to the fuel
manifold. The control system governs the amount of fuel being used by
the engine.
The air/fuel is brought into the cylinders on the Intake stroke,
compressed on the Compression stroke, and ignited. This drives thepiston down in the Power stroke, which rotates the crank shaft. The
crank shaft drives the load.
Exhaust is ported on the Exhaust stroke.
8/20/2019 GOVERNOR Basics
11/37Slide 13
Example of a Diesel Engine
8/20/2019 GOVERNOR Basics
12/37Slide 14
Example of a Diesel Engine
The Intake stroke acts as a positive displacement pump and draws air
into the piston.The piston then compresses the air on the Compression stroke.
At the top of the Compression stroke, diesel fuel is injected, throughinjectors. The control system regulates the amount of fuel beingdelivered to the injectors. The Air-Fuel mixture ignites, expanding, anddriving the piston down. This is called the Power stroke. Work is
extracted from the piston on the power stroke.
As the piston ascends, exhaust gasses are ported on the Exhauststroke.
The four cycles are then repeated.
Other types of diesel engines are, Two-stroke, Turbo-charged, Naturallyaspirated.
8/20/2019 GOVERNOR Basics
13/37
Slide 15
Section Two
Why Do We Need Governors?
What Is A Governor
History of the Governor
Simple Mechanical Governor
Hydraulic-Mechanical Governor
Droop and Isochronous
8/20/2019 GOVERNOR Basics
14/37
Slide 16
Introduction to GovernorsFlyBall Governor EGB-2P Act./ Gov.
723 Plus Digital Control MicroNet Digital Control
EGB-13P Act./ Gov. EG-3P Actuator L-Series Speed Control
2301A Load Sharing
And Speed Control
Atlas Control
2301D Load Sharing And Speed Control
CLOSETOOVERRIDELOSSOFSPEED
SIGNAL
OPENFORMINFUEL
CLOSEFOR
RATED
ACTUATOR
20-40VDCSUPPLY
15WMAXCB
AUX
LOADSIGNAL
LOADSHARING
LINES
SPEEDTRIMOR
JUMPER
SPMSYNCINPUT
SPEEDSIGNALINPUT
COM
CTCTCTNOTUSED
A
0 1 2 3 4 5 6 7 8 9 1 0 1 1 12 1 3 14 1 5 16 1 7 1 8 19 2 0 21 2 2 23 2 4 25 2 6 27 2 8 29
RATEDSPEEDGAIN
ACTUATORCOMPENSATION
LOWIDLESPEED
0 10
LOADGAINDROOP
®UL
LOWVOLTAGE2301A LOADSHARING& SPEEDCONTROL
WARNING:MORETHANONELIVECIRCUIT.SEEDIAGRAM. ADVERTISSEMENT:CETEQUIPMENTRENFERNEPLUSIEURSCIRCUITSSOUSTENSION.VOIRLESCHEMA.
LISTEDIND.CONT.EQ.61N6
CB
0 10 (10T)0 10
0 10RAMPTIME
0 100 10
0 10RESET
®®
STARTFUELLIMIT
0 10
FWDSINGLE
200 mA
REVTANDEM
20 mA
FT.COLLINS, COLORADO,
HOOFDORP,THE
CAMPINAS,S.P.,BRAZIL
SLOUGH,BERKS, ENGLAND
SYDNEY,AUSTRALIA
TOMISATO, CHIBA, JAPAN
400mA
P A RT N O. S E RI A LNO.
SPEED RANGE (HZ)
WARNING
SPEEDRANGEFACTORYSETFOR2000 HZTO 6000 HZ. REFER
TO INSIDECOVERTO CHANGE
SPEEDRANGEANDPREVENTPOSSIBLEOVER-SPEED.
WARNING
®
GND
INTERNALCTBURDENMUSTBE
CONNECTEDACROSSPOWERSOURCECURRENT
TRANSFORMERSATALLTIMESTOPREVENTLETHALHIGHVOLTAGE
90-240VACPT
A B C
W DOODWAR
DPG Speed Control
EPG Speed Control EPG Actuator
8/20/2019 GOVERNOR Basics
15/37
Slide 18
What is a Governor ?
Governor Definition:
An attachment to a machine for automatic control or limitation ofspeed.
A device giving automatic control (as of pressure or temperature).
A Governor is a device which controls the energy source to a prime
mover to control its power for a specific purpose.
Basic governors sense speed and sometimes load of a prime moverand adjust the energy source to maintain the desired level.
Governors are often referred to as Control Systems and consist of an
electronic control and an actuator.
8/20/2019 GOVERNOR Basics
16/37
Slide 19
DESIRED SPEED
ACTUAL SPEED
Constant Load
8/20/2019 GOVERNOR Basics
17/37
Slide 20
Constant Load
The driver of the car is the control or governor.
The speed limit sign is the desired speed setting.
The speedometer senses actual speed.
The driver compares desired speed to actual speed, If they are the
same, fuel is held steady.
If desired speed and actual speed are different, the fuel setting isadjusted by the driver to make actual speed equal desired speed.
Fuel is held steady until a speed or load change occurs.
8/20/2019 GOVERNOR Basics
18/37
Slide 21
Increased Load
8/20/2019 GOVERNOR Basics
19/37
Slide 22
Increased Load
The car starts up the hill, load increases, speed decreases.
The actual speed is less than desired speed.
Driver increases the fuel to increase the speed, which returns the
actual speed to the desired speed.
Before the actual speed reaches the desired speed, the driver reduces
the fuel to prevent overshoot of speed. This is called Compensation
and is adjusted to match the response time of the prime mover.
It takes more fuel to pick up load than to maintain load.
8/20/2019 GOVERNOR Basics
20/37
Slide 23
Decreased Load
8/20/2019 GOVERNOR Basics
21/37
Slide 24
Decreased Load
The car starts down the hill, load decreases, speed increases.
Actual speed is greater than desired speed.
Driver decreases fuel to decrease speed, which returns the actualspeed to desired speed.
Before the actual speed reaches the desired speed, the driverincreases the fuel to prevent overshoot of speed. This is called
Compensation and is adjusted to match the response time of the primemover.
8/20/2019 GOVERNOR Basics
22/37
Slide 25
Closing the Loop
Actual Speed
or Load
ControlOf The
Energy
Desired Speed or
Load Reference
8/20/2019 GOVERNOR Basics
23/37
Slide 26
Closing the Loop
The governor functions the same as the car driver.It automatically changes the Fuel Flow to maintain the desired speed or
load.
Closed Loop Definition: When used as an automatic control system for
operation or process in which feedback in a closed path or group of
paths to maintain output at a desired level.If parameter(s) of the loop change, it will effect the entire loop and fuel
will automatically be corrected to maintain the desired set point.
8/20/2019 GOVERNOR Basics
24/37
Slide 27
History of the Governor
James Watt, b. Jan. 19, 1736, d. Aug. 25,
1819, was a Scottish engineer and inventor
who played an important part in the
development of the steam engine as a
practical power source.
James Watt invented the centrifugal or flyball
governor in 1788. The governor
automatically regulated the speed of an
engine. It embodied the feedback principle of
a servo-mechanism, linking output to input,
which is the basic concept of automation.
8/20/2019 GOVERNOR Basics
25/37
Slide 28
History of the Governor
Amos Woodward patented hisunique waterwheel governor in
May 1870.
8/20/2019 GOVERNOR Basics
26/37
Slide 35
Oil Pump and Hydraulic Force
Supply Oil
Relief
Valve High Pressure Oil
29 Ft.- Lbs
13 Ft.- Lbs
3 Ft.- Lbs
Positive
DisplacementOil Pump
8/20/2019 GOVERNOR Basics
27/37
Slide 36
Oil Pump and Hydraulic Force
Positive Displacement Oil Pump
The positive displacement oil pump develops flowby carrying oil between the teeth of two meshedgears.
Oil is carried around the outside of the gears, andas the teeth mesh together, the oil is pressurized
and forced out.
Hydraulic ForceThe amount of force a hydraulic cylinder cangenerate is equal to the hydraulic pressure timesthe “effective area” of the cylinder.
Using the formula F = P x A can determine theoutput work Force, if Pressure and effective Areaare known.
8/20/2019 GOVERNOR Basics
28/37
Slide 37
Simple Droop Governor
8/20/2019 GOVERNOR Basics
29/37
Slide 39
Droop Curve
8/20/2019 GOVERNOR Basics
30/37
Slide 40
Droop Curve
Droop Definition: A decrease in desiredspeed setpoint for an increase in load
or output servo position (feedback).
Droop Calculation:
% DroopNo Load Speed - Full Load Speed
Rated Speed
X 100=
8/20/2019 GOVERNOR Basics
31/37
Slide 41
Droop versus Isochronous
Droop or
Isochronous?
8/20/2019 GOVERNOR Basics
32/37
Slide 42
Droop versus Isochronous
Droop:Isolated system load sharing with droopgovernors.
Isochronous - Droop Load Sharing
Droop - Droop Load sharing
Droop Base Load to the Utility Grid with droopgovernors.
Isochronous:Used on Isolated or Islanded systems.
Isochronous load sharing using electroniccontrols.
Isochronous Base Load to the Utility Grid usingelectronic controls.
8/20/2019 GOVERNOR Basics
33/37
Slide 43
Isochronous Definition
Isochronous
ISO + CHRONOS = SAME + TIME
Constant Speed
No change in speed setting with a change
in load.
Usually used in isolated or islanded
load applications (not tied to the utilitygrid).
8/20/2019 GOVERNOR Basics
34/37
Slide 44
Isochronous Curve
8/20/2019 GOVERNOR Basics
35/37
Slide 45
What Happens if I Don’t Have Droop?
UtilityLoad
Utility
PRIME
MOVER
Generator
MechanicalFlyballGovernor
UtilityTie
Breaker
8/20/2019 GOVERNOR Basics
36/37
Slide 47
Generator Tied to Utility Grid
8/20/2019 GOVERNOR Basics
37/37
Generator Tied to Utility Grid
When the governor is in droop, as the
speed reference is increased, fuel isapplied to the engine, the engine
converts the fuel to torque.
The torque is applied to the generator
and current or power is produced.