DISTRIBUTED GENERATION SYSTEM
ECE 610
ENERGY CONVERSION)
GROUP MEMBERS :
- CANSU SENER
- RAVI NALAM
- KARTHIK KODALI
ABSTRACT :Modelling and simulation of a synchronous generator which is being run by a prime mover of a steam turbine or any conventional energy plant supplying a load of 100 KVA. Half of this load demand is supplemented an alternative energy source which is a combination of Photovoltaic panels and wind turbines in turn reducing the usage of conventional energy source raw materials thus by reducing the pollution caused of them. While connecting different energy sources to a common load it is necessary that they should be operating at same voltage and frequency levels along with the phase difference for a safer and reliable operation of the whole system. Filters are used to reduce the ripples and distortion in the output of the converters cause of high switching frequencies.
INTRODUCTION
• This projects mainly focuses on presenting a schematic of a
distributed energy system which has been increasingly
chosen as a complete alternative or an adjunct for an already
existing system of conventional central power stations for a
better environment and reliable source of energy.
• This integration of different smart sources of energy calls for
a better interfacing technologies which are robust, safe and
reliable for the both integration itself and better control of
the whole system which is with the help of power electronic
devices.
OVERVIEW:• Modelling and simulation of Synchronous
Generator
• Modelling and Simulation of Voltage Controlled Source with the help of PWM
• Passing through the Low-Pass Filter for reducing the ripples and High frequency components
• Analyzing and Synchronization of outputs of the both
• Connecting to the common load, In which half of the load is supplied by each.
CONTROL STRATEGY:
Figure 1: Schematic Figure 2: Block Diagram
MODELLING OF THE GENERATOR
Figure 3: q - axis
Figure 5: 0 - axis
Figure 4: d - axis
Figure 7: Winding configurationsFigure 6: fd - axis
EQUATIONS AND BLOCK DIAGRAM
Stator voltage: (2-1)
(2-2) (2-3)
Rotor voltage:
(2-4) (2-5) (2-6) (2-7)
(2-9)
(2-10)
Stator flux:
(2-11)
Rotor flux:
(2-12)
(2-13)
(2-14)
Torque equations:
(2-15)
(2-18)
(2-8)
EQUATIONS AND BLOCK DIAGRAM
(2-21)
(2-22)
(2-23)
(2-24)
(2-26)
(2-25)
(2-28)
PARK’S EQUATION
(2-27)
MODELLING OF CONTROLLED VOLTAGE SOURCE
(2-28) (2-29) (2-30)
(2-31) (2-32)
(2-33)
The pole voltages are given as,, can be defined as a function of the state of switches as:
And their respective output voltages,,are defined as :
BLOCK DIAGRAM AND EQUATIONSWhere Vn0 is the neutral voltage and is given as:
(2-34)
The state of switches is defined based on the input voltage () (2-35) (2-36)
Here for a balanced three phase system sum of output voltages will be zero. (2-37)
LOW-PASS FILTER• Output of the voltage controlled source is distorted and with full of ripples, harmonics from high level
switching from the converter circuit. • So, we pass the output of the VCS through a low pass filter to eliminate the high frequency components
of the output wave signal.• In this case which is a Low-Pass RC filter. The above figure shows the output of the three phase
controlled voltage passed through the filter.
• PWM control strategy along with the RC low pass filter connected to resistive load. The state of switches is defined using.
• This value is based on the input reference voltage and Vdc values. Any offset values of the reference voltage are corrected to be half of Vdc value to provide accurate switching.
SYNCHRONOUS GENERATOR OUTPUTS
0.5 0.55 0.6 0.65 0.7 0.75 0.8-600
-400
-200
0
200
400
600vabcs
Time (seconds)
Synchro
nous G
enera
tor
Voltages
Vas
VbsVcs
0.5 0.55 0.6 0.65 0.7 0.75 0.8-80
-60
-40
-20
0
20
40
60
80iabcs
Time (seconds)S
ynchro
nous G
enera
tor
Curr
ents
Ias
IbsIcs
Figure 8: 3-Phase voltage outputs for synchronous generator
Figure 9: 3-Phase current outputs for synchronous generator
CONTROLLED VOLTAGE SOURCE OUTPUT
0.5 0.55 0.6 0.65 0.7 0.75 0.8-600
-400
-200
0
200
400
600vlpf
Time (seconds)
Low
Pass F
ilte
r V
oltages
Vlpfa
VlpfbVlpfc
Figure 10: Voltages of low pass filter outputs
SYNCHRONIZATION OF OUTPUTS
0.5 0.55 0.6 0.65 0.7 0.75 0.8
-600
-400
-200
0
200
400
600
vas vs vlpa
Time (seconds)
Synchro
niz
ed P
hase A
Voltages
Vas
Vlpfa
0.5 0.55 0.6 0.65 0.7 0.75 0.8
-600
-400
-200
0
200
400
600
vbs vs vlpb
Time (seconds)
Synchro
niz
ed P
hase B
Voltages
Vbs
Vlpfb
0.5 0.55 0.6 0.65 0.7 0.75 0.8
-600
-400
-200
0
200
400
600
vcs vs vlpc
Time (seconds)
Synchro
niz
ed P
hase C
Voltages
Vcs
Vlpfc
Figure 11: Harmonized outputs for phase “a” Figure 12: Harmonized outputs for phase “b”
Figure 13: Harmonized outputs for phase “c”
RESULT: SUPPLYING TO THE COMMON LOAD
Figure 14: Power Output
100 KVA Load
50 KVA
50 KVA
=+
COMPARISON AND HOW VARIABLES AFFECT EACHOTHER
In this section we will be comparing power that synchronous generator produces and the power that low pass filter produces. To do this we change the input values which are mechanical torque, speed, Vdc and V10.
Table 1: Effect of changing R-load values
0.8 0.85 0.9 0.95 1 1.05 1.1 1.15 1.2-600
-400
-200
0
200
400
600vabcs
Time (seconds)
Synchro
nous G
enera
tor
Voltages
0.8 0.85 0.9 0.95 1 1.05 1.1 1.15 1.2-600
-400
-200
0
200
400
600vlpf
Time (seconds)
Low
Pass F
ilte
r V
oltages
Figure 15: Vabcs when R load is 5ohms Figure 17: Vlpf when R load is 5ohms
0.8 0.85 0.9 0.95 1 1.05 1.1 1.15 1.2
-800
-600
-400
-200
0
200
400
600
800
vabcs
Time (seconds)
Synchro
nous G
enera
tor
Voltages
0.8 0.85 0.9 0.95 1 1.05 1.1 1.15 1.2-600
-400
-200
0
200
400
600vlpf
Time (seconds)
Low
Pass F
ilte
r V
oltages
Figure 18: Vlpf when R load is 20ohmsFigure 16: Vabcs when R load is 20ohms
Table 2: Effect of changing values
0.95 1 1.05 1.1 1.15
-800
-600
-400
-200
0
200
400
600
800
vabcs
Time (seconds)
Synchro
nous G
enera
tor
Voltages
0.8 0.85 0.9 0.95 1 1.05 1.1 1.15 1.2-600
-400
-200
0
200
400
600vlpf
Time (seconds)
Low
Pass F
ilte
r V
oltages
0.95 1 1.05 1.1 1.15
-800
-600
-400
-200
0
200
400
600
800
vabcs
Time (seconds)
Synchro
nous G
enera
tor
Voltages
0.8 0.85 0.9 0.95 1 1.05 1.1 1.15 1.2-600
-400
-200
0
200
400
600vlpf
Time (seconds)
Low
Pass F
ilte
r V
oltages
Figure 5.5 Vabcs when TL is 1000 Figure 5.6 Vlpf when TL is 1000
Figure 5.7 Vabcs when TL is 250 Figure 5.8 Vlpf when TL is 250
CONCLUSIONWe successfully modelled and simulated the synchronous machine and Voltage controlled source along with the PWM mechanism, thus connecting them together to a load of 100 KVA in which each half is supplied by the synchronous machine and Voltage controlled source which is generated by the photovoltaic and wind turbines.
This schematic can be implemented on a big scale with successful operation, In advancement to this schematic where we synchronize the output of a generator along with the voltage controlled source’s output it is very important that both the voltages are in phase with exact same amplitude and frequency we can use a PLL (Phase Locked Loop) strategy which automatically detects the phase of the incoming circuit and acts as a switch to connect two systems in synchronization.
So, this whole new schematic can be a great help in regulate the pollution cause by the conventional power plants.
Thank you !
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