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 !