advanced power sysytem1 170905 labmanuals

8/11/2019 Advanced Power Sysytem1 170905 Labmanuals

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LAB MANUALS

SUB: Advanced Power

System-I (170905)

BE. IV , Sem:-VII

Electrical Engineering

Department,

SCET, Surat.


2/22

Sarvajanik College of Engineering and Technology

Department of Electrical Engineering

B. E. IV SEMESTER VII/VIII

List of practicals

Advanced Power System-I

1) Find the Active, Reactive and Apparent power for 400 km long Transmission line

using matlab simulation.

2) Find the active, reactive and apparent power for a given transmission line parameters

using matlab programming.

3) Plot mid point voltage Vr, Vm and (load angle) as a function of (P/P0) for a 735KV

symmetrical lossless transmission line with l=0.932mh/km, c= 12.2 nf/km & line

length = 800 km, f= 50Hz using matlab programming.

4) To study the performance of Thyristor Controlled Reactor (TCR) using MATLAB.

5) Perform simulation ofthree phase 6-pulse converter for = 0, 30, 60, 90, 120 using

PSIM software with R load.

6) Perform simulation ofthree phase 6-pulse converter for = 0, 30, 60, 90 using PSIM

software with RL load.

7) Perform simulation of three phase 6-pulse converter with effect of source inductance

with PSIM software.

8) Perform simulation of three phase 12-pulse converter using MATLAB software with

R load.

9) To study the performance of Thyristor Switch Capacitor (TSC) using MATLAB.


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Department of Electrical Engineering, SCET

Subject: ________________Subject Code:__________________

LIST OF EXPERIMENTS AND RECORD OF PROGRESSIVE ASSESSMENT

Sr.No.

Name of Experiment PageNo.

Date ofPerformance

Date ofSubmission

Assessment(Max. Marks10)

Sign of Teacherand Remarks

Grade / Remarks for overall performance:

Date & Sign of Teacher:


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PRACTICAL 1

AIM: Find the Active, Reactive and Apparent power for 400 km long Transmission line.

THEORY:1. ACTIVE POWER

Active Power is also known as real power or simply power. Active power is

the rate of producing, transferring, or using electrical energy. It is measured in watts

and often expressed in kilowatts (KW) or megawatts (MW).

2. APPARENT POWERApparent Power is the product of the voltage (volts) and the current (amperes).It

comprises both active and reactive power .It is measured in volt-amperes(VA) and

often expressed in kilovolt-amperes (KVA) or megavolt-amperes (MVA).

3. REACTIVE POWER

In an AC system, such as inductive motors, transformers internal electrical energy

is required for magnetization. This internal stored energy is referred to as reactive

power is measured as volts amps reactive (VAR).

CIRCUIT DIAGRAM:


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WAVEFORM:

RESULT TABLE:

CONCLUSION WITH JUSTIFICATION:


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PRACTICAL 2

AIM:Consider a sinusoidal supply voltage v(t)=2.230 cos wt supplying a linear load ofimpedance Zl= 12+j13 at w= 2f radian/sec. & f=50hz. Express current i(t) as a function oftime based on v(t) and it:

1) Determine the following:

a) Instantaneous power p (t)

b)Instantaneous active power P (t)

c)Instantaneous reactive power Q (t)

2) Compute average real power P, Q and apparent power S & power factor.

3) Repeat the above when load is Zl= 12-j13, Zl= 12, & Zl= j13.4) Comment upon the result.

SOLUTION:


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MATLAB PROGRAM:

RESULTS:

CONCLUSION:


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PRACTICAL 3

AIM: Plot mid point voltage Vr, Vm and (load angle) as a function of (P/P0) for a 735KVsymmetrical lossless transmission line with l=0.932mh/km, c= 12.2 nf/km & line length =

800 km, f= 50Hz.

THEORY:

It is important to calculate the required additional reactive power to hold the receiving-end

voltage to 1 pu (735 kV). Let us assume that connected at the receiving end is a load of fixed

power factor 0.9 lagging. For any load condition, the reactive-power balance at the receiving-

end bus shown in Fig. ShowsQc Qr+Ql, whereQr is the reactive-power flow from thereceiving end into the line, Ql is the reactive-power component of the load, and Qc is the

reactive power needed from the system to holdVrto the rated value (1 pu).

Figure showsQr/P0,Ql/P0 andQc/P0 as functions ofP/P0. It should be observed that at no

load (P0), nearly 1090-MVAR or 0.557-pu reactive power must be absorbed to hold the

receiving-end voltage to 1 pu. To avoid overinsulating the line so that it might withstand

overvoltages under no-load or light conditions, a common practice is to permanently connect

shunt reactors at both ends to allow line energization from either end. Unfortunately, this

natural protection becomes a liability under increased load conditions, for extra reactive

power,Qc, is needed to hold the terminal bus voltages at the desired level. The midpoint

voltage of this line is calculated and typical voltage distribution on a distributed line.Alternatively, consider the receiving half of the line.

MATLAB PROGRAM:


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RESULT:

CONCLUSION:


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PRACTICAL 4

AIM: To study the performance of Thyristor Controlled Reactor (TCR) using MATLAB.

THEORY:

The Single-Phase TCR:

A basic single-phase TCR comprises an anti-parallelconnected pair of thyristor Valves,T1and T2, in series with a linear air-core reactor, as illustrated in Fig. The anti-parallel

connected thyristor pair acts like a bidirectional switch, with thyristor valveT1 conducting in

positive half-cycles and thyristor valveT2 conducting in negative half-cycles of the supply

voltage. The firing angle of the thyristors is measured from the zero crossing of the voltage

appearing across its terminals.

The controllable range of the TCR firing angle, a, extends from 90to 180. A firing angle of

90results in full thyristor conduction with a continuous sinusoidal current flow in the TCR.

As the firing angle is varied from 90to close to 180, the current flows in the form ofdiscontinuous pulses symmetrically located in the positive and negative half-cycles, as

displayed in Fig. 3.7. Once the thyristor valves are fired, the cessation of current occurs at its

natural zero crossing, a process known as theline commutation. The current reduces to zero

for a firing angle of 180. Thyristor firing at angles below 90 introduces dc components in the

current, disturbing the symmetrical operation of the two antiparallel valve branches.

A characteristic of the line-commutation process with which the TCR operates is that once

the valve conduction has commenced, any change in the firing angle can only be

implemented in the next half-cycle, leading to the so-called thyristor deadtime. The source

voltage be expressed asvs(t) =Vsin wt

whereVis the peak value of the applied voltage and q the angular frequency

of supply voltage. The TCR current is then given by the following differentialequation:

L *(di/dt) vs(t)=0

whereL is the inductance of the TCR. Integrating above Eq., we get,

i(t)= 1/L vs(t)dt+Cs

whereCis the constant Alternatively,

i(t) = V/wL* cos wt+C

For the boundary condition,i(wt=a)=0,

i(t) = (V/wL)*(cos a=coswt)

where athe firing angle measured from positive going zero crossing of the applied voltage.

Fourier analysis is used to derive the fundamental component of the TCR currentI1(a), which

in general, is given as

I1(a) =a1 cos wt+b1 sin wt


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CIRCUIT DIAGRAM:

RESULTS:

CONCLUSION:


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PRACTICAL 5

AIM: Perform simulation ofthree phase 6-pulse converter for = 0, 30, 60, 90, 120 usingPSIM software with R load.

PSIM BASICS:

THEORY of CONVERTER:


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3-Phase Thyristor Converter Waveforms

Zero ac-side inductance; purely dc current;DC-side voltage waveforms assuming

zero ac side inductance


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CIRCUIT DIAGRAM:

RESULTS:

CONCLUSION:


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PRACTICAL 6AIM: Perform simulation ofthree phase 6-pulse converter for = 0, 30, 60, 90 using PSIMsoftware with RL load.

THEORY:


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CIRCUIT DIAGRAM:


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RESULTS:

CONCLUSION:


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PRACTICAL 7AIM: Perform simulation of three phase 6-pulse converter with effect of source inductancewith PSIM software.

THEORY:

Three-Phase Thyristor Converter

AC-side inductance is included

10) Current Waveforms

Constant dc-side current


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PRACTICAL 9

AIM: To study the performance of Thyristor Switch Capacitor (TSC) using MATLAB.

THEORY:

The circuit shown in Fig. Consists of a capacitor in series with a bidirectional thyristorsswitch. It is supplied from an ideal ac voltage source with neither resistance nor reactance

present in the circuit. The analysis of the current

transients after closing the switch brings forth two cases:

1. The capacitor voltageis not equal to the supply voltage when the thyristors

are fired. Immediately after closing the switch, a current of infinite magnitude flows and

charges the capacitor to the supply voltage in an infinitely short time. The switch realized by

thyristors cannot withstand this stress and would fail.

2. The capacitor voltageis equal to the supply voltage when the thyristors

are fired. The analysis shows that the current will jump immediately to the value of the

steady-state current. The steady state condition is reached in an infinitely short time.

Although the magnitude of the current does not exceed the steady-state values, the thyristors

have an upper limit ofdi/dtvalues that they can withstand during the firing process. Here,

di/dtis infinite, and the thyristors switch will again fail.

It can therefore be concluded that this simple circuit of a TSC branch is not

suitable.

Switching a Series Connection of a Capacitor and Reactor

To overcome the problems discussed in the preceding list, a small damping

reactor is added in series with the capacitor, as depicted in Fig. Let thesource voltage be,

v(t) =Vsin w0 t

where q0 is the system nominal frequency. The analysis of the current after

closing the thyristor switch att=0 leads to the following result.

i(t) =IACcos(w0t+ ) nBC(VC0 (n2/n2 1)Vsin ). sin wn tIACcos cos wn t

where the natural frequency is,

wn =nw0 = 1/LCHere,VC0 is initial capacitor voltage att=0.


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CIRCUIT DIAGRAM:

RESULT:

CONCLUSION:

advanced power sysytem1 170905 labmanuals

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