Solid State Controller of Drives_Experiment

7/28/2019 Solid State Controller of Drives_Experiment

1/37

Department Of Electrical& Electronics Engineering, VITS Indore 1

Vindhya Institute of Technology & Science, Indore

Name: - Roll No: -

Class: - Department: - Electrical &Electronics

Subject: -Solid State Controllers of Drives Subject Code: - MEPE201

Signature of Student: - Signature of Professor:-

Experiment No: - 1

Objective:-

To study & analysis of Single Phase Fully Uncontrolled Rectifier Fed

DC Drive by using MATLAB.

Apparatus required:-

MATLAB, Simpower System Toolbox.

Theory:-

MATLAB:-

MATLAB (Matrix laboratory) is an interactive software system for numerical

computations and graphics. As the name suggests, MATLAB is especially designed for matrix

computations: manipulating arrays, solving systems of linear equations, computing Eigen values

and eigenvectors, factoring matrices, and so forth. In addition, it has a variety of graphical

capabilities: plotting data, creating animations, creating user interfaces, and can be extended

through programs written in its own programming language.

In order to simulate a model, the model is converted to a set of differential equations. The solver

functions are used to compute solutions for those equations at different time intervals, giving the

model's states and outputs over a span of time. You can then plot these outputs from your

simulation.


2/37


Single Phase Fully Uncontrolled Rectifier:-

A single-phase full-wave rectifier consists of four

diodes arranged is called a bridge. This rectifier circuit produces an output waveform that is the

positive half of the incoming a voltage waveform and the inverted negative half.

The bias path for the positive output pulse is through diode D1, then the load, thenD4, and back

to the other side of the power supply. The current flow through the load is in the down direction

for the figure shown. Diodes D2and D3are reverse-biased during this part.

The bias path for the negative cycle of the input waveform is through diode D3, then the load,

thenD2, and back to the opposite side of the power supply. The current flow through the load

resistor is once again down. That is, it is flowing through the load in the same direction as during

the positive cycle of the input waveform. Diodes D1and D4 are reverse-biased during this part.The resulting output waveform is a series of positive pulses without the gaps of the half-wave

rectifier output.

The split supply full wave single phase rectifier offers as good performance as possible from a

single phase rectifier in terms of the output voltage form factor and ripple factor. They have a

few disadvantages however. These are:-

>They require a split power supply which is not always available.

>Each half of the split power supply carries current for only one half cycle. Hence they are

underutilized.

>The ratio of the required diode PIV to the average output voltage is rather high.

The mathematical expression of DC output voltage is:-

Fig 1.1 Single phase uncontrolled full bridge rectifier with R, L, E load


3/37


Rectifier Fed Dc Drives:-

In dc drives, the dc motor is controlled by the dc voltage V0

applied to its terminals .the convertor consists of two bi-directional swicting power-poles,which

are pulsewidth modulated .allowing the power(and hence the current) through this convertor to

be bi-directional facilities the machine to operate both in motor & as well in its genertator

mode.in either direction of rotation ,in terms of average terminal quantities .motoring mode in

the forward direction rotation is represented by quadrant 1 with positive voltage & current while

rotating in the forward direction ,this machine can be slowed down by making the machine go

into its generator mode in which the power flow reverse ,as in quadrant 2 with a positive voltage

& a negative current. Motoing in the reverse direction of rotation requires voltage & current both

negative ,corresponding to quadrant 3 ,while rotating in the reverse direction ,the generator mode

in quadrant4 slows down the machine.

.

Fig1.2 Rectifier Fed Dc Drives


4/37


Waveforms:-

I. Continuous Conduction Mode:-

II. Discontinuous Conduction Mode:-

Fig 1.3 Single phase uncontrolled full bridge rectifier waveforms


5/37


Simulation & Result:-

Simulation

Fig 1.4 Single phase uncontrolled full bridge rectifier fed DC Motor (simulated diagram)

Parameter:-Vi/p = 230 v

F = 50 Hz

R = 10

L = 0.7 H

E = 100V


6/37


Result

1. Voltage waveform

2. Current Waveform

Fig 1.5 Output Voltage and Current Waveform

Conclusion:-


7/37



Name: - Roll No: -




Experiment No: - 2

Objective:-

To study & analysis of Single Phase Fully-Controlled Convertor Fed




Theory:-

MATLAB:- MATLAB (Matrix laboratory) is an interactive software system for numerical



and eigenvectors, factoring matrices, and so forth.




simulation.


8/37


Single Phase fully-controlled Convertor

Single phase fully controlled converters are widely

used in many industrial applications. They can supply unidirectional current with both positive

and negative voltage polarity.

It is one of the most popular converter circuits and is widely used in the speed control of

separately excited dc machines. The single phase fully controlled bridge converter is obtained by

replacing all the diode of the corresponding uncontrolled converter by thyristors. Thyristors T1

and T2

are fired together while T3

and T4

are fired 180 after T1

and T2. From the circuit diagram

it is clear that for any load current to flow at least one thyristor from the top group (T1, T

3) and

one thyristor from the bottom group (T2, T

4) must conduct. It can also be argued that neither

T1T

3nor T

2T

4can conduct simultaneously.

For the same reason T1T

4or T

2T

3can not conduct simultaneously. Therefore, the only possible

conduction modes when the current i0

can flow are T1T

2and T

3T

4. Of course it is possible that at

a given moment none of the thyristors conduct. This situation will typically occur when the load

current becomes zero in between the firings of T1T

2and T

3T

4. Once the load current becomes

zero all thyristors remain off. In this mode the load current remains zero. Consequently the

converter is said to be operating in the discontinuous conduction mode

Fig 3.1 Single phase Fully-controlled convertor with R, L, E Load


9/37


Convertor Fed Dc Drives:-

In dc drives, the dc motor is controlled by the dc voltage V0

applied to its terminals .the convertor consists of two bi-directional swicting power-poles,which

are pulsewidth modulated .allowing the power(and hence the current) through this convertor to

be bi-directional facilities the machine to operate both in motor & as well in its genertator mode.

In either direction of rotation ,in terms of average terminal quantities .motoring mode in the

forward direction rotation is represented by quadrant 1 with positive voltage & crrent .while

rotating in the forward direction ,this machine can be slowed down by making the machine go

into its generator mode in which the power flow reverse ,as in quadrant 2 with a positive voltage

& anegative current.motoing in the reverse direction of rotation requires voltage & current both

negative ,corresponding to quadrant 3 ,while rotating in the reverse direction ,the generator

mode in quadrant4 slows down the machine.

.

Fig3.2 Convertor Fed Dc Drives


10/37


Waveforms:-

III. Continuous Conduction Mode:-

IV. Discontinuous Conduction Mode:-

Fig 3.3 Single phase Fully-controlled convertor waveforms


11/37



Simulation

Fig 3.4 Single phase fully controlled converter fed dc drive (simulated diagram)

Parameter:-

Vi/p = 230 v

F = 50 Hz

R = 10

L = 0.7 H

E = 100V


12/37


Result

1. Voltage Waveform

2. Current Waveform

Fig 3.5 Output Voltage & Current Waveform

Conclusion :-


13/37



Name: - Roll No: -




Experiment No: - 3

Objective:-

To study & analysis of Single Phase Semi-controlled Convertor Fed




Theory:-

MATLAB:- MATLAB (Matrix laboratory) is an interactive software system for numerical



and eigenvectors, factoring matrices, and so forth.




simulation.


14/37


Single Phase Semi-controlled Convertor

A single phase semi converter feeds the armature

circuit. it is a one quadrant drive and is limited to application up to 15KW.the converter in the

field circuit can be a semiconverter.the current waveforms for a highly inductive load.

The complexity of the circuit is not reduced, however. For that, two of the thyristors of a single

phase fully controlled converter has to be replaced by two diodes as shown in Figure2.1. The

resulting converters are called single phase half controlled converters. As in the case of fully

controlled converters, the devices T1

and D2

conducts in the positive input voltage half cycle after

T1

is turned on. As the input voltage passes through negative going zero crossing D4

comes into

conduction commutating D2

in Figure2.1. The load voltage is thus clamped to zero until T3

is

fired in the negative half cycle. As far as the input and output behavior of the circuit is concerned

the circuits in Figure are identical although the device designs differs. However, in this Figure

both the thyristors and the diodes carry current for half the input cycle.

Fig 2.1 Single phase Semi-controlled convertor with R, L, E load


15/37


Convertor Fed Dc Drives:-

In dc drives, the dc motor is controlled by the dc voltage V0 applied to its

terminals .the convertor consists of two bi-directional swicting power-poles,which are pulse

width modulated .allowing the power(and hence the current) through this convertor to be bi-

directional facilities the machine to operate both in motor & as well in its genertator mode.

.Fig2.2 Convertor Fed Dc Drives

Waveforms:-

V. Conduction Mode:-


16/37


VI. Discontinuous Conduction Mode:-

Fig 2.3 Single phase Semi-controlled convertor waveforms


17/37



Simulation

Fig 2.4 Single phase uncontrolled full bridge converter fed DC Motor (simulated diagram)

Parameter:-

Vi/p = 230 v

F = 50 Hz

R = 10

L = 0.7 H

E = 75 V


18/37


Result

1. Voltage Waveform

2. Current waveform

Fig 2.5 Output Waveform

Conclusion :-


19/37



Name: - Roll No: -




Experiment No: - 4

Objective:-

Simulation and Modeling of DC Motor are using MATLAB.

Apparatus Required: -Software MATLAB Toolbox.

Theory: -

About MATLAB Software-:

MATLAB is a programming environment for algorithm development, data analysis,

visualization, and numerical computation. Using MATLAB, you can solve technical computing

problems faster than with traditional programming languages, such as C, C++, and FORTRAN.

MATLAB is a high-performance language for technical computing. It integrates computation, visualization, and

programming in an easy-to-use environment where problems and solutions are expressed in familiar

mathematical notation

About Speed Control of DC Motor-The DC motor input armature voltage (Vt) summed with

the internal EMF. The result is then fed into the electrical characteristics transfer function block


20/37


to produce the armature current (Ia). It is then pass through a torque constant to produce torque.

This is then summed with a torque load, giving an output torque which is then fed into the

mechanical characteristics transfer function block. The output is the rotor speed (Wm), which is

fed back into the speed constant providing the constant EMF.

DC motors are used to drive mechanical loads. Some applications require that the speed remain

constant as the mechanical load is applied to the motor changes. On the other hand, some

applications require that the speed be controlled over a wide range. The speed equation of DC

Motor is;

Simulation Model:-

Result:-


21/37


Q.1 Write a mathematical expression for speed control method of DC Motor.

Q.2 Find the transfer function of DC Motor.


22/37



Name: - Roll No: -




Experiment No: - 5

Objective: -Simulation of DC Motor using 3-phase fully controlled converter with PSIM 9.1

Apparatus Required: -Software PSIM 9.1, Power Electronics & Drive Toolbox.

Theory: -

About PSIM Software- PSIM is the leading simulation and design software for power

electronics, motor drives, and dynamic system simulation. With fast simulation and easy-to-use

interface, PSIM provides a powerful and efficient environment to meet your simulation needs.

About Three Phase full converter-The three phase fully controlled converter has been probably

the most widely used power electronic converter in the medium to high power applications. The

controlled rectifier can provide controllable output dc voltage in a single unit instead of a three

phase. The controlled rectifier is obtained by replacing the diodes of the uncontrolled

rectifier with thyristors. Control over the output dc voltage is obtained by controlling the

conduction interval of each thyristor. This method is known as phase control and convertersare also called phase controlled converters. Since thyristors can block voltage in both

directions it is possible to reverse the polarity of the output dc voltage and hence feed power

back to the ac supply from the dc side.

In phase controlled rectifiers though the output voltage can be varied continuously the load

harmonic voltage increases considerably as the average value goes down. Of course the

magnitude of harmonic voltage is lower in three phase converter compared to the single phase


23/37


circuit. Since the frequency of the harmonic voltage is higher smaller load inductance leads to

continuous conduction. Input current wave shape become rectangular and contains 5th

and

higher order odd harmonics.

Simulation Model:-


24/37


Results:-


25/37



Name: - Roll No: -




Experiment No: - 6

Objective: -Simulation of DC Series Motor using 1-phase Semi controlled Rectifier with

PSIM 9.1


Theory: -

About PSIM Software-

PSIM is the leading simulation and design software for power electronics, motor drives, anddynamic system simulation. With fast simulation and easy-to-use interface, PSIM provides a

powerful and efficient environment to meet your simulation needs.

About Semi converter Control of DC Motor-

A single phase semi converter feeds the armature circuit. it is a one quadrant drive and is limited

to application up to 15KW.the converter in the field circuit can be a semiconverter.the current

waveforms for a highly inductive load.

A single phase semi converter bridge with two thyristor and three diodes as shown in figure

alongside the two thyristor are T1, T2 ; The two diodes are D1,D2 the third diode connected

across load is freewheeling diodes FD. The load is of RLE type. Various voltage and current

waveforms for this converter are shown in fig. where load current is assumed continuous over

the working range.


26/37


Working - At 0t thyristor T1 is forward biased only when source voltage exceeds E. thus,

T1 is triggered at a firing angle delay such that sinVm E .with T1 on, load gets connected to

source through T1 and D1 for period t to load current Io flows through RLE, D1

,source and the load terminal voltage Vo is of the same wave shape ac the source voltage Vs.

soon after t ,load voltage Vo tends to reverse as the ac source voltage changes polarity

just as Vo tends to reverse(at t ) ,FD is forward biased and starts conducting. The loador output current Io is transferred from T1, D1 to FD. As SCR T1 is reversed biased at t

through FD, T1 is turned off at t .the load terminals are short circuited through FD;

therefore load, or output, voltage Vo is zero during ( )t . after t ,during the

negative half cycle .T2 will be forward biased only when source voltage is more than E.

t at ,source voltage exceeds E, T2 is therefore triggered .soon after ( ) , FD is

reverse biased and is therefore turned off; load current now shift from FD to T2 ,D2 . At 2t ,

FD is again forward biased and output current Io is transferred from T2, D2 to FD. The source

current Is is positive from to when T1, D1 conduct and is negative from ( ) to 2 when

T2, D2 conduct.

During the interval to T1 and D1 conduct and ac source delivers energy to the load circuit.

This energy is partially stored in inductance L< partially stored as electric energy in load _circuit

emf E and partially stored as freewheeling period to ( ) energy stored in inductance is

recovered and is partially dissipated in R and partially added to the energy stored in load emf e.

no energy is fed back the source during freewheeling period.

(1 cos )mV

Vo

Simulation Model:-


27/37


Results:-


28/37


Q.1 Why semi converter is also known as the semi controlled converter.

Q.2 Write down the advantages of freewheeling diode.

Q.3 Write down the mathematical expression for output Voltage, Output current, Harmonic

Analysis for Semi converter.


29/37



Name: - Roll No: -




Experiment No: - 7

Objective: -Simulation of DC Series Motor using 1-phase fully controlled converter with

PSIM 9.1


Theory: -




About Full Converter Control of DC Motor-

Full converter control of DC Motor is also called phase-angle controlled drive.

1. By changing the firing angle, variable DC output voltage can be obtained.

2. Single phase (low power) and three phase (high and very high power) supply can be used.

3. The line current is unidirectional, but the output voltage can reverse polarity. Hence 2-

quadrant operation is inherently possible. 4-quadrant is also possible using two sets of

controlled rectifiers.


30/37


In the 1-phase full controlled rectifier, Ls is source inductance .the load current is assumed

constant. When terminal 1 of source voltage Vs is positive current I1 flows through Ls , T1, load

and T2 this is shown as V1, Ls ,T1T2 and load similarly when terminal 2 Vs is positive load

current I2 flows through T3, load T4 this is shown as V2 , Ls T3 T4 and load. When T1 T2 are

triggered at a firing angle the commutation of already conducting thyristor T3, T4 begins.

Because of presence of source inductance Ls the current through out going device T3,T4

decreases gradually to zero from its initially value of I0 where as an incoming thyristor T1,T2 the

current build up gradually from zero to full value from load current I0 . The output voltage of full

converter is:

cos 0mVVo for

Simulation Model:-


31/37


Results:-


32/37


Q.1 Why fully controlled converter is batter then semi controlled converter.

Q.2 Write down the mathematical expression for continuous conduction and discontinuous

conduction of fully controlled converter fed DC Drives.

Q.3 Write down the mathematical expression for output Voltage, Output current, Harmonic

Analysis for Full converter.


33/37



Name: - Roll No: -




Experiment No: - 8

Objective: -Simulation of DC Series Motor using 3-phase semi controlled converter with

PSIM 9.1


Theory: -




About 3-phase Semi converter Control of DC Motor-For 3-phase semiconductor feeding a

separately exited dc motor. The field winding of the motor is also connected to 3 phase

semiconductor. This drive offer one quadrant operation and is used up to about 115 KW rating.

On the assumption of continuous and ripple free armature current wave form for line current Ia

and thyristor current IT1. For firing angle =30 and also for =90.An examination of these wave

form would reveals that inform firing angle 60, each thyristor conductor for 120 and

For 60


34/37


In 3-phase semi controlled rectifier circuit T1 T2 T3 are thyristor and D1 D2 D3 are diodes, and

RLE load is connected.

The output voltage V across the load terminal is controlled by varying the firing angle of SCRs

T1 T2 and T3. The diode D1 D2 and D3 provide a return path for the current to the most

negative line terminal.

The firing angle delay of =0, Thyristor T1 T2 T3 acts as a diode and the output voltage of semi

converter would be symmetrical 6 pulse per cycle.

For semi converter in the armature circuit, the average output voltage, from Equation is given by

0for)cos1(30m

t

VVV

Simulation Model:-


35/37


Results:-


36/37


Q.1 Write a mathematical expression for speed control of DC Motor with transient and steady

state analysis.

Q.2 Draw the block diagram of DC Motor control with Semi-control converter.


37/37

Documents

Solid State Controller of Drives_Experiment