The Modern Transient Network Analyser and Its Role in Analysis and Design of Electrical Systems

8/19/2019 The Modern Transient Network Analyser and Its Role in Analysis and Design of Electrical Systems

1/6

The modern transient ne tw ork analyser and its

role in analysis and design of electrical systems

W M Ritchie, M.Sc, and J.T. Pender, B.Sc, C.Eng., M.I.E.E.

Indexing terms: Network analysers. Transient analysers

Abstract

The complementary functions of the transient network analyser and the digital computer are examined and

further consideration is given to the most approp riate spheres of application of the analyser. A description is given

of the design of a new versatile solid-state analyser and its use in a specific investigation of overvoltages due to

transmission-line energisation.

1

Introduction

As early electrical networks became more complex, analysis

by unaided conventional calculation became progressively more

approximate, requiring considerable system reduction and simplified

component representation to be feasible. The steady-state network

analyser was developed to reduce the labour involved in investigating

actual and possible operating problems in power-supply systems and

predicting the effect of extensions. Small static generators and other

small electrical com ponents were used in a physical model to represent

the important parameters of complex networks.

1

'

2

A further development in this approach to network analysis was

the transient network analyser (t.n.a.), with facilities for switching

and generating other surges. The component parts of the t.n.a. were

designed to give a better approximation to the high-frequency charac-

teristics of electrical equipment, and the output was displayed on an

oscilloscope to give time resolution.

3

'

4

Finally, the digital computer

was developed to a degree which allowed large electrical networks to

be modelled and analysed m athematically.

The digital x;omputerv,haslai:geJ.y-suipjei sededlhe'aetwQrlt analyser

for routine analysis of power-system networks. For some aspects of

transient analysis the transient version of the network analyser re-

mains superior, and developments in solid-state circuitry, printed-

circuit technology, miniaturisation and unit construction have com-

bined to make the modern t.n.a. a relatively cheap, transportable and

versatile instrument.

5

Although its main application is in power-

systems analysis it has further use in problem solving, analysis and

design in other electrical and analogous systems and associated plant.

2 The complementary functions of the digital

computer and the t.n.a.

The modern large multipurpose digital computer is widely

used for power-systems analysis, and a considerable range of effective

programs exists, each of which only requires the appropriate data to

be inserted to perform a study for a given set of conditions in any sys-

tem. Consequently, the use of the appropriate digital program is the

most economic way of obtaining answers to most steady-state and

transient-stability problems and some fast-transient problems, particu-

larly if they are of a routine nature. However, if a trend is being

investigated, such as one due to intentional changes in system par-

ameters for design or operational reasons, the number of computer

runs required may make the cost considerable.

For fast-transient investigations using a digital computer, two

related and relatively simple methods of solution can be used.

These are the Schnyder-Bergeron graphical technique

6

which is

based on the mathematical method of characteristics, and the Bewley

lattice-diagram technique based on reflection and refraction coef

ficients for travelling waves when they reach discontinuities in the sys-

tem.

7

When 3-phase system configurations are being considered the

individual surge impedances must be replaced by appropriate surge-

impedance matrices.

8

A useful additional mathematical technique is

to describe surge propagation along a multiconductor line in terms of

Paper 8033

P

first received 17 th January and in revised form 29th September

1977

Mr. Ritchie was with A. Reyrolle Co. Ltd., Hebburn, Tyne

Wear

England,

and is now with Kennedy Donkin, Consulting Engineers Premier House,

Woking, Surrey GU21 IDG, England. Mr. Pender is with the Department of

Electrical Engineering, University of S tratchlyde, R oyal C ollege Building,

204

eorge

Street,

lasgow

G1 1XW

Scotland

PROC.

1EE Vol. 125, No. 2, FEBRU ARY 1978

natural propagation modes.

9

Both the Schnyder-Bergeron and lattice-

diagram methods have considerable limitations when dealing with

frequency-dependent parameters.

A further technique used in digital fast-transient studies is based on

the modified Fourier transform. The advantage of this approach lies in

the facility with which the frequency dependence of system par-

meters can be taken into account. The method involves the use of

Fourier transforms to allow the calculation of the system response

over an appropriate frequency range.

10

By combining the lattice technique with the Fourier-integral

approach some account may be taken of the frequency dependence of

system parameters and of earth-resistivity effects.

There are distinct advantages, often complementary to those in-

herent in the use of digital computer, to be obtained in some investi-

gations from the use of an analogue device such as the t.n.a. The

operator of an analyser gains immediate feedback from the power-

system model when any parameter is altered, and since such alterations

can be perform ed in rapid succession, considerable assistance is

"obtainedunnmderstartding the--nature

1

ofthe ^problem.being investigated.

••

This advantage can be reinforced in the modern t.n.a. by autom atic

methods of rapidly scanning a complex system for possible adverse

situations and automa tic recording of the worst conditions. It is poss-

ible to achieve great speed and economy in solving some complex

problems in this way.

As with digital-computer techniques there are inherent difficulties

associated with accuracy and cost when considering the use of the

t.n.a. for transient studies. Transient switching operations involve

building a model system or portion of system and opening or closing

switches placed at the appropriate positions. Line and cable models

are approximated by ladder networks of lumped elements in the form

of 7r-sections. An artificial line of this type behaves in exactly the

same way as an actual line with completely distributed parameters for

a particular frequency, but it has a bandwidth approximately equal to

the natural frequency of 7r-section. High-frequency components of

transient which exceed this bandwidth are attenuated, thus introducing

some error in the high-frequency response. Flexibility in building a

variety of systems is achieved by using decade resistance, inductance

and capacitance units , but cost limits the size of network which can be

feasibly represented. A useful technique is to decide the maximum

time of interest for a transient, then to calculate the distance to a

position in the system w hich a reflected travelling wave would return

to the switching position at the limit of the time of interest. Any sys-

tem plant connected at or slightly beyond a radius equal to this dis-

tance can be represented by a resistance equal to its surge impedance,

and nothing is required beyond this radius.

There are considerable difficulties in building accurate physical

models of e.h.v. transmission plant with the correct response to high-

frequency transients, although some ingenuity has been shown in this

field

11

and equivalent circuits can usually be made as adequate as the

mathematical models incorporated in computer programs. Accurate

knowledge of the high-frequency characteristics of the actual plant is

often the main problem, rather than representation. Earth-path

penetration based on Carson's equations can be quite well represented

by a frequency-dependent

R- L

ladder network.

When comparing the various methods available for transient

analysis

12

one should consider the accuracy of the method, the

econom ic efficiency and th e ease of application . The weighting of

these factors will vary from case to case and there is no overall best

method. If a transient analyser is available, one can easily and rapidly

129

0020-3270/78/8033-0129 1-50/0


2/6

Fig. 1

Ne w transient network analyser

1 oscillator unit

2 generator unit

3 master timer unit

4—7 switch units

8 monitor ing selection

9 patch panel

10 variable passive units

11 model transmission-line units

modify the sequence and time at which circuit-breaker poles close or

open, introduce additional circuit elements and faults and immediately

observe the behaviour of the system. When only a digital computer is

available, both the lattice and Schnyder-Bergeron methods applied to

overhead-line problems give results which are probably adequate for

most engineering studies. For some cases, e.g. transient induction in

adjacent cables where parameters such as propagation constan ts, surge

impedances and modal matrices are frequency dependent to a con-

siderable degree, it is desirable to use the Fourier m ethod .

In general, however, t.n.a. studies are most effective when an

unknown or improperly understood effect is being investigated, and

digital studies are most effective for routine analysis or for obtaining

accurate results when the effect is reasonably well understoo d. A

useful and economic approach to the solution of some complex prob-

lems is to use the rapid-scanning facility of the t.n.a. to identify net-

work conditions which pose a problem, then to investigate methods of

overcoming the problem, also on the t.n.a., and finally to obtain an

accurate solution using the digital computer.

3 Deve lopm ent in t.n.a . design

Most transients are isolated events which occupy a very short

time. In order to simulate and study such transients on the t.n.a. the

operation is arranged to occur repetitively in a model system, and by

triggering an oscilloscope timebase with a synchronous signal, regularly

superimposed oscilloscope traces give a steady waveform of the

response. If the waveshape is not required a digital voltmeter is

adequate to record the transient response at any position. The com-

ponents used to build the model networks, which can be of various

degrees of sophistication, have been described elsewhere,

Sl

" '

I3> 14

and one form of model transmission line is illustrated later, but the

core of the t.n.a. consists of the active sections containing the

electronic devices which energise the model networks and perform

switching functions.

The active and control units in early analysers used thermionic

devices, and in most cases they operated at a frequency of the order

of 1 kHz, although the ERA analyser

2

could operate at variable fre-

quency. The limitations encountered in operating a t.n.a. of this type,

such as fixed operating frequency and repetition rate, poor reliability

of thermionic valves and inadequate facilities for altering circuits, have

caused the design philosophy to be modified and increased flexibility

to be achieved. A modern design, illustrated in Fig. 1, has an operating

frequency which is infinitely variable over the range 10 Hz -

10

kHz

and a variable repetition rate of 1-99 cycles of the operating fre-

quency. This facility allows frequency scaling to be employed, thus

allowing greater flexibility in the use of existing power-system models,

an example being improvement in the representation of the distributed

parameters of transmission lines and cables of different lengths.

Variable-frequency operation is also useful for frequency-scanning a

system, thereby obtaining an indication of whether or not harmonic

problems are liable to occur.

Comparable capacity to that of the earlier counterpart has been

achieved with a fourfold reduction in size by the use of integrated-

circuit technology and the compact patch-panel arrangement shown in

Fig. 1. In this arrangement the various analyser components are con-

nected to columns and the rows form busbars; the required system

configuration is obtained by inserting connecting pins at the appropri-

ate positions. Beryllium-copper plated contacts used throughout the

patch panel have given no trouble during extensive use in the proto-

type. Modular construction allows the capacity of the analyser to be

extended as required.

o

?̂ ui

>

o

m I

I

J

master timer

swi tch control

c i rcu i ts

I ;

I *

i

I

I If

I 'i

r

switch control

circuits

I I.

switch control

c i rcui ts

[elec tronic switch es I electronic switc

i . i , w-t i i L _ , , , —

3-phase generator 1

model power system

L _

Fig. 2

T.N.A. block diagram

angle information

b cycle information

I

130

PROC. IEE, Vol. 125, No. 2, FEBRU ARY 1978


3/6

A block diagram of the t.n.a. is shown in Fig. 2. The 3-phase

sinusoidal output of the oscillator is applied to the generator units and

the master timer.

In

each generator unit, phase-angle control

is

obtained from frequency-independent passive phase-shifting circuits,

the outputs from which supply integrated-circuit power amplifiers

through automatic gain- and amplitude-control circuits. The three

power amplifiers act as a 3-phase voltage source with a maximum volt-

age

of

10 V r.m.s. The master timer unit derives control information

for the electronic switches from its 3-phase sinusoidal input. This

information, which is fed to two sets of information busbars, is in two

forms:

(a) cycle-control pulses obtained by counting a train of pulses which

is synchronised

to the

operating frequency

and

which

can be

terminated by setting the digital counter at the required rep

etition rate, and b) point-on-wave control signals which are a set

of 6-phase sinusoidal voltages.

The electronic switch-control circuits select the appropriate signals

from the information busbars and operate on them to produce the

switch-control signal. The technique described enables the switch con-

trols

to be

calibrated

in

cycles and degrees

of

the op erating frequency

irrespective of its value.

In order to study large numbers of system-operating conditions the

basic t.n.a. can be modified for automatic operation, a proposed

scheme being described

in

Section

6. In

the meantime the effectiveness

of the analyser has been improved

by a

technique which provides con-

tinuously variable automatic point-on-wave switching. An additional

oscillator is used to supply the switch controls while the

analyser oscillator continues

to

supply

the

generators.

By

operating

the oscillators at slightly different frequencies the switching instan t is

progressively altered, and the maximum switching overvoltage over

the 360° possible closing angle for given conditions can be rapidly

obtained using a 3-phase peak-reading voltmeter.

An additional feature is a 'sample and hold' recording system

which is clocked by a high-frequency train of pulses, synchronous

with

the

t.n.a. controls. This enables a waveform

to

be examined w ith

high definition, and information such as time and amplitude of peaks,

rates of rise, time of zero amplitude etc. to be easily obtained.

Provision is made for the samples to be stored in a form suitable for

analysis

by

digital computer. Automatic interaction between

a

t.n.a.

and a digital computer is considered in Section 6.

4 Fields o application o the t.n.a.

The t.n.a. in a versatile machine with application in investi-

gating a wide variety of unusual occurrences in electrical systems,

assisting

in

determining possible causes, helping

to

indicate remedial

action and giving an insight into the processes which occur in complex

cases. Examples

of

power-system applications include

the

study

of

magnetising inrush in transformer circuits and overvoltages which

occur with cross-bonded cable systems and transformer feeders, the

investigation

of

electric-arc models and resistance switching in circuit-

breaker development, and the optimisation of circuits and control

timing for circuit-breaker synthetic tests.

14

'

1S

Transient studies can be

performed

for any

system involving quantities which

can be rep

resented by an electrical analogue such as heat flow and m ovement of

mechanisms.

16

In the field of power-systems analysis, probably the most effective

and efficient application

of

the t.n.a.

is in

fast-transient studies,

par

ticularly those concerned with transmission-line energisation;

in

this

context the term fast-transient is taken to apply to any transient fre

quency significantly above the supply frequency. Since developments

in

the

operation

of

transmission systems have made switching more

frequent,

and the

high cost

of

insulation

at

progressively higher oper-

ating voltages has given a strong incentive to reduce overvoltages, it

has become increasingly necessary to investigate the magnitude of

switching overvoltages

and the

methods

of

limiting them.

The

wide

range of system configurations under different operating conditions

requires extensive investigation of possible overvoltages, which may be

difficult to predict, and although digital-computer programs are avail-

able

to

investigate such phenomena

an

investigation

in the

necessary

detail would seldom be attempted due to prohibitive cost. The less

accurate t.n.a. can be used to survey a system over a wide range of

conditions rapidly and cheaply,

17

'

18

and if necessary particular over-

voltage conditions which have been identified

can be

examined more

accurately using a digital computer. The inherent accuracy of digital

computation, however, is sometimes of no benefit if the available sys-

tem data is approximate. A similar approach can be adopted for

investigating transient recovery voltages due

to

circuit interruption.

Fig. 3 shows waveforms obtained from a digital program , a t.n.a.

PROC.

IEE, Vol. 125, No. 2, FEBRUARY 1978

and a full-scale test in a power system

for

energisation

of

a transmission

line under identical conditions ,

19

and Fig. 4 shows waveforms obtained

from a digital program, a t.n.a. and a full-scale test for a particular

transient recovery-voltage condition.

In

both

of

these cases

it can be

seen that reasonable agreement is obtained between the analogue

(t.n.a.) results and the others for most of the transient period. Good

agreement

is

obtained

for the

maximum overvoltage, which is the im-

portant quantity in the line-energisation study , and for the initial rise

in voltage, which is the significant factor in circuit interrup tion.

It is not practicable to obtain a comprehensive overall picture of

all possible energising and re-energising overvoltages, owing to the

large number and spread

of

both system and circuit-breaker parameters

involved. To do so would require a prohibitive number of t.n.a. or

computer studies,

and the

number

of

variables makes anlaysis

of the

results and their portrayal a complex problem.

20

It is consequently

extremely difficult to formulate general rules which would allow one

to forecast

the

effect

of

energising

a

specific transmission line with

Keadby

275kV

Burton

HighMarnham

^

C o | | a m

37km | 29km |18km

7km

166km

Cowley Claydon

3-C 5-LrSundon

line energised

Fig. 3A

System arrangement for 400 kV line energisation tests

-3

Fig.

3B

Typical receiving end waveform on line energisation

Comparison

of

-waveforms obtained from t.n.a. with computed

and

actual test

results

— calculated

analogue results

test

1-6

1-2

3 1-0

0-6

(K

0-2

1-6

K 0-8 1-2

t ime ms

Fig.

4

27 5 kV system transient recovery voltage on clearing a 13 kA

3-phase

to earth fault

Comparison of waveforms obtained from t.n.a. with computed and actual test

results

computer study

test results

t.n.a. study

131


4/6

particular system conditions. Important trends have been established

from the results of a large number of switching-surge investigations

carried out in various countries,

20

but although these results have

wide app lication further investigation is required in specific cases, and

it is of considerable help to have avaliable a method of undertaking a

rapid survey when general experience suggests a possible prob lem. The

t.n.a. is well suited for this work, an example of which is given in the

next Section.

d) switching-resistor insertion time . This is the time between initial

energisation and the resistor being short-circuited by additional

circuit breaker contacts

e) the fault level at the energising source

/) various combinations of remanent charge of the three conductors

under reclosing conditions

g) the degree of reactive power compensation due to shun t

reactors

• — •

source

equivalent source

fau lt level 5-»GVA

circuit breaker

pole scatter 0-120°

insertion time 180°

insertion resistor

0-600 1

Fig.

5

System used in

overvoltage survey

Fig.

6

One

section of a 3 phase transmission line

Model transmission-line section incorporating

a compensating resistors

b frequency-dependent earth path

A typica l overvoltage study

The investigation involved a survey of the manner in which

various system parameters affect the receiving-end overvoltages pro-

duced when a 320 km, 60 kHz, 500 kV overhead line is energised. The

system is shown in Fig. 5, the line being represented by 32 3-phase

7r-sections, each of the form shown in Fig. 6.

The 3-phase source used in this study is an equivalent empirical

representation of a mixed source of generators and transmission lines.

The derivation of this equivalent circuit has been described elsewhere

5

and has been used in the t.n.a. study which gave good correlation with

full-scale power-system tests.

19

A considerable number of factors affect the overvoltage produced

including:

a) the point on the supply-voltage wave at w hich the circuit is

energised

b) variation in the instants at which each of the three phases is

energised, often termed circuit-breaker pole scatter

c) the value of the resistor through which each phase is energised.

Such resistors are known as switching resistors and their use

reduces the m agnitude of the voltage surge

transmission l ine reactor

500kV, quad x 1-94crrf\0-3 in

2

) compensation

single circuit 320km 0, 50, 100°o

remane nt charge zero

or

r 0«8 p.u.

y»0«8 p u .

b-0-8 p.u.

In a more general study additional factors would be:

h) line geometry and variations in the earth path

/) variation of the transmission-line length

17

/) differences in the n ature of the energising source .

18

Since the number of possible combinations of these variables is ex-

tremely large, any survey must be done rapidly and the result for each

condition must be immediately apparent. The point on the wave at

which the circuit breaker closes is one of the main variables, and the

automatic technique previously described, which causes the electronic

switch simulating the circuit breaker to operate at a slightly different

point on the voltage wave at each repetition, can be used. The 3-phase

peak-reading voltmeter which records the most severe overvoltage can

be connected at any position on the model transmission line. This

technique considerably reduces the time required for an investigation

of this nature. In the present case the voltage at the receiving end of

the model transmission line was monitored in this w ay.

2-6

2-4

2-2

•

S>

2-0

o

1-8

1-6

1-2

1-0

100

2 0 0 3 0 0 4 0 0 5 0 0

sw i tch ing r es i s to r

va lue,

fl

600

Fig.

7

Comparison of maximum overvoltages with and without remanent

charge for various system source fault levels

resistor insertion t ime 180°

remane nt charge zero

— r + 0-8 p.u.

y +

0-8 p.u.

b — 0-8 p.u.

132

PROC IEE, Vol. 125, No. 2, FEBRUARY 1978


5/6

From Figs

7—11

which summarise the results of the study some trends

can be detected and conclusions drawn.

In general the receiving-end overvoltages become larger as the

source fault level increases. A possible inconsistency could occur if a

resonant condition existed with a low fault level at the source. It

must be stressed that these results apply to the type of source in this

study and that different trends can be noted with other source con-

figurations.

17

'

18

This serves to illustrate the difficulty of obtaining

general conclusions from line-energising studies due to the complexity

involved when travelling waves with multiple and varied reflections

occur.

The study shows that the existence of remanent charge on this line

100 200 300 A 00 500

switching resistor value, i l

60 0

Fig.

8

Maxim um overvoltage against insertion-resistor value with varying

degrees of compensation on a system with a 5 GVA source fault level

resistor insertion time 180°

remanent charge zero

source fault level 5 GVA

100

200 300 A 00 500

switching resistor value, fl.

6 00

Fig. 9

Maxim um overvoltage against insertion-resistor value with varying

degrees o f compensation o n a system with a 20 GVA source fault level




can cause severe energising transients, and that the optimum value of

insertion resistance varies according to whether or not remanent

charge exists, being of the order of 150 O with no charge and 200—

25012 with remanent charge. The optimum condition occurs when

the overvoltages produced by the initial closure, and later by short-

circuiting the insertion resistor, are equal in m agnitude. With remanent

charge the transient on initial closure is more severe and the optimum

value of resistance is therefore greater. In the case being considered

the results indicate that resistors of 250 fi inserted in each phase for

10 ms would be suitable to limit energising overvoltages to 1 -8 p.u.

Pole scatter has a large effect in determin ing the magnitude of the

overvoltages, as closing circuit-breaker poles nonsimultaneously causes

the mutual effects to interact with the transients generated on the

individual phases and results in greater overvoltages than with simul-

taneous closure.

Figs.

8—11 illustrate the reduction in overvoltage with increasing

2-6

30 0

400 500

60 0

switching resistor value, A

Fig. 10

Maximu m overvoltage against insertion-resistor value with varying

degrees o f compensation on a system with a 40 GVA source fault level

resistor insertion time 180



100 200 300

400 500

switching resistor value, XI

6 0 0

Fig.

11

Maximu m overvoltage against insertion-resistor value with varying

degrees o f compensation on a system with a solid source


remanent charge zero-

source fault level < > G VA

PROC.

IEE, Vol. 125, No. 2, FEBRU ARY 1978

133


6/6

reactive compensation. It must be added, however, that this is for the

case of initial energisation or autoreclosing with a long dead time (i.e.

with no remanent charge on the line). If the reclose sequence is fast

the initial conditions will depend on the circuit-breaker opening

sequence, the degree of reactive compensation and the system losses.

Reclosing on shunt-reactor compensated lines may, however, give rise

to increases in switching overvoltages due to oscillatory decay of

trapped charge.

6 Furthe r developments in t.n.a . techniques

The behaviour of some items of power plant such as circuit

breakers, insulators and surge diverters is subject to significant statisti-

cal variation. Due to this statistical variation in equipment behaviour

and response, and to the large number of combinations of switching

variables, the statistical distribution of overvoltages is becoming an im-

portant aspect of power-system analysis and the t.n.a. is supreme in

obtaining the necessary large volume of information. To obtain and

process such extensive information a t.n.a. can be coupled to a digital

computer to provide a hybrid machine with 2-way analogue-digital

traffic and a decision-making capab ility in the digital po rtion. The

ease with which the t.n.a. can be automatically controlled, and the

analytical capability of the computer, result in a very powerful com-

bination.

21

Fig. 12 outlines the manner in which a t.n.a. of the type described

in Section 3 can be adapted to perform this hybrid function. For each

switch in the system the digital computer calculates the statistical dis-

tribution of the instants of opening and closing using random-number

generation and Monte Carlo techniques. This information is stored in

the computer which successively generates signals to appropriately

control the operation of the t.n.a. electronic switches. The system-

transient waveforms of interest which result from each particular set

of switching operations in the distribution are obtained in digital form

by sampling the waveform and are fed to the com puter w here they are

processed to give the corresponding statistical distribution of system

overvoltages. With more complex interaction the computer could be

used to vary the parameters of the model system and even implement

changes in the system configuration.

oscillator

digital computer

main computer:

calculation of operating

conditions

analysis of results

switch control

r

X X X

switch switch switch

1 2 n

3-phase

generator

• U

model power system

phase

generator

L

digital recording

Fig.

12

Digital computer -

t.n.a.

hybrid

7 Conclusion

The modern t.n.a. is a versatile instrument with application

in analysis arid design of electrical and analogous systems. Its main use

is in power-systems analysis, where its major attributes of an instant

portrayal of transient response and the ability to rapidly and auto-

matically examine a large number or system conditions make its

function complementary to that of the more accurate digital com-

puter. A hybrid arrangement of both types of machine can be used to

study the effects of statistical variation on the behaviour of electrical

equipment.

8

Acknowledgments

The authors wish to thank A. Reyrolle & Co. Ltd. for per-

mission to publish this paper, and wish to acknowledge the co-

operation of the Department of Electrical Engineering, University of

Strathclyde. Thanks are also due to the CEGB for permission to

publish the test results shown in Fig. 4.

9 References

1 HAZHN, H.L. , SCHURIG, O.R., and GARDNER, M.F.: 'The M.I.T. network

analy

ser' ,AIEE Trans. ,

1 9 3 0 , p p . 1 1 0 2 -1 1 1 3

2 'The E.R.A. network analyser'. ERA Report V/T 122, 1954

3 PETERSON, H.A.: 'An electric circuit transient analyser', Gen. Elec. Rev

1939,

p.

39 4

4 PENDER, J.T. : 'A combined steady state and transient a .c . network ana-

lyser',

Int. J. Electr. Eng. Educ,

1 9 6 8 , 6 , p p . 3 5 3 -3 6 2

5 RITCH IE, W.M.: 'Power systems transient analysis using analogue tech-

niques ' . 1 l th Universit ies Power engineering Conference, Paper 3 .6.1 97 6

6 ARL ETT , P. , and M URRA Y-SHEL LEY, R.E.: T he stu dy of overvoltage

transients in large systems', Proceedings of the Power System Computation

Conference, Roy al Insti tute of Technology, Stoc kholm , Pt. 3, Repor t 5.6,

1966

7 BICKF ORD , J.P. , and DO EPEL, P.S. : 'Calculatio n of switching transients

with particular reference to l ine energ isation \Proc. IEE, 1 9 6 7 , 114 , 4 ) , pp

4 6 5 - 4 7 7

8 WF.DEPOHL, L.M.: 'Application of matrix metho ds to the solution of

travell ing-wave phenomena in polyphase systems',

ibid.,

1 9 6 3 ,

110 ,

(12) , pp .

2 2 0 0 - 2 2 1 2

9 McELR OY, A. ]. , and SMITH , H.M.: 'Propagation of switching surge wave-

fronts on e.h.v. transmission lines',

IEEE Trans.,

1963, PAS-82, p . 983

10 BATTISON, M.J. , DAY, S J . , MULLINEUX , N. , PARTON, K.C. , and R EED,

J.R.: 'Calculation of switching phenomena in power systems',

Proc. IEE,

1967,

114,

(4 ) , p p . 4 7 8 -4 8 6

11 WRIG HT, I.A. , and MO RSZTYN , K.: 'An improved method of simulating

the transient performance of power system transformers',

Int. J. Electr. Eng.

Educ,

1969,6 pp. 49 9- 51 6

12 PENDER, J.T. : 'Fast transients in electrical power systems',

ibid.,

1969, 7 ,

p p . 4 1 9 - 4 2 9

13 BROWN, J.I. , MORSZTYN, K., and WRIGHT, I.A.: 'A new transient net-

work analyser', Inst. Eng. Aust. Electr. Eng. Trans. 1 9 6 9 , EE5 , p p . 2 6 3 -

27 0

14 CLERICI, A. , and MANARA, R.: 'Transient network analyser study of over-

voltages in cross-bonded a.c. cables' in 'Progress in overhead lines and cables

for 220 kV and above'. IEE Conf. P u b l . 4 4 , 1 9 6 8 , p p . 4 5 4 -4 6 0

15 'A t .n.a . study on synthetic testing as applied to circuit-breakers using

switching resistors of low ohmic value '. Reyrolle internal report , 1962

16 'The use of the t .n.a . for problems of mechanical impact ' . Reyrolle internal

report , 1965

17 BI CK FO RD J.P . , and EL-DEWIENY, R.M.K.: 'Energisation of transmission

lines from inductive sour ces',

Proc. IEE,

1 9 7 3 , 120, (8 ) , p p . 8 8 3 -8 9 0

18 BICKFORD, J.P. , and EL-DEWIENY, R.M.K.: 'Energisation of transmission

lines from mixed sources',

ibid.,

1974,

121 ,

(5) , p p . 3 5 5 -3 6 0

19 BATTISON, M.J. , BICKFORD, J.P. , CORCORAN, J.C.W., JACKSON, R.L. ,

SCOTT, M., and WARD, R.J.S. : 'Brit ish investigations on the switching of

long e.h.v. transmission l ines'. CIGRE, Report 13.02, 1970

20 CATEN ACCI, G. , and PA LV A,V .: 'Switching overvoltages in e .h.v. and

u.h.v. systems with special reference to closing and reclosing transmission

lines', Electro, 1 9 7 3 , 3 0 , p p . 7 0 - 1 2 2

21 MORSZTYN, K.: 'Computer controlled transient network analyser hybrid

t.n.a . ' Proceedings of the Power System Overvoltages Conference, Paper 2,

University of Manchester Insti tute of Science and Technology, 1976

134

PROC.

IEE,

Vol.

125, No. 2, FEBRU ARY 1978

Documents

The Modern Transient Network Analyser and Its Role in Analysis and Design of Electrical Systems