Modeling of Reconnection of Decentralized Power Energy Sources Using EMTP ATP

Modeling of Reconnection of Decentralized Power Energy Sources Using EMTP ATP

Ing. Dušan MEDVEĎ, PhD.

Železná Ruda-Špičák, 25. May 2010

FEI

TECHNICAL UNIVERSITY OF KOŠICEFACULTY OF ELECTRIC ENGINEERING AND

INFORMATICSDepartment of Electric Power Engineering

Contents

• Theoretical problems of reconnection of decentralized electric sources in power system

• Choosing of suitable model of power system for reconnection of decentralized sources

• Simulations of chosen electric sources in power system model in EMTP-ATP

• Conclusion

Problems of Reconnection of Decentralized Power Energy Sources to Distribution Grid

Problems of reconnections of wind power plant:

• convention sources must be „on“ and prepared, in the case of wind power plants outage;

• dependence on actual meteorological situation;

• relatively small power of wind power plants;

• they are not possible to operate when the wind velocity is above 30 m/s or below 3 m/s.

Problems of reconnections of solar power plants:

• convention sources must be „on“ and prepared, in the case of solar power plants outage;

• problems with the season variations of sunlight (in December is 7-times weaker than in July);

• difference between night and day is very significant

Problems of reconnections of water power plants:

• they generate electric power only when the water flow is in allowable range;

Review of present possibilities of computer simulation of power system

at our department

• MATLAB/SIMULINK

• EUROSTAG

• PSLF

• EMTP-ATP

• ...

EMTP ATP(Electromagnetic Transient Program)

• Generally, there is possible to model the power system network of 250 nodes, 300 linear branches, 40 switchers, 50 sources, ...

• Circuits can be assembled from various electric component of power system:

• Components with the lumped parameters R,L,C;

• Components with the mutual coupling (transformers, overhead lines, ...);

• Morephase transmission lines with lumped or distributed parameters, that can be frequency-dependent;

• Nonlinear components R, L, C;

• Switchers with variable switching conditions, that are determined for simulation of protection relays, spark gaps, diodes, thyristors and other changes of net connection;

• Voltage and current sources of various frequencies. Besides of standard mathematical functions, there is possible to define also sources as function of time;

• Model of three-phase synchronous engine with rotor, exciting winding, damping winding;

• Models of universal motor for simulation of three-phase induction motor, one-phase alternating motor and direct current motor;

• Components of controlling system and sense points.

• This program EMTP ATP is not only computational. Because of better representation of results and simplifying of inputting data, this program has spread with another sub-programs as follows:

• ATPDraw – graphical preprocessor;

• PCPLot , PlotXY, GTPPLot – graphical exporting of ATP;

• Programmer‘s File Editor (PFE) – text editor for creating and editing of output files;

• ATP Control Center – program that concentrate all controlling sub-programs into one general controlling window.

EMTP ATP(Electromagnetic Transient Program)

Scheme of electric power network for simulations

Scheme of electric power network for simulations in EMTP-ATP

Parameters of power system

• Parameters setting of sources of power system


• Parameters setting of overhead lines of power system


• Parameters setting of transformers of power system

Sources reconnection• There were reconnected various sources in different locations of power system

• First source was connected from the beginning of simulation, the second one was connected in 0,5 s and the third one in 1 s

• All parameters of components in power system were inserted as card data of given components

• Consequently, there were changed voltages and powers of connected sources

• The measured data (voltages, currents, ...) were recorded and evaluated in various nodes of network

• The maximal possible connected power were calculated and tested with permitted difference of voltages (quality of voltages must agree with conditions of ± 2 % from nominal voltage in grid)

• The result were evaluated for phase L1 (A), because the loads were almost symmetrical

Simulation of reconnection of two sources with the same values and the maximal voltage of 326 V

Sources reconnection

Voltage arising with sequential sources reconnecting


Voltage deviation in the node, closest to third source


Voltage deviation in the node, closest to the third source (detail)


Simulation of reconnection of two sources with the various parameters and the maximal voltage of 391 V (2nd source) and 333 V (3rd source)


Power of first source, when it operates alone (0-0,5 s), with the second one (0,5-1 s) and consequently with third one (1-2 s)


Power of second source, when it operates with first one (0-0,5 s), and with the third one (1-2 s)


Power of third source, when it operates with first and third one (1-2 s)


Maximal voltages, that are possible to reach with the respecting of ± 2 % voltage variation in every node:

Source 1: Um1 = 89815 V Source 2: Um2 = 391 V Source 3: Um3 = 333 V

Maximal immediate power measured in the closest distances from the sources:

Power of source 1 (single) = 2,2643 MW Power of sources 1 + 2 = 3,5280 MW = 2,2541 MW + 1,2739 MWPower of sources 1 + 2 + 3 = 3,5653 MW = 2,1458 MW + 1,2621 MW + 0,1574 MW


Simulations of transient phenomena

Complemented scheme for simulation of transient phenomenaM1,M2,M3 – places of failure event; measuring places

0V

3V

1V

2V

5V

4V

6V

7V

8V

9V

11V

12V

13V

14V

15V

16V

TR16

BCT

Y

V

01V

U1

TR0

BCT

Y

AFLCC

ABLCC

AGLCC

AHLCC

ACLCC

1.002 km

ADLCC

AELCC

AILCC

AJLCC

AK 0k

LCC

AALCC

TR11

BCT

Y

I

TR1

BCT

Y

TR10

BCT

Y

TR9

BCT

Y

AAO00LCC

TR2

BCT

Y

TR3

BCT

Y

ADALCC

TR13

BCT

Y

TR14

BCT

Y

TR4

BCT

Y

AEALCC

TRnz

BCT

Y

TR5

BCT

Y

AFALCC

AFBLCC

AFCLCC

AFDLCC

AGALCC

TR12

BCT

Y

TR8

BCT

Y

TR7

BCT

Y

TR6

BCT

Y

I17

V

V

10V

TR15

BCT

Y

I

110kV

M2

22 kV M3

M1

Simulated transient phenomena:• short-circuits• load (branch) disconnection• phase interruption• atmospheric overvoltage

Three-phase short circuit – overvoltage after short circuit elimination

Voltage characteristics before short-circuit creation in location M1, during short circuit and after short circuit, measured in location M1

(file 3fskrat_M1.pl4; x-var t) v:X0080A v:X0080B v:X0080C 0,040 0,062 0,084 0,106 0,128 0,150[s]

-80

-46

-12

22

56

90

[kV]

Three-phase short circuit – measured resultsMeasured place

Location M1 Steady state Overvoltage after shot-ciruit interuption

Peak current during short-circuit

Mutual distances [km]

U[V]

U[V]

ip[A]

M1 0 17309 88722 6533,5

M2 4,110 16969 69337 203,5

M3 8,121 16701 71948 36,453Measured place




U[V]

U[V]

ip[A]

M1 -4,110 17309 178560 3813,5

M2 0 16969 182420 3840,9

M3 4,011 16701 172670 36,373Measured place




U[V]

U[V]

ip[A]

M1 7,466 17309 45529 2453,3

M2 4,011 16969 48449 2432,2

M3 0 16701 57918 2402,8

Two-phase short circuit – overvoltage after short circuit elimination


(f ile 2f skrat_M1.pl4; x-v ar t) v :X0080A v :X0080B v :X0080C 0,040 0,062 0,084 0,106 0,128 0,150[s]

-90

-60

-30

0

30

60

90

[kV]

Two-phase short circuit – measured results

Measured place




U[V]

U[V]

ip[A]

M1 0 17309 86268 3122,3

M2 4,110 16969 71133 197,08

M3 8,121 16701 69032 36,822Measured place




U[V]

U[V]

ip[A]

M1 -4,110 17309 167630 2536,6

M2 0 16969 178690 2697,5

M3 4,011 16701 163660 36,975Measured place




U[V]

U[V]

ip[A]

M1 7,466 17309 69409 1881,2

M2 4,011 16969 67746 1854

M3 0 16701 98249 1938

One-phase short circuit – overvoltage after short circuit elimination


(f ile 1f skrat_M1.pl4; x-v ar t) v :X0081A v :X0081B v :X0081C 0,040 0,062 0,084 0,106 0,128 0,150[s]

-70

-40

-10

20

50

80

[kV]

One-phase short circuit – measured results

Measured place




U[V]

U[V]

ip[A]

M1 0 17309 78221 5100,5

M2 4,110 16969 47897 157,81

M3 8,121 16701 55168 36,45Measured place




U[V]

U[V]

ip[A]

M1 -4,110 17309 129130 2607,7

M2 0 16969 147370 2711,3

M3 4,011 16701 144980 36,43Measured place




U[V]

U[V]

ip[A]

M1 7,466 17309 55513 1672,5

M2 4,011 16969 59507 1641,2

M3 0 16701 91992 1676,2

Phase interruption

Voltage characteristics during phase interruption in location M1, measured in location M2

(file M1.pl4; x-var t) v:M2A v:M2B v:M2C 0,09 0,10 0,11 0,12 0,13 0,14 0,15[s]

-20

-15

-10

-5

0

5

10

15

20

[kV]

Voltage characteristics during phase interruption in location M1, measured in location M3

(f ile M1.pl4; x-v ar t) v :P17A v :P17B v :P17C 0,09 0,10 0,11 0,12 0,13 0,14 0,15[s]

-20

-15

-10

-5

0

5

10

15

20

[kV]

Phase interruption

Load disconnection

Voltage characteristics after disconnection of branch AFA, measured in location M1

(f ile AFA.pl4; x-v ar t) v :X0080A v :X0080B v :X0080C 0,09 0,10 0,11 0,12 0,13 0,14[s]

-20

-15

-10

-5

0

5

10

15

20

[kV]

Current characteristics after disconnection of branch AFA, measured in location M1

(f ile AFA.pl4; x-v ar t) c:X0080A-M1A c:X0080B-M1B c:X0080C-M1C

0,09 0,10 0,11 0,12 0,13 0,14[s]-200

-150

-100

-50

0

50

100

150

200

[A]

Load disconnection

Atmospheric overvoltage

During the direct lightning strike to overhead line pole (HV), it is considered line impedance Z0=300-500 Ω and lightning current of I = 20 kA, then the theoretical peak voltage magnitude of overvoltage wave is in the range 3-5 MV.

HH

Atmospheric overvoltage

Simulation of direct lightning strike to bus bar 22kV in location M1

(f ile M1.pl4; x-v ar t) v :X0002A v :X0002B v :X0002C 0,00 0,03 0,06 0,09 0,12 0,15[s]

-6

-4

-2

0

2

4

6

[MV]

Atmospheric overvoltage – measured results

Measured place

Location of failure M1 Steady state Overvoltage


U[V]

U[MV]

M1 0 17309 5,304

M2 4,110 16969 4,96

M3 8,121 16701 2,83

Location of failure M2

M1 -4,110 17309 2,65

M2 0 16969 4,01

M3 4,011 16701 4,28

Location of failure M3

M1 7,466 17309 5,28

M2 4,011 16969 6,23

M3 0 16701 10,43

Conclusion

• using of EMTP-ATP it is possible to relatively quickly consider connectivity of new power source (voltage change, short-circuit ratio, overvoltage, ...);• there were confirmed theoretical assumptions that the most important points with the highest quantity change are the closest branches to connection node, i.e.:- the highest increasing of voltage magnitude is in the node of source connection,- the highest increasing of short-circuit current is in the node of source connection,• if there were connected 3 sources, the voltage in the power system was increased to permitted maximum voltage, and then it is possible to connect another load to the grid without significant complications,• the similar procedure can be used for various small power systems

Thank you for your attention

Modeling of Reconnection of Decentralized Power Energy Sources Using EMTP ATP

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