Fault analysis with the location of SFCL for the application of smart grid networks using simulink

THE PROJECT REPORT IS SUBMITTED BY

P.BHARGAVI(113H5A0201) S.REDDY MOUNIKA(103H1A0241)

P.V.V.DIVYA(103H1A0232) T.SIREESHA(103H1A0243)

Under The Guidance ofSri. N. Bala Venkata Muni

Associate professor &H.O.DDepartment of EEE

In recent years, superconducting fault current limiter(SFCL) has become one of the forefront topic of current-limiting technology in the world.

The implementation of FCL devices may also provide the opportunity to increase distribution and transmission equipment utilization and reduce reinforcement requirements.

Resistive type superconducting fault current limiter is used to reduce the fault current level within first cycle of fault current.

Fault Current Limiter is used to limiting the fault current in the power system network under abnormal conditions.

By optimally placing the SFCL in the network and then performance of the network is evaluated.

Matlab / simulink/simpower system was selected to design and implement the SFCL model and power system model.

ABSTRACT

INTRODUCTION

Almost in every field of modern civilization there is the requirement of electrical energy which has resulted in a considerable increase of electrical power consumption.

Fault –current limiters using high temperature super conductor offer a solution to controlling fault-current levels on utility distribution and transmission networks .

Development of superconducting fault-current limiter is began pursued by several utility and electrical manufactures around the world , and commercial equipment is expected to be available by turn of the century.

Smart grid is a novel term used for future grid which integrates the modern communication technology and renewable energy sources.

Smart grid model including generation, transmission, distribution network with dispersed energy resources of SFCL .

Smart grid is decentralization of the power grid network into smaller grid which are known as micro grid. As per a dispersed energy resource ,10 MVA wind farm was considered for

simulation. Three phase fault have been simulated at different locations in smart grid

What is smart grid ?

These characteristics require:

Zero dc resistance. High current density(high power). High electro magnetic shielding(low EMF). Cooling below a critical temperature Current levels below a critical current. Magnetic field below a certain magnitude.

SUPER CONDUCTOR CHARACTERISTICS

SFCL is a new power device to automatically limit a fault current to safe level with the superconducting property.

When superconductor is cooled down to critical temperature (about -186 degree centigrade) or less, the resistance become zero then superconductor losses are reduced.

Superconductivity and resistance occurs rapidly(quench), when excessive current flows and exceeds certain value(critical current). SFCL device use this property.

A superconductor is a material that can conduct electricity or transport electrons from one atom to another with no resistance.

By suppression of fault current results in an increased transient stability.

SUPERCONDUCTING FAULT CURRENT LIMITER(SFCL)

Resistive Reactance Hybrid Magnetic shielding Saturated iron core Bridge Active In which three-phase resistive type SFCL was modeled considering

4 fundamental parameters. They are Response time Minimum impedance and Maximum impedance Triggering current Recovery time

Some types of Superconducting Fault Current Limiters are:

Single phase Resistive SFCL model developed in Simulink/Simpower system

FIGURE:1

Because the resistance of superconductive material is so low, there is no current wastage when they are used to conduct electricity.

When used in the process of magnetic levitation, no kinetic energy is wasted due to friction from contact with the ground.

By using SFCL increased transient stability is obtained and carrying high power with greater stability.

By using resistive SFCL cost of circuit breaker is reduced.

Harmonic content and surges are also reduced.

ADVANTAGES OF SUPERCONDUCTING FAULT CURRENT LIMITER

To show their properties, and be of any use, they must be at critical temperature, which can be costly.

They emit strong magnetic fields which can effect humans by causing blindness, sterility, brain cancer and other things.

DISADVANTAGES OF SUPERCONDUCTING FAULT CURRENT LIMITER

Simpower systems provides component libraries and analysis tools for modeling and simulating electrical power systems.

The libraries offers models of electrical power components, including three phase

machines, electrical drives, and components for applications such as FACTS and Renewable energy systems.

This Models can be used to develop and design control systems for electrical power system in simulink and also using MATLAB variables.

SIMPOWER SYSTEM:

The modeled power system was based on korean electric transmission and distribution power system . Newly developed micro grid model was designed by integrating a 10 MVA wind farm with the distribution network. As below shows the power system model designed in simulink/sim power system.

POSITIONING OF SFCL IN SMART GRID: Artificial faults and locations of SFCL are indicated in the diagram. Three kinds of faults are marked as fault1,fault2 and fault3 which represent three-

phase-to-ground faults in Distribution grid ,customer grid ,transmission line respectively.

POWER SYSTEM MODEL

BLOCK DIAGRAM:

FIGURE:2

Four locations for SFCL installation are marked as

location1(Substation) location2(Branch Network) location 3(wind farm integration point with the grid) location 4(Wind farm)

Generally ,conventional fault current protection devices are located in Location1and location2.

The output current of wind farm (output of TR3) for SFCL locations have been measured and analyzed for determining the optimum location of SFCL in a micro grid.

Fig.1&fig.2 shows the SFCL model and power system model developed in Simulink/ simpower system.

Finally , when the current level falls below the triggering current level the system waits until the recovery time and then goes into normal state.

Characteristics of it gives the result of verification test of SFCL model conducted on power network model depicted in fig.2

As below graph indicates the SFCL impedance values vs its fault current reduction operation.

Comparison of the wind farm fault currents for four SFCL locations in

case of fault in distribution grid (Fault1)

In fault .1 when SFCL is installed at the integration point of wind farm with the wind farm fault current has been successfully reduced.

SFCL gives 68% reduction of fault current from wind farm and also reduce the fault current coming from conventional power plant because SFCL is located in the direct path of any fault current flowing towards fault.1

In fault .1 when SFCL is installed at the integration point of wind farm with the grid, marked as location 3 .

Comparison of the wind farm fault currents for four SFCL locations in

case of fault in customer grid (Fault 2)

Comparison of the wind farm fault currents for four SFCL locations in

case of fault in transmission line(Fault3)

Comparison of the reduction in wind farm fault current for four SFCL installation scenarios

GRAPH:1

Fault.2 is comparatively a small fault as it occurred in low voltage customer side distribution network.

The results obtained are similar to what were observed in the case distribution grid as explained above graph.

Fault3 indicates SFCL was located at a point of integration of wind farm with the grid(location3) the highest fault current reduction was achieved as compared with dual SFCL.

TablePercentage change in wind farm current due to

SFCL locationsFault .1 distribution grid

Fault.2 customer grid

Fault.3 transmission line

SFCL location

% Affect % Affect % Affect

Location1

38% increased 60% increased 57% decreased

location2 37% increased 33% increased 60% decreased

location3 68% decreased 30% decreased 0%

location1 and location4

47% decreased 6% decreased 72% decreased

DESING OF SFCL MODEL USING SIMULINK:

SFCL performance evaluation graph indicating the relationship between SFCL impedance and reduction in fault

DESING OF POWER SYSTEM MODEL USING SIMULINK

OUTPUT:1

OUTPUT:2

This paper presented a feasibility analysis of positioning of the SFCL in rapidly changing modern power grid.

It has been observed that SFCL should not be installed directly at the substation or the branch network feeder. The strategic location of SFCL in a power grid which limits all fault currents and has no negative effect on the DG source is the point of integration of the wind farm with the power grid.

With increase in generation, comes an increase in short circuit current in a transmission line during faults.

Utilities usually predict how much fault current exists in the line and can forecast its increase over a period of time.

The result is a lower cost system that is smaller and has much lower losses.

CONCLUSION

QUERIES

THANKS