Assignment on Network Design and Automation

 Table of Contsents

Introduction. 3

Substations equipment 3

Transformer 3

Circuit breaker 3

Isolating switches (Isolators) 3

Potential and current transformer 4

Busbars. 4

Protective relays. 4

Lightning arrestors (Surge Arrestors) 5

Earthing Switch. 5

Station earthing system.. 5

Cable size selection. 5

Cable selection sizing formulation. 6

For single circuit 7

For group. 7

Fault level studies. 7

Fault level consideration. 8

Tapings of distribution transformers. 9

132kv Lower voltage transformer 9

Conclusion. 9

References

Introduction of Network Design and Automation

A substation will be the combination of controlling, switching as well as voltage step-down equipment which is also arranged and reduced the sub-transmission voltage for the primary distribution voltage for the industrial, and commercial along with the residential loads.

Substations equipment of Network Design and Automation

The main equipment in the Industrial Estate consists of;

Transformer of Network Design and Automation

To step down the 132Kv primary voltage to the 11Kv suitable for the purpose of distribution. One the 132Kv/0.415 auxiliary transformer is also required which supplied the substation by the reliable AC power.

Circuit breaker of Network Design and Automation

To disconnect as well as isolate the faulted section then the circuit breaker is needed. The Sulphur-hexa-fluoride (SF6) circuit breaker is selected for this factory design requirement.

Isolating switches (Isolators)

When the repair work or the maintenance is carried out it is the main requirement on the equipment of substation or the feeders, then it to be disconnected form the supply of the isolator which is normally operated at no load.

The isolators which are normally interlocked by the circuit breakers as well as the earthing switches.

Rotating center post disconnector with grounding switch

Potential and current transformer

The voltage as well as current transformer were required which has to step down the line current from the purpose of the relaying along with the metering.

Busbars of Network Design and Automation

The outgoing as well as incoming circuit which is connected with the Busbars. Then the flexible ACSR stranded conductors bus bar is also supported from the two ends which is the strain insulators selected for the 132Kv Busbars.

Protective relays of Network Design and Automation

When the fault occurs then the protective relays will also operate as well as it also sends to the trip signal to the circuit breakers. A relays was housed in the panels of the control room as well as in the Ring Main units.

Lightning arrestors (Surge Arrestors)

The lightning arrestors will also protect the equipment of substation from the switching as well as lighting surges.

Earthing Switch of Network Design and Automation

The earthing which is usually connected among the earth and line conductor as well as it is also mounted on the isolator frame. It is normally open to the position, where the line is also disconnected the earth switch and it is closed to discharge and trapped the charges to earth.

Station earthing system of Network Design and Automation

A station earthing system function is to provide the low resistance path for the flow of earth with the fault currents as well as also for the protection devices for proper operation along with the safety equipment as well as personnel (Electrical-engineering-portal.com, 2019).

Cable size selection of Network Design and Automation

The methods of cable sizing as well as calculation for the electrical cable. The objective of its report is developing the effective cable sizing model for the design of substation of factor design on the industrial states. Cable sizing is very important at the design stage because the cable sizing is to function endlessly under the full load condition where the exclusive being is damage (Edvard, 2017).

Sizing cable methods is following the unchanged process;

·         Collect the data about the cables

·         Installation  surrounding

·         Load that it will carry

There are basic steps which determine the cable sizing and the voltage drop as shown in the below figure;

Figure: Determine the cable sizing

Cable selection sizing formulation of Network Design and Automation

The rating of the installed current which is calculated through the multiplying of base current rating by the every derating factor;

Whereas is installed rating current (A), and base current rating, and  product of derating factor.

The cable requires only to be sized to the cater for the full load current of the motor;

Full load current,  protective device rating, and  installed cable current rating

For single circuit of Network Design and Automation

=0.725 otherwise =1. = 0.9. For cables installed above ground = 1. Ca= Ambient temperature, = Soil resistivity, =dept of burial, = Thermal Insulation, = the value of current for ingle circuit at ambient temperature. For cables installed above ground  and  =1.

For group of Network Design and Automation

Cables’ having cross sectional area 16mm 2 or less, design value of mV/A/m is obtained by multiplying tabulated value by factor given by (Nair et al , 2016):

Fault level studies of Network Design and Automation

The outdoor open terminal 132Kv switchgear shall not be considered for 132kv/11kv BSPS either there are new installations for the existing assets which can be replaced. A cost differential among the outdoor as well as indoor alternative I now generally open terminal arrangement of outdoor where ether is no longer offer for the economic solution of life time cost is taken into the account.

For the given design of factory as shown in the below figure, the outdoor layout also added the risk failures due to the environmental as well as visual amenity. Thus the requirements for the land of the factory design on the industrial estate for the open terminal arrangement is supposed and it greater then the indoor switchgear which is supposed the bearing cost and the values of land are not premium.

Figure: Factory design

Fault level consideration  of Network Design and Automation

The network planning in order to ensure the correct IDMT for the protection system which is also operating below the reasonable as well as normal abnormal condition where the network should also be planned as well as arranged.

 (Cuddihey, 2017)

 Tapings of distribution transformers

A tapings which could also be paced either on Low voltage winding and high voltage windings. Normally a tapping is provided the High voltage winding.

The fine voltage regulation is also possible by the high voltage winding which is also carries the large number of turns (Ukpowernetwork, 2012).

A low voltage winding for the transformer which is also carries the large current.

132kv Lower voltage transformer

The winding of transformer is 132kv which should be the star connected by the non-uniform insulation like the defined IEC 60076. The 11kv and 33kv winding should also have the uniform insulation like the IEC 60076. On 132/11kV Star/Star Vector Group Transformers a tertiary winding shall be providing. This shall be rated at 30% of a transformer rating (Warrington, 2005).

Design of substation layout

Substation layout

Design of Network Design and Automation

The blow design is 132kV/11kV substation and includes the entire 11kV network up to each factory substation including the 400V main circuit breaker on the LV side of the transformer.

SCADA system to monitor and control

SCADA system is typically control system and in the present analysis it controls and monitor the network. The process increases money and profitability with the implementation conditions. The implementation system can be sinkhole of cost overruns, limited capabilities, and delay. The essentials of SCADA network technology evaluated parameters measure the best network fit for the system. In the SCADA networks for the network and delivery to substations, there are two main elements. The process is required to monitor and control power plant, water system, delivery of services to the substations, and critical infrastructure. The network combines intelligent devices with the suitable interfaces in the system control output and sensors. The SCADA system can be used to improve the control factor. In the electric power generation, distribution and transmission, SCADA system is designed to detect the current flow and line voltage. The process also measures and monitor the operation of circuit breaker and sections of power grid offline and online. The normal functionality of SCADA is to control the remote equipment from the operation centers.

Recommendation for SCADA functionality

The SCADA functionality can be used for the improved outcomes with all on-site equipment and survive under different conditions. The exceptional functionalities are as follows,

1.      Enough capacity that provide support to the equipment.

2.      Rugged construction with the ability to the withstand and how the services will be delivered under the extreme conditions of humidity and temperature.

3.      SCADA network is secure and redundant power supply. 

Figure 1: A typical SCADA system

Source: https://www.researchgate.net/figure/A-typical-SCADA-system_fig1_330133572

Conclusion of Network Design and Automation

Summing up all the discussion it is concluded that the report is about the design of the substation 132kv/11 kV for the factor design on industrial estates. All the requirement and the different points which is mentioned are achieved.