SUBSTATION SUBSTATION LAYOUT LAYOUT & & DESIGN DESIGN BISENIO, LORENA B. MAGISTRADO, KENT G. SINFUEGO, JAY B. VILLA, BETTY MAE B. WHAT WHAT IS IS AA SUBSTATION? SUBSTATION? ELECTRICAL SUBSTATION SUBSTATION ELECTRICAL • also known as Network of Electrical Components. • is composed of power transformers, busbars, auxiliaries, and switchgear etc. • The substation receives electrical energy directly from generating stations through incoming power supply lines while it delivers electricity to the consumers through outgoing transmission lines. • A substation is a part of an electrical generation, transmission, and distribution system, where voltage is transformed from high to low, or low to high, or many other important functions. SUBSTATION LAYOUT LAYOUT SUBSTATION Major Task of of Substation: Substation: • It serves as protection hub of the transmission system. • It maintains the frequency of system confined in targeted limits and has to deal with load shedding. • It controls the exchange of electrical energy amid consumers and generating stations. • It is ensuring transient stability along with steady-state stability of the system. • It delivers sufficient line capacity hence securing supply. Major Task of of Substation: Substation: • It helps in reducing the flow of reactive power, hence gaining voltage control. • Through line carrier, it performs data transmission to ensure monitoring of network, protection, and control. • It helps in fault analysis and pinning cause for a failure, hence improving the performance of the electrical network. • It ensures reliable supply through feeding network at numerous points. • It assists in determining energy transfer with help of transmission lines. Four Four major major types types of of electric electric substations: substations: ➢ Switchyard at a generating station ➢ Customer Substation ➢ Switching Substation ➢ Distribution Substation ➢ Switchyard at a generating station - It can be considered as the heart of the power plant. - It is the mediator among the transmission as well as generation, and equal voltage can be maintained in the switchyard. - The main purpose of this is to supply the generated energy from the power plant at the particular level of voltage to the nearby transmission line or power grid. ➢ Switchyard at a generating station - It is an assembly of apparatus which transforms the characteristics of electrical energy from one place to another and controls the flow of power which plays a major role in power quality. - It carries the generated power to the destination and plays a major part in the security of the system. ➢ Customer Substation - Functions as the main source of electric power supply for one (or more) business customers. - The technical requirements and the business case for this type of facility depend highly on the customer’s requirements, more so than on utility needs. - It is a substation that is located on the premises of a larger customer, such as a shopping center, commercial building, or industrial plant. ➢ Switching Substation - Facilitate the transfer of bulk power across the network. - These large stations typically serve as the endpoints for transmission lines originating from generating switchyards. - It enables the transmission of large blocks of energy from the generators to the load centers. - These system stations are strategic facilities and usually very expensive to construct and maintain. ➢ Switching Substation ➢ Distribution Substation - Provide the distribution circuits that directly supply most electric customers. - They are typically located close to the load centers, meaning that they are usually located in or near the neighborhoods that they supply, and are the stations most likely to be encountered by the customers. ➢ Distribution Substation - Distribution type substations are placed where the main voltage distributions are stepped-down to supply voltages to the consumers using a distribution network. - The voltage of any two phases will be 400 volts, and the voltage between neutral and any phase will be 230volts. ➢ Distribution Substation ➢ Distribution Substation DIFFERENT SUBSTATION SUBSTATION LAYOUTS SINGLE BUSBAR SUBSTATION SECTIONALIZED SINGLE BUSBAR SUBSTATION MAIN AND TRANSFER BUS DOUBLE BUS DOUBLE BREAKER SCHEME RING BUS ARRANGEMENT ONE AND-A-HALF CIRCUIT BREAKER ARRANGEMENT SINGLE BUSBAR SUBSTATION - simplest and has an ease of operation and maintenance. - This design has a minimum reliance over signaling for the necessary protection of its operation. - Furthermore, there is a facility for supporting economical operations of feeder bays. | DIFFERENT SUBSTATION LAYOUTS SINGLE BUSBAR SUBSTATION CHARACTERISTICS - There is a circuit breaker for protection of each circuit, hence there is no loss of supply in outages. In case of fault on the transformer of a feeder, circuit breaker results in loss of feeder or transformer circuit which is restored after isolation of faulty circuit breaker. Loss of circuit is involved in the maintenance of the circuit breaker of the transformer of the feeder. There are bypass isolators amid circuit isolator and busbar hence allowing maintenance of circuit breaker without any loss to the circuit. Any fault in busbar is causing loss of a transformer or feeder. Hence, maintenance of a busbar will result in an outage of 2 circuits. | DIFFERENT SUBSTATION LAYOUTS SINGLE BUSBAR SUBSTATION ADVANTAGES - Simple in concept, operation and application. Small land area required and easily expandable. Cost of construction is relatively low. DISADVANTAGES - Reliability is low Failure of a circuit breaker or a bus fault causes loss of the entire substation? Low Operational Flexibility (E.g Outage required on associated element for maintenance of switchgear) SUITABLE WHERE: - Load & Availability requirements are low | DIFFERENT SUBSTATION LAYOUTS SINGLE BUSBAR SUBSTATION | DIFFERENT SUBSTATION LAYOUTS SECTIONALIZED SINGLE BUSBAR SUBSTATION - This arrangement is basically two or more single bus schemes, each tied together with bus sectionalizing breakers. - This type of busbar system uses an isolator and a circuit breaker as a switch. - The isolator disconnects the faulty section of the busbar, hence protects the system from complete shutdown. | DIFFERENT SUBSTATION LAYOUTS SECTIONALIZED SINGLE BUSBAR SUBSTATION ADVANTAGES - The faulty section is removed and disconnected without interrupting the main power supply. - The maintenance of the individual section can be done without disturbing the system supply. - The system has a current limiting reactor which decreases the occurrence of the fault. DISADVANTAGES - Using more than one circuit breaker increases the cost of the system. | DIFFERENT SUBSTATION LAYOUTS SECTIONALIZED SINGLE BUSBAR SUBSTATION | DIFFERENT SUBSTATION LAYOUTS MAIN AND TRANSFER BUS - All elements (transformers and transmission lines) are directly connected to main bus. - There is two busbar scheme, one is main bus and the other is transfer bus. - A main advantage is that whole of the load is transferred to the transfer busbar when maintenance or repair are being done on the main busbar. - The bus coupler is used for transferring the load from one bus to another in case of overloading. | DIFFERENT SUBSTATION LAYOUTS MAIN AND TRANSFER BUS ADVANTAGES - In case of any fault in any busbar the continuity of the supply remains same, because the entire load can be shifted to the another bus. - The repair and maintenance can easily be done on the busbar without disturbing their continuity. - The maintenance cost of the arrangement is less. - It is easy to connect to outgoing feeder from either main bus or transfer bus. - The potential of the bus is used for the operation of the relay. - The load can easily be shifted on any of the buses. | DIFFERENT SUBSTATION LAYOUTS MAIN AND TRANSFER BUS DISADVANTAGES - During normal operation it is just similar to the single bus arrangement – all circuits are connected to the main bus. - The cost of this type of arrangements is increased because of the added transfer bus and switching devices. - The operating reliability is low; a main bus fault will de-energize all circuit and would cause the complete shutdown on the whole substation. SUITABLE WHERE: - Load & Availability requirements are low | DIFFERENT SUBSTATION LAYOUTS MAIN AND TRANSFER BUS | DIFFERENT SUBSTATION LAYOUTS DOUBLE BUS DOUBLE BREAKER SCHEME - Involves two breakers and two buses for each element. - It does not use a bus coupler and extra switches like Main and Transfer Bus Arrangement. - With two breakers and two buses per circuit, a single bus failure can be isolated without interrupting any circuits or loads. | DIFFERENT SUBSTATION LAYOUTS DOUBLE BUS DOUBLE BREAKER SCHEME ADVANTAGES - The supply meets the constant load and in case of a fault, the load is automatically transferred from one bus lane to another - Increased reliability (Bus fault does not affect any element) - Increased Operational Flexibility (Isolation of either main bus or circuit breaker for maintenance without disrupting service.) DISADVANTAGES - The cost of the system is increased because of the two buses and two circuit breakers. Maintenance cost is very high. SUITABLE WHERE: - Reliability and Availability of the circuit is a high priority. | DIFFERENT SUBSTATION LAYOUTS DOUBLE BUS DOUBLE BREAKER SCHEME | DIFFERENT SUBSTATION LAYOUTS RING BUS ARRANGEMENT - Is an extension of the sectionalized bus arrangement and is accomplished by interconnecting the starting point of the bus bar and the endpoint with the help of a ring. - This results in a closed loop or ring with each bus section separated by a circuit breaker. Each section supply only one circuit. | DIFFERENT SUBSTATION LAYOUTS RING BUS ARRANGEMENT ADVANTAGES - Such type of arrangement will provide two paths for the supply. Thus the fault will not affect their working. - Increased reliability (Bus fault limited to affected section & faults to individual elements do not affect the whole circuit.) - Increased Operational Flexibility (Circuit breaker can be maintained without interrupting the supply) - Double feed to each circuit. - No main buses. | DIFFERENT SUBSTATION LAYOUTS RING BUS ARRANGEMENT DISADVANTAGES DISADVANTAGES - There are many difficulties in adding a new circuit. - Overloading occurs on the system if any of the circuit breakers are opened. - Cost of construction is relatively high. SUITABLE WHERE: - Reliability and Availability of the circuit is a high priority. | DIFFERENT SUBSTATION LAYOUTS RING BUS ARRANGEMENT | DIFFERENT SUBSTATION LAYOUTS ONE AND-A-HALF CIRCUIT BREAKER ARRANGEMENT - In this arrangement, three circuit breakers are required for two circuits. - The each circuit of the bus bar uses the one and a half circuit breaker. - Such type of arrangement is preferred in large stations where power handled per circuit is large. - The breaker-and-a-half configuration provides for circuit breaker maintenance, since any breaker can be removed from service without interrupting any circuits. | DIFFERENT SUBSTATION LAYOUTS ONE AND-A-HALF CIRCUIT BREAKER ARRANGEMENT ADVANTAGES - It protects the arrangement against the loss of supply. The potential of the bus bar is used for operating the relay. In such type of arrangement, the additional circuits are easily added to the system. Increased reliability (Bus fault does not affect any element) Increased Operational Flexibility (Can isolate main bus or circuit breaker for maintenance without disrupting service.) DISADVANTAGES - The circuit becomes complicated because of the relaying system. Their maintenance cost is very high. SUITABLE WHERE: - Reliability and Availability of the circuit is a high priority. | DIFFERENT SUBSTATION LAYOUTS ONE AND-A-HALF CIRCUIT BREAKER ARRANGEMENT | DIFFERENT SUBSTATION LAYOUTS ANY ANY QUESTION? QUESTION? THANK YOU! THANK YOU! THANK YOU!
