Electrical Power Systems :
is a network of electrical components used to supply, transmit and use electric power. An example of an electric power system is the network that supplies a region's homes and industry with power - for sizable regions, this power system is known as the grid and can be broadly divided into the generators that supply the power, the transmission system that carries the power from the generating centres to the load centres and the distribution system that feeds the power to nearby homes and industries. Smaller power systems are also found in industry, hospitals, commercial buildings and homes. The majority of these systems rely upon three-phase AC power - the standard for large-scale power transmission and distribution across the modern world. Specialised power systems that do not always rely upon three-phase AC power are found in aircraft, electric rail systems, ocean liners and automobiles. 1- Electrical power generation2- Electrical power transmission 3- Electrical power distribuion What is the component of the electrical power system ?suplies - loads - conductor - capacitor and reactors - power electronic - protective devices - scada system..................................................................................................... Renewable Energy :is energy which comes from natural resources such as sunlight, wind, rain, tides, and geothermal heat, which are renewable (naturally replenished). In 2008, about 19% of global final energy consumption came from renewables, with 13% coming from traditional biomass, which is mainly used for heating, and 3.2% from hydroelectricity. New renewables (small hydro, modern biomass, wind, solar, geothermal, and biofuels) accounted for another 2.7% and are growing very rapidly. The share of renewables in electricity generation is around 18%, with 15% of global electricity coming from hydroelectricity and 3% from new renewables.What are the Mainstream forms of renewable energy ? 1- Wind power 2- Hydropower 3- Solar energy or solar cell ( photovoltaics ) 4- Biomass 5- Biofuel .................................................................................................... Power Transformer : A transformer is a static device that transfers electrical energy from one circuit to another through inductively coupled conductors—the transformer's coils. A varying current in the first or primary winding creates a varying magnetic flux in the transformer's core and thus a varying magnetic field through the secondary winding. This varying magnetic field induces a varying electromotive force (EMF) or "voltage" in the secondary winding. This effect is called mutual induction. What are the main types of transformer ?1- Polyphase transformers 2- Autotransformer 3- Leakage transformers 4- Audio transformers 5- Instrument transformers ( current and voltage transformer ) .................................................................................................... Circuit Breaker : is an automatically operated electrical switch designed to protect an electrical circuit from damage caused by overload or short circuit. Its basic function is to detect a fault condition and, by interrupting continuity, to immediately discontinue electrical flow. Unlike a fuse, which operates once and then has to be replaced, a circuit breaker can be reset (either manually or automatically) to resume normal operation. Circuit breakers are made in varying sizes, from small devices that protect an individual household appliance up to large switchgear designed to protect high voltage circuits feeding an entire city. Circuit breaker contain tow contacts : fixed and movable contact What are the types of circuit breaker ................................................................................................... Power Electronic : is the application of solid-state electronics for the control and conversion of electric power. .................................................................................................... Power cables : A cable is two or more wires running side by side and bonded, twisted or braided together to form a single assembly. In mechanics cables, otherwise known as wire ropes, are used for lifting, hauling and towing or conveying force through tension. In electrical engineering cables used to carry electric currents. An optical cable contains one or more optical fibers in a protective jacket that supports the fibers. What are types of power cables ? Solid Cables with Extruded Polyolefin insulation: XLPE, PE or EPR insulation. Dry-type and wet-type constructions. Self-Contained Cables (cables fully protected within their own metallic/polymeric sheaths): Fluid filled cables (self contained fluid filled - SCFF) with taped insulation with Paper, or PPL tapes, (*formerly termed low pressure oil-filled LPOF). Pre-impregnated gas filled cables: with paper or PPL tapes. Mass impregnated (MI) cables with paper or PPL tapes, draining and non-draining compound types (MIND). Gas Compression Cables (mass impregnated self-contained cores pulled into pre-laid steel pipes, these are indirectly gas pressurised via their flexible membrane sheath). Pipe-Type Cables (insulated cable cores pulled into pre-layed steel pipes and operated in direct contact with the pressurising medium). High-pressure fluid filled (HPFF) with paper or PPL tapes. High-pressure gas filled (HPGF) with paper or PPL tapes. Gas Insulated Lines (metal busbar insulated with a pressurised dielectric gas and supported on spacers within a metallic pipe). SF6 gas. SF6/N2 gas mixture. .................................................................................................... Electrical Protection : Power system protection is a branch of electrical power engineering that deals with the protection of electrical power systems from faults through the isolation of faulted parts from the rest of the electrical network. The objective of a protection scheme is to keep the power system stable by isolating only the components that are under fault, whilst leaving as much of the network as possible still in operation. Thus, protection schemes must apply a very pragmatic and pessimistic approach to clearing system faults. For this reason, the technology and philosophies utilized in protection schemes can often be old and well-established because they must be very reliable. What are the types of electrical protection devices ? 1- Distance protection relays
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