Electrical Systems PDF

Atoms hold onto their electrons tightly but some materials will hold onto their electrons more tightly than others. Materials which can pass electrons are known as “Conductors” meaning they can conduct electricity. Most Metals are conductors. Atoms which do not have free electrons are known as i...

Atoms hold onto their electrons tightly but some materials will hold onto their electrons more tightly than others. Materials which can pass electrons are known as “Conductors” meaning they can conduct electricity. Most Metals are conductors. Atoms which do not have free electrons are known as insulators, materials like glass and rubber are good examples of this. -end- ELECTRICITY Is the movement of Electrons  ELECTRICITY Transfer of energy through an insulated metallic conduit medium Electricity - A form of energy - Generated by friction, induction or chemical change, having magnetic, chemical and radiant effect - Electrons in motion - Is a property of basic particles of matter, like an atom consists of: a. electrons – negatively charge b. protons – positively charge c. neutron – not electrically charge  Principles of Electricity In the most basic terms, electricity is the movement of electrons. The movement of electrons creates electric current or charge, which is harnessed to do work like power a lightbulb. More specifically, electric current is made up of free electrons that transfer from one atom to the next as they flow through a wire or metal conductor. So the more free electrons a material has, the better it conducts.  Principles of Electricity There are three key elements of electrical charge: Voltage: the difference in charge between two points Current: the rate at which charge is flowing Resistance: a material’s tendency to resist the flow of charge (current) Voltage - is the pressure from an electrical circuit's power source that pushes charged electrons (current) through a conducting loop, enabling them to do work such as illuminating a light. - Electromotive force - In brief, voltage = pressure, and it is measured in volts (V) Volt - Volts (V), measurement for voltage - In electricity's early days, voltage was known as electromotive force (emf). This is why in equations such as Ohm's Law, voltage is represented by the symbol E. - The term recognizes Italian physicist Alessandro Volta (1745-1827), inventor of the voltaic pile—the forerunner of today's household battery. He discovered that electrons flow when two different metals are connected by a wire and dipped into a liquid that conduct or carry electrons Current - Current is the rate at which electrons flow past a point in a complete electrical circuit. - Too much flow of electricity in smaller conductor, heat is produced which may cause problem to fuse or cause the burn of insulator. - At its most basic, current = flow, and is measured in amperes (A) - A current of 1 ampere means that 1 coulomb of electrons - that’s 6.24 x 1018 electrons - is moving past a single point in a circuit in 1 second. Ampere - An ampere (A), or amp, is the international unit used for measuring current. - It expresses the quantity of electrons (sometimes called "electrical charge") flowing past a point in a circuit over a given time. - Symbols used for amps: A = amperes, for a large amount of current (1.000); mA = milliamperes, a thousandth of an amp (0.001); µA = microamperes, a millionth of an amp (0.000001). - Amps are named for French mathematician/physicist Andrè-Marie Ampére (1775-1836) Resistance - Resistance is a measure of the opposition to current flow in an electrical circuit. - It is the friction to the flow of current by the wires and transformers - The higher the resistance, the lower the current flow. All conductors give off some degree of heat, so overheating is an issue often associated with higher resistance. - The lower the resistance, the higher the current flow. Possible causes: insulators damaged by moisture - Resistance is measured in Ohms (Ω) Ohm - Resistance is measured in ohms, symbolized by the Greek letter omega (Ω) - Ohms are named after Georg Simon Ohm (1784-1854), a German physicist who studied the relationship between voltage, current and resistance. He is credited for formulating Ohm's Law. - Ohm's law states that the current through a conductor between two points is directly proportional to the voltage across the two points. Introducing the constant of proportionality, the resistance.  Principles of Electricity Electric Current Is the rate of flow of electric force in a Conductor (flow of electrons) Circuit Electric Current will only flow in a complete loop – known as a circuit  Series Circuit refers to the wire installation that supply currents to lights and convenient outlets Types of Circuit 1. Series circuit – a single path exist for current flow, the elements are arranged in a series one after the other with no branches. Being a single path in a series arrangement, Total voltage and total resistance Parallel Are summation of each respectively 2. Parallel Circuit – also known as multiple connection where the loads are placed across the same voltage constituting a separate circuit. It is the standard arrangement for house wiring connections Electric Current Electric current will only flow in a complete circuit comprising the following: 1. source of voltage (source) 2. a means of opening and closing the circuit (switch) 3. an electric load (load) 4. a closed loop of wiring (type of circuit) Classifications of Electric Current 1. Direct Current (DC) – electricity flows in one direction, from positive to negative (Conventional Flow Theory by Benjamin Franklin). This type of current is mostly seen on electronics 2. Alternating Current (AC) – the electricity constantly reverses direction of flow. It is easily produced, cheaper to maintain, can be easily transformed to higher voltage, can be distributed to far distances with low voltage drop and is more efficient. This type of current is what we widely use for daily electricity. Ohm’s Law Ohm's law states that the current through a conductor between two points is directly proportional to the voltage Ohm's Law is a formula used to calculate across the two points. Introducing the the relationship between voltage, current constant of proportionality, the resistance and resistance in an electrical circuit. V = IR I – current V – voltage R – resistance for direct current 𝑽 𝑽 I= R= 𝑹 𝑰 Series Parallel 𝑽𝑻 𝟏 𝑹𝑻 = or 𝑹𝑻 = 𝑹𝟏 + 𝑹𝟐 + 𝑹𝟑 … 𝑰𝑻 𝟏 𝑹𝟏 + 𝟏 𝑹𝟐 + 𝟏 𝑹𝟑 … 𝑰𝑻 = 𝑰 𝟏 = 𝑰 𝟐 = 𝑰 𝟑 … 𝑰𝑻 = 𝑰𝟏 + 𝑰𝟐 + 𝑰𝟑 … 𝑽𝑻 = 𝑽𝟏 + 𝑽𝟐 + 𝑽𝟑 … 𝑽𝑻 = 𝑽𝟏 = 𝑽𝟐 = 𝑽 𝟑 … Energy - Energy, in physics, the capacity for doing work. It may exist in potential, kinetic, thermal, electrical, chemical, nuclear, or other various forms. Energy can neither be created nor destroyed. - The SI derived unit used to measure energy or work is Joule. One joule is equal to the energy used to accelerate a body with a mass of one kilogram using one newton of force over a distance of one meter. Electric Power - In physics, electric power measures the rate of electrical energy transfer by an electric circuit per unit of time. Denoted by P and measured using the SI unit of power which is watt or one joule per second. Electric power is commonly supplied by electric batteries and produced by electric generators. Watt - is the rate or measure of power used or consumed. It represents the equivalent heat volts and ampere consumed by lights, appliances or motors. - The watt is a measure of the rate of energy transfer over a unit of time, with one watt equal to one joule (J) per second: - Named after a Scottish instrument maker and inventor James Watt Electrical Power Power is the product of voltage and Working Power is expressed as kilowatts (kW) and is the “true”or“real” power used by all electrical appliances to current expressed in watts. A kilowatt is perform the work of heating, lighting, moving, etc. Resistive equivalent to 1000 watts loads are loads that use true or real power. Common resistive loads include electric heating and lighting. P = IV Reactive Power is an Inductive load, such as a motor, I – current compressor or ballast that requires reactive power to V – voltage generate and sustain a magnetic field needed to operate. P – power (watts) Reactive power is often referred to as non-working power and expressed as kilovolt-amperes-reactive (kVAR). Power Efficiency Apparent Power is the ratio between working power and Power factor is a measure of how effectively reactive power. Every home and business has both resistive you are using electricity. is the ratio of working and inductive loads. The ratio between these two types of power to apparent power, or kW / kVA. For loads becomes important as more inductive equipment is example, an operation runs at 100 kW (working added. Apparent power is called kilovolt-amperes (KVA) power) and the apparent power meter records 125 kVA. Dividing 100 kW by 125 kVA yields a power factor of 80 percent, meaning only 80 percent of incoming power does useful work. Voltage Drop Wires carrying current always have inherent resistance, or impedance, to current flow. Voltage drop is defined as the amount of voltage loss that occurs through all or part of a circuit due to impedance. Excessive voltage drop in a circuit can cause lights to flicker or burn dimly, heaters to heat poorly, and motors to run hotter than normal and burn out. This condition causes the load to work harder with less voltage pushing the current. The National Electrical Code recommends limiting the voltage drop from the breaker box to the farthest outlet for power, heating, or lighting to 3 percent of the circuit voltage. Generation of Electricity And the Electricity Grid Source: https://enviliance.com/regions/southeast- asia/ph/ph-renewable-energy-transition (Department of Energy, 2023) Source: https://enviliance.com/regions/southeast- asia/ph/ph-renewable-energy-transition (Department of Energy, 2023) Power Plant A power station, also referred to as a power plant and sometimes generating station or generating plant, is an industrial facility for the generation of electric power. The energy source harnessed to turn the generator varies widely. Most power stations in the world burn fossil fuels such as coal, oil, and natural gas to generate electricity. Clean energy sources include nuclear power, and an increasing use of renewables such as solar, wind, wave, geothermal, and hydroelectric. Power stations are generally connected to an electrical grid. Electromagnetic Induction Electromagnetic Induction was discovered by Michael Faraday in 1831 and was described as Faraday’s law of induction. Electromagnetic Induction is a current produced because of voltage production (electromotive force) due to a changing magnetic field. This either happens when a conductor is placed in a moving magnetic field (when using an AC power source) or when a conductor is constantly moving in a stationary magnetic field. Electromagnetic Induction As per the setup given on the right, Michael Faraday arranged a conducting wire attached to a device to measure the voltage across the circuit. When a bar magnet is moved through the coiling, the voltage detector measures the voltage in the circuit. Through his experiment, he discovered that there are certain factors that influence this voltage production. They are: 1. Number of Coils: The induced voltage is directly proportional to the number of turns/coils of the wire. Greater the number of turns, greater is voltage produced 2. Changing Magnetic Field: Changing magnetic field affects the induced voltage. This can be done by either moving the magnetic field around the conductor or moving the conductor in the magnetic field. Generators Many power stations contain one or more generators, a rotating machine that converts mechanical power into three-phase electric power. The relative motion between a magnetic field and a conductor creates an electric current. Motors An electric motor is a machine that converts electrical energy into mechanical energy. Most electric motors operate through the interaction between the motor's magnetic field and electric current in a wire winding to generate force in the form of torque applied on the motor's shaft. Stator and Rotor Stator refers to the stationary component in an electric motor or generator. It is the part of the motor or generator that remains fixed. Itis typically composed of a series of coils or windings that generate or receive magnetic fields to facilitate the operation of the motor or generator. While the rotor (the rotating part) spins. In an electric motor, the stator serves to produce a rotating magnetic field when an electric current flows through its coils. This magnetic field interacts with the magnetic field produced by the rotor, resulting in the generation of force and torque that drives the rotation of the motor. In a generator, the stator acts as the component that receives the magnetic field produced by the rotor. As the rotor rotates, the changing magnetic field induces an electric current in the coils of the stator, generating electrical energy. Electric Power Generation - Most of the electricity is produced in steam turbines - A turbine converts the kinetic energy of a moving fluid (liquid or gas) to mechanical Energy - Steam turbines have series of blades mounted on a shaft against which steam is forced, thus rotating the shaft connected to the generator which produces electricity The Electrical Grid Electrical power travels from the power plant to your house through a system called the power distribution grid. National Grid Corporation of the Philippines (NGCP) The National Grid Corporation of the Philippines (NGCP) is the transmission system operator. It is in charge of operating, maintaining, and developing the country's state-owned power grid, controls the supply and demand of power and updates the daily power situation outlook for Luzon, Visayas, and Mindanao power grids Transformer Is a device that transfers electric energy from one alternating-current circuit to one or more other circuits, either increasing (stepping up) or reducing (stepping down) the voltage. A transformer is an electrical device that takes electricity of one voltage and changes it into another voltage. Types of Transformer Step-up transformers convert low voltages to high voltages. Note that there are more turns on the secondary coil. Step-down transformers convert high voltages to low voltages. Note that there are less turns on the secondary coil. - A power plant generates around 25,000V - A power station steps up the voltage to 345,000V so it can be transferred through power line - A substation steps the voltage down to 100,000 V - A distributing substation steps the voltage down to 20,000 V - A step-down transformer outside your house steps the voltage down to 240 V Substation A substation is a part of an electrical generation, transmission, and distribution system. Substations transform voltage from high to low, or the reverse, or perform any of several other important functions. Service Transformer A distribution transformer or service transformer is a transformer that provides a final voltage transformation in the electric power distribution system, stepping down the voltage used in the distribution lines to the level used by the customer. If mounted on a utility pole, they are called pole- mount transformers. If the distribution lines are located at ground level or underground, distribution transformers are mounted on concrete pads and locked in steel cases, thus known as pad-mounted transformers. Electrical Distribution Single Phase Three Phase Single-phase power is a two-wire alternating Three-phase power is a three-wire ac power current (ac) power circuit. Residential homes circuit. Commercial and industrial facilities usually are usually served by a single-phase power use a three-phase supply. Three-phase power supply. Single-phase power supplies are most supply better accommodates higher loads. A commonly used when typical loads are three-phase power supply delivers power at a lighting or heating, rather than large electric steady, constant rate and therefore much motors. Single-phase systems can be derived efficient than single phase. from three-phase systems. Electrical Distribution 230V 60Hz The main voltage and frequency to be used for the load schedule. It is the mean voltage and AC power most residence receives Rectifier Inverter A rectifier is an electrical component that An inverter is an electrical component that converts alternating current (AC) to direct converts to direct current (DC) to alternating current (DC). current (AC).  AEC - Angeles Electric Corporation ANECO - Agusan del Norte Electric Cooperative, Inc. BELS - Bauan Electric Light System BEZ - Balamban Enerzone Corporation Private Distribution Utilities BLCI - Bohol Light Co., Inc. BOHECO - Bohol Electric Company Private Distribution Utilities are electric distribution CEDC - Clark Electric Distribution Corporation companies that are owned by private entities. CELCO - Camotes Island Electric CELCOR - Cabanatuan Electric Corporation CEPALCO - Cagayan Electric Power and Light Co., Inc. COLIGHT - Cotabato Light and Power Company, Inc. DECORP - Dagupan Electric Corporation DLPC - Davao Light and Power Company, Inc. FICELCO - First Catanduanes Electric Cooperative, Inc. IEC - Ibaan Electric Corporation ILPI - Iligan Light & Power, Inc. LEZ - Lima Enerzone Corporation LUECO - La Union Electric Company, Inc. MARELCO - Marinduque Electric Cooperative, Inc. MEPC - MORE Electric and Power Corporation MECO - Mactan Electric Company, Inc. MEZ - Mactan Enerzone Corporation Meralco - Manila Electric Company PECO - Panay Electric Co., Inc. SFELAPCO - San Fernando Electric Light and Power Co., Inc. SEZ - Subic Enerzone Corporation SURNECO - Surigao Del Norte Electric Cooperative, Inc. TEI - Tarlac Electric, Inc. VECO - Visayan Electric Company, Inc.