Automatic Transfer Switch using microcontroller Higher Technological Institute Electrical Department Automatic Transfer Switch using microcontroller Graduation Project Presentation July 30, 2013 Advisor/Dr Hussein Taraf By/ Heba Mohamed Mohamed Farouk Abdallah Mohamed Mohamed Ali

Starting Quotation… EXIT HOME PAGE Power failure or outage in general does not promote development in the public and private sector. Investors do not feel secure to operate in a country with constant or frequent power failure. Most industrial and commercial processes are dependent on electrical power. The need for continuous power supply and its reliability has increased rapidly over the years, especially in all those areas where uninterrupted power supply is a must. Modern systems are power dependent. Their complexity has increased as continuous information and communications are needed to control automated process, be it in industries, commercial complexes, hospitals, hotels and airports. EXIT HOME PAGE

So, The need for independent standby power system has therefore increased . So it is necessary to use either ups or the transfer switches as alternative power source. AND NOW What is the difference between ups and transfer switches? EXIT HOME PAGE

We will notice that The difference between them lies in the difference in the dark time Where dark time can be defined as the time where there is no current load. So the following graph shows this difference: EXIT HOME PAGE

In UPS there is no dark time. EXIT HOME PAGE

However, there is a dark time in ATS. EXIT HOME PAGE

Transfer switches: EXIT HOME PAGE Transfer Switches allow switching from a primary power source to a secondary power source and are employed in some electrical power distribution systems; most often transfer switches can be seen where emergency power generators are used to back up from the utility source. The transfer switching allows safely switching from utility power to emergency generator power while maintaining isolation of each source from the other. EXIT HOME PAGE

EXIT HOME PAGE The Transfer switches may be Manual Automatic Combination between manual and automatic 2013 EXIT HOME PAGE

● Manual transfer switches Manual transfer switch are simple toggle type switches that can be manually turned on or off to transfer the source of power to the back-up. 2013 EXIT HOME PAGE

● Automatic transfer switches Automatic transfer switches, on the other hand, do not require any mechanical action. These automatically transfer power from one source to another. They are extremely convenient to use and do not need to be toggled manually. 2013 EXIT HOME PAGE

So, let us illustrate our project theme…… EXIT HOME PAGE

The purpose of this project is to design and construct an automatic changeover switch that provides a solution to the erratic power supply problem we are facing today. The automatic changeover switch is a unique switching system that can be used to effect the change from one power supply to another as well as to ensuring consistency in the supply to a particular network or load. The another function of changeover switch is to interface between two different electrical power sources (the mains supply and the generator). EXIT HOME PAGE

ATS theory: EXIT HOME PAGE

EL0: emergency load zero , EL1: emergency load one , EL2: emergency load two , EL3: emergency load three , EL4: emergency load four EXIT HOME PAGE

EXIT HOME PAGE what is the sequence of operation in ATS project??? So,

EXIT HOME PAGE (1) Main exists: Simulated by connecting the main supply socket (main lamp will light up). load is supplied from the main supply (load lamp will light up). Main Contactor ON Generator Contactor OFF Engine OFF EXIT HOME PAGE

(2) Main fails: EXIT HOME PAGE

Generator contactor ON Main return (3) Main return: Delay Generator contactor ON Main Contactor ON Delay Engine cooling Fuel solenoid OFF EXIT HOME PAGE

Timing model of operation: The following graph clarifies the operating time of each case operation: EXIT HOME PAGE

Where :- - T1 Delay to start. - T2 Start sequence time. - T3 Generator builds up time. - T4 Main returns delay. - T5 Engine cooling time. - T6 Transition time. - T Dark time. EXIT HOME PAGE

Flow chart of the circuit : EXIT HOME PAGE

Circuit diagram: EXIT HOME PAGE

And now, let us talk about diesel generator?.... EXIT HOME PAGE

Diesel generator : EXIT HOME PAGE

A diesel generator is the combination of a diesel engine with an electrical generator (often an alternator) to generate electrical energy. Diesel generating sets are used in places without connection to the power grid, as emergency power-supply if the grid fails, as well as for more complex applications such as peak-lopping, grid support and export to the power grid. Sizing of diesel generators is critical to avoid low-load or a shortage of power and is complicated by modern electronics, specifically non-linear loads. EXIT HOME PAGE

Diesel generators are capable of providing power at various sites where power is required like civil work and construction sites as well as are also employed in various facilities as emergency power source for critical equipment like medical equipment in hospital, bank online system and traffic signals etc. EXIT HOME PAGE

General inspection : EXIT HOME PAGE

In our project we use the microcontroller for controlling the project we will show what is the microcontroller briefly…….. EXIT HOME PAGE

Microcontroller: EXIT HOME PAGE A microcontroller (sometimes abbreviated μC, uC or MCU) is a small computer on a single integrated circuit containing a processor core, memory, and programmable input/output peripherals.Program memory in the form of NOR flash or OTP ROM is also often included on chip, as well as a typically small amount of RAM. Microcontrollers are designed for embedded applications, in contrast to the microprocessors used in personal computers or other general purpose applications. EXIT HOME PAGE

Microcontrollers are used in automatically controlled products and devices, such as automobile engine control systems, implantable medical devices, remote controls, office machines, appliances, power tools, toys and other embedded systems. EXIT HOME PAGE

And those are some of classic components which we use for our project……. EXIT HOME PAGE

Miniature Circuit Breaker: A 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 must be replaced, a circuit breaker can be reset (either manually or automatically) to resume normal operation. EXIT HOME PAGE

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. EXIT HOME PAGE

RELAY: A relay is an electrically operated switch. Many relays use an electromagnet to operate a switching mechanism mechanically, but other operating principles are also used. EXIT HOME PAGE

Relays are used where it is necessary to control a circuit by a low-power signal (with complete electrical isolation between control and controlled circuits), or where several circuits must be controlled by one signal. The first relays were used in long distance telegraph circuits, repeating the signal coming in from one circuit and re-transmitting it to another. Relays were used extensively in telephone exchanges and early computers to perform logical operations. EXIT HOME PAGE

SWITCH: In electrical engineering, a switch is an electrical component that can break an electrical circuit, interrupting the current or diverting it from one conductor to another. EXIT HOME PAGE

PUSH BUTTON: EXIT HOME PAGE A push-button or simply button is a simple switch mechanism for controlling some aspect of a machine or a process. Buttons are typically made out of hard material, usually plastic or metal. The surface is usually flat or shaped to accommodate the human finger or hand, so as to be easily depressed or pushed. EXIT HOME PAGE

T a k Y u h n o EXIT HOME PAGE