The working principle of the self-excited DC generator in series is that the magnetic field coil is connected in series with the armature winding and the output of the generator, so this type of generator is called DC generator. serial coil excitation current The magnetic field that flows through the magnetic field coil of this generator is It is the same as the current that the generator supplies to the load, so we make the output voltage depend on the current flowing through the load.
The mixed DC generator is to bring the advantages of the generator. Direct current in parallel and in series are combined into one device, becoming a hybrid generator. This is an even better feature. Types of DC generators can be divided according to the circuit connection characteristics of the coil. A magnetic field has two characteristics:
The stator steel core is the part used to wind the armature coil. The stator steel core is made of thin steel sheet. stacked by reason to design The stator steel core to look like this It is to reduce losses due to hysteresis (Hysteresis Loss) or the loss of magnetic lines created by the coil. with eddy currents in the steel core (Eddy Current Loss) and the steel core also It is a thin soft iron which contains silicon compounds. When they are stacked together, they are made possible. Steel core with greater strength In addition, each steel plate has grooves. air for cooling There are 3 types of stator core grooves which are
A rotating float with a winding embedded around the rotor axis. by the rotor will produce from a dense silicon sheet with an insulating barrier In order to create a eddy current which the electric current is obtained from the exciter, the rotor can be divided into two types.
Salient – Pole Type rotor is used in low speed generators. or medium-speed generators such as generators that use upstream power as water turbines of various dams
Smooth (Cylindrical Type) rotors are used in generators powered by turbine or gas turbines with high rotational speeds of approximately 1,500 rpm and 3,000 rpm. The rotor is a sheet of steel sheet stacked in a long cylinder shape. They are smaller in diameter than the standing pole rotor. The smooth pole rotor is more balanced than the extended pole type and reduces power loss. because of the friction of the wind and centrifugal force to escape the center while rotating is driven at the speed itself
Damper coil will look like a copper bar which is embedded at the surface area The face of the rotating magnetic pole They are short-circuited to the copper rings on both sides of the rotor. The damper windings prevent vibration or oscillation when the generator speed is uneven.
Parts that produce and supply DC power to coils Alternator Magnetic Field Wire where Exeter will be installed. in the same shaft position as the generator However, large generators It uses a batteryless exciter or a Brushless Generator for convenience. in maintenance compared to the use of slippings and carbon brushes In addition, the system excitation complete magnetic coil There is still no need to use an external power source to stimulate it. Instead, the pilot exciter is mounted in the shaft position of the rotor. which is a small 3-phase alternator with a rotating magnetic pole Permanent Magnet
Objective
to study the transformation of mechanical energy into electrical energy using a bicycle dynamo
Theory
A dynamo is a type of generator that can convert mechanical energy into electrical energy by Michael Faraday. “Inductive current is caused by a change in the magnetic field that passes through a coil.” The dynamo consists of a coil of conductors and a permanent magnet.
Bike dynamo
This is because bicycles do not have lights like a motorcycle or a car with a battery. and from the principle of converting mechanical energy into electrical energy of dynamo therefore can be adapted to bicycles Because when cycling, it will give mechanical energy and then go to spin a dynamo that has a magnet inside. This causes a change in the magnetic field through the coil and an electric current is induced in the coil conductor. According to Michael Faraday's principle, and make any electrical device or light bulb connected to this dynamo shine. The electric current depends on the rotation speed of the spinning. notice the brightness of the light
Experimental equipment
1. 1 bicycle dynamo
2. The spinning wheel connects the belt to the dynamo head.
3. Light bulb with on-off switch
4. Electrical wires connect the dynamo, electric lamp and switch in a circuit.
5. Plug jack with plug
Experimental method
1. Plug the power jack from the bicycle dynamo into the plug that connects to the light bulb and switch as shown in Figure 4.
2. Turn on the power switch, use 1 lamp, then turn the hand wheel, gradually increasing the speed of rotation. and observe the brightness of the lamp and record the results
3. Repeat the experiment in step 2, but turn on the switch of 2 lamps and 3 lamps respectively.
4. Record the results and summarize the results of the experiment.
Summary of experimental results
The rotation speed of the wheel is related to the electric current (the faster it spins, the more current. making it noticeable that the light bulb is brighter)
light bulb brightness In addition to changing with speed in rotation It also changes according to the number of incandescent lamps used, that is, if one light is switched on, the light is brighter than the 2 light switches on, and two light bulbs are switched on, the light is brighter than the 3 light switches on. even more when the rotation speed is constant)
Generator and is officially called a generator. There will be important equipment inside such as a generator. It is also a common folk name for a generator. because it is a machine that is used to convert mechanical energy into electrical energy Based on the working principle of the magnetic field with the coil cut. Or maybe it's the movement of the coil. To cut off the magnetic field and then come out into electricity that works well. The word generator comes from its full name, dynamo generator. It looks like an engine that has been made to have internal mechanisms. able to produce electricity They are divided into slow cycles or low cycles. and get high speed or high speed with different details as follows
Using a slow drive engine It has been used since ancient times. It is the development of diesel engines to work efficiently. but will work only about 1,500 cycles, which in the market for generators in the past This type of machine is very popular. because it can be directly connected to the diesel engine But with various parts and spare parts, the interior of the slow drive is very large, and the sound is quite loud. Therefore, it is not very popular nowadays.
Fast drying drive or high speed drive It was developed from famous brands to be more modern and functional. Able to produce electricity at approximately 3,000 cycles with development for use in gasoline and direct connection Also known as Direct Coupling, it makes for a versatile use. and reduce the volume of the machine to be smaller The internal parts and spares are not too complicated or overly complicated. therefore lighter weight
With the engine that works at speeds from 30-40 cycles, the price is cheaper than a diesel engine or a slow engine. You can also add gasoline for energy. thus helping to save on fuel costs But at the same time, the high-revving engine can also be adapted for diesel engines. which is mostly used as a bed for water cooling It also needs to be cut to become a belt tool for testing. can provide the same 3000-4000 cycles
The benefits of using the generator drive. There will be several items. Because as you know, every area needs electricity for use. Because if as long as humans still have to use tools, devices or machines that are connected to electricity The use of a generator is important. The benefits are:
The engine is the source of mechanical energy fed to the generator. The size of the engine is directly proportional to the maximum output power at the generator.
There are several factors that must be taken into account while evaluating a generator engine. Consult the engine manufacturer for complete engine operating specifications and maintenance schedules.
Fuel type used - Generator engines run on a variety of fuels such as diesel, gasoline, propane. (in liquid or gas form) or natural gas Small engines usually run on gasoline, while larger engines run on diesel, liquefied propane, propane gas or natural gas. Some engines can also run on both diesel and gas dual-fuel in dual-fuel mode.
An alternator, also known as a 'genhead', is the part of a generator that generates electricity from the mechanical input provided by the engine. It consists of an assembly of movable and moving parts encased in the housing. The components work together to cause the relative motion between a magnetic field and an electric field, which in turn generates an electric current.
Usually, the fuel tank has enough capacity to keep the generator running for an average of 6 to 8 hours. In the case of a small generator, the fuel tank is either part of the generator skid or mounted. located on top of the generator frame For commercial use it may be necessary to build and install an external fuel tank.
The general characteristics of the fuel system are as follows:
- connection of pipes from the fuel tank to the engine The supply line directs the fuel from the tank to the engine and the return line directs the fuel from the engine to the tank.
- Ventilation pipe for oil tank The fuel tank is equipped with a vent hose to prevent pressure or vacuum build-up during filling and draining the tank. When you refuel, make sure there is metal-to-metal contact between the injector and the fuel tank to avoid sparks.
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- Overflow connection from fuel tank to drain This is necessary so that the overflow during tank filling does not cause liquid to spill on the generator set.
- fuel pump This is the transfer of fuel from the main storage tank to the day tank. The fuel pump is generally electrically operated.
- Fuel Water Separator / Fuel Filter This separates water and foreign matter from the liquid fuel to protect other components of the generator from corrosion and contamination.
- fuel injector Atomizes liquid fuel and injects the required amount of fuel into the engine's combustion chamber.
This component controls the generator output voltage. It is a cyclical voltage regulation process. until the generator starts producing an output voltage equivalent to its full working capacity. As the generator output increases, the voltage regulator produces less DC current. When the generator is fully operational, the voltage regulator goes into equilibrium and produces enough DC current to maintain the generator output at full operating level.
It is essential to have a cooling and ventilation system to extract the heat generated in the process. Sometimes raw/fresh water is used as a coolant for generators. But this is mostly limited to situations such as small generators in urban applications or very large units over 2250 kW or more. Hydrogen is sometimes used as a coolant for the stator windings of large generators. Because it is more efficient at absorbing heat than other coolants, hydrogen removes heat from the generator and transfers heat through the heat exchanger to the secondary cooling circuit with demineralized water as the foundry. cool This is why large generators and small power plants often have large cooling towers next to them. For other common applications, both residential and industrial, standard radiators and fans are mounted on the generator and function as the primary cooling system.
is the same as the exhaust from diesel or other gas line engines and contain highly toxic chemicals that need to be handled properly. Therefore, it is imperative to install an adequate exhaust system to remove exhaust gases. This point cannot be emphasized enough, as carbon monoxide poisoning remains one of the most common causes of death in hurricane-affected areas, as people often don't think about it until it's too late.
Exhaust pipes are usually made of cast iron, ductile iron or steel. The exhaust pipe is normally attached to the engine using flexible connectors to reduce vibration and prevent damage to the generator exhaust system. Make sure that the generator exhaust system is not connected to any other equipment. In addition, the operation of the generator must be approved by local authorities or comply with local laws.
Since the generator consists of moving parts in the engine, it must be lubricated. to ensure durability and smooth operation for a long time. The generator engine is lubricated with oil stored in the pump.
**Oil level should be checked every 8 hours of generator operation. Oil leaks should be checked and lubricant should be replaced every 500 hours of generator operation**.
The battery charger allows the generator battery to charge by supplying an accurate 'float' voltage. If the float voltage is very low, the battery will still charge low. If the float voltage is very high, it will shorten the life of the battery. Battery chargers are usually made of stainless steel to prevent corrosion. It is also fully automatic and does not require any adjustments or any settings to be changed. The battery charger DC output voltage is set at 2.33 volts per cell, which is the float voltage. precise for lead acid batteries The battery charger has a separate DC voltage output which will interfere with the normal operation of the generator.
- Electrical starting and shutdown The auto start control panel automatically starts your generator during a power outage, monitors the generator while it is running and automatically shuts down when it is no longer needed.
- engine gauge Different gauges indicate important parameters such as oil pressure, coolant temperature. Battery voltage, engine rotation speed and duration of work Continuous measurement and monitoring of these parameters allow the built-in generator to be turned off when these cross the relevant threshold levels.
- generator gauge The panel also has a meter for measuring the output current and voltage and operating frequency.
- Other controls, phase selector switch, frequency switch and engine control switch. (manual mode, automatic mode) and so on.
Portable or stationary generator Every unit has a customized housing that provides a support for the structure. The frame also allows for a safe grounding.
1. Generators can be used anywhere with ease.
Portable generators can be moved around. suitable for construction since foundation work until the pipe work which has to move the work point Maintenance work by the service team telecommunication satellite broadcasting outdoor event various music events
2. Enhancing work efficiency and consistent power supply
We can choose the number of generators. to have an appropriate amount for the current that you want to use in maintenance work or In the event of a disruption of emergency power supply We can use another generator as a backup at the construction site. The generator will be used as mainstream electricity.
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3. Can be installed to work easily.
to start or stop working of the generator can be done easily compared to other types of motors Start-up takes only 10 to 40 seconds, and we can even automate it. which the installation has both use for emergency pay as mainstream and installed on wheels for mobile on the job site as well
4. Save and control the heat properly.
accumulated heat generated by working have the right proportions and effective compared to other types of motors This makes it possible to save a lot of fuel. The fuel used is easy to find. such as diesel and gasoline
5. It doesn't take long to produce. and reasonable price
Because the engine is a general industrial engine. so production And the delivery of the machines took a short time. It's also inexpensive. and installation can be done easily
- Soundproof enclosure type generator (Canopy/Soundproof Type) The interior is lined with sound-absorbing material all around. low noise Reduces the noise of the generator during operation 30-40% more than an open type generator (open type), with a standard noise level of not more than 85 dB(A). 1 m. The soundproof enclosure can be installed both inside and outside the building. easy to move and is durable
- Open Type Generator consists of a Diesel Engine and an Alternator. Suitable for installation in the machine room or in permanent buildings such as hotels, hospitals, shopping malls. Educational institutions / universities, etc., in which the installation must take into account the appropriate size of the area. ventilation system fuel system Sound proofing and vibration dampening devices, etc. are appropriate according to academic principles.
