How Do Generators Work?
Nowadays, power outages have become quite common. A major reason for this is the growing demand of electricity due to the increase in the number of consumers. Moreover, since everything is done through home appliances and smart devices, electricity is needed for virtually everything in today’s world. With these increasing shortages, people have to look for alternative sources of power, or backup power, and generators are one of the most suitable options for this purpose.
Electrical generators are machines that produce electricity and supply it when the local grid is shut off. They can be of different types: portable generators, industrial generators, residential generators, etc. Plus, they can be used to power up homes, offices, industries, and even an entire apartment building. In areas where there is no electrical system, such as rural areas and mining districts, generators are also used as the primary source of electricity.
Whatever your need, having a generator is always useful, since you may never know when the power goes out. You can find generators in different sizes, and they are marked by their power rating. So, you can find a portable generator that has a power output of 100W, and you can even find huge power generators that provide up to 20,000MW of power!
If you aren’t aware of how much power you would require for your home or office, you can enlist the services of an electrician in Vancouver to help you find out how big of a generator you need. Then, the same electrician would also be able to help you with the installation and configuration of the generator.
In case you are wondering how a generator works and provides electricity in such large quantities, give this article a read and you will be able to understand everything in detail. Without further ado, let’s get into it.
The Main Components of a Generator
Whether you have a portable generator or an industrial generator, all of them have some common components. The sizes of these components vary according to the size of the generator, and the ones with a larger power output may have some more components as compared to the low output options.
Here are some of the main components that make up generators.
Engine
The engine is the heart of any generator. It runs and supplies mechanical energy to the generator, which is then converted into electrical energy. The power rating that you read on the generator’s body is actually the amount of power generated by the engine itself. You may find different types of engines inside generators, and they also differ in the type of fuel they run on, i.e. gas, diesel, petrol, etc. Typically, smaller engines run on gasoline, whereas larger engines make use of diesel, propane gas, or liquid propane.
Engines also come in two different configurations: Overhead Valve (OHV) and non-OHV. In the former, you can find the intake and exhaust valves mounted on the head of the engine cylinder whereas in non-OHV engines, these are located on the engine block. In terms of performance, OHV engines are much better and more compact. Moreover, they also produce less heat and less noise, making them particularly suitable for homes and offices.
Another useful feature in the OHV engine is the Cast Iron Sleeve, or CIS, which is located inside the cylinder and reduces wear and tear inside the engine, thus enhancing its durability and life span. It isn’t an essential feature that you should have in your generator, but it has an important role to play.
Alternator
Along with the engine, the alternator is also a crucial component of your generator. Also known as the ‘genhead’, it is connected to the engine and its primary responsibility is to receive mechanical energy from the engine and convert it into electrical energy. The alternator has many small fixed and moving parts that work in tandem to generate electricity from the mechanical energy supplied to it.
The stator is one of the stationary components inside the generator, and it has a set of electrical conductors that are surrounded by copper coils and placed over an iron core. The moving component is known as the rotor or armature, and it produces a magnetic field through different methods, such as:
• By induction, with the use of brushless alternators
• By permanent magnets in small alternators
• By using an exciter, which produces a small DC current to power up the rotor
The rotor creates a rotating magnetic field around the stator, thus creating a voltage difference in the copper windings of the stator. This produces the AC current that the generator outputs to the electrical system. The efficiency of the alternator is dependent on a number of factors, such as the material with which its housing is made, the use of ball bearings, and also whether the alternator has brushes or a brushless design.
Fuel System
The fuel system comprises the fuel tank, fuel pump, and a pipe that supplies fuel to the engine from the tank. The fuel tank has enough capacity to keep the generator-powered up for 6 to 8 hours, regardless of its power output or size. Usually, the fuel tank is mounted on top of the generator body, but in industrial or commercial generators, there may be an external fuel tank. Along with the pipe that supplies fuel to the engine, there is also a return line that throws back any fuel that isn’t used at the moment.
Moreover, there is also a ventilation pipe inside the fuel tank, which is responsible for dissipating any pressure or vacuum created inside the tank during its filling or draining. An overflow connection is also set up between the fuel tank and the drainpipe so that if you accidentally fill the tank more than its capacity, the excess fuel will flow through to the drainage instead of coming out from the opening.
Next, the fuel pump moves fuel from the tank to the engine, where an injector sprays it into the combustion chamber, causing the piston inside the engine to move and rotate the crankshaft, which in turn moves the flywheel. The fuel always goes through a fuel filter to remove any water or debris from it, so that the generator doesn’t corrode or malfunction.
Voltage Regulator
The mechanical energy that is converted into electrical energy by the alternator isn’t controlled, and the voltage regulator is installed inside the generator for this purpose. In most cases, the regulator will also convert the AC current to DC current, if required. It outputs a fixed voltage, no matter what its input voltage or other factors may be. The regulator transfers this current to the exciter windings that are installed in the stator.
The exciter windings receive the DC current and they are responsible for converting it back into AC current. They are further connected to rotating rectifiers, which ‘rectify’ the AC current and convert it back into DC current. Next, this current is transferred into the rotor, which generates an electromagnetic field and converts DC current into AC voltage, and induces it across the stator windings, which helps in producing a much larger AC voltage output.
This process keeps repeating itself until the generator reaches its defined output voltage capacity. Once the voltage output starts to increase, the amount of DC current produced by the regulator keeps decreasing. Eventually, a state of equilibrium is reached. The regulator only produces enough DC current to maintain the generator’s output voltage.
Cooling System
Since the generator runs at a high RPM, generators can produce a lot of heat and it is very important to keep them cool, just like with any engine. Therefore, the cooling system is present in every generator to make sure that the generator doesn’t overheat and start to malfunction. There are different types of liquids used for keeping the generator cool.
In most portable generators, raw or freshwater is used as a coolant and in large power generators, hydrogen is one of the most common coolants being used. It absorbs heat better and helps greatly in cooling down the stator windings, which have a lot of current running through them. Hydrogen moves the heat from the generator to a cooling circuit by a method called heat exchange.
Once the heat is transferred to the cooling circuit, de-mineralized water inside the circuit helps in reducing the temperature and maintaining a smooth operation. In common residential and commercial generators, you can find a radiator and exhaust fan, which help keep the generator at its optimum temperature.
The generator should always be installed with adequate clearance space on all sides, especially in industrial applications. Moreover, it is also important to monitor the coolant levels from time to time to avoid overheating or any error inside the generator.
Exhaust System
Next comes the exhaust system, which is fitted with the cooling system. Its job is to remove any fumes from the generator, thus keeping it functioning smoothly and without any problems. These fumes contain a lot of toxic substances that can be dangerous for your health. The generator contains metal pipes that are held together using flexible connectors so that they can’t come loose due to the vibrations from the engine.
Whether you have installed the generator at your home, office, or factory, it is very important that the exhaust pipe from your generator should lead outdoors and not in front of any doors or windows, as it can be quite suffocating if you inhale the fumes coming from your generator. Therefore, ensuring that your generator has a working exhaust system is crucial to its performance.
Lubrication System
Generators have lots of small and large mechanical parts that work together to produce electrical energy, which means that there is a lot of friction that needs to be taken care of. Therefore, the lubrication system is installed inside the generator to keep the parts well-oiled, so that they can perform smoothly.
The lubrication system consists of an oil pump that stores engine oil or lubricant. Every now and then, the pump moves a small amount of oil towards the machinery, so that it keeps moving smoothly and its function isn’t impaired in any way. Make sure to keep an eye on the oil level, especially if your generator runs for a few hours every day.
Battery Charger
Most generators come with an ignition system, where you turn the key to start it. Other generators have a rope that you pull on to turn the flywheel and start the engine. Whichever the case, there is a battery installed inside generators that gives it the required voltage to begin its operations. This is known as the ‘float voltage’.
A battery charger is also installed with the battery, and its job is to maintain the float voltage of the generator so that it doesn’t increase or decrease the efficiency of the battery. The voltage output of the charger is different from that of the generator, and it doesn’t interfere with the normal function of the generator.
Control Panel
The control panel is mostly present on the larger industrial generators, and you may have seen them on the Hyundai or Generac generators in your office or your site. This panel is used to start up and turn off the generator, as well as to control the running speed or RPM. Some of the modern generators also come with sensors that turn off the generator automatically if the power from the main grid goes out.
Most commercial and industrial generators also have engine gauges that output different readings, such as the oil level, battery voltage, coolant level, voltage output, and also how long the generator has been running. These readings make it easy for you to ensure the smooth operation of your generator.
Moreover, the control panel may also feature meters for operating frequency, as well as output current and voltage. Depending on its model, you can also find different switches to control the function of your generator.
Frame
The frame, or body, of the generator, holds all of the main components in place. Most of the portable generators also have wheels underneath their frame, which makes it easy to move them around. Usually, frames are also earthed properly, so that you don’t accidentally get electrocuted in case the current makes it way to the metal frame of the generator.
Be it a Generac generator or a Cummins generator, these components will be present inside it, and they are crucial to making the generator work properly.
How Does a Generator Produce Electricity?
When all of the aforementioned components work together, it produces electricity at a certain voltage, which you can harness by connecting a plug to the power outlet on your generator. The plug is connected to a thick wire with two or three cores and on the other end, there is another plug that goes into a wall socket that is connected to your electrical panel. This socket may be wired directly inside the main breaker, which means that all of your home or office’s electrical sockets, lights, and other electrical fixtures will receive electrical power.
The other thing to do is to connect the wire from the socket separately into different circuit breakers. This way, you can control which parts of the house receive power and which ones don’t, especially if you have a generator that simply can’t bear the load of the entire house. You can do the same for offices and industries.
How to Determine the Power You Need?
When choosing a generator, the important question is how much power will you actually need. As mentioned above, generators come in different power ratings, ranging from 100W to 20,000MW. Choosing the right power rating or size is highly crucial, as it can protect you from electrical damage, unnecessary operational expenses, and also system failure.
Determining the power required depends on what you need a generator for. Your choices can vary between home use, office use, industrial use, commercial use, etc. For homes and offices, you won’t need any more than 5000W to 7000W, no matter how big it may be. In both settings, the main electrical components are lighting fixtures and electrical appliances, which can be easily managed in this power rating.
If you are looking to run your HVAC system or air conditioner on the generator too, then you may have to take up the power requirement to 10,000W, but no more than that. So, you can safely choose between 1kW and 10kW generators for the home. But if you have a lot of large appliances or have a larger home with more people living in it, then you can opt for a generator greater than 10kW power, but no more than 50kW.
Typically, offices can also be covered in this category but if you have a large company with hundreds of employees, then your power requirements may stretch anywhere between 50kW and 100kW. If you are looking to cater to an office scattered across 8 or more floors, then you may need to increase the power rating between 100kW and 200kW.
For industries and factories, you will definitely need a lot more power than you do for your home since you have to run heavy machinery as well. If you have a small industry, you may make do with a generator that has a power rating between 200kW to 400kW. However, if you have a large industry with a lot of heavy machinery and other electrical components, you will definitely need to go for power generators that offer a power output exceeding 500kW.
The best way to find out your power requirements is to measure your peak power output or energy consumption, i.e. the electricity consumed when all the electrical appliances inside your home, office or industry are running at the same time. You can do so by using an ammeter and making the required calculations to arrive at the precise figure.
This culminates in our guide on how generators work. Hopefully, you have a better idea about the operations of your generator than you did before reading this article. If you are looking to buy a generator and get it installed, make sure to employ the services of a trusted and reliable electrician in Vancouver who can guide you through the entire process and also give proper consultation.