In general, the concept of synchronization means doing several tasks simultaneously in parallel. Synchronous diesel generators are for applications that require two or more diesel generators to be used simultaneously. This happens when a generator alone does not meet our needs as a generator. The most important purpose of synchronization in all types of diesel generators is to increase the power consumption.
Synchronous diesel generator
The simultaneous use of two or more diesel generators to produce more power or ensure electricity production is called synchronous diesel generator. The diesel generator consists of three main parts: the generator, the engine and the control panel, and electricity is generated by the rotation of the engine and the creation of a rotating field. Similar synchronous generators do the same on a larger scale.
When synchronizing diesel generators, if the voltages produced by two or more diesel generators are not in the same phase (the voltages can be single-phase or three-phase), in addition to damaging all devices, a high-pressure internal current is created, which is very dangerous. Also, this happens when the voltages are in the same phase but the range of the voltages is different. In other words, to synchronize diesel generators, some characteristics such as voltage, phase, frequency and a series of other characteristics in diesel generators must be equalized. In general, it can be said that for synchronous diesel generators, the engine speed, phase and amplitude of all diesel generators involved in synchronizing must be the same.
Synchronization conditions of diesel generators
The best way to parallelize diesel generators is to use identical generators. Or that the generators used have the same output and degree or pitch. However, you can use at least two generators that have variable output for parallelization. The duration of the synchronization operation varies between 2 and 4 weeks based on the capacity of the production power.
The important point is that with both methods, you can connect diesel generators in parallel to the parallel synchronous switchboard and whenever emergency power is needed, calculate and ramp the output current to the minimum and maximum.
The control panel in the diesel generator is responsible for controlling the speed and outputs. Some control panels have the power to synchronize diesel generators. To parallelize, the generators must be connected in parallel to the synchronous switchboard. After this happens, the panel measures the engine speed and the voltage of the first diesel and performs the equalization of these factors in all the connected diesel generators.
The important advice about synchronizing diesel generators is that despite the many benefits of synchronizing, if this work is not done by an expert, it can be disastrous. The high amount of load power that is produced can lead to serious life risks if it is produced incompletely or incorrectly.
Synchronous methods of diesel generators
Use independently
The first method is independent and separate use. This means that the diesel generator is connected to the load alone or individually to provide the required electricity. This method is used when you have a small place, or you want to provide temporary emergency power.
Use in parallel or synchronizing
When several generators are used in parallel to generate electricity independently of the grid or the generators themselves are connected in parallel to the grid to generate the necessary power. When they need very high power, they synchronize the generators with one another, or so called synchronization.
Whenever there is a need to repair synchronized generators, an emergency shutdown is needed, or a change in consumption is required, it is enough to disconnect the generators from the system and reconnect them to the network, but it is necessary to synchronize the parameters of the generators with the parameters of the network.
Synchronization of diesel generators in the past
In the past, for synchronization, in addition to the main synchronization controller, each diesel generator had its own controller. The multiplicity of controllers and the need to coordinate them with each other caused problematic events. Today, only a special controller is used for synchronization.
For synchronization, we connect the generators to the controller and then by starting the generators and slowly raising the output voltage, we synchronize and equalize the frequency of the generators with the network. Please note that voltmeter and frequency meter are used around the circuit to check the frequencies. In the last step, we need to use a device called rst. This device makes the phase sequence of the network and generators the same. It should be noted that we should refrain from connecting them until we are sure that the voltage of the network and the generators are equal, because this can cause accidents.
Benefits of synchronizing diesel generators
The advantages of synchronizing diesel generators are many, but its limitations, such as the need for a large space and the complexity of the setup, maintenance and resynchronization procedures, have made many businesses reluctant to parallelize their generators. But today, thanks to integrated digital control technologies, synchronizing diesel generators has become much easier and has brought many benefits to businesses. Here are the benefits of synchronization:
Increasing production power: If we have several small diesel generators, by synchronizing them, we can produce a significant amount of load power.
Increased security in the system: if one of the devices fails, you can continue working by using other diesel generators and the whole system will not be faulty; In industries where important and vital devices need to operate constantly, it is not possible to supply the entire network with the help of a diesel generator. Therefore, the best solution is to use at least two generators in the network, and in such cases, the synchronization of diesel generators becomes very important.
The possibility of improving diesel generator capacity matching: If you want to match the diesel generator load with the work load, you will not have an easy task. If its value is not predicted correctly and you have a single generator, very bad results will follow; Because the result is replacing the device with a more powerful diesel generator. This is if by synchronizing the diesel generators, even if the total capacity of the diesel generators is low, you have two ways to increase their capacity. One of them is to upgrade the diesel generator with low cost and the other one is to add another diesel generator. You can even take some generators out of the circuit when the load drops by synchronizing the generators.
Being more cost-effective: generators used in parallel synchronous system have less capacity and the engines of these generators with advanced manufacturing design and high volume are mostly industrial and road. Therefore, the production of these engines is cheaper and more affordable, and their purchase has more economic value.
Flexibility: By synchronizing diesel generators, their flexibility increases. This means you can put small generators anywhere without worrying about space for a large generator.
The method of parallelizing the diesel generator with city electricity
In order for the operation of synchronizing and paralleling the diesel generator with the city electricity or common pasbar, you must provide a series of conditions to connect the generators and the network, which are:
The rms value of the generator line and network voltages should be the same.
The sequence of phases should be the same.
New generator frequencies should be higher than the grid frequency.
Phases with the same name are called the same.
Different parts of synchronous or parallel generators
Synchronized diesel generator systems include basic and complex types that have remote control and router start-up. An example of basic system components are:
Diesel generator: includes generator, operator and engine board.
Operator board: to communicate with automatic load transfer switch, motor and generator. Also, the operator board is used to control the start, alarm and monitoring activities.
Automatic load transfer switch – monitor in the switch panel: For times when power drops or increases are too high, the HMI transfers the load to the appropriate generator operator panel to start or shut down the engine.
Control Board – Parallel Synchronous: The main HMI board commands the breakers and contactors to distribute the power in different circuits. With the help of generators, two different modes will be possible to set up and configure, which includes redundant configuration and unwanted increase configuration.
