Diesel generator sets are widely used in our daily lives. Many people do not understand the basic composition and working principle of diesel generator sets. Today, this article takes diesel generators as an example to briefly explain the basic structure and working principle.

The basic components of a diesel generator set include cylinder, piston, cylinder head, intake valve, exhaust valve, piston pin, connecting rod, crankshaft, bearings, and flywheel. The diesel generator set of a diesel generator is usually a single cylinder or multi cylinder four stroke diesel generator set. The following only explains the basic working principle of a single cylinder four stroke diesel generator set: The starting of a diesel generator set is achieved by manually or other power to rotate the main shaft of the diesel generator set to make the piston move up and down in the top sealed cylinder. The piston completes four strokes in motion: intake stroke, compression stroke, combustion and work (expansion) stroke, and exhaust stroke. When the piston moves from top to bottom, the intake valve opens, and fresh air filtered through the air filter enters the cylinder to complete the intake stroke. The piston moves from bottom to top, the intake and exhaust valves are closed, the air is compressed, the temperature and pressure increase, and the compression process is completed. When the piston is about to reach its peak, the fuel injector sprays the filtered fuel into the combustion chamber in a mist form and mixes it with high-temperature and high-pressure air to immediately ignite and burn on its own. The high-pressure formed pushes the piston downwards to do work, pushing the main shaft to rotate and complete the work stroke. After completing the work stroke, the piston moves from bottom to top, and the exhaust valve opens to exhaust, completing the exhaust stroke. Rotate the crankshaft half a turn per stroke. After several work cycles, the diesel generator set gradually accelerates into operation under the inertia of the flywheel.

A DC generator specifically consists of a generator casing, magnetic pole iron core, magnetic field coil, armature, and carbon brush. Principle of homework power generation: When the diesel generator set drives the generator armature to rotate, due to residual magnetism in the magnetic pole core of the generator, the armature coil cuts magnetic field lines in the magnetic field. According to the principle of electromagnetic induction, a single current is generated by magnetic induction and output current through the carbon brush.

In the cylinder, after being filtered by the air filter, clean air is sprayed with the fuel injector to fully mix high-pressure atomized diesel. Under the upward compression of the piston, the volume decreases and the temperature rapidly increases, reaching the ignition point of diesel. Diesel fuel is ignited, and the mixture of gases burns violently. Its volume rapidly expands, pushing the piston down, which is called "work done". Each cylinder works in a certain order, and the thrust acting on the piston is converted into the force that drives the crankshaft to rotate through the connecting rod, never driving the main shaft to rotate. By coaxially installing a brushless synchronous AC generator and a diesel generator crankshaft, the rotation of the diesel generator can drive the rotor of the generator. Using the principle of "electromagnetic induction", the generator will output an induced electromotive force, which can generate current through a closed load circuit.

This only describes the basic working principle of the generator set. To achieve usable and stable power output, a series of diesel generators and generator control, protection devices, and circuits are also required.

One or more diesel generators operating without being connected to the power grid are referred to as islanded operation modes. Parallel operation generators can achieve better efficiency under partial loads. Island power plants used as the main power source for isolated communities will generally have at least three diesel generators, any two of which are rated to carry the required load.

Generators can be electrically connected together through synchronization programs. Synchronization involves matching voltage, frequency, and phase before connecting the generator to the system. Failure to synchronize before connection may result in high short-circuit current or wear of the generator or its switchgear. The synchronization process can be completed automatically by the automatic synchronization module or manually by guided operators. The automatic synchronizer will read voltage, frequency, and phase data from the generator and bus voltage, and adjust the speed through the generator set governor or ECM (generator set control module).

The load can be shared between parallel generators through load sharing. Load sharing can be achieved by using a descent speed control controlled by the generator frequency, while continuously adjusting the fuel control of the generator set to transfer the load to or from the remaining power source. When the fuel supply to its combustion system increases, the diesel generator will bear more load, and if the fuel supply decreases, the load will be released.

The packaging combination of diesel generator set generator and various auxiliary devices (such as base, top cover, sound attenuation, operating system, circuit breaker, jacket water heater, and starter motor) is called "generator set".

Standard units are widely used in common locations for installation in computer rooms. The unit mainly consists of diesel generator set, generator, controller, base, shock absorber, cooling system, oil supply system, and output protection switch.

Protective units are used in outdoor places where there are no special requirements for noise. Specifically, the standard unit and protective cover are not equipped with noise reduction devices, as long as they meet ventilation and rain and snow protection factors, so their external volume is small and the cost is low. Open doors and windows for ventilation during unit operation. A protective power station can be used as a single unit or in parallel with multiple units. Multiple units in parallel are particularly suitable for situations with significant load changes, high reliability requirements for continuous operation, and low-cost economic use, such as matching oilfield drilling rigs.

Sound proof units are widely used in outdoor or indoor environments with special requirements for environmental protection, which require protection and noise reduction. They are composed of standard units, sound proof covers, air intake and exhaust noise reduction devices, and exhaust noise reduction devices. The specific features include sound proof covers with sound insulation and absorption layers, air intake and exhaust channels for noise reduction and elimination, and exhaust using a combination of industrial and residential silencers to reduce their high-frequency and low-frequency noise, respectively. The noise of standard soundproof units is generally between 78-85dB (A), while the noise of super soundproof units is usually between 70-78dB (A). The super soundproof unit adopts stricter control methods for noise emissions on the basis of the standard soundproof unit, such as using maze style inlet and outlet duct design.

Super soundproof units are usually larger in size and have much higher manufacturing costs than standard soundproof units. Both soundproof and super soundproof units are typically operated, maintained, and repaired outside the soundproof casing.

Low noise release power stations and container power stations are usually used in outdoor environments with special requirements for environmental protection. They can be directly placed outdoors for use, eliminating the need for building computer rooms. They also have strong mobility and short operating cycles. The noise level of low-noise cabin power stations and container power stations is usually between 75-85dB (A), and can be operated, maintained, and inspected inside the cabin and cabin.

Airborne power stations are widely used in communication, television broadcasting, highways, emergency rescue, power supply, and emergency power supply situations where the military requires high speed, maneuverability, and reliability. The unit is mainly assembled in the Cummins cabin and can be equipped with electric cable winches, multiple output sockets, and mechanical (or hydraulic) support legs. It is also convenient to achieve parallel use of multiple airborne mobile generator sets. The noise level of airborne mobile generator stations is usually between 70-80dB (A).