There are many classification methods for generator sets, which can be classified into high, medium, and low-speed units based on the rated speed of the engine; According to the rated power output of the unit, it can be divided into large, medium, and small units; According to the output voltage frequency of the generator set, it can be divided into AC generator set (intermediate frequency 400Hz, power frequency 50Hz) and DC generator set. When the voltage frequency is 50Hz, the calibration voltage of small and medium-sized generators is generally 400V (three-phase) or 230V (single-phase), and the calibration voltage of large generators is generally 6.3-10.5k/V. However, the more commonly used classification method is based on the type of fuel used in the internal combustion generator set, control mode, purpose, and appearance structure.

(1) Classified by fuel type

① The rated output power of gasoline generator sets is generally relatively small, usually between 0.5 and 12kw; Most of its engines use single cylinder, air-cooled gasoline engines; The output voltage is mostly single-phase 220V, with a frequency of 50Hz; In a few special places, multi cylinder, water-cooled engines with intermediate frequency (400Hz) and two-phase (380V) outputs are also used; Gasoline generator sets have a series of advantages such as small size, light weight, relatively low noise, low price, and easy mobility. They are mainly used in general situations where the load power is small and temporary emergency power supply is required (such as independent storefronts facing the street, emergency lighting for temporary power outages on small construction sites, and night lighting for lack of electricity users). When the user's load power is greater than 6kw, it is recommended to prioritize the selection of corresponding models of diesel generator sets to increase the reliability of the power supply system.

② The production cost of diesel generator sets is higher than that of gasoline generator sets of the same power level, but their working stability is better than that of gasoline generator sets, so the application field of diesel generator sets is much wider than that of gasoline generator sets. The output power of diesel generator sets varies from 1kw to thousands of kilowatts, and the output voltage is mostly single-phase 220V/50Hz or three-phase 380v/50Hz. There are also a few high-power, high-voltage, grid connected diesel generator sets. Diesel generator sets are widely used in various fields such as industry, agriculture, and national defense, and have been widely recognized by users.

(2) Classified by control method

① Manual units are the most common type of units, which have automatic voltage and speed adjustment functions. Operators can start, close, open, and stop the units on site in the machine room. This type of unit is usually used as a main or backup power source.

② The self starting unit is an automatic control system added to the manual unit. When the mains power suddenly goes out, the unit has functions such as automatic start, automatic voltage regulation, automatic frequency regulation, automatic switch on/off, and automatic shutdown; When the oil pressure of the unit is too low, the oil temperature and cooling water temperature are too high, an automatic sound and light alarm signal can be issued; When the unit exceeds the speed limit, it can automatically stop and protect the unit. The advantage of a self starting unit is that it greatly reduces the dependence on operators and shortens the interval between mains power interruption and power supply from the unit. This type of unit is usually used as a backup power source.

③ The microcomputer controlled automation unit consists of a high-performance internal combustion engine, synchronous generator, fuel (oil, cooling water) automatic compensation device, and automatic control panel. The automatic control screen adopts programmable logic controller (PLC) or microcontroller control. In addition to the various functions of self starting the unit, it can also automatically increase or decrease the unit according to the load size, automatically handle faults, automatically record the operation report and fault situation of the printer group, and implement comprehensive automatic control of the unit. Real time remote control, remote signaling, and telemetry (commonly known as "three remote") of scattered units by the central station are achieved through serial communication interfaces (RS232, RS422, or RS485), thus achieving unmanned operation. The degree of automation of the unit can be configured according to actual needs. This type of unit is particularly suitable for use as an emergency power source.

(3) Classified by purpose

① Commonly used generators, such as generator sets, operate year-round and are usually located in areas far from the power grid (or city power) or near industrial and mining enterprises to meet the construction, production, and living electricity needs of these areas. At present, in regions with rapid economic development, the construction of power grids cannot keep up with the needs of users, and commonly used internal combustion generator sets with short construction cycles are set up to meet the needs of users. This type of generator set generally has a large capacity and provides continuous power supply for non constant loads. There is no limit on the duration of continuous operation, and an overload power supply time of 1 hour is allowed every 12 hours. The overload capacity is 10% of the rated output power. This type of unit has a longer operating time and heavier load, and the allowable power relative to the maximum power of the unit is adjusted to a lower point.

② Under normal circumstances, the power required by users is supplied by the municipal power supply. The standby unit is a generator set set up to ensure the basic production and life of users when the municipal power supply is limited or interrupted due to other reasons. This type of generator set is commonly used in important power consuming units such as telecommunications departments, hospitals, industrial and mining enterprises with tight power supply, airports, and television stations. This type of unit is always in standby mode, capable of providing continuous power supply to non constant loads, and has no limit on the duration of continuous operation.

③ Emergency generator sets are often set up to provide emergency power to electrical equipment that may cause significant losses or personal accidents due to sudden interruption of mains electricity, such as fire protection systems in high-rise buildings, evacuation lighting, elevators, control systems for automated production lines, important communication systems, and medical equipment undergoing important surgeries for patients. This type of unit should be able to quickly start and operate in the event of a sudden interruption of mains power, and provide stable AC power to the load in the shortest possible time (minimizing the power supply time of UPS - AC uninterruptible power supply) to ensure timely power supply to the load. This type of unit requires a high degree of automation.

(3) Classified by appearance and structure

① The appearance of the basic unit is as follows. The basic type unit is the most commonly seen internal combustion generator set, which may be a manual unit, a self starting unit, or a microcomputer controlled automation unit.

② The appearance of a silent unit. The essential difference between a silent unit and a basic unit is that the unit is equipped with an external soundproof cover and a built-in muffler, which reduces the noise of the unit. This type of unit is suitable for special occasions that require low noise, such as schools, hospitals, and high-end elevator apartments.

③ The appearance of the onboard unit. Vehicle mounted unit is a unit designed and manufactured specifically for emergency power supply, which installs the entire internal combustion generator set in the car compartment and usually requires noise reduction treatment.

④ The appearance of the trailer unit (power station). Usually, trailer units are equipped with trailer trucks on the basis of silent units, achieving convenient movement of the unit and suitable for short distance emergency power supply within urban areas.

⑤ The appearance of a container unit. A cabin type unit is a unit that sends the entire engine

The motor unit is installed inside the shelter and is specially designed and manufactured for power supply in field engineering construction. The power of the unit is generally above 500kw.