Comparison Of High Voltage And Low Voltage Diesel Generator Sets

Guangxi Dingbo Power Equipment Manufacturing Co., Ltd. Guide: With the expansion of the machine room, the capacity of the diesel generator set as the standby power supply is required to be larger and larger, and multiple high-power diesel generator sets are required to be single or connected to the grid to meet the functional requirements of the load, so high voltage diesel generator sets are required. Now let's take a look at the comparison between high voltage diesel generator set and low voltage diesel generator set. The composition of the high voltage diesel generator set is basically the same as that of the low voltage diesel generator set. The main difference is that for the diesel generator set with the same capacity, the generator outlet current of the 400V unit is more than 25 times greater than that of the 10kV unit.

1. Selection of installation site: 

Low voltage unit: it should be set near the load center.

High voltage unit: it can be set outside the machine room building to solve the vibration, noise, air inlet and exhaust problems of the generator room when multiple generator units are running at the same time, and it can be far away from the load center.

2. Capacity:

Low voltage units: the single unit capacity is basically 2000kW and below, and single or multiple units can operate in parallel, but the parallel capacity is limited by the output power supply when the parallel capacity is too large.

High voltage unit: the single unit capacity is basically 2000kW and above, and single or multiple units can operate in parallel, and the machine room can be built in a centralized way.

3. Conveying distance:

Low voltage unit: it can transmit power in short distance, but it is uneconomical to transmit power in long distance, and the voltage drop is large.

High voltage unit: it can transmit power for a long distance (10kV for 15-20km, 6.6kV for some). The lines with transmission voltage above 110kV are called ultra-high voltage transmission lines.

4. Losses:

Low voltage unit: large line loss in power transmission and distribution.

High voltage unit: In the transmission and distribution, the line loss is small, there is no transmission heating problem, and the high-voltage transmission current is equivalent to 1/25 of the low-voltage.

5. Oil storage and supply pipeline:

Low pressure unit: underground oil tanks are scattered near the standby power station of each machine room. If underground oil tanks are set in a centralized way, there are many intersections of pipelines inside and outside the machine room.

High voltage unit: underground oil tanks shall be set in the area near the buildings of the standby power station to avoid crossing with other pipelines (cables, water pipes, etc.) in the area. The external network is relatively simple.

6. Operation and maintenance:

Low voltage unit: the operation is relatively simple, and the requirements for operators are low.

High voltage unit: the operation and use are relatively complex, and the requirements for operators and users are high. The operation and maintenance can only be carried out with corresponding qualifications such as high voltage operation certificate.

7. Configuration:

Low voltage unit: the configuration is relatively simple, and the power transmission and distribution are basically standard low-voltage cabinets.

High voltage unit: the configuration is relatively complex, especially the generator and output distribution cabinet are all high-voltage equipment.

8. Parallel operation:

Low voltage unit: limited by the current of low-voltage distribution equipment, its parallel capacity is small, and it is greatly affected by nonlinear load.

High voltage unit: it is convenient to realize parallel connection of high-power units into a large capacity system, and it is less affected by nonlinear load.

9. Security:

Low voltage unit: high safety performance, mature technology and low technical threshold.

High voltage unit: high safety performance, mature technology and high technical threshold.

10. Development trend:

Low voltage units: the small power segment maintains the traditional market, while the large power segment tends to be replaced by the high voltage system.

High voltage unit: the application trend of high voltage system is to adopt high power section, and the demand is gradually increasing.

11. Switching with mains power

Low voltage unit: ATS is adopted, with large current, large number of ATS, large floor area and high cost.

High voltage unit: it can be switched at 10kV bus through integrated protection control switch, with small floor area and low cost.

Guangxi Dingbo Power Equipment Manufacturing Co., Ltd. is a professional manufacturer of generators, diesel generator sets, Shangchai generator sets, Volvo generator sets, etc. It has 24 sales and service departments, and provides users with one-stop service of design, supply, debugging and maintenance at any time. Welcome the majority of users call for consultation. For more details, please contact us with sales@dieselgeneratortech.com.