與三相電動機(jī)匹配需注意的問題。柴油發(fā)電機(jī)組與三相電機(jī)容量選配時(shí)，必須考慮到負(fù)載的啟動電流。同時(shí)需要注意額定功率和后備功率的關(guān)系，KVA和KW的關(guān)系。KVA是視在功率，KW是有效功率，他們之間的關(guān)系為1KVA=0.8KW。進(jìn)口機(jī)組一般用KVA表示功率單位，而國內(nèi)用電設(shè)備一般都用KW表示。所以核算功率時(shí)應(yīng)把KVA打8折換算成KW。

Diesel generator sets play a very important role in daily life, but people still don't know how to choose the type that suits them. Today, we will explain in detail several types of diesel generator sets.

When choosing a diesel generator set, the main factors to consider include: the purpose of the set, mechanical and electrical performance, load capacity and variation range, environmental conditions for the use of the set (including altitude, climate conditions, noise), automation functions, etc. Due to the fact that diesel generator sets can be used in three situations: common, backup, and emergency, the requirements for diesel generator sets vary depending on their usage.

1、 Common Unit Selection

The commonly used diesel generator set refers to the use of a diesel generator set as the main power source in the absence of mains electricity. Long usage time, high mechanical wear and tear, and high failure rate. In this case, it is recommended that the minimum configuration should be a domestically produced first-line brand diesel engine, and joint venture or imported brands can also be chosen.

2、 Selection of standby units

A backup diesel generator set refers to a temporary power generation unit that operates normally with only occasional power outages. Low frequency of use, short usage time, low mechanical wear and tear, and low failure rate. In this case, there is no need to blindly pursue units with high-end imported diesel engine configurations. Generally, units with domestically produced diesel engine configurations can fully meet the needs of use. There is no need to consider too many indicators such as fuel consumption, noise, failure rate, and overhaul time.

3、 Emergency Unit Selection

Emergency diesel generator sets are generally recommended to use high-speed, turbocharged, low fuel consumption, and same capacity diesel generator sets. High speed turbocharged diesel engines have a larger single unit capacity and occupy less space; Diesel engines are equipped with electronic or hydraulic speed control devices, which have good speed control performance; Synchronous motors with brushless excitation or phase compound excitation devices should be selected for generators, which are more reliable, have a low failure rate, and are easier to maintain and repair.

Issues to be noted when matching with three-phase motors. When selecting the capacity of diesel generator sets and three-phase motors, the starting current of the load must be considered. Attention should also be paid to the relationship between rated power and backup power, as well as the relationship between KVA and KW. KVA is apparent power, KW is effective power, and their relationship is 1KVA=0.8KW. Imported power units are generally expressed in KVA, while domestic electrical equipment is generally expressed in KW. So when calculating power, KVA should be converted to KW at a 20% discount.