Power Factor in Diesel Generator Operation

What is power factor? When current passes through electrical appliances, they consume a certain amount of electrical energy to convert into other forms of energy. The consumed electrical energy includes two parts: active power actually used by the appliances and reactive power consumed in other aspects during operation. Power factor is the percentage of active power in apparent power. A higher power factor indicates higher effective utilization of electricity, but it will never be equal to 1.

1. Too High Power Factor (Low Reactive Power) During Diesel Generator Operation

Excessively high power factor (insufficient reactive power) during generator operation reduces the system's reactive power margin and affects the steady-state stability of the generator. Although it optimizes costs in the short term, it increases the probability of accidents in the long run. In case of sudden incidents, the generator may not withstand minor disturbances or vibrations and could lose synchronization.

When the power factor increases, reactive power decreases (reactive power is zero when power factor is 1). At this time, the excitation current drops, reducing the magnetic attraction between the generator rotor and stator magnetic poles, thereby undermining the static stability of the generator. As noted by Guangxi Dingbo Power, when the power factor decreases, reactive power increases. Since inductive reactive power has a demagnetizing effect, the excitation current must be increased to maintain the stator voltage, leading to higher temperature and overheating of the rotor windings.

Furthermore, low reactive power causes a drop in the generator terminal voltage, affecting auxiliary motors in the plant. The increased current drawn by motors further lowers the voltage, creating a vicious cycle that may cause the entire system to lose stable operation and collapse. During leading phase operation, the generator ends tend to overheat.

2. Too Low Power Factor (High Reactive Power) During Diesel Generator Operation

Excessively low power factor (excessive reactive power) during operation leads to increased excitation current, higher temperature of rotor windings, and shortened service life.

In addition, power loss increases during power transmission, and generator consumption also rises. Low power factor causes an increase in generator terminal voltage, higher magnetic flux density in the iron core, increased losses, and elevated core temperature. When operating at rated load with low power factor, the generator's output will be limited, and its efficiency will be significantly reduced.

Guangxi Dingbo Generator Set Manufacturing Co.,Ltd. was founded in 1974 and is one of the earliest manufacturers of generators and diesel generator sets in China. The company has a registered capital of 218.88 million yuan. The company covers an area of 86,000 square meters and a building area of 55,000 square meters. There are more than 660 employees, including 456 professional technicians and 106 senior technicians. It has 46 sales and service outlets nationwide. The main products are diesel engines, generator sets, and diesel generators, providing users with a one-stop service of design, supply, debugging and maintenance at any time. Dingbo has always insisted on using first-class talents, building first-class enterprises, manufacturing first-class products, creating first-class services, and making every effort to build a first-class domestic enterprise. If any question please feel free to visit our website https://www.dieselgeneratortech.com/ or send email to [email protected].