In modern power systems, capacitor compensation devices of low voltage power distribution cabinets play a key role in improving power factor and reducing energy consumption. At the same time, harmonic control has become an important part of ensuring the stable operation of the system.
First, the optimal configuration of capacitor compensation devices requires accurate determination of compensation capacity. The calculation should be based on the load characteristics, power factor status and target power factor connected to the low voltage power distribution cabinet. For systems with inductive loads such as motors, by reasonably increasing the capacitor capacity, reactive power can be effectively offset, reactive current transmission of the power grid can be reduced, line losses can be reduced, and energy utilization can be improved. However, if the compensation capacity is not properly selected, over-compensation or under-compensation problems may occur, affecting the voltage stability of the power grid.
Secondly, in a harmonic environment, the configuration of capacitor compensation devices is more complicated. Harmonics in the power grid may come from nonlinear loads such as inverters and rectifiers. These harmonics will cause additional heating and overvoltage in the capacitors, and even damage the capacitors in severe cases. Therefore, harmonics need to be controlled. One method is to use a series reactor to form a resonant circuit with the reactor and the capacitor to filter or suppress harmonics of a specific order, thereby protecting the capacitor and improving the power quality.
Furthermore, the harmonic source and its characteristics must be accurately analyzed during the harmonic control process. Use a professional power quality analyzer to measure parameters such as harmonic content, harmonic order and phase, so as to select a suitable filter device and determine the filter parameters in a targeted manner. For example, for a system dominated by the 5th harmonic, a 5th harmonic filter can be designed to present a low impedance at this harmonic frequency, effectively shunt the harmonic current and prevent it from flowing into the capacitor.
At the same time, the coordination of the capacitor compensation device with other equipment should be considered. In the low voltage power distribution cabinet, in addition to capacitors and reactors, there are also electrical components such as circuit breakers and contactors. When optimizing the configuration, it is necessary to ensure that these components can work normally in a harmonic environment and will not cause malfunctions or failures due to harmonics. For example, a circuit breaker with anti-harmonic capability is selected, and its rated current and breaking capacity must be able to adapt to working conditions containing harmonic currents.
In addition, with the development of smart grid technology, the capacitor compensation device of low voltage power distribution cabinet can realize intelligent control. By real-time monitoring of grid parameters such as power factor, harmonic content, voltage and current, the intelligent controller can automatically adjust the number and time of capacitor switching groups to achieve dynamic compensation and precise harmonic control, and improve the adaptability and reliability of the system.
In the actual operation process, the capacitor compensation device needs to be maintained and inspected regularly. Check whether the appearance of the capacitor is swollen or leaking, measure whether its capacitance and insulation resistance are normal, verify whether the harmonic control effect continues to meet the requirements, etc., timely discover and deal with potential problems, and ensure the long-term stable operation of the low voltage power distribution cabinet.
The optimal configuration and harmonic control of the capacitor compensation device of the low voltage power distribution cabinet need to comprehensively consider many factors, from capacity calculation, harmonic analysis to equipment coordination and intelligent control, in order to achieve efficient, stable and safe power supply.
