How does Air Cooled Capacitor improve the operation level of power system through reactive power compensation?

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The operation mechanism of inductive load in power system is relatively special. When current passes through inductive devices such as motors and transformers, there will be a phase difference between current and voltage, resulting in a part of electric energy being continuously converted between electric field and magnetic field, but it cannot be truly converted into useful work. This part of electric energy is reactive power. Although reactive power does not directly do work, it is indispensable for maintaining the normal operation of inductive loads. However, the presence of a large amount of reactive power will increase the current and generate more losses on the line resistance. At the same time, it will also cause the line voltage drop to increase, making the voltage of the end user low, seriously affecting the power quality and system operation efficiency. ​
Air Cooled Capacitor is used for reactive power compensation in power system and has a scientific working principle. Capacitor is essentially a component that stores charge. In AC circuit, it can store electric energy when the voltage increases and release electric energy when the voltage decreases. This characteristic enables it to generate capacitive reactive power of opposite nature to the reactive power consumed by inductive load. After the air-cooled capacitor is connected to the power system, the capacitive reactive power it generates and the inductive reactive power consumed by the inductive load offset each other, thereby reducing the total reactive power transmitted in the system. This is like reducing some "ineffective" vehicles on a crowded road, making the road smoother and the operation of the power system more efficient. ​
From the specific process, after the air-cooled capacitor is connected to the power system, it first has a significant impact on the power factor. The power factor reflects the degree of effective utilization of electric energy. The presence of inductive loads reduces the power factor, and the capacitive reactive power injected by the air-cooled capacitor can adjust the phase relationship between current and voltage, making them as close to the same phase as possible, thereby improving the power factor. When the power factor is improved, the effective value of the current in the power system will decrease accordingly. Because according to the circuit principle, when transmitting the same active power, the current is inversely proportional to the power factor. After the current decreases, the power loss in the line also decreases. This is because the line loss is proportional to the square of the current. The reduction in current can greatly reduce the heat loss on the line resistance and reduce the energy waste in the power transmission process.​

Air-cooled capacitors also play an important role in improving voltage quality. The line voltage drop is closely related to the current size. When the current decreases due to reactive power compensation, the line voltage drop will also decrease. This makes the voltage of each node in the power system more stable, especially in the terminal area far away from the power source, the problem of low voltage can be effectively alleviated. Stable voltage is not only conducive to the normal operation of various types of electrical equipment and prolongs the service life of equipment, but also ensures the safe and stable operation of the entire power system and reduces the risk of failure caused by voltage fluctuations. ​
In actual power systems, air-cooled capacitors are used in various ways. Large-capacity air-cooled capacitor groups can be installed centrally in substations, and centralized compensation can be performed according to the overall reactive power demand of the system. This method can macro-control the reactive power of the entire regional power grid and improve the power factor and voltage level of the regional power grid. Small air-cooled capacitors can also be installed on the low-voltage side of the distribution transformer to compensate on-site for the load characteristics of a specific area. This can more accurately meet the reactive power demand of local loads, reduce reactive transmission of low-voltage lines, and reduce line losses. In addition, on high-voltage transmission lines, series air-cooled capacitors are used to compensate for the inductive reactance of the line, improve the transmission capacity of the line, and increase the distance and capacity of power transmission. ​
Although air-cooled capacitors perform well in reactive power compensation in power systems, they also face some challenges. The operating conditions of the power system are complex and changeable, and the reactive power demand of the load may change at any time, which requires air-cooled capacitors to respond quickly and adjust flexibly. If the compensation is not timely or the compensation amount is inaccurate, not only will the expected reactive power compensation effect fail to be achieved, but new problems such as system voltage fluctuations and resonance may also be caused. At the same time, air-cooled capacitors will be affected by environmental factors such as high temperature, humidity, and dust during long-term operation. These factors may cause the performance of the capacitor to deteriorate or even fail, affecting the reliability and stability of its reactive power compensation. ​
In order to better play the role of air-cooled capacitors in reactive power compensation in power systems, related technologies are also constantly developing and innovating. On the one hand, more advanced control strategies are developed, and intelligent control technology is used to monitor the reactive power and voltage changes of the system in real time, accurately control the input and removal of air-cooled capacitors, realize dynamic reactive power compensation, and improve the timeliness and accuracy of compensation. On the other hand, the manufacturing process and materials of air-cooled capacitors should be improved to enhance their ability to resist environmental interference and improve the reliability and service life of the equipment. In addition, the coordinated application with other reactive compensation equipment, such as static reactive generators, should be explored to give full play to the advantages of different equipment and build a more complete reactive compensation system.