The reactive power capacitor compensation plays an important role in improving the power factor of the power supply system, reducing the loss of the power supply transformer and the transmission line, improving the power supply efficiency and improving the power supply environment. Reasonable selection of the reactive power capacitor compensation device can reduce the loss of the power grid as much as possible and improve the quality of the power grid. On the contrary, if a reactive power capacitor compensation device has been selected or used improperly, it may cause many faults, such as the increased fluctuations in voltage, increased harmonic and faults in the supply system. But how much do you know about the reactive power capacitor compensation device, you might as well review and study the relevant knowledge with the writer.
I. The concept of power
Power is the amount of work which has been done or the amount of energy which has been converted per unit time.
Apparent power: The apparent power refers to the total power emitted by a generator, which can be divided into two parts: the active part and the reactive part.
The active power: The active power is the electric power needed to maintain the normal operation of the electrical equipment, that is, the electric power for converting the electric energy into other forms of energy (the mechanical energy, the light energy, the thermal energy).
The reactive power: It is used for the exchange of the electric field and the magnetic field in the circuit, and is used to establish and maintain the electric power of the magnetic field in the electrical equipment. It does not work outside, but is transformed into other forms of energy. As to any the electrical equipment which is equipped with the electromagnetic coils, if the magnetic field is to be established, it is necessary to consume the reactive power. The reactive power does not do work. However, in order to ensure the transmission of the active power, the reactive power of the power grid must be satisfied first.
II. Why is the reactive power capacitor compensation necessary?
Under the normal circumstances, the electrical equipment should not only obtain the active power from the power supply, but also obtain the reactive power from the power supply. If the reactive power supply in the power grid exceeds the demand, the electrical equipment will not have enough reactive power to establish the normal electromagnetic field, then these electrical equipment will not be able to maintain the rated condition, and the terminal voltage of the electrical equipment will decrease, thus affecting the normal operation of the electrical equipment.
However, the reactive power supplied from by the generators and the high voltage transmission lines is far from meeting the needs of load, so some reactive power capacitor compensation cabinets should be set up in the power grid to supplement the reactive power so as to ensure the needs of the users for the reactive power. Thus the electrical equipment can work at rated voltage. The reactive power capacitor compensation is to connect in parallel a device with the capacitive power load and a device with the inductive power load to the same circuit, so that the energy is exchanged between the two kinds of loads, therefore, the reactive power which is needed by the inductive load can be compensated by the capacitive load.
III. The general methods of reactive power capacitor compensation
There are three main methods of reactive power capacitor compensation: The decentralized reactive power low voltage capacitor compensation, the centralized reactive power low voltage capacitor compensation and the centralized reactive power high voltage capacitor compensation. The following is a brief introduction to the applicable scope of the above three reactive power capacitor compensation methods and the advantages and disadvantages of using these reactive power capacitor compensation methods.
1. The decentralized reactive power low voltage capacitor compensation
In the decentralized reactive power low voltage capacitor compensation, a single or more low voltage capacitor banks are to be connected with the electrical equipment according to the reactive power required by the individual electrical equipment. The low voltage capacitor(s) will share the same set of circuit breaker with the electricity consuming equipment and are to be switched on and switched off at the same time as the motor, by means of the control device and the protection device. The random reactive power capacitor compensation is suitable for performing compensation for the reactive power consumption of individual equipment which has a large capacity and performs continuous operation (such as a large and medium-sized asynchronous motor), which mainly includes the compensation for the excitation reactive power. The advantages of the decentralized reactive power low voltage capacitor compensation are as follows: when the electricity consuming equipment is running, the reactive power capacitor compensation cabinet is put into operation, and when the electricity consuming equipment is shut down, the compensation equipment will also be switched off, so it will not cause reversed delivery of the reactive power. It has the following advantages: the investment outlay is less , the space to be occupied is small, the installation work is easier, the configuration is convenient and flexible, the maintenance is simple, the accident rate is low and so on.
2. The centralized reactive power low voltage capacitor compensation
The decentralized reactive power low voltage capacitor compensation means that the low voltage capacitors are connected to the low voltage bus bar side of the distribution transformer through the low voltage switch, and the reactive power capacitor compensation switching device is used as the control protection device. According to the reactive power load on the low voltage bus bar, the switching on and switching off of the capacitors is directly controlled in groups, so it is not possible to achieve the smooth adjustment. The advantages of the reactive power low voltage capacitor compensation are as follows: The wiring is simple, the operation and maintenance workload is small, the reactive power is locally balanced; as the result, the utilization rate of the distribution transformer has been improved, the network loss has been reduced, a higher economy is available; it is one of the commonly used means by the reactive power capacitor compensation cabinets.
3.The centralized reactive power high voltage capacitor compensation
The centralized reactive power high voltage capacitor compensation refers to the reactive power capacitor compensation mode in which the shunt capacitor banks are directly installed on the 6~10KV high voltage bus bar of the substation. It is suitable for the occasion where the user who stays away from the end of the power supply line where the substation is located and the user himself has a certain high voltage load. Here the reactive power capacitor compensation cabinet can reduce the reactive power consumption of the power system and perform the reactive power compensation to a certain extent. The reactive power capacitor compensation cabinet can automatically be switched on and switched off according to the size of the load, so the benefit of the reactive power capacitor compensation cabinet is high.
DELITER has focused on the R&D and production of the reactive power capacitor compensation cabinet for the 16 years. The company will provide you with a dedicated scheme of the reactive power capacitor compensation cabinet, so as to completely solve the issue of penalties related to the users’ electricity consumption! The company has been focused on this field for many years just because it is the expert in this field! For more information, please contact: 400 / 176 / 0551.