Brian (Shanghai) Technology Co., Ltd.
Contact: Gaojing Li
Address: Room 2292, 868 Jinqi Road, Fengxian District, Shanghai
With the increase in electricity demand and power equipment in China, the reliability of power supply and the quality of power supply have put forward higher requirements. In the power system to install reactive power compensation device is to improve the power quality and reduce the important means of loss. The development of power power electronics technology and intelligent system control technology also provides the guarantee for the application of reactive power compensation technology. Import reactive power compensation
Reactive power compensation is an important method of economic operation of power enterprises. It is the main way of intensive development. It should attach great importance to the application and implementation of reactive power compensation technology. Reduce the power line loss and increase the economic efficiency of power enterprises through the practical application of reactive power compensation device , To achieve the power enterprise management and technical aspects of the common progress.
2 reactive power compensation principle
In situ balance is the basic principle of reactive power compensation in the grid. Reactive power compensation is a complicated work, which requires global planning and reasonable compensation and layout to achieve the local balance of reactive power compensation. Therefore, in the development of grid reactive power compensation program or plan to highlight this principle, to systematically analyze reactive power demand and vacancy, and then in the best way to determine the compensation capacity and manner, the formation of reactive power compensation in situ balance.
3 Reactive power compensation for different devices
3.1 Reactive power compensation of synchronous motor
There are many types of synchronous motors in the power grid. Every year, the pumps, blowers and motors in the daily production and life belong to the synchronous motor. Under the condition of economic conditions and equipment conditions, the power factor should be compensated by the advanced operation. The synchronous motor can be used as the Carry the form of reactive power compensation.
3.2 asynchronous motor synchronous reactive power compensation
Asynchronous motor synchronization can absorb a large amount of reactive power from the grid, must be effective reactive power compensation, especially for the wire wound asynchronous motor should be reactive compensation, to start to the rated speed, the better time The rotor is driven in a DC-excited manner.
3.3 Reactive power compensation of power capacitors
Power capacitors are common types of equipment in the power grid. Since the power capacitors belong to the static reactive power compensation equipment, the performance and scope should be taken into consideration in the design, so that the function of the reactive power compensation of the capacitor should be realized.
3.4 Thyristor dynamic compensator
This is a new type of reactive power compensation device, in the system to the crystal valve for the system and the main components in the adjustment on the use of automated way to the rapid action, effective coordination of the way to adjust the reactive power compensation in the grid. At present, the application trend of the thyristor dynamic compensator has been formed, especially in the distribution network which is closely related to production and life.
4 reactive power compensation method
Reactive power compensation according to the voltage can be divided into: high pressure compensation, low voltage compensation, power grid reactive power compensation according to the effect can be divided into: loss compensation and Pressure compensation. According to the national regulations, industry norms and the actual compensation, we advocate: the combination of loss compensation and pressure compensation to reduce the compensation; low-pressure compensation and high-pressure compensation combined to low-pressure compensation; decentralized compensation and centralized compensation , Mainly to decentralized compensation.
5 to improve reactive compensation management measures
5.1 Measures to improve the reactive power compensation effect of substation
First of all, the power companies generally take automatic compensation for substation and centralized compensation methods. This method is beneficial to reduce the reactive power load of the transformer main transformer, which can achieve the adjustment of the compensation by the switching operation of the compensation capacitor, and has good adaptability and pertinence for the common decentralized capacitor capacity. But at the same time there are shortcomings such as the dispersion of compensation. Second, the compensation capacitor should be concentrated in 2-3 groups, the peak load when the grid into the substation operation, play the effect of compensation in the grid load can be targeted to cut off the compensation capacitor, to reduce the capacitor to the Power loss. According to the local economy and the actual development of power to adjust the capacity of substation reactive power compensation to prevent the increase in power equipment due to the lack of reactive power compensation device, control line loss increases.
5.2 measures to improve the reactive power compensation effect of distribution lines
First of all, the distribution line generally take reactive power automatic dispersion compensation way. That is, in the distribution line to install automatic dispersion capacitor group. Distribution network is an important part of the power grid, the line loss accounted for a large proportion of the power grid. Its advantages are: can compensate for distribution network and transformer reactive power loss, significantly reduce the agricultural network line loss, improve the voltage level. The drawback is: scattered installation and maintenance inconvenience, light load voltage is too high, timely switching inconvenient. Second, to determine the number of capacitors on the distribution line and compensation methods should be based on the principle of minimizing the loss of reactive power to consider, according to the reactive load situation, to compensate for decentralized compensation. When the installation of only one set of capacitors on the line, the installation point should be selected at the first end of the distribution line 2/3, set the compensation device; when the two sets of capacitors on the line, the first set of installation points should be set in the line Start 2/5, the second group of 4/5, each group compensation capacity for the line dispersion compensation half of the total capacity. When the installation of three sets of capacitors on the line, the first set of installation points should be set at 2/7 from the beginning of the line, the second group of 4/7, the second group of 6/7, the compensation capacity for each line dispersion compensation 1% of total capacity. It should be noted that the compensation effect of the number of groups (or points) of the dispersion compensation is better than the compensation amount when the number of compensation groups (or points) is small. However, maintenance is less convenient and increases the fault point of the line. Therefore, according to the characteristics of the distribution line on the number of decentralized compensation points and compensation for the installation of the capacitor is reasonable to test, for the special circumstances should be considered as appropriate to facilitate the efficient implementation of the distribution line reactive power compensation.
5.3 Measures to optimize the compensation of distribution area
Distribution network is too strong to take a random compensation, which is the industry's norms, but also a summary of reactive power compensation time. Decentralized compensation is the way the capacitor directly connected in parallel with the electrical equipment (such as motor) side, or the capacitor installed in the distribution of 380V bus, which can effectively improve the compensation effect, to reduce the distribution line loss has a direct The role. Practice has proved that the loss of Taiwan transformer to account for more than 80% of the total loss of power network, so to strengthen the Taiwan area of reactive power compensation, especially for grass-roots power companies should do a good job of Taiwan's reactive power compensation, through the lack of capacity , The performance of old, backward function of the transformer reactive power compensation to enhance the effect of reducing the line loss, the total amount of wire damage control effect. Many county-level power companies in the Taiwan area into the installation of low-voltage reactive power compensation device, has achieved good economic benefits, worthy of the majority of power companies to be concerned about.
In summary, reactive power compensation can be used in a large number of practical effects, not only can enhance the voltage, and can improve the power factor of the entire network, from the basic aspects and points to reduce the power line loss. In the future reactive power compensation work should continue to inherit the methods and points have been effective, through the continuous development and innovation to form a new type of reactive power compensation, more effectively tap the inherent potential of power companies to further reduce the operating costs of enterprises to develop Innovative ways to increase revenue and expenditure, and strive to complete the power production, safety, economic work of the overall task for the development of power enterprises to create a new technology road.