高低压无功补偿方法High and low voltage reactive power compensation method.docx

1、高低压无功补偿方法High and low voltage reactive power compensation method高低压无功补偿方法（High and low voltage reactive power compensation method）High and low voltage reactive power compensation method to help | message exchange | loginMy home page theme library reading wonderful boutique Tags membership directory

2、Wenyuan browsing method of reactive power compensation of high and low recommendation (original) lfzht included in 2009-10-06Number of reads: View collection number: 5Public disclosureWelcome to the article collected in lfzhts personal library. Do you want to collect this good article? Hurry up. 1 m

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4、transmission loss of reactive power and improve the efficiency of power transmission and distribution equipment, the configuration of reactive power compensation equipment should be in accordance with the principle of grading compensation, balancing in place, and reasonable distribution.A,(1) the co

5、mbination of overall balance and local balance is mainly local.(2) the compensation of the power sector is combined with the user compensation.In the distribution network, the reactive power consumed by the user accounts for about 50% to 60%, and the remaining reactive power is consumed in the distr

6、ibution network. Therefore, in order to reduce the transmission of reactive power in the network, it is necessary to realize local compensation and local balance as much as possible, so the compensation must be made by the power sector and users together.(3) the combination of decentralized compensa

7、tion and centralized compensation is mainly decentralized.Centralized compensation is to install a larger capacity compensation capacitor in the substation. Distributed compensation refers to reactive power compensation in dispersed load areas such as distribution lines, distribution transformers an

8、d power equipment for users. Centralized compensation is mainly to compensate the reactive power loss of the main transformer itself, and to reduce reactive power of the transmission line above the substation, thereby reducing the reactive power loss of the power supply network. But it can not reduc

9、e the reactive power loss in the distribution network. The reactive power required by the user is delivered to the load through the distribution line below the substation. Therefore, in order to effectively reduce line loss, we must do reactive power where it occurs, where should be compensated?. Th

10、erefore, the medium and low voltage distribution network should be mainly distributed compensation.(4) combining loss reduction with pressure regulation to reduce loss.Two, the main factors affecting the power factorThe generation of power factor is mainly due to the AC power equipment in the course

11、 of its work, in addition to the consumption of active power, but also the need for reactive power. When the active power P is constant, if the reactive power Q is reduced, the power factor can be improved. In the extreme case, when Q=0, the rate of =1. Therefore, the essence of improving the power

12、factor problem is to reduce the reactive power requirement of the power equipment.2.1 、 asynchronous motor and power transformer are the main equipments to consume reactive powerThe air gap between stator and rotor of asynchronous motor is the main factor that determines the asynchronous motor needs

13、 more reactive power.The reactive power of asynchronous motor is composed of two parts: reactive power under no-load and added value of reactive power under certain load. Therefore, to improve the power factor of asynchronous motor, it is necessary to prevent the no-load operation of the motor and t

14、o increase the load rate as much as possible. The main component of the transformers reactive power is its no-load reactive power, which is independent of the load rate. Therefore, in order to improve the power factor of the power system and the enterprise, the transformer should not run without loa

15、d or be in a low load running state.2.2, the power supply voltage beyond the prescribed range will also have a great impact on the power factorWhen the supply voltage is higher than the rated value of 10%, due to the influence of magnetic saturation, reactive power will grow very fast, according to

16、the relevant statistics, when the supply voltage is 110% of the rated value, the General Factory of reactive power will increase by about 35%. When the supply voltage is lower than the rated value, the reactive power is reduced accordingly, so that their power factor is improved. But the reduction o

17、f the power supply voltage will affect the normal operation of the electrical equipment. Therefore, measures should be taken to keep the power supply voltage of the power system as stable as possible.2.3, the fluctuation of power network frequency will also affect the magnetizing and reactive power

18、of induction motors and transformersTwo.4, discusses some main factors influencing power factor in electric power system, it is necessary to seek some effective and able to make some practical methods of low-voltage power network to improve the power factor, make diyawang can realize the balance of

19、reactive power,Achieve the effect of reducing loss and energy saving.Three 、 reactive power compensation method in low voltage distribution network:A. stochastic compensationThe random compensation is to connect the low voltage capacitor set with the motor and switch it through the control, protecti

20、on device and motor at the same time. The random compensation is applicable to the reactive power consumption of the compensated motor, and the reactive power is mainly based on the excitation excitation. This method can restrict the reactive power load of the power unit.The advantages of random com

21、pensation: when the power equipment is running, the reactive power compensation is put into use, and when the power equipment is stopped, the compensation equipment is also exited, and the compensation capacity is not frequently adjusted. The utility model has the advantages of low investment, small

22、 occupation, easy installation, convenient and flexible configuration, simple maintenance, low accident rate, etc.B. follower compensationFollower compensation means that the low voltage capacitor is connected to the two side of the distribution transformer through low-voltage insurance, so as to co

23、mpensate the no-load reactive power compensation of the distribution transformer. With change in light load or no-load reactive load is the main load excitation transformer reactive power distribution transformer no-load reactive power is the main part of the electricity unit reactive load, for ligh

24、t load distribution, this part of the loss accounted for a large proportion of supply, resulting in the increase of electricity price.With the advantages of compensation: simple wiring, convenient maintenance and management, can effectively compensate the transformer no-load reactive power limits, r

25、eactive power baseload, so that the partial reactive power balance, so as to improve the utilization rate of distribution transformer, reduce the loss of reactive power,With high economic efficiency, it is one of the most effective methods to compensate reactive power.C. tracking compensationTrackin

26、g compensation means that the reactive power compensation switching device is used as the control and protection device, and the compensation method of the low-voltage capacitor bank is compensated on the 0.4kV bus of the large user. The utility model is suitable for users of special distribution tr

27、ansformer 100kVA or more, and can replace the two compensation modes of random and follower, and the compensation effect is good.The advantage of tracking compensation is that the running mode is flexible, the operation and maintenance work is small, and the service life is longer and the operation

28、is more reliable than the former two kinds of compensation methods. Priority should be paid to tracking compensation.Four 、 reactive power compensation of HV distribution network:OneThe national power company issued on the electric power industry to create first-class file, 10kV power factor is not

29、less than 0.9, the loss is less than 5%, and the quality of voltage and reactive power compensation operation management, one of the key problems of the main solution, is the input capacitors in the 10kV line, using fixed or automatic phase according to the input mode to realize reactive power compe

30、nsation. If the capacitor is fixed on a power supply line is generally low, according to line load calculation, automatic compensation amount is calculated in line with the full load value, a line with fixed and automatic compensation in two ways, you can achieve the desired effect.TwoThe principle

31、of reactive compensation is in place balance, according to the actual situation of rural power distribution network is more complex,It can not be unified mode, so we should adopt the method of combination of dispersion and centralization, fixed and automatic, which is carried out in three steps. Fir

32、st, the fixed compensation capacitor bank is installed at about 15% of the main transformer capacity in the substation. The two is to fix the fixed capacitor bank at the line load center or somewhere according to the reactive demand when the load is low. The three is to install an automatic compensa

33、tion capacitor bank on the upper side of the line load center.3. for the 10 kV distribution network system mainly used in rural power network, complete reactive compensation should include centralized compensation of substation, 10KV line compensation and user side low voltage compensation, plus random