Analysis of reactive power compensation technology for power dispatch

The main function of reactive power compensation is to minimize power consumption. Through effective control of the power network, the entire power network can operate normally. When the power equipment and reactive power compensation equipment are complete, it can be fully utilized. Can make reactive power compensation technology play better. Here, we can understand the many details of reactive power compensation technology by studying the status quo, existing problems and development trends of reactive power compensation technology.

1 Status of reactive power compensation technology

With the continuous progress of various high-tech products in the society, people’s demand for electricity is increasing faster and faster, which makes the power supply from the grid more and more, and more and more of it is consumed, whether it is a grid company It is the masses of the people who are increasingly eager to develop reactive power compensation technology. At present, the reactive power compensation technology in my country's power system is mainly the following aspects.

1) Synchronous motor. Synchronous motors include three aspects: synchronous generators, synchronous motors and synchronous tuning cameras. Once the synchronous generator is operating normally, it can provide a steady stream of reactive power to the power system through the operation of lagging power factor; the synchronous motor is used to change and adjust the excitation current, and the magnitude and direction of the output reactive current In-depth processing, but the cost of synchronous motors is generally high, and maintenance is also more difficult. Synchronous tuning cameras are the representative of reactive power compensation used by the power system in the early days, but it is only limited to the grasp of dynamic regulation, and its mechanism construction is more complicated. After a problem occurs, the maintenance is more complicated, so now the use of synchronized cameras is becoming less and less.

2) Parallel capacitors. Shunt capacitors generally automatically adjust the amount of reactive power required in the power system, and switch the compensation capacitors. The power consumption of the parallel capacitor is generally small and the installation is very convenient, but it is very easy to have too much or too little compensation for the capacitor, which will cause compensation errors and make the reactive power compensation less than the best effect.

3) Static var compensator. The static var compensator is composed of a reactor and a capacitor that control the switching of the thyristor. It is very easy to quickly and smoothly compensate the reactive power to assist the work, but it often produces harmonics in the switching process.

4) Static var generator. Since the basic circuit of the static var generator is a three-phase bridge converter circuit, energy storage components such as large-capacity reactors and capacitors are not used. As long as a small capacitor is installed on the DC end of the power system, the voltage can be kept normal.

5) Active power filter. The characteristic of the active power filter is the reactive power compensation operation in the filtering process, and it can carry out continuous adjustment and the response is relatively fast. It can perform individual compensation for a single harmonic and reactive power source, and can perform centralized compensation for several harmonics and reactive power sources. But its cost is also relatively high, and the realization of the work process is more complicated.

6) Unified power flow controller. The function of the unified power flow compensator is the functional embodiment of multiple functions such as parallel and series. It can comprehensively control the power system and realize the accurate adjustment of active and reactive power of the line. It is more flexible in actual work and has a good development prospect.

2 Problems with reactive power compensation

In the practical application of reactive power compensation technology, because almost all kinds of equipment have defects in one way or another, as well as operator errors, many problems will arise.

1) The problem of compensation methods. Nowadays, many electric power departments directly carry out reactive power compensation on the spot. They only pay attention to the consideration of the factors of compensating power, but ignore the understanding of reducing power system network consumption. Therefore, some construction workers only pay attention to the control of the corner of the place in front of them, and forget the overall consideration.

2) Harmonic issues. Capacitors are resistant to harmonics to a certain extent, but if the content of harmonics is relatively large, the capacitors will be overwhelmed and prone to damage or partial holes. At the same time, the capacitor also has the disadvantage of amplifying harmonics. Sometimes, not only will the harmonics not be effectively controlled, but it will also increase its radiation surface. This has the opposite effect.

3) Reactive power transmission problem. Reactive power reverse transmission directly causes voltage surges, leading to the loss of control of the power system. Therefore, reactive power reverse transmission should receive good attention from construction personnel in reactive power compensation.

4) Compensation for detailed problems caused by equipment. According to the advantages and disadvantages of the compensation equipment described above, we can find that most of the equipment has shortcomings, and the compensation process will bring many obstacles to many aspects of the power system and cause undesirable consequences.

3 Development trend of reactive power compensation technology

Today, with the continuous advancement of science and technology, the technology of reactive power compensation is also constantly improving. In order to make the compensation work more stable, relevant personnel in our country conduct continuous research and development, continuously improve the technology of reactive power compensation, and comprehensively consider it. , To suppress harmonics, and at the same time enable reactive and dynamic automatic stepless adjustment.

1) Intelligent compensation device for thyristor switching capacitor (tsc). This kind of equipment uses a microprocessor in tsc to make dynamic reactive power compensation possible. Its core component is a controller. This controller analyzes and measures the power factor to make the data clear and correct. It can better control the switching of the non-contact switch, and at the same time can store and display the actual data of undervoltage, overvoltage and power factor.

This kind of device is useless to operate, responds quickly, and has multi-directional protection capabilities, which should be trusted by more people.

2) Static var generator (svg). The static var generator uses gto to make it an integral part of itself, forming a self-commutated converter. If the method is used properly, it can control the generation of harmonic currents in the compensation of reactive power. It has a faster adjustment speed, avoids the appearance of more harmonics, and does not require large-capacity energy storage components. At the same time, it can also make the voltage more stable, which is more comprehensive in terms of technology.

If svg can be used properly, it will make the reactive power compensation work smoother and make it more capable of adjusting reactive power under undervoltage conditions. Therefore, attention should be paid to it so that it can be widely used. used.

3) Power active filter. The active power filter can effectively control the harmonics in an instant, so that it can reduce the harm to the power system. At the same time, it responds more quickly, can realize dynamic compensation of harmonics and reactive power in operation, and has very little influence on the impedance parameters of the grid.

Therefore, the power active filter can be widely put into the market, so that it can really contribute to the development of the power system.

4) Integrated power flow controller (upfc). The integrated power flow controller can combine the AC voltage generated by the thyristor and add it to the phase voltage of the transmission line, so that its amplitude and phase angle can be continuously changed, and the power of active and reactive power of the line Carry out accurate and effective control, and while improving the transmission capacity, it can dampen the continuous oscillation of the system.

In the working practice of modern reactive power compensation, UPFC is the most stable compensation equipment with the highest technological content and should be widely used.

4 summary

In the progress of reactive power compensation in our country, I believe that the power construction technology department will develop more and better compensation equipment, so that we can overcome more difficulties in reactive power compensation, and make harmonics and some influences. The factors of the power system can be easily solved, so that the power system can operate more normally, and the construction of the power grid can be more smoothly carried out under the normal operation of high-tech equipment.