On reactive power compensation of power grid

2022-08-16
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Random talk on reactive power compensation of electricity

Abstract: in the actual power system, asynchronous motor, as the traditional main load, makes electricity produce inductive reactive current; Most power factors of power electronic devices are very low, resulting in a large number of reactive power in electricity. There is no doubt that the utilization of carbon fiber composites will be further increased. Reactive current produces reactive power, which brings extra burden to electricity and affects the quality of power supply. Therefore, reactive power compensation (hereinafter referred to as reactive power compensation) has become one of the main means to maintain high-quality operation of electricity, which is also a major topic facing the development of electrical automation technology and power system research field, and is receiving more and more attention

key words: Electric reactive power compensation Untitled Document at present, there is an upsurge of environmental protection around the world. The power system is a specific environment. The reactive power in public electricity is determined by the operation law of electricity itself, but it brings a lot of trouble to the operation of electricity. Reactive power is a kind of power that can not do active work, but will cause loss in electricity, and it is indispensable. In the actual power system, as the traditional main load, asynchronous motor produces inductive reactive current; The power factor of most power electronic devices is very low, resulting in a large amount of reactive current in electricity. Reactive current produces reactive power, which brings extra burden to electricity and affects the quality of power supply. Therefore, reactive power compensation (hereinafter referred to as reactive power compensation) has become one of the main means to maintain high-quality operation of electricity, which is also a major topic facing the development of electrical automation technology and power system research field, and is receiving more and more attention. Setting reactive power compensation capacitor is a traditional method to compensate reactive power, which is widely used at home and abroad. The capacitor is connected in parallel with the network inductive load, and compensating reactive power with the shunt capacitor has the advantages of simple structure, economy and convenience, but its impedance is fixed, so it can not track the change of load reactive power demand, that is, it can not realize the dynamic compensation of reactive power. With the development of power system, reactive power is required to be dynamically compensated, resulting in synchronous condenser (SC). It is a synchronous motor specially used to generate reactive power. It can generate capacitive or inductive reactive power of different sizes under overexcitation or underexcitation. Since the high-tech of 2 waterproof experimental machine products, in the decades since the 1920s and 1930s, the synchronous condenser once played a major role as an active reactive power compensation in the power system, so it is called the traditional reactive power dynamic compensation device. However, because it is a rotating motor, the loss and noise in operation are relatively large, the operation and maintenance are complex, and the response speed is slow, which is difficult to meet the requirements of fast dynamic compensation. Since the 1970s, synchronous condenser has been gradually replaced by static var compensator (SVC). At present, synchronous condenser is no longer used in some countries. The early static var compensation device was of saturated reactor (SR) type. In 1967, British GEC company made the world's first batch of this type of var compensation device. Compared with synchronous condenser, saturated reactor has the advantages of static and fast response; However, its iron core needs to be magnetized to saturation state, so the loss and noise are still large, and there are some special problems of nonlinear circuit, and it cannot be adjusted by phase to compensate for the imbalance of load, so it fails to occupy the mainstream. The development of power electronic technology and its application in power system have pushed the static var compensation device of thyristor onto the stage of var compensation. In 1977, Ge Corporation of the United States first demonstrated the static var compensation of thyristors in the actual power system to ensure that the supply voltage meets the input voltage compensation device specified by the tension machine. This kind of device was put into actual operation in 1978. Subsequently, major electrical companies in the world launched a series of products with their own characteristics. In recent 10 years, it has occupied the dominant position of static var compensation devices. So the static var compensation device (SVC) has become a static var compensation device that specifically refers to the use of thyristors, including thyristor controlled reactor (TCR) and thyristor switched capacitor (TSC), as well as the hybrid device of the two (tcr+tsc), Or TCR and fixed capacitor (FC) or mechanically switched capacitor (MSc) mixed devices (tcr+fc, tcr+msc), etc. With the further development of power electronics technology, since the 1980s, a more advanced static reactive power compensation device has appeared, which is reactive power compensation using self commutating phase-change current circuit. Some people call it static var generator (SVG), Some people also call it advanced static var compensator (asVC) or static condenser (statco), which is not only an indispensable basic production link of a large number of industrial and agricultural products n). Recently, several SVG devices have been put into actual operation in Japan and the United States respectively. At present, in addition to the further discussion of SVC and SVG reactive power compensation, people also study other forms of static converters for dynamic reactive power compensation, including gambling type self commutation bridge circuit, AC-AC frequency conversion circuit and AC chopper circuit. Until recently, the United power flow controller (UPFC) has been proposed by the American Electric Power Research Institute. In fact, SVC, SVG and UPEC are all devices in flexible AC transmission system (FACTS). The so-called flexible AC transmission system is a new concept proposed by the American Electric Power Research Institute since the 1980s. Its essence is to apply the high-voltage and high-power power power electronic technology to the power system to enhance the control ability of the power system and improve the transmission capacity of the original power system

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