What is the function of three-phase reactor?

The reactor used in power network is essentially a hollow conductor without magnetic conductive material. 1. Reactor \x0d\ The concept of reactor is also called inductance. When a conductor is electrified, it will produce a magnetic field in a certain space it occupies, so all electrical conductors that can carry current have general inductance. However, the inductance of the electrified long straight conductor is small and the magnetic field generated is not strong, so the actual reactor is in the form of a wire wound into a solenoid, which is called an air-core reactor; Sometimes, in order to make this solenoid have greater inductance, an iron core is inserted into the solenoid, which is called an iron core reactor. Reactance is divided into inductive reactance and capacitive reactance. The scientific classification is that inductive reactance (inductance) and capacitive reactance (capacitance) are collectively called reactors. However, due to the existence of inductance in the past, it was called reactor. Now the capacitance is called capacitive reactance, and the reactor refers to inductance \x0d\ II. Classification of reactors: \x0d\ According to structure, cooling medium, connection, function and use. \x0d\ 1 According to the structure and cooling medium, it can be divided into air-core reactor, core reactor, dry reactor and oil-immersed reactor, such as dry air-core reactor, dry core reactor, oil-immersed air-core reactor, clamping dry air-core reactor, wrapped dry air-core reactor and cement reactor. \x0d\2 Connection mode: divided into parallel reactors and series reactors. \x0d\3 is divided into current limiting and compensation by function. \x0d\4 It is subdivided according to specific purposes, such as current limiting reactor, filter reactor, smoothing reactor, power factor compensation reactor, series reactor, balanced reactor, grounding reactor, arc suppression coil, incoming reactor, outgoing reactor, saturation reactor, self-saturation reactor, variable reactor (adjustable reactor and controllable reactor), yoke current reactor, series resonant reactor and parallel resonant reactor. X0d reactor, as a means of reactive power compensation, is indispensable in power system. \x0d\ shunt reactor: The reactor used for generator full load test is the prototype of shunt reactor. Due to the attraction of alternating magnetic field between segmented core cakes, the noise of core reactors is generally about 10dB higher than that of transformers with the same capacity. \x0d\ Current limiting reactor: Current limiting reactors are generally used in distribution lines. Branch feeders from the same bus are often connected in series with a current limiting reactor to limit the short-circuit current of the feeder and keep the bus voltage from being too low due to the short-circuit of the feeder. \x0d\ Damping reactors (also called series reactors) are connected in series with capacitor banks or dense capacitors to limit the closing inrush current of capacitors. At this time, a filter reactor similar to a current-limiting reactor and a filter capacitor are connected in series to form a resonant filter, which is generally used for resonant filtering from 3rd order to17th order or higher-order Qualcomm filtering. Converter stations, phase-controlled static compensation devices, medium and large rectifier devices, electrified railways, and even all power electronic circuits controlled by high-power thyristors are harmonic current sources, which must be filtered to prevent them from entering the system. The electric power department has specific regulations on harmonics in the power system. P \x0d\ arc suppression coil: arc suppression coil is widely used in 10kv-6kV resonant grounding system. Due to the non-oily tendency of substation, arc suppression coils below 35kV are mostly dry cast. P \x0d\ smoothing reactor: the smoothing reactor is used for DC circuit after rectification. The number of pulses in the rectifier circuit is always limited, and there is always ripple in the output rectified voltage. This ripple is usually harmful and needs to be suppressed by smoothing reactors. The converter stations of DC transmission are equipped with smoothing reactors to make the output DC close to the ideal DC. Smoothing reactor is also essential in DC-powered thyristor electric drive. \x0d\ DC-controlled saturable reactor: a choke or self-saturated reactor connected in series in the circuit. In the period of voltage sine wave, the saturable reactor absorbs a certain volt second before saturation, reaches saturation, and then becomes fully open. Therefore, its output voltage is non-sinusoidal, and this saturated reactor acts like a thyristor. The main components of \x0d\ circuit are resistance, capacitance and inductance. Inductor can restrain the change of current and shift the phase of alternating current. The wound electrostatic induction device with inductance is called a reactor. \x0d\ Function of reactors \x0d\ The reactors commonly used in power systems are series reactors and shunt reactors. Series reactors are mainly used to limit short-circuit current, and some are connected in series or parallel with capacitors in the filter to limit higher harmonics in the power grid. Reactors in 220kV, 1 10kV, 35kV and 10kV power grids are used to absorb the charging capacitive reactive power of cable lines. The working voltage can be adjusted by adjusting the number of shunt reactors. The EHV shunt reactor has many functions to improve the reactive power of power system, mainly including: \x0d\( 1) produces capacitance effect on light-load or light-load lines, and reduces power frequency transient overvoltage. \x0d\(2) Improve the voltage distribution on long transmission lines. \x0d\(3) Under light load, the reactive power in the line should be partially balanced as much as possible to prevent the unreasonable flow of reactive power and reduce the power loss on the line. \x0d\(4) Reduce the power frequency steady-state voltage on the high-voltage bus when large units are connected in parallel, so that generators can be connected in parallel at the same time. \x0d\(5) Prevent self-excited resonance that may occur in generators with long lines. \x0d\(6) When the neutral point of the reactor is grounded by a small reactance device, the small reactor can also be used to compensate the phase-to-phase and ground capacitance of the line, so as to speed up the automatic extinguishing of the secondary current, which is convenient to use. \x0d\ reactors are connected in series and in parallel. Series reactors usually limit current, and parallel reactors are often used for reactive power compensation.