One, overview
1 in order to ensure the normal operation of the train, the traction network voltage at any point of not less than 21kV, in the most serious cases shall not be less than 19kV, therefore, we mustimprove the traction network voltage. In general, by using the method of parallel capacitor compensation to improve the traction network voltage.
2 in the substation capacitor compensation device connection as shown in figure 1. Capacitors C1,C2 for L1, L2 for the compensation capacitor, coil, DK is the filter reactor.
Two, connection mode
The 1 reactor is the role of the electric locomotive produce harmonic filter, to reduce the influence of harmonics on the power system. In recent years, a new outdoor dry hollow reactor, the reactorcan overcome the shortcomings of oil filled type reactor, with low noise, the advantages of easy maintenance. But this kind of reactor has insufficient places: in the inductance of reactor test site is more difficult, but in practice found that the dry air core reactor is not suitable for the use of ironmesh.
2 when the reactor is put into operation, to the reactor and a sinusoidal variation with time of thecurrent I, expressed as: where =2 is the initial phase of PI F, i.
3 reactor with current I, from the first end (A or B terminal), tail (DA or DB) outflow. Then, reactor coil having a magnetic. According to the law of electromagnetic induction, the pressure drop along the direction of reactor coil coil ADA (or BDB) at both ends of the EMF, flux: Phi = phi MSIN t.
Three, a detailed description of
1 we know that, the establishment of a magnetic field, only need to reactive power from the power supply. So the flux of M current and flux of M phase, and the backward phase voltage source voltage UA to 90 degrees, known as the magnetization current, Iro, reactive component is also known as the excitation current. The permeability of ferromagnetic materials than the non ferromagnetic material is much larger, about a hundred times. In the condition of alternatingmagnetization, there exists hysteresis iron mesh, a hysteresis loss. The establishment of flux of mapart from the power supply to the reactive power, also need to provide to the active power, active power hysteresis loss grid needs. Obviously, the active power only by a UA with the power supplycurrent in the same phase brought in. In addition, through alternating flux of M, there are still largeeddy current grid, also produced significant heat loss in the eddy current effect, the eddy current loss.
The active component of current hysteresis loss and eddy current loss of the Ioa 2 mesh is theexcitation current, hysteresis and eddy current loss of the active power consumption, while in thegrid is transformed into heat energy. Grid iron material, permeability is very large. In the magnetization process of magnetic iron magnetic material, according to the applied magnetic fieldarrangement, the reciprocating swing domains, so to meet each other's resistance, will consume some energy. This part of the hysteresis phenomenon, in the form of heat energy is dissipatedhysteresis loss. The cyclic alternating magnetization frequency is higher, the hysteresis loss. Can be proved, hysteresis loss is proportional to the magnetization caused by the use of current frequency, thus the mesh in the hysteresis loss is in the form of heat dissipation. In addition to thealternating magnetic flux through the cross section of the M mesh, section on the induced current,in the eddy current under the action of heat loss, the eddy current loss. Current frequency eddy current loss and reactor coil is proportional to the square of the grid, which is composed of a closed loop magnetic permeability strong iron materials, so that the diameter of M eddy current generatedis relatively large, relatively large Ioa. By IA=Ior+Ioa we can see that the Ioa increases, if the IA invariant, Ior also decreases. In other words, the active component of IA=Ior+Ioa reactor in theincrease of the excitation current, reactive power component decreases, which is very unfavorable for the substation, the active component in the grid will be transformed into a large amount of heat.
3 of the active component we do not have a specific measure, but from the situation at the scene,when the reactor is put into operation, the mesh vibration, reactor bottom insulator connectedground vibration is relatively large (a larger vibration and sound), at the same time grid fever.Reactor input time more long, mesh more heat, heat the red gate lock network, mesh. In view of the above situation, we put all the mesh to replace, brick wall. In this way, not only the economic saving,beautiful, and unfavorable factors we eliminate all above analysis,
For personal, equipment is safe, reliable. The practical application proves that this method iseffective, can ensure the safe and reliable operation of dry-type air core reactor.
