Distribution Network Ferroresonance Analysis And Research On Treatment Measures

At present, the distribution network of power system, the resonance phenomenon is very common. Due to the resonance occurs when the overvoltage, caused a great threat to the safety of power grid, such as do not take effective measures to eliminate, may cause damage to the equipment, and even induced more serious accident of power systemThe normal operation of the power network, is the basic guarantee of development of electric power. From the state of power grid in recent years, operation situation is not optimistic. In the numerous failures, the harm to power system over voltage is caused, the most prominent. The so-called power system overvoltage refers to, because the fault, switching operation and other reasons, so the voltage caused by transmission of electromagnetic energy within the system increases. Over voltage operation overvoltage and temporary overvoltage in two forms, temporary overvoltage is divided into the power frequency overvoltage and resonance overvoltage. In the power system contains such as inductance element transformer, voltage transformer, is also like a capacitor element compensation capacitor, lead to a phase, the switch operation or fault occurs, the inductance and capacitance component parameters may match, in magnetic resonance phenomenon resulting in power function, cause the resonance over voltage. Resonance overvoltage once forms, it will cause damage to electrical equipment and large area power cut accident, put forward a serious challenge to the reliability of power supply. Due to the resonance over voltage duration is relatively long, therefore, in the choice of protective measures, there are certain difficulties. Especially for the voltage rating of35KV and below power distribution network, this issue is more outstanding.Resonance overvoltage overvoltage linear resonance, ferromagnetic resonance, parameter resonance in three ways, in the voltage rating of35KV and below power distribution network system in the running process, the harm of the ferromagnetic resonance overvoltage caused by the more prominent. This paper focuses on the analysis of such resonance, depth analysis of the mechanism of resonance generated, describes the characteristics of the ferromagnetic resonance, summarizes the ferromagnetic resonance conditions. Taking10KV system of Zhucheng power grid as the prototype, the overvoltage fault two resonance of its occurrence that is caused by the disconnection caused by ferroresonance and single-phase grounding fault after the disappearance of the ferromagnetic resonance is analyzed, ferromagnetic resonance caused by processing the single process phase to ground short circuit fault after the disappearance, selection of system neutral grounding via arc suppression coil and voltage transformer winding triangular openings with damping resistance of the two kinds of harmonic elimination methods were analyzed, and the simulation is carried out with MATLAB software. Can be seen from the simulation results, the overvoltage amplitude is the highest voltage amplitude system run several times.Eliminate ferroresonance from two aspects of changing system parameters and the consumption of system resonance energy measures, this paper summarizes the commonly used measures of eliminating harmonics, and analyzes their advantages and disadvantages and practicability. Over voltage on the two resonance, respectively, to take corresponding measures. The results showed that, the process of ferroresonance overvoltage caused by disconnection in the treatment, selection of TV high voltage side of the neutral point of the installation of a high voltage harmonic elimination device and TV neutral point connected in series single-phase voltage mutual inductor of the two harmonic elimination methods were analyzed, from the simulation results we can see that, voltage transformer high voltage side is additionally provided with a time harmonic elimination device to the high pressure side is better than the neutral point of TV series connection of single-phase voltage transformers, in order to consolidate a harmonic elimination effect, in the TV open delta side mounted two times harmonic elimination device, the users will be TV at a side all changed operation mode grounded; ferromagnetic resonance caused by processing the single process phase to ground short circuit fault after the disappearance, selection of system neutral grounding via arc suppression coil and voltage transformer winding triangular openings with damping resistance of the two kinds of harmonic elimination methods were analyzed, from the simulation results it can be seen, the system neutral grounding via arc suppression coil is superior to the opening of the voltage mutual inductor with damping resistor delta winding, real-time monitoring, in order to prevent such resonance over voltage occurs, the final selection of the automatic tracking compensation device.The implementation of these measures, improve safety and reliability of power supply, guarantee the good quality of electric energy, ensure the economical operation of the power system, a better interpretation of "you electricity-my heart" service concept, to lay a solid foundation for the safe and stable operation of power system.