Research On Full-Compensation Arc-Suppression Coil And Its' Control Technology

With the power system development, the medium voltage distribution network of our country using resonant neutral grounding is growing. However with the popular resonant grounding used, the fault line detection results and arc suppression results are not ideal. It is eager to find a better arc suppression method to meet the reliability requirements of the power system. Based on the detailed analysis various forms of existing arc suppression coil structure and control approach, this paper presents a new full compensation arc suppression coil which could compensate both active and harmonic component of the ground fault current. Then this paper mainly studies with this new arc-suppression control technology, including the structure of the full compensation Arc suppression coil and its'operational control strategy, the system earth capacitor current detection method, the fault line selection technology, and so on.Firstly, we study the control technology which suits the structure of new arc suppression coil for the need of full compensation arc suppression. Tuning in normal operation system, this paper presents an on-line capacitive current detection method of injected signal based on the natural system frequency. It is used for the online reference automatic tuning of main arc suppression coil to ensure that the main arc suppression coil operates in the near of full compensation point. When the system single-phase ground fault occurred, for the better compensation to the ground fault residual and to the smallest of it, this paper presents an adaptive ground fault residual flow harmonic detection algorithm based on the fuzzy inference, which provided the accurated reference of output current injection for the auxiliary coil.Then, for the control of full compensation arc suppression system, this paper presents a full compensation arc suppression coil control technology based on the H_∞control theory against the uncertainty of system model, the complexity factors of power system fault and outside interference. Through the establishment of control objectives of the mixed sensitivity analysis function, we transform control system into a standard H_∞control problem to solve, and reduce order processing using leading to the final node to create the conditions for practical application. With this technology, we realize the rapidly and steadily control of full compensation arc suppression coil.Subsequently, this paper presents a transient fault line selection algorithm based on the multi-scale morphology wavelet analysis against the problem of fault lines selection in resonant grounding system. We combine the advantages of wavelet analysis details to signals multi-scale and mathematical morphology computing simple, easy to program to achieve. We use alternative morphology operator wavelet operator, building the pyramid theory signal the shape-resolved multi-scale wavelet algorithm, to solve transient earth fault line selection problems.Finally, this paper studies pseudo-fault by ferroresonance in distribution network with the detection needs of the power system before full compensation arc suppression control. Based on the detailed analysis of ferroresonance and insurance issues fuse mechanism in the distribution network, this paper presents the corresponding suppression programme and verifies the correctness through high-pressure physics simulation and experiment.Over all aspects of research has been verified through theoretical analysis, simulation analysis and some high-pressure physics experiment, which provide the necessary research base for the practical control technology of full-compensation arc suppression. They are useful supplement and improvement for the arc suppression control and fault lines selection technology in the resonant grounding system.