Study On Insulation State Detection Of High Voltage Storage Capacitor Based On DC Partial Discharge

High-Voltage (HV) storage capacitor is the common device in pulse power system, which is widely used in weapons. In order to satisfy the demand of development of pulse power system, the storage density of this kind capacitors must be improved, which means decreasing the cubage and increasing the storage energy capability of dielectrics. Higher load-carrying properties of insulation dielectrics have to be required. It will bring hidden trouble to the insulation capability and the work reliability of capacitors. Detecting the insulation state and judging the work reliability of capacitor are significant to the weapon system.The work process of high voltage storage capacitor is charged under DC and large discharge in short time. Such process is the main course to insulation aging. As for the large current magnitude of large impulse, partial discharge signals can't get through sensor directly under such large impulse. According to the work process of high voltage storage capacitor, partial discharge measurement under DC voltage was put forward. With the analysis and discharge simulation about DC partial discharge (DCPD), there is a relationship between discharge parameters and defect, lifespan of insulation. So they can be used to effectively reflect the situation of insulation.According to the manufacture technology and aging effect, the defects of capacitors were divided into inner defect, contact defect, overlap defect and oiliness defect. In this thesis, a DCPD detection and analysis system with high sensitivity was used to collect and analyze DCPD signals of capacitors with defects. As an effective parameter,â–³t was introduced into the analysis. Based on q,n andâ–³t, the discharge spectrum was calculated out as a basic sample base for capacitor PD signal analysis .Based on the support vector machine (SVM), the defect types in the storage capacitors and those appeared during the aging test can be effectively identified. This thesis mainly does some research on the HV storage capacitors which were aged. Due to different aged degree of capacitor, DCPD measurement adopted the same connection form and the reverse one respectively. The PD parameters had relationship with the aging times of capacitors; some special phenomena are analyzed which appeared during the process of aging test. The work of this thesis would effectively promote the design, manufacture and evaluation work on storage capacitor for further guaranteeing its work capability.