Research On Temperature Rise Of High Voltage Capacitor Under Specific Harmonic Condition

This paper introduces the reason of harmonic generation, which in turn adversely affects the system equipment and the typical electricity load. In this paper focuses on the system as reactive power compensation equipment of shunt capacitors and harmonic interaction interpretation, identified in the current national standard for the equipment normal operation voltage, current, the capacity limit, and to come under harmonic conditions as the main criterion for harmonic overload capacity capacitor bank will be more accurate. For the presence of harmonics, the system shunt capacitor may cause the grid to enlarge the types of circumstances in detail. The distribution of the field, such as a capacitor plate folds element inside bubbles, impurities, and other major internal fault of finite element analysis,to determine the presence of these types of variation under fault condition internal electric field intensity distribution, to reduce the risk of an internal capacitor commissioning grid for reference.In the paper utilized the test platform to explore the effect of harmonic to capacitor dielectric loss, to draw a relationship between the presence of the typical number of harmonic voltage distortion and loss rate.There will come a loss peak, then the increase in the number of harmonic losses will be decreased because of the harmonic capacitor variation of capacitance with frequency.The capacitors are respectively arranged on the two conditions to explore.First, under natural conditions,to verify the distribution of the capacitor during normal operation temperatures,identify key hot spots, in order to further explore the impact of health to establish harmonic main observation node, and capacitor and the hot spot temperature will varies with changes in the external environment. This basic test based on capacitor test at constant temperature of 60℃under the condition that the current strict control in the standard range, the internal temperature of the capacitor hot rise about 5 ~ 6℃.By using the constant current method, the temperature of each harmonic is slightly lower than that of the pure fundamental wave, and the influence of the harmonics on the temperature is not obvious.In the paper, the relevant results of the tests drawn capacitor temperature, and existing through inspections, infrared temperature monitoring deficiencies and other capacitor, and the key factors affecting the life of the capacitor can be measured by test at different temperatures for capacitors thermal equilibrium curve. Using the heat balance curve to monitor the parameters of the capacitor in operation, determine thereasonable service life of the capacitor, to replace the capacitor in time, to reduce the probability of failure, to improve the system safety and reliability. At present, due to the test platform, the cost is expensive and the test cycle is longer, to carry out research few of such high pressure, large capacity power capacitor, so as to further strengthen the study of the influence of harmonics on the capacitor has a certain guiding value.