Performance and Countermeasures of Capacitor in High Temperature Environment

Fundamentals of 1. Capacitance A capacitor is an element that stores electrical charge and is usually composed of an insulating material between two conductive plates. When a voltage is applied across the capacitor, the capacitor will store charge and form a certain electric field force line. The main performance indicators of capacitors include capacitance, interpolar voltage, dielectric loss, and so on. 2. high temperature influence mechanism In the high temperature environment, the electrical properties of the capacitor will be greatly affected, mainly in the following aspects: 1. Change in capacitance: High temperature will increase the resistance of the capacitor conductor plate, which in turn will cause the capacitance of the capacitor to decrease. 2. Capacity drift: Under high temperature environment, the medium of the capacitor will undergo thermal expansion, which will cause the plate spacing and plate area to change, resulting in its capacity drift. 3. Temperature coefficient change: The electrical properties of the capacitor are not only affected by high temperature, but also affected by the temperature coefficient. At high temperatures, the temperature coefficient changes, causing the capacitor capacitance to drift. 3. response measures In order to reduce the influence of high temperature on the electrical properties of capacitors, the following measures can be taken: 1. Select the appropriate dielectric material: select the dielectric material with good stability at high temperature as the dielectric of the capacitor. 2. Control of high temperature environment: for capacitors in high temperature environment, cooling measures can be taken or ventilation can be increased to reduce the ambient temperature. 3. Take protective measures: such as limiting the maximum voltage, ensuring the board spacing, installing insurance, etc., to protect the performance of the capacitor from damage. Summary: In high temperature environment, the electrical performance of the capacitor is easily affected, resulting in the capacitance change of the capacitor, temperature drift and other problems. In order to ensure the normal use of the capacitor, we should choose the appropriate dielectric material, control the high temperature environment, take protective measures and other means.

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Influence of High Temperature on Capacitor and Fault Performance

Capacitor is a common component in the circuit, it has the ability to store charge and release charge. However, in a high temperature environment, the performance of the capacitor may be affected to a certain extent, mainly in the following aspects: 1. Lower the capacitance value In a high temperature environment, the dielectric of the capacitor may decompose due to heat, resulting in a decrease in the capacitance value. This situation is more likely to occur in capacitors with poor high temperature resistance. 2. Increase leakage current Under high temperature environment, the leakage current of the capacitor may increase, which is due to the properties of the dielectric affected by thermodynamic factors. The increase of leakage current will reduce the stability of the circuit and affect the normal operation of the circuit. 3. Increase ESR ESR(Equivalent Series Resistance) is the internal resistance of the capacitor. It refers to the electric power generated inside the capacitor when the capacitor is energized. Because the current has many factors affecting the impedance, the ESR of the capacitor usually increases in high temperature environment, which will lead to the decline of the performance of the capacitor and affect the normal operation of the circuit.

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Operating temperature of high temperature capacitors

-40 ℃ to 125 ℃ The normal operating temperature range for high temperature capacitors is -40°C to 125°C. 1 High temperature capacitors are designed to maintain stable operating performance in high temperature environments. Different types of capacitors have different heat resistance properties, and some of them are able to operate under extreme high temperature conditions. For example, benzyl silicone oil impregnated film paper composite dielectric capacitors can operate normally in a temperature environment of -40°C to 125°C. This capacitor uses heat-resistant polyester film and silicone oil as key materials, enabling it to function for a long time under high temperature conditions. In addition, the metalized polypropylene film dry capacitor is also a high temperature capacitor, its operating temperature range is -55 ℃ to 125 ℃, long-term operation of the operating temperature of 105 ℃. This kind of capacitor adopts high temperature resistant polypropylene film, which can increase the upper limit of the operating temperature of the capacitor, so as to adapt to a wider range of high temperature working environment. In general, the design and material selection of high-temperature capacitors enable them to maintain stable working performance in high-temperature environments, and their operating temperature range usually covers a wide range from low temperature to high temperature to meet the needs of different application scenarios.

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