工業自動化程度的不斷提高，變頻器得到了更廣泛的應用，其中電容在變頻器是不可或缺的，那么到底該選擇什么規格的電容器更適合在變頻器中使用呢？
With the continuous improvement of industrial automation, frequency converters have been more widely used, in which capacitors are indispensable. So what specifications of capacitors should be selected to be more suitable for use in frequency converters?
變頻器是利用電力半導體器件的通斷作用將工頻電源變換成另一頻率的電能控制裝置。變頻器主要由整流（直流變交流）、制動單元、驅動單元、微處理單元等組成。在電容器中鋁電解電容和薄膜電容都應用于變頻器中。
Frequency converter is a power control device that uses the on-off function of power semiconductor devices to convert power frequency power supply into another frequency. The frequency converter is mainly composed of rectifier (DC to AC), braking unit, driving unit, micro processing unit, etc. In capacitors, aluminum electrolytic capacitors and film capacitors are used in frequency converters.
電容器家族當中
電解電容、薄膜電容、超級電容、貼片電容、陶瓷電容等應用于不同的領域中。
Among the capacitor families, electrolytic capacitors, film capacitors, super capacitors, patch capacitors, ceramic capacitors, etc. are used in different fields.
電解電容作為整流濾波電容在變頻器中起著重要作用。不過在工作過程中，鋁電解電容器的損耗很大，其中無功損耗可以占到總無功容量的20%，而且會隨著頻率的增大而增大，損耗以熱量形式散發，導致鋁電解電容更容易發熱，使用工作時間短，故障率更高。鋁電解電容的損壞常常導致整臺設備無法繼續運轉。
Electrolytic capacitor plays an important role in frequency converter as a rectifier and filter capacitor. However, in the process of operation, the loss of aluminum electrolytic capacitors is very large, among which the reactive power loss can account for 20% of the total reactive capacity, and will increase with the increase of frequency. The loss is distributed in the form of heat, which leads to aluminum electrolytic capacitors being easier to heat up, shorter working time and higher failure rate. The damage of aluminum electrolytic capacitor often causes that the whole equipment cannot continue to operate.
薄膜電容具有無極性、介質損耗小，寄生電感低、阻抗低、溫度特性好、體積小、工作時間長等優勢。在同等容量中，薄膜電容的耐紋波電流能力要高于鋁電解電容器的耐紋波電流，薄膜電容器的低阻抗使開關管上的電壓應力大大減小，有利于開關管工作的可靠性和穩定性。
Thin film capacitors have the advantages of non polarity, low dielectric loss, low parasitic inductance, low impedance, good temperature characteristics, small size, long working time, etc. In the same capacity, the ripple current resistance of the film capacitor is higher than that of the aluminum electrolytic capacitor. The low impedance of the film capacitor greatly reduces the voltage stress on the switch tube, which is conducive to the reliability and stability of the switch tube.
和鋁電解電容相比，薄膜電容更適合變頻器。在使用過程中薄膜電容能工作很長時間，在變頻器中可以做到免維護，大大節約維護成本和人力，避免了變頻器電器替換電容器的麻煩和成本的提高。在變頻器中薄膜電容逐漸取代鋁電解電容是必然選擇。
Compared with aluminum electrolytic capacitor, thin film capacitor is more suitable for frequency converter. The film capacitor can work for a long time in the process of use, and can be maintenance free in the frequency converter, which greatly saves maintenance costs and manpower, and avoids the trouble of replacing capacitors with inverter appliances and the cost increase. It is inevitable to replace aluminum electrolytic capacitor with thin film capacitor in frequency converter.
