Film capacitors have strong practicality in the field of energy storage welding machines

In China's capacitor market, the share of traditional aluminum electrolytic capacitors is gradually decreasing, while a new type of capacitor—more advanced and environmentally friendly—is steadily taking center stage: the film capacitor. Since the development of the capacitor industry began in the 1980s, and with its continuous expansion in scale, China's capacitor industry has experienced rapid growth, attracting active investment from foreign companies. To this day, the industry continues to advance with confidence. Through more than twenty years of continuous exploration and experimentation, film capacitor technology has matured, creating new opportunities for emerging products such as solar vehicles, electric vehicles, and energy storage welding machines.

Film capacitors are carving out a new path in the field of energy storage welding machines

In the field of energy storage welding machines, capacitor energy storage welders use industrial frequency AC power, which is rectified to charge capacitors. The stored energy is then discharged through a welding transformer, converting it into low-voltage, stable, and concentrated pulse current. This current generates resistance heat at the contact points of the workpieces, thereby fusing the metals. As a result, capacitors account for a significant proportion of energy storage welding machines. Currently, the mainstream energy storage welding machines on the market primarily use aluminum electrolytic capacitors. However, the service life of aluminum electrolytic capacitors is generally short. Foreign aluminum electrolytic capacitors, such as those from Chemi-Con, Nippon Chemi-Con, and Rubycon, typically last about five to six years, while domestically produced capacitors generally have a service life of only one to two years. Therefore, in the field of energy storage welding machines, foreign brands like Chemi-Con are still widely used. However, foreign capacitors often face issues such as slow supply, long order lead times, and high prices, which increase operating costs for small and medium-sized enterprises in terms of maintenance and inventory. This has also brought significant challenges and frustrations to these companies. As a result, large domestic capacitor manufacturers such as Jianghai, Faratronic, and VTCO have intensified their research and development efforts for film capacitors.

Technologically, film capacitors are gradually replacing aluminum electrolytic capacitors, which is more conducive to China's industrial development. However, the main obstacle to this substitution is the cost. Film capacitors are more expensive than traditional aluminum electrolytic capacitors, which is related to their production costs. In response, domestic film capacitor manufacturers have adopted a strategy of high-ratio substitution, using DC-Link polypropylene film capacitors to replace aluminum electrolytic capacitors. These film capacitors can meet the "filtering" capacitor requirements of frequency converters in terms of performance. If the price of polypropylene film capacitors is not higher than that of aluminum electrolytic capacitor banks, this substitution solution can meet performance requirements under the same economic benefits. After replacing aluminum electrolytic capacitors with polypropylene film capacitors, the issue of lifespan limitations is essentially eliminated, thereby avoiding the trouble and cost of periodically replacing aluminum electrolytic capacitors in high-reliability frequency converter applications.

Film capacitors vs. traditional energy storage aluminum electrolytic capacitors: which will prevail? Currently, traditional energy storage capacitors, namely aluminum electrolytic capacitors, still hold a larger share of China's capacitor market compared to film capacitors. However, due to the superior performance of film capacitors, their market penetration is steadily increasing. Will film capacitors completely replace aluminum electrolytic capacitors, or will they share the market equally? The facts show that the upward trend of film capacitors is unstoppable. They not only account for a significant share in the field of energy storage welding machines but are also making inroads into applications such as solar energy, wind power, hybrid electric vehicles, and subways. The image above illustrates the best example of film capacitor application in the field of energy storage welding machines.

From this perspective, the process of film capacitors replacing aluminum electrolytic capacitors is accelerating. In China's capacitor market, the share of traditional aluminum electrolytic capacitors is decreasing, while a new type of capacitor—more advanced and environmentally friendly—is steadily taking center stage: the film capacitor. Since the development of the capacitor industry began in the 1980s, and with its continuous expansion in scale, China's capacitor industry has experienced rapid growth, attracting active investment from foreign companies. To this day, the industry continues to advance with confidence. Through more than twenty years of continuous exploration and experimentation, film capacitor technology has matured, creating new opportunities for emerging products such as solar vehicles, electric vehicles, and energy storage welding machines.