Views:1 Author:Site Editor Publish Time: 2018-03-14 Origin:Site
The key to replace aluminum electrolytic capacitors with thin film capacitors is price. If the film capacitor with rated voltage of 700V can be used to replace the aluminum electrolytic capacitor, the capacitance of 1F ~ 2F per RMB can be replaced.
Some capacitor manufacturers believe that the price of each RMB 2F is absolutely impossible to manufacture, and some capacitor manufacturers think that after careful calculation, it is possible to achieve. Such a solution would be better if there was sufficient capacity and the price was close to or lower than that of aluminum electrolytic capacitors. When it is necessary to replace aluminum electrolytic capacitor with thin film capacitor, it should be replaced by small capacity replacement ratio.
The scheme of replacing aluminum electrolytic capacitor with 5-film capacitor
The biggest obstacle to replacing aluminum electrolytic capacitors with thin film capacitors is the price of thin film capacitors. If the capacitor is replaced by one to one, it is certainly not realistic in price. From the above analysis, we can know that the poly-phase rectifier output filter capacitor is no longer a smooth function, but a DC bus power bypass, so long as the capacity can meet the requirements of the power bypass. As a matter of fact, the capacity requirement of DC busbar power bypass is not as large as that of aluminum electrolytic capacitor, which leads to the poor current bearing capacity of aluminum electrolytic capacitor, and the reason that ESR is relatively high.
Because the capacitor filter of three-phase bridge rectifier is actually DC support, DC-Link or DC busbar bypass capacitor. The key to this problem is whether the current bearing capacity of the filter capacitor meets the requirements. Manufacturers of thin film capacitors have produced corresponding metallized polypropylene film capacitors.