JP-2021502702-A5 -

Dates

Publication Date

20230501

Application Date

20181108

Description

It is known that using DC link capacitors in constant voltage DC links can cancel out these undesirable electrical effects. The success of this method particularly depends on establishing the best possible electrical and mechanical connection of the DC link capacitor to the power semiconductor or power semiconductor module using appropriate assembly and connection techniques. A DC link capacitor is typically formed from two opposing electrode plates, with one or more wound capacitor elements held between them. Each wound capacitor element has two opposing end faces that can be electrically contacted by shoeing. The shoeed end faces are usually soldered or welded to the corresponding electrode plates. The electrode plates are then firmly connected to a busbar having terminal elements for connecting to external circuits, cables, etc. In one embodiment, an electrode plate with a wound capacitor element held between it and a busbar, excluding the internally provided terminal element, are sealed in a potting compound. DC link capacitors are typically purchased by power electronics equipment manufacturers from suppliers that manufacture DC link capacitors according to the manufacturer's specifications. Therefore, if the manufacturer's specifications change, the supplier needs to manufacture a correspondingly compliant DC link capacitor. This is cumbersome and costly. According to a first aspect of the present invention, a DC link capacitor module is proposed in which wound capacitor elements are electrically attached to two opposing electrode plates, and a plurality of first connecting means are provided on each electrode plate to form a detachable or non-detachable plug connection with a corresponding second connecting means attached to a busbar of a power electronics module. The DC link capacitor module may have another wound capacitor element conductively mounted on the electrode plate. The DC link capacitor module may be supplied by the supplier with a different number of wound capacitor elements and/or wound capacitor elements having different characteristics, as required by the power electronics equipment manufacturer. Nevertheless, the shape of the electrode plate and the arrangement and design of the first connection means can be maintained. This allows the manufacturer to quickly and easily mount DC link capacitor modules with different capacitances, for example, while maintaining the mounting shape of the busbar mounted on the power electronics module. For the supplier, the costly and time-consuming process of mounting the busbar to the electrode plate is eliminated. Alternatively, such DC link capacitor modules may be supplied by the supplier in smaller units, and the manufacturer may then mount a number of these units on the busbar using plug connections. In another advantageous embodiment, a first pair of electrode plates, each containing a first wound capacitor element , and a second pair of electrode plates, each containing one or more second wound capacitor elements, are arranged in parallel. The subdivision of the DC link capacitor module into the first and second pairs of electrode plates, each containing a wound capacitor element , allows for a reduction in the area spread between the electrode plates while maintaining a predetermined shape. This reduces the leakage inductance of the DC link capacitor module. Such a DC link capacitor module is particularly suitable for high-speed switching operations. The power electronics device of the present invention may further include a cover element that hermetically encloses the wound capacitor element . The cover element protects the wound capacitor element from moisture and heat, which can damage the wound capacitor element , particularly during transport. It is especially preferable that the cover element is deformable so that pressure equalization is possible between the wound capacitor element housed within the cover element and the surrounding environment without gas exchange. In particular, this makes it possible to eliminate the need for commonly used disposable metal foil, which conventionally tightly encloses wound capacitor elements during transport. Figure 1 shows a DC link capacitor module, generally indicated by reference numeral 1. The DC link capacitor module 1 has first electrode plates 2a and second electrode plates 2b arranged opposite each other to form a first electrode plate pair 2, and third electrode plates 3a and fourth electrode plates 3b arranged opposite each other to form a second electrode plate pair 3. A plurality of first wound capacitor elements 4 are provided between the first electrode plate pair 2, and a plurality of second wound capacitor elements 5 are provided between the second electrode plate pair 3. The front sides of the wound capacitor elements 4 and 5 are shoeed. The wound capacitor elements 4 are connected to the electrode plates 2a and 2b, and the wound capacitor elements 5 are connected to the electrode pl