摘要 |
An inverter for the selective feeding of effective power and reactive power into a power grid has two serially connected intermediate circuit capacitors, the joint connection of which defines a median voltage level between a positive voltage level and a negative voltage level. It also has first, second, third, and fourth semiconductor switches having free-wheeling diodes respectively connected in parallel, which are arranged serially in this sequence between the positive and the negative voltage levels, the joint connection of the second and third semiconductor switches being connected to the power grid via a choke. The inverter also has serially connected first and second diodes, the joint connection of which is at the median voltage level, and whose second connection is connected to the joint connection of the first and second semiconductor switches and of the third and fourth semiconductor switches. Joint connections of two of the first to fourth semiconductor switches are connected to additional chokes, which by additional semiconductor switches form switchable paths for accepting free-wheeling currents. In this manner, it is possible to avoid putting stress on diodes as a result of the reverse recovery effect.
|