Abstract: A photovoltaic device includes a first group of photovoltaic cells of a first cell type, the first group of photovoltaic cells operable to produce a first current and a first voltage, and a second group of photovoltaic cells of a second cell type that is different than the first cell type, the second group of photovoltaic cells operable to produce a second current and a second voltage. A first power electronics unit is connected to the first group of photovoltaic cells, and a second power electronics unit is connected to the second group of photovoltaic cells. The second power electronics unit is separate from and not communicating with the first power electronics unit. A control device is operable to vary a first property of the first power electronics unit to vary the first current and the first voltage and to vary a second property of the second power electronics unit to vary the second voltage and the second current independent of the first voltage and the first current.

Abstract: A photovoltaic device includes a first group of photovoltaic cells of a first cell type, the first group of photovoltaic cells operable to produce a first current and a first voltage, and a second group of photovoltaic cells of a second cell type that is different than the first cell type, the second group of photovoltaic cells operable to produce a second current and a second voltage. A first power electronics unit is connected to the first group of photovoltaic cells, and a second power electronics unit is connected to the second group of photovoltaic cells. The second power electronics unit is separate from and not communicating with the first power electronics unit. A control device is operable to vary a first property of the first power electronics unit to vary the first current and the first voltage and to vary a second property of the second power electronics unit to vary the second voltage and the second current independent of the first voltage and the first current.

Abstract: The invention relates to a tandem PV cell group (1) having two PV cells (11, 21) of different cell types. A separate power electronic unit (31, 32) is assigned to each of the PV cells in such a manner that a voltage generated in the particular PV cell or the corresponding power yield can be supplied to the assigned power electronic unit. The power electronic units can be operated independently of one another with the aid of a control device (40) in such a manner that each PV subsystem having one of the PV cells in each case and the power electronic unit assigned to the particular PV cell operates at the optimum operating point thereof. For this purpose, the control device can operate in such a manner that, during operation of the power electronic unit of each PV subsystem, a product of the power yield and the cell voltage of the PV cell assigned to the particular power electronic unit is at a maximum.

Abstract: For diagnosing a self-blast circuit breaker (1), a switching operation of the self-blast circuit breaker (1) is triggered to initiate a pressure wave in a filling gas of the self-blast circuit breaker (1). A pressure as a function of time in at least one region of the self-blast circuit breaker (1) which occurs in response to the switching operation is detected. A state of a burn-off nozzle (11) of the self-blast circuit breaker (1) which is burnt off in a switching operation under load for blowing the filling gas onto a switching arc is determined in dependence on the pressure as a function of time.

Abstract: A spring-loaded safety valve provided with an integrated damping element that achieves a damping effect by the dissipative action of a shearing current and which involves a single-layer or multiple-layer virtually coaxial arrangement of tubes or active surfaces that can be moved telescopically with respect to one another.