Monitoring device for an isolated network of a photovoltaic system, a photovoltaic system with such a monitoring device and a method for safe operation of a photovoltaic system

摘要

Monitoring device for an insulated electrical network (2) of a photovoltaic system (4) having a short circuit measuring circuit comprising a first electrical measuring circuit conductor (12) for connecting a first electrical pole (8) of the photovoltaic system (4) via at least one protective component (13) with a Reference point (20) and a second electrical measuring circuit conductor (14) for connecting a second electrical pole (10) of the photovoltaic system (4) via at least one further protective component (13) to the reference point (20), wherein the protective components (13) for avoiding high Currents through the short-circuit measurement circuit and high losses across the short-circuit measuring circuit serve and the two measuring circuit conductors (12, 14) together form a short circuit between the two electrical poles (8, 10) of the photovoltaic system by the two measuring circuit conductors (12, 14) at their the poles (8, 10) of the photovoltaic system opposite the second ends are connected to one another between a measuring circuit conductor (12, 14) and the reference point (20) connected component (16) for measuring an electrical characteristic and a measuring and evaluation device (22) for measuring an electrical characteristic of the first component (16), wherein by means of Measuring and evaluation device (22) an amount of the characteristic variable not equal to zero and / or a change in the amount of the parameter is detectable and wherein this indicates an electrical connection of the photovoltaic system (4) with the reference point (20).