Abstract: The invention describes a method for detecting isolated operation of power generation instillations (5) which are set up to generate electrical power and can be coupled to an interconnected power supply system (1) for feed operation. The power generation installation (5) operates in isolation with respect M the interconnected power supply system when no power is exchanged between the power generation installation (5) and the interconnected power supply system (1). The method has the steps of; recording the temporal profile of the maims frequency present in the region in which the power generation installation (5) is connected to the interconnected power supply system (1) and evaluating the temporal profile of the mains frequency in order to detect isolated operation.

Abstract: A conditioning device is described for power supply networks (2) having a network voltage measurement unit (3) which can be connected to a three-phase power supply network (2), having a computation unit (1) which is connected to the network voltage measurement unit (3) and is used to determine conditioning current values (K) and having an inverter unit (4) which is connected to the power supply network (2) and is used to feed in conditioning currents (IK) as a function of the determined conditioning current values (K). The computation unit (1) is designed for modeled simulation of a synchronous machine in order to determine at least one component of the conditioning current values (K) as stator currents of the simulated synchronous machine as a function of freely variable synchronous machine parameters, using the network voltages (UN), measured in three phases, of the power supply network (2) as input variables.