Wind energy system having a connection protection device

A wind energy installation comprising:

• a rotor;
• a generator driven by the rotor and having a converter configured to generate electrical power which is output into a power supply system via a transformer;
• an open-loop control system comprising an open-loop converter control unit, the open-loop control system supplying an actuating signal for a reactive component to the converter;
• and
• a voltage measurement device arranged on the transformer, a voltage signal of the voltage measurement device being applied to an input of a state-dependent setpoint value shifter configured to shift the reactive component in the event of an overvoltage toward an underexcited status and in the event of an undervoltage toward an overexcited status, the output signal of the setpoint value shifter being applied to a limitation module for the reactive component acting on the converter, the limitation module limiting the reactive component actuating signal supplied by the open-loop control system.