Regulated voltage generating apparatus, comprising: - a mechanically driven, separately excited generator device, - an exciter device, with which the generator device is electrically excited, - a rectifier device, with which an output voltage of the generator device is rectified, - a regulating apparatus, by means of which an excitation voltage (u err) is provided for the exciter device, wherein the regulating apparatus comprises a voltage regulating device and a current regulating device and the voltage regulating device is functionally interconnected with the current regulating device, characterized in that the voltage regulating device comprises a calculation device, which is supplied with measured current values (i G1, i G3) of output currents of the generator device and with the output voltage (u d) of the rectifier device, wherein a power (P Gen) of the generator device is ascertained by calculation by means of the calculation device, said power being supplied to an ascertainment device as output variable of a measured power value, - wherein the voltage regulating device comprises the ascertainment device, which is also supplied with a rotational speed setpoint value (n d,Soll) of the generator device, wherein a first setpoint value of the excitation current (i err,Soll1) is ascertained by means of the ascertainment device and supplied to a summing point, - wherein the voltage regulating device comprises the summing point and an auxiliary regulating device, wherein a second setpoint value (i, err,Soll2) of the excitation current is also supplied to the summing point, said second setpoint value being an output variable of the auxiliary regulating device, wherein the auxiliary regulating device ascertains the second setpoint value (i, err,Soll2) from the output voltage (u d) of the rectifier device and a setpoint value of the output voltage (u d,Soll) of the rectifier device from a defined mapping of a rotational speed setpoint value (n d,Soll), - wherein the summing point forms an output signal (i err,Soll) of the voltage regulating device by summation, said output signal being supplied to the current regulating device, wherein the current regulating device forms an electric actuation signal in the form of the excitation voltage (u, err) for the exciter device therefrom, - wherein the generator device is operated at at least two defined rotational speeds, respectively when idling and at rated load, wherein a value of the electric excitation current (i, err) is ascertained from a linear interpolation of four value triples obtained thereby, wherein a value triple consists of excitation current, rotational speed and load. - a mechanically driven, separately excited generator device, - an exciter device, with which the generator device is electrically excited, - a rectifier device, with which an output voltage of the generator device is rectified, - a regulating apparatus, by means of which an excitation voltage (u err) is provided for the exciter device, wherein the regulating apparatus comprises a voltage regulating device and a current regulating device and the voltage regulating device is functionally interconnected with the current regulating device, - wherein the voltage regulating device comprises the ascertainment device, which is also supplied with a rotational speed setpoint value (n d,Soll) of the generator device, wherein a first setpoint value of the excitation current (i err,Soll1) is ascertained by means of the ascertainment device and supplied to a summing point, - wherein the voltage regulating device comprises the summing point and an auxiliary regulating device, wherein a second setpoint value (i, err,Soll2) of the excitation current is also supplied to the summing point, said second setpoint value being an output variable of the auxiliary regulating device, wherein the auxiliary regulating device ascertains the second setpoint value (i, err,Soll2) from the output voltage (u d) of the rectifier device and a setpoint value of the output voltage (u d,Soll) of the rectifier device from a defined mapping of a rotational speed setpoint value (n d,Soll), - wherein the summing point forms an output signal (i err,Soll) of the voltage regulating device by summation, said output signal being supplied to the current regulating device, wherein the current regulating device forms an electric actuation signal in the form of the excitation voltage (u, err) for the exciter device therefrom, - wherein the generator device is operated at at least two defined rotational speeds, respectively when idling and at rated load, wherein a value of the electric excitation current (i, err) is ascertained from a linear interpolation of four value triples obtained thereby, wherein a value triple consists of excitation current, rotational speed and load.