A method for controlling a multiphase separately excited synchronous generator in a wind turbine, wherein - the synchronous generator has a stator and an armature, - the armature has an excitation input for inputting an excitation current (i err) or an excitation voltage (v err), - the excitation input has an excitation controller connected to it for inputting the excitation current (i err) or the excitation voltage (v err), - the stator has a stator output for delivering stator currents, - the stator output of the stator has a rectifier connected to it for rectifying the stator currents and for providing said currents to a DC link connected to the rectifier, and - the rectifier is controllable in order to control the stator currents, comprising the steps of: - detecting a speed (n) of the armature or aerodynamic rotor of the wind turbine, - determining a setpoint power (P Soll), to be delivered by the synchronous generator or the wind turbine, on the basis of the detected speed (n), - determining an excitation current (i err) or an excitation voltage (v err) on the basis of the detected speed (n) and the determined setpoint power (P Soll), - inputting the thus determined excitation current (i err) or the thus determined excitation voltage (v err) by means of the excitation controller at the excitation input, - determining the stator currents to be delivered as setpoint stator currents on the basis of the detected speed (n) and the determined setpoint power (P Soll) and - controlling the rectifier in order to set the determined stator currents to be delivered at the stator output to the setpoint stator currents, wherein at least one of the steps of - determining the excitation current (i err) or the excitation voltage (v err) and - determining the stator currents to be delivered as setpoint stator currents is effected by means of an adaptive control device, wherein the excitation current (i err) or the excitation voltage (v err) or the stator currents to be delivered form control variables for the control device, characterized in that - parameters of the synchronous generator, namely magnetization inductances (L md, L mq) and/or a stator resistance and/or an excitation resistance, are estimated as estimate quantities for the synchronous generator by means of an estimating device, and - the adaptive control device determines its control variables by taking into consideration the estimate quantities. - the synchronous generator has a stator and an armature, - the armature has an excitation input for inputting an excitation current (i err) or an excitation voltage (v err), - the excitation input has an excitation controller connected to it for inputting the excitation current (i err) or the excitation voltage (v err), - the stator has a stator output for delivering stator currents, - the stator output of the stator has a rectifier connected to it for rectifying the stator currents and for providing said currents to a DC link connected to the rectifier, and - the rectifier is controllable in order to control the stator currents, comprising the steps of: - detecting a speed (n) of the armature or aerodynamic rotor of the wind turbine, - determining a setpoint power (P Soll), to be delivered by the synchronous generator or the wind turbine, on the basis of the detected speed (n), - determining an excitation current (i err) or an excitation voltage (v err) on the basis of the detected speed (n) and the determined setpoint power (P Soll), - inputting the thus determined excitation current (i err) or the thus determined excitation voltage (v err) by means of the excitation controller at the excitation input, - determining the stator currents to be delivered as setpoint stator currents on the basis of the detected speed (n) and the determined setpoint power (P Soll) and - controlling the rectifier in order to set the determined stator currents to be delivered at the stator output to the setpoint stator currents, wherein at least one of the steps of - determining the excitation current (i err) or the excitation voltage (v err) and - determining the stator currents to be delivered as setpoint stator currents is effected by means of an adaptive control device, wherein the excitation current (i err) or the excitation voltage (v err) or the stator currents to be delivered form control variables for the control device, characterized in that - parameters of the synchronous generator, namely magnetization inductances (L md, L mq) and/or a stator resistance and/or an excitation resistance, are estimated as estimate quantities for the synchronous generator by means of an estimating device, and - the adaptive control device determines its control variables by taking into consideration the estimate quantities.