A method for control of a voltage of a power semiconductor of an electric power circuit, comprising the following steps: - predisposing an electric circuit comprising a power semiconductor having at least a first terminal and a second terminal, which semiconductor is a unidirectional switch and is switchable between a conduction state and a blocking state; - making a voltage (Va) available between the first and the second terminal (2A, 2B) of the semiconductor by a supply voltage (V'a); - controlling the voltage (Va) present between the first and the second terminal (2A, 2B) of the semiconductor during the transition from the conduction state to the blocking state of the semiconductor according to the following steps: - limiting a time derivative of the voltage (Va) present between the first and the second terminal (2A, 2B) to a lower value than a first predetermined limit value; - limiting the voltage (Va) present between the first and the second terminal (2A, 2B) to a second predetermined limit value by a snubber device; the method being characterised in that the step of limiting the voltage (Va) present between the first and the second terminal (2A, 2B) to said second predetermined limit value comprises steps of: - predisposing a clamp device connected to the first and second terminal and having a predetermined capacitance; - predisposing a regulating power supply device; - connecting the regulating power supply device to the capacitance of the clamp device in order to load the capacitance at a control voltage (Vc); - regulating the control voltage (Vc) for limiting the voltage (Va) present between the first and the second terminal (2A, 2B) to said second predetermined limit value. - predisposing an electric circuit comprising a power semiconductor having at least a first terminal and a second terminal, which semiconductor is a unidirectional switch and is switchable between a conduction state and a blocking state; - making a voltage (Va) available between the first and the second terminal (2A, 2B) of the semiconductor by a supply voltage (V'a); - controlling the voltage (Va) present between the first and the second terminal (2A, 2B) of the semiconductor during the transition from the conduction state to the blocking state of the semiconductor according to the following steps: - limiting a time derivative of the voltage (Va) present between the first and the second terminal (2A, 2B) to a lower value than a first predetermined limit value; - limiting the voltage (Va) present between the first and the second terminal (2A, 2B) to a second predetermined limit value by a snubber device; the method being characterised in that the step of limiting the voltage (Va) present between the first and the second terminal (2A, 2B) to said second predetermined limit value comprises steps of: - predisposing a clamp device connected to the first and second terminal and having a predetermined capacitance; - predisposing a regulating power supply device; - connecting the regulating power supply device to the capacitance of the clamp device in order to load the capacitance at a control voltage (Vc); - regulating the control voltage (Vc) for limiting the voltage (Va) present between the first and the second terminal (2A, 2B) to said second predetermined limit value. - predisposing a clamp device connected to the first and second terminal and having a predetermined capacitance; - predisposing a regulating power supply device; - connecting the regulating power supply device to the capacitance of the clamp device in order to load the capacitance at a control voltage (Vc); - regulating the control voltage (Vc) for limiting the voltage (Va) present between the first and the second terminal (2A, 2B) to said second predetermined limit value.