Abstract: A method is provided for operating a drive train comprising an internal combustion engine or an electric machine as a primary drive and an electric machine as a secondary drive, wherein the electric machine is detachably coupled, together with an inverter and controller, on one of the vehicle axles. The electric machine and at least one switchable element is actuated in order to minimize drag losses of the electric machine and to provide a defined connection time for the electric machine. The electric machine is stationary and decoupled during a first speed range. The electric machine is actuated at a preset speed during a second speed range, where a defined connection time is not possible if the electric machine were stationary. The electric machine is coupled to the axle and rotates at the vehicle speed in the third range, when losses while coupled are lower than if uncoupled.

Abstract: A controller for a converter is designed to receive from a measuring device measurement signals from an output line of the converter, and to analyze the measurement signals in order to generate a switching signal that has a switching frequency, wherein the controller comprises a sampler for generating a sample signal by sampling received measurement signals. The sampler is designed to perform the sampling at a sampling frequency that is less than three times the switching frequency. A converter comprises a controller in accordance with the invention.

Abstract: A controller for a converter is designed to receive from a measuring device measurement signals from an output line of the converter, and to analyze the measurement signals in order to generate a switching signal that has a switching frequency, wherein the controller comprises a sampler for generating a sample signal by sampling received measurement signals. The sampler is designed to perform the sampling at a sampling frequency that is less than three times the switching frequency. A converter comprises a controller in accordance with the invention.