Method for determining at least one property of a rotational movement of a three-phase rotary current machine in generator operation and electromechanical drive

A method for determining at least one property of a rotational movement of a three-phase rotary current machine in generator operation, the method including the following steps:

• continuously recording an electrical parameter for a phase voltage of the relevant phase of the three-phase alternating voltage of the rotary current machine generated in generator operation metrologically for each of the three phases,
• forming three electrical parameter pairs from the three electrical parameters, whereby a first electrical parameter pair comprises the electrical parameters of a first and a second phase, a second electrical parameter pair comprises the electrical parameters of the second phase and a third phase, and a third electrical parameter pair comprises the electrical parameters of the third phase and the first phase,
• continuously determining a sign of a difference between the electrical parameters of each parameter pair,
• determining the property of the rotational movement from change times (t4,1, t4,2, t4,3, . . . , t5,1, t5,2, t5,3, . . . , t6,1, t6,2, t6,3, . . . ), wherein the change times (t4,1, t4,2, t4,3, . . . , t5,1, t5,2, t5,3, . . . , t6,1, t6,2, t6,3, . . . ) correspond to times of immediately successive sign changes of the differences between the three parameter pairs, and
• using the property of the rotational movement to control an electromechanical drive or the rotary current machine in generator operation.