Electric machine
In a method for operating an electric machine a first test signal is fed into the electric machine and a first response signal of the electric machine is measured. A first state variable for a rotor of a synchronous reluctance motor of the electric machine is determined as a function of the first response signal, and a second state variable for the rotor of the synchronous reluctance motor is determined. The first state variable and the second state variable are evaluated together.
1. A method for operating an electric machine embodied as a synchronous reluctance motor, said method comprising:
feeding a first test signal into the electric machine;
measuring a first response signal of the electric machine;
determining a first state variable for a rotor of the synchronous reluctance motor as a function of the first test signal;
determining a second state variable for the rotor of the synchronous reluctance motor; and
evaluating the first state variable and the second state variable together.
2. The method of claim 1 , further comprising:
feeding a second test signal into the electric machine to determine the second state variable;
measuring a second response signal; and
determining the second state variable as a function of the second response signal.
3. The method of claim 2 , wherein at least one of the first test signal and the second test signal is an overlaid signal.
4. The method of claim 2 , wherein at least one of the first test signal and the second test signal is a signal fixed to the rotor or a signal fixed to a stator of the synchronous reluctance motor.
5. The method of claim 2 , wherein the first test signal and the second test signal are used to determine a same state of the rotor.
6. The method of claim 2 , wherein the first test signal is orthogonal to the second test signal.
7. The method of claim 5 , wherein the state is a position, a speed or an acceleration.
8. The method of claim 2 , wherein at least one of the first test signal and the second test signal is torque-forming.
9. The method of claim 1 , wherein the electric machine is an encoderless electric machine.
10. The method of claim 1 , further comprising:
comparing the first state variable and the second state variable with one another when they are evaluated together; and
identifying a state of the electric machine when the first state variable and the second state variable agree.
11. The method of claim 10 , wherein the state is a position of the rotor.
12. The method of claim 2 , further comprising using a pulse signal for at least one of the first test signal and the second test signal.
13. A drive system, comprising:
an electric machine; and
a converter driving the electric machine, said converter configured to impress a first test signal into the electric machine, wherein the converter is configured to measure a first response signal of the electric machine, determine a first state variable for a rotor of the synchronous reluctance motor of the electric machine as a function of the first test signal, determine a second state variable for the rotor of the synchronous reluctance motor, and evaluate the first state variable and the second state variable together.
14. The drive system of claim 13 , wherein the electric machine is a synchronous reluctance motor.
15. The drive system of claim 13 , wherein the converter is configured to impress a second test signal into the electric machine.
16. The drive system of claim 15 , wherein the converter includes an ASIC with pulse logic configured to generate the first test signal and/or the second test signal.
17. The drive system of claim 13 , wherein the electric machine is an encoderless electric machine.