Computer-implemented method for real-time testing of a control unit

1. A computer-implemented method for real-time testing of a control unit with a simulator, the simulator having a simulator I/O interface and the control unit having a control unit I/O interface, the control unit and the simulator being connected to one another through their I/O interfaces via at least one data channel, the method comprising:

transmitting, via the control unit, converter control data to the simulator through the data channel;

calculating by the simulator a load current and a load voltage as electrical load state variables via the converter control data and via an electrical load model that excludes current discontinuities caused by the converter;

transmitting by the simulator at least a portion of the load state variables to the control unit;

implementing a control observer on the simulator;

calculating via the control observer at least the load current as a load state variable, based on the converter control data and an observer load model;

detecting, via the control observer, a zero-crossing of the load current and a current discontinuity caused thereby from the calculated load current; and

upon detection of a current discontinuity, calculating via the control observer an electrical compensating quantity such that when the compensating quantity is additionally applied to the electrical load in the load model, the calculation of the load current using the load model takes place with reduced error in the presence of current discontinuities.

2. The method according to claim 1 , wherein the load modeled by the load model is a commutated machine, an asynchronous machine, or a synchronous machine, and wherein the phase or phases of the machine are mathematically reproduced by at least one RLC network or at least one RL network.

3. The method according to claim 1 , wherein the calculation of the observer load model takes place in observer time intervals that are synchronized by external switching events of the converter that are determined by analysis of the converter control data.

4. The method according to claim 1 , wherein the observer load model contains at least one explicit function for the load state variable to be calculated.

5. The method according to claim 4 , wherein the explicit functions are solution functions for linear differential equations that constitute the observer load model.

6. The method according to claim 1 , wherein the observer load model is an average-value model, or wherein the observer load model is calculated numerically.

7. The method according to claim 6 , wherein the calculation of the observer load model is driven by load state variables calculated with the load model.

8. The method according to claim 1 , wherein the control observer detects a zero-crossing of the load current and a current discontinuity caused thereby by a change in sign of the calculated load current by analyzing values of the load current at a beginning and at an end of observer time intervals during which no element of the converter is switched on by corresponding converter control data.

9. The method according to claim 8 , wherein a behavior of the current in observer time intervals with a zero-crossing of the load current is approximated linearly.

10. The method according to claim 1 , wherein the control observer calculates the current discontinuity time interval upon detection of a zero-crossing of the load current and of a current discontinuity caused thereby.

11. The method according to claim 10 , wherein the control observer calculates a compensating voltage as the compensating quantity, wherein the compensating voltage depends in on a ratio of the current discontinuity time interval to the switching period duration of the converter.

12. The method according to claim 11 , wherein the compensating voltage calculated by the control observer is added in the load model to the load voltage switched by the converter, so that the calculation of the load current with the load model takes place based on a summed voltage at the load.

13. The method according to claim 1 , wherein the electrical load model is calculated with a processor of the simulator, and wherein the control observer is calculated with a different processor of the simulator or the control observer is calculated with an FPGA of the simulator.