# US 2019/0356254 A1 · Method and apparatus for operating a synchronous machine having a permanent-magnet rotor

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- Number: US 2019/0356254 A1
- Document ID: US20190356254A1
- Status: Published application
- Kind: A1
- Application number: 15/979,763
- Filed: 2018-05-15
- Published: 2019-11-21
- Earliest claimed: 2018-05-15
- Assignees: Dr. Ing. h.c. F. Porsche Aktiengesellschaft
- Applicants: Dr. Ing. h.c. F. Porsche Aktiengesellschaft
- Inventors: Jan Nägelkrämer; Axel HEITMANN; Thomas HUBERT; Sven LUTHARDT; Stefan SCHMITZ
- Web page: https://patentgrep.com/patent/US20190356254A1

## CPC

- H02P 21/0017: {Model reference adaptation, e.g. MRAS or MRAC, useful for control or parameter estimation}
- H02P 21/50: {Vector control arrangements or methods not otherwise provided for in H02P21/00- H02P21/36}
- G06F 30/23: using finite element methods [FEM] or finite difference methods [FDM]
- H02P 6/34: Modelling or simulation for control purposes
- H02P 21/14: Estimation or adaptation of machine parameters, e.g. flux, current or voltage
- H02P 21/22: Current control, e.g. using a current control loop
- H02P 25/024: controlled by supply frequency
- G06F 2111/10: Numerical modelling
- H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N)

## Abstract

A method for operating a synchronous machine having a rotor, comprising the following features: the synchronous machine is modelled, with respect to the rotor, as a two-phase system with a direct-axis current and a quadrature-axis current, rotor losses of the synchronous machine, which rotor losses occur in the rotor, are numerically described by an evaluation function of the first direct-axis current, of the quadrature-axis current and of a specified rotation speed of the synchronous machine, and, on the basis of the evaluation function, the direct-axis current and the second quadrature-axis current are controlled for the specified rotation speed and a required torque in such a way that the synchronous machine outputs the required torque and the rotor losses are low and a corresponding synchronous machine, a corresponding computer program and a corresponding storage medium.

## Claims

### Claim 1

A method for operating a synchronous machine having a rotor, comprising:
modeling the synchronous machine, with respect to the rotor, as a two-phase system with a direct-axis current and a quadrature-axis current,
numerically describing rotor losses in the rotor of the synchronous machine, an evaluation function of the direct-axis current, of the quadrature-axis current and of a specified rotation speed of the synchronous machine, and,
controlling, the direct-axis current and the quadrature-axis current on the basis of the evaluation function for the specified rotation speed and a required torque such that the synchronous machine outputs the required torque and the rotor losses are minimized.

### Claim 2 (depends on 1)

The method as claimed in claim 1, wherein:
a numerical simulation of the synchronous machine, on the basis of which the evaluation function is determined, is carried out by means of finite elements,
the evaluation function is calculated by derating during operation of the synchronous machine, or
the evaluation function is prespecifled.

### Claim 3 (depends on 2)

The method as claimed in claim 2, wherein:
the simulation is performed in a two-dimensional manner,
the simulation is performed in a three-dimensional manner, or
the simulation is performed in an analytical manner.

### Claim 4 (depends on 2)

The method as claimed in claim 2, wherein the synchronous machine further has a stator and wherein:
iron losses and magnetic losses in the rotor and copper losses and iron losses in the stator are calculated on the basis of the simulation, and
the evaluation function is determined on the basis of the iron losses, the copper losses and the magnetic losses.

### Claim 5 (depends on 1)

A synchronous machine,
characterized by the following feature:
the synchronous machine is designed to be operated in accordance with the method as claimed in claim 1.

### Claim 6 (depends on 1)

A computer program which is designed to carry out all of the steps of the method as claimed in claim 1.

### Claim 7 (depends on 6)

A machine-readable storage medium with the computer program as claimed in claim 6 stored therein.