Operation of switching elements of an inverter of an in particular rail-bound vehicle driven by way of least one at least three-phase synchronous machine

Patent metadata

Field	Value
Publication number	US-11845341-B2
Application number	US-201917415109-A
Country	US
Kind code	B2
Filing date	Dec 12, 2019
Priority date	Dec 17, 2018
Publication date	Dec 19, 2023
Grant date	Dec 19, 2023

Abstract

A method for operating switching elements of an inverter of a vehicle that is driven by way of a three-phase synchronous machine. The inverter has a series circuit of switching elements for the phases. When the vehicle brakes, the synchronous machine is used to set a cycle rate for the operation of the switching elements depending on a frequency of AC phase currents of the synchronous machine. The electrical energy provided by the synchronous machine is fed to a DC voltage intermediate circuit. The cycle rate is set according to the frequency of the AC phase currents, such that it corresponds to the frequency of the respective AC phase currents of the synchronous machine. Zero points of the AC phase currents are determined, and the switching elements are operated to set a predefined phase difference between the respective AC phase current and a respectively associated AC phase voltage.

First claim

The invention claimed is:

1. A method of operating switching elements of an inverter of a vehicle that is driven by at least one synchronous machine, wherein the inverter has at least one series connection of the switching elements for each phase of the synchronous machine electrically coupling the synchronous machine to a DC voltage intermediate circuit that is connected to the inverter, the method comprising:
when the vehicle is braked by way of the synchronous machine, setting a clock-pulse rate for operating the switching elements to correspond to a frequency of respective phase alternating currents provided by the synchronous machine, determining zero points of the phase alternating currents and operating the switching elements to set a predetermined phase difference between the respective phase alternating current of the phase alternating currents and a respectively associated phase alternating voltage, to thereby supply electrical energy provided by the synchronous machine at least in part to the DC voltage intermediate circuit.

2. The method according to claim 1 , wherein the vehicle is a rail-bound vehicle.

3. The method according to claim 1 , wherein the synchronous machine is one of a plurality of synchronous machines for driving the vehicle.

4. The method according to claim 1 , wherein the synchronous machine is a multi-phase synchronous machine having at least three phases.

5. The method according to claim 1 , wherein the DC voltage intermediate circuit has two intermediate circuit potentials and the method comprises activating, at least in part simultaneously, only the switching elements that are directly coupled to the same intermediate circuit potential of the DC voltage intermediate circuit.

6. The method according to claim 5 , which comprises selecting the intermediate circuit potential in dependence upon an instantaneous phase position of the phase alternating currents.

7. The method according to claim 1 , which comprises determining the predetermined phase difference in dependence upon an instantaneous intermediate circuit voltage of the DC voltage intermediate circuit.

8. A method for braking a vehicle that is driven by at least one synchronous machine, wherein the synchronous machine is electrically coupled by way of an inverter, which has, for each phase of the synchronous machine, at least one series connection with switching elements to a DC voltage intermediate circuit that is connected to the inverter, the method which comprises:
specifying a braking power for braking the vehicle;
setting a clock-pulse rate for operating the switching elements in dependence upon a frequency of respective phase alternating currents generated by the synchronous machine when the vehicle is braked by the synchronous machine to thereby supply electrical energy provided by the synchronous machine to the DC voltage intermediate circuit;
converting the electrical energy supplied by the synchronous machine to the DC voltage intermediate circuit when the vehicle is braked into heat by an electrical resistance unit that is connected to the DC voltage intermediate circuit;
thereby operating the switching elements in accordance with the method according to claim 1 , and setting a phase difference between the respective phase alternating current and a respectively associated phase alternating voltage in dependence upon the braking power.

9. The method according to claim 8 , wherein the vehicle is a rail-bound vehicle.

10. The method according to claim 8 , wherein the synchronous machine is one of a plurality of synchronous machines for driving the vehicle.

11. The method according to claim 8 , wherein the synchronous machine is a multi-phase synchronous machine having at least three phases.

12. The method according to claim 8 , which comprises further setting the phase difference in dependence upon a current rotational speed of the synchronous machine.

13. The method according to claim 8 , wherein the braking power is determined in dependence upon an instantaneous maximum possible braking power.

14. An electrically drivable vehicle, comprising:
at least one synchronous machine for driving the vehicle in a driving operation;
at least one DC voltage intermediate circuit;
at least one inverter connected to said at least one DC voltage intermediate circuit;
at least one series connection for each of phase of said at least one synchronous machine, said at least one series connection containing switching elements for connecting to a respective phase of said at least one synchronous machine, in order to electrically couple said at least one synchronous machine to said at least one DC voltage intermediate circuit;
at least one electrical resistance unit connected to said at least one DC voltage intermediate circuit and configured to convert electrical energy that is supplied by said at least one synchronous machine to said DC voltage intermediate circuit when the vehicle is braked by said synchronous machine into heat; and
a clock-pulse generator according to claim 8 ,
said clock-pulse generator being configured for operating said switching elements of said at least one inverter and being configured, when the vehicle is braked by said at least one synchronous machine, to set a clock-pulse rate for operating said switching elements in dependence upon a frequency of respective phase alternating currents that are generated by said at least one synchronous machine, in order to supply at least in part to said at least one DC voltage intermediate circuit electrical energy that is provided by said at least one synchronous machine; and
said clock-pulse generator being configured to set a phase difference between the respective phase alternating current of the phase alternating currents and a respectively associated phase alternating voltage in dependence upon a predeterminable braking power.

15. The vehicle according to claim 14 , wherein the vehicle is a rail-bound vehicle.

16. The vehicle according to claim 14 , wherein the at least one synchronous machine is one of a plurality of synchronous machines for driving the vehicle.

17. The vehicle according to claim 14 , wherein the synchronous machine is a multi-phase synchronous machine having at least three phases.

18. A clock-pulse generator for operating switching elements of an inverter of a vehicle to be driven by at least one synchronous machine, wherein the inverter has, for each phase of the at least one synchronous machine, at least one series connection with the switching elements for electrically coupling the at least one synchronous machine to a DC voltage intermediate circuit that is connected to the inverter, and wherein:
the clock-pulse generator is configured, when the vehicle is braked by the synchronous machine, to set a clock-pulse rate for operating the switching elements in dependence upon a frequency of respective phase alternating currents that are provided by the synchronous machine in order to supply at least in part to the DC voltage intermediate circuit electrical energy that is provided by the synchronous machine;
the clock-pulse generator is configured to set the clock-pulse rate according to the frequency of the phase alternating currents so that the clock-pulse rate corresponds to the frequency of the respective phase alternating currents that are provided by the synchronous machine, to determine zero points of the phase alternating currents, and to operate the switching elements to thereby set a predetermined phase difference between a respective phase alternating current of the phase alternati

Assignees

• Siemens Mobility GmbH

Inventors

• Bergner Hans
• Ditterich Juergen
• Hoke Karsten
• Rueger Niklas

Classifications

• B60L15/04 Primary

  using DC · CPC title

• H02P3/18 Primary

  for stopping or slowing an AC motor · CPC title

• H02P27/06

  using DC to AC converters or inverters (H02P27/05 takes precedence) · CPC title

• B60L2200/26

  Rail vehicles · CPC title

• H02P6/15

  Controlling commutation time · CPC title