Method for rapid de-energizing of a rotor of a separately excited synchronous machine of a motor vehicle, separately excited synchronous machine for a motor vehicle and motor vehicle

Abstract

Method for rapid de-energizing of a rotor (4) of a separately excited synchronous machine (2) of a motor vehicle (1), wherein the motor vehicle (1) or the synchronous machine (2) comprises an excitation circuit (10) having at least one transistor (11, 12) for controlling a rotor current of the synchronous machine (2), - wherein in normal operation of the motor vehicle (1) or the synchronous machine (2) the at least one transistor (11, 12) is operated in a switching mode in which it implements an electronic switch, - wherein in an emergency operation of the motor vehicle (1) or the synchronous machine (2) the at least one transistor (11, 12) is operated in a resistive operation in which it realizes a resistance, wherein for rapid de-energization of the rotor (4) the rotor current is at least partially reduced by means of the at least one transistor (11, 12) realizing the resistance.

Claims

[1] Method for quickly de-exciting a rotor (4) of a separately excited synchronous machine (2) of a motor vehicle (1), wherein the motor vehicle (1) or the synchronous machine (2) comprises an excitation circuit (10) having at least one transistor (11, 12) for controlling a rotor current of the synchronous machine (2), - wherein, in normal operation of the motor vehicle (1) or the synchronous machine (2), the at least one transistor (11, 12) is operated in a switching mode in which it implements an electronic switch, - wherein in an emergency operation of the motor vehicle (1) or the synchronous machine (2) the at least one transistor (11, 12) is operated in a resistance mode in which it realizes a resistance, wherein for the rapid de-excitation of the rotor (4) the rotor current is at least partially reduced by means of the at least one transistor (11, 12) realizing the resistance. [2] Method according to claim 1, characterized bythat the at least one transistor (11, 12) in resistance mode is operated in a linear mode in which it realizes a variable resistance. [3] Method according to claim 1 or 2, characterized by that in the emergency operation the excitation circuit (10) is brought into a switching state such that the rotor current is reduced in a freewheel into which the at least one transistor (11, 12) realizing the resistance is integrated. [4] Method according to one of the preceding claims, characterized by that in the emergency operation the excitation circuit (10) is alternately brought into several different switching states in which the rotor current is reduced via different transistors (11, 12), each realizing a resistance. [5] Method according to one of the preceding claims, characterized bythat an asymmetrical full-bridge circuit comprising a plurality of, in particular two, transistors (11, 12) is used as the excitation circuit (10), and / or that a bipolar transistor with an insulated gate electrode or a metal-oxide-semiconductor field-effect transistor is used as the at least one transistor (11, 12). [6] Method according to all preceding claims, wherein the excitation circuit (10) is a full-bridge circuit comprising two transistors (11, 12), characterized by in that in the emergency operation the excitation circuit (10) is alternately brought into two different switching states, wherein the rotor current in one of the switching states is reduced in a high-side freewheel by means of one of the transistors (11, 12), wherein the rotor current in the other of the switching states is reduced in a low-side freewheel by means of the other of the transistors (11, 12). [7] Method according to one of the preceding claims, characterized bythat in normal operation the excitation circuit (10) is brought into a switching state such that the rotor current is built up, or that electrical energy is fed back from the synchronous machine (2) to a high-voltage battery (3) of the motor vehicle (1) and / or to an intermediate circuit capacitor (13), or that the rotor current is reduced, in particular in a freewheel. [8] Separately excited synchronous machine for a motor vehicle (1), comprising a rotor (4), an excitation circuit module (6) which implements an excitation circuit (10) having at least one transistor (11, 12) for controlling a rotor current of the synchronous machine (2), and a control device (8) which is designed to apply a control voltage to a control terminal of the at least one transistor (11, 12) in such a way that - in normal operation of the synchronous machine (2), the at least one transistor (11, 12) can be operated in a switching mode in which it implements an electronic switch, and - in an emergency operation of the synchronous machine (2), the at least one transistor (11, 12) can be operated in a resistance mode in which it realizes a resistance, wherein for the rapid de-excitation of the rotor (4) the rotor current can be at least partially reduced by means of the at least one transistor (11, 12) realizing the resistance. [9] Separately excited synchronous machine according to claim 8, characterized by that the high-voltage battery (3) is electrically connected to the rotor (4) via the excitation circuit module (6) and / or to a stator (5) of the synchronous machine (2) via a main converter module (7) implementing a main converter (9). [10] Separately excited synchronous machine according to claim 8 or 9, characterized bythat the excitation circuit module (6) and / or the or a main converter module (7) is coupled to at least one intermediate circuit capacitor (13). [11] Separately excited synchronous machine according to one of claims 8 to 10, characterized by at least one cooling module (22), which is integrated or can be integrated in particular into a cooling circuit (23), which is thermally coupled to the excitation circuit module (6) so that in emergency operation the at least one transistor (11, 12) by means of which the rotor current is reduced can be cooled via the at least one cooling module (22). [12] Motor vehicle, comprising a separately excited synchronous machine (2) according to one of claims 8 to 11 and a high-voltage battery (3) for supplying power to the separately excited synchronous machine (2).

Images