ELECTRIC DRIVE SYSTEM

• US 20170070175A1
• Filed: 01/08/2015
• Published: 03/09/2017
• Est. Priority Date: 02/27/2014
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Butzmann, Stefan, Braun, Martin
• Granted Patent: US 9,899,948 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B60L 15/007 Physical arrangements or structures of drive train converters specially adapted for the propulsion motors of electric vehicles
• CPC Class Codes: B60L 2200/32 Waterborne vessels
• CPC Class Codes: B60L 2220/12 Induction machines
• CPC Class Codes: B60L 2220/14 Synchronous machines
• CPC Class Codes: B60L 2220/16 DC brushless machines
• CPC Class Codes: B60L 2220/18 Reluctance machines
• CPC Class Codes: B60L 2220/58 with more than three phases
• CPC Class Codes: B60L 50/51 characterised by AC-motors
• CPC Class Codes: B60L 58/21 having the same nominal voltage
• CPC Class Codes: H02M 1/0074 Plural converter units whose inputs are connected in series
• CPC Class Codes: H02M 1/14 Arrangements for reducing ripples from dc input or output
• CPC Class Codes: H02M 7/003 Constructional details, e.g. physical layout, assembly, wiring or busbar connections
• CPC Class Codes: H02M 7/493 the static converters being arranged for operation in parallel
• CPC Class Codes: H02M 7/5387 in a bridge configuration
• CPC Class Codes: H02M 7/53871 with automatic control of output voltage or current
• CPC Class Codes: H02P 25/22 Multiple windings; Windings for more than three phases
• CPC Class Codes: H02P 27/06 using dc to ac converters or inverters H02P27/05 takes precedence
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

The invention relates to an electric drive system with an n-phase electric machine, n>1, having at least two multiphase winding strands; a first inverter, the output connections of which are connected to the phase connections of a first of the multiphase winding strands of the electric machine; a second inverter, which is connected in parallel to the first inverter and the output connections of which are connected to the phase connections of a second of the multiphase winding strands of the electric machine; and a DC voltage source, which has a plurality of battery modules connected in series and a first output connection of which is connected to a first input connection of the first inverter and second output connection of which is connected to a first input connection of the second inverter. A second input connection of the first inverter and a second input connection of the second inverter are connected to each other such that the first inverter and the second inverter are arranged in a series circuit, and the second input connection of the first inverter and the second input connection of the second inverter are connected to a center tap of the DC voltage source between two sub-groups of the battery modules connected in series.

Claims

1. An electric drive system (30), comprising:

an n-phase electric machine (6), n>

1, having at least two multiphase winding strands (6a, 6b);

a first inverter (3a), output connections of which are connected to the phase connections of a first of the multiphase winding strands (6a, 6b) of the electric machine (6);

a second inverter (3b), the output connections of which are connected to the phase connections of a second of the multiphase winding strands (6a, 6b) of the electric machine (6); and

a DC voltage source (1), which has a plurality of battery modules (5) connected in series and a first output connection of which is connected to a first input connection of the first inverter (3a) and a second output connection of which is connected to the first input connection of the second inverter (3b),

wherein a second input connection of the first inverter (3a) and a second input connection of the second inverter (3b) are connected to each other such that the first inverter (3a) and the second inverter (3b) are arranged in a series circuit, and

wherein the second input connection of the first inverter (3a) and the second input connection of the second inverter (3b) are connected to a center tap (M) of the DC voltage source (1) between two sub-groups of the battery modules (5) connected in series.

2. The electric drive system (30) according to claim 1, wherein the first and the second inverter (3a, 3b) each comprise a three-phase, self-piloted inverter, which includes three symmetrical half bridges each including two power semiconductor switches (H1, H2;

H3, H4;

H5, H6) in a series circuit.

3. The electric drive system (30) according to claim 2, wherein the power semiconductor switches (H1, H2;

H3, H4;

H5, H6) are MOSFET switches or IGBT switches.

4. The electric drive system (30) according to claim 2, further comprising:

a control device configured to actuate the power semiconductor switches (H1, H2;

H3, H4;

H5, H6) of the first inverter (3a) and the second inverter (3b),

wherein the control device is disposed on a central control circuit board for the first inverter (3a) and the second inverter (3b).

5. Electric drive system (30) according to claim 1, further comprising:

at least one inverter (3c) connected in parallel to the first inverter (3a), input connections of which are each coupled to input connections of the first inverter (3 a); and

at least one inverter (3d) which is connected in parallel to the second inverter (3b) and the input connections of which are each coupled to input connections of the second inverter (3b).