Transformer sub-circuit

• US 9,401,651 B2
• Filed: 07/23/2012
• Issued: 07/26/2016
• Est. Priority Date: 07/27/2011
• Status: Active Grant

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Komma, Thomas
• Primary Examiner(s): Han, Jessica
• Application Number:
  US14/235,209
• Publication Number:
  US 20140204618A1
• Time in Patent Office: 1,464 Days
• US Class Current: 1/1
• CPC Class Codes: B60L 2210/30 AC to DC converters
• CPC Class Codes: B60L 2210/40 DC to AC converters
• CPC Class Codes: B60L 53/122 Circuits or methods for driving the primary coil, e.g. supplying electric power to the coil
• CPC Class Codes: B60L 53/126 Methods for pairing a vehicle and a charging station, e.g. establishing a one-to-one relation between a wireless power transmitter and a wireless power receiver
• CPC Class Codes: B60L 53/22 Constructional details or arrangements of charging converters specially adapted for charging electric vehicles
• CPC Class Codes: B60L 53/36 by positioning the vehicle
• CPC Class Codes: H02M 3/33523 with galvanic isolation between input and output of both the power stage and the feedback loop
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility
• CPC Class Codes: Y02T 90/12 Electric charging stations
• CPC Class Codes: Y02T 90/14 Plug-in electric vehicles

Abstract

A transformer sub-circuit for use in an electrically operated vehicle includes a bridge circuit which has at least four MOSFETs and capacitors connected in parallel with the MOSFETs, and an inductor connected to the bridge circuit for use as a primary side of a transformer. A control device or controller for the inverter is configured to cause switching of the MOSFETs in such a way that operation is performed at a frequency that is higher than the resonance frequency.

Claims

1. A transformer sub-circuit for charging an electrically operated vehicle, the transformer sub-circuit comprising:

a stationary-side bridge circuit having a least two semiconductor switches being MOSFETs;

a stationary-side inductance connected to said bridge circuit and configured to be used as a primary side of a transformer; and

a controller for said semiconductor switches of said bridge circuit, said controller configured to operate said bridge circuit as an inverter and to carry out switching off of one of said semiconductor switches when a current flow through said one semiconductor switch reaches a definable threshold value differing from zero.

2. The transformer sub-circuit according to claim 1, wherein said controller is configured to use a switching frequency which is higher than a resonance frequency.

3. The transformer sub-circuit according to claim 1, which further comprises means for determining a variable representing a measure of a current in the sub-circuit in conjunction with said inductance.

4. The transformer sub-circuit according to claim 1, wherein said switching off takes place at a current flow of between 2 A and 10 A.

5. The transformer sub-circuit according to claim 1, wherein said controller is configured, after one of said semiconductor switches is switched off, to switch on at least one other of said semiconductor switches after a period has elapsed.

6. The transformer sub-circuit according to claim 5, wherein said period is between 100 ns and 200 ns.

7. The transformer sub-circuit according to claim 1, wherein said controller is configured to switch said semiconductor switches with a frequency of more than 100 kHz.