DC charging station for a battery of an electric vehicle

Patent metadata

Field	Value
Publication number	US-9764650-B2
Application number	US-201113825959-A
Country	US
Kind code	B2
Filing date	Aug 31, 2011
Priority date	Sep 23, 2010
Publication date	Sep 19, 2017
Grant date	Sep 19, 2017

Abstract

A DC voltage source, for example an AC/DC converter, has an output producing a controllable DC voltage for a DC charging station to charge the battery of an electric vehicle. A voltage balancing unit is connected between the output of the converter and the output terminal of the DC charging station. The voltage balancing unit has a controllable switch by which the connection between voltage source or converter and battery can be made or broken as desired. The switch is controlled as a function of the voltage on the input and output side of the voltage balancing unit to the effect that the switch breaks the connection before and while the battery is being connected to the DC output terminal, and makes a connection only when the voltage on the input side of the voltage balancing unit corresponds substantially to the voltage on the output side of the voltage balancing unit.

First claim

The invention claimed is:

1. A DC charging station for charging a battery of an electric vehicle, the DC charging station comprising:
a DC voltage source with an output providing a DC voltage at least during operation of the DC charging station;
a DC output terminal, to which the battery to be charged is able to be connected and connectable to the DC voltage source via at least one line, charging the battery during the operation of the DC charging station;
a voltage balancing unit, connected between the output of the DC voltage source and the DC output terminal, the voltage balancing unit comprising:
a first switch that selectably makes and breaks a connection between the output of the DC voltage source and the DC output terminal;
a shunt resistor via which the input-side voltage is measured, and
a second switch connected in series with the shunt resistor and controlled in opposition to the first switch,

a first voltage detection unit, detecting an input-side voltage of the voltage balancing unit;
a second voltage detection unit, detecting an output-side voltage of the voltage balancing unit; and
a first open-loop and closed-loop control unit controlling and regulating the voltage balancing unit, to which measured values detected by the first and the second voltage detection unit are supplied, configured to:
control the first switch to:
break the connection between the output of the DC voltage source and the DC output terminal before and while the battery is connected to the DC output terminal, and
make the connection between the output of the DC voltage source and the DC output terminal, at least to the battery connected to the DC output terminal, if the input-side voltage detected by the voltage balancing unit corresponds substantially to the output-side voltage detected by the voltage balancing unit; and

control the second switch to:
switch on the shunt resistor when the voltage balancing unit carries out the voltage balancing, and
switch off the shunt resistor when the input-side voltage of the voltage balancing unit corresponds substantially to the output-side voltage of voltage balancing unit.

2. The DC charging station as claimed in claim 1 , wherein the DC voltage source is a voltage-regulatable voltage source,
wherein the DC charging station further comprises a second open-loop and closed-loop control unit, controlling and regulating the DC voltage source, configured to regulate the DC Serial No. 13/825,959 voltage source at least during operation of the DC charging station and at least for the battery connected to the DC output terminal so that the input-side voltage of the voltage balancing unit corresponds substantially to the output-side voltage.

3. The DC charging station as claimed in claim 2 , wherein the second open loop and closed-loop control unit is a cascaded voltage and current regulation unit having a current regulator in an inner regulation circuit and a voltage regulator in an outer regulation circuit.

4. The DC charging station as claimed in claim 1 , wherein insulation monitoring, provided at the output of the voltage balancing unit, detects damage to at least one of a charging cable and a charging socket on the vehicle and damage to the electrical connection to the battery in the vehicle.

5. The DC charging station as claimed in claim 4 , wherein the DC voltage source is an AC-DC converter, having an input receiving an AC voltage, at least during operation of the DC charging station, and converting the AC voltage into the DC voltage available at the output of the DC charging station.

6. A method for charging a battery of an electric vehicle using a DC charging station with a DC voltage source, which makes a DC voltage available, at least in the operating state of the DC charging station, a DC output terminal to which the battery to be charged is able to be connected and connectable to the DC voltage source via at least one line, a voltage balancing unit connected between the output of the DC voltage source and the DC output terminal of the DC charging station and having a first switch controllable to make or break a connection between the output of the DC voltage source and the DC output terminal of the DC charging station, a shunt resistor via which the input-side voltage is measured, and a second switch connected in series with the shunt resistor and controlled in opposition to the first switch, said method comprising:
breaking the connection between the output of the DC voltage source and the DC output terminal before and while the battery is connected to the DC output terminal;
detecting the input-side voltage and the output-side voltage of the voltage balancing unit after the battery to be charged has been connected to the DC output terminal;
controlling the first switch to make the connection between the output of the DC voltage source and the DC output terminal by the first switch only when the input-side voltage detected by the voltage balancing unit corresponds substantially to the output-side voltage detected by the voltage balancing unit; and
controlling the second switch to switch on the shunt resistor when the voltage balancing unit carries out the voltage balancing, and switch off the shunt resistor when the input-side voltage of the voltage balancing unit corresponds substantially to the output-side voltage of voltage balancing unit.

7. The method as claimed in claim 6 ,
wherein the DC voltage source is a voltage-regulatable voltage source, and
wherein said method further comprises regulating the DC voltage source, at least during operation of the DC charging station and at least for the battery connected to the DC output terminal so that the input-side voltage of the voltage balancing unit corresponds substantially to the output-side voltage.

8. The method as claimed in claim 7 , further comprising:
initially breaking the connection between the output of the DC voltage source and the DC output terminal of the DC charging station before electrical connection of the battery to the DC charging station;
determining the output-side voltage of the voltage balancing unit after the electrical connection has been made between the DC charging station and the battery;
determining the input-side voltage of the voltage balancing unit;
regulating the DC voltage available at the output of the DC voltage source so that the input-side voltage of the voltage balancing unit and the output-side voltage of voltage balancing unit substantially correspond prior to said making of the connection between the output of the DC voltage source and the DC output terminal of the DC charging station; and
charging or discharging current ramped up to a nominal value.

9. The method as claimed in claim 8 , further comprising waiting after making the connection between the output of the DC voltage source and the DC output terminal and before said charging or discharging.

10. The method as claimed in claim 9 , wherein said determining of the input-side voltage includes measurement using a resistor, connected for measurement purposes by a second switch prior to said regulating.

11. The method as claimed in claim 10 , further comprising disconnecting the resistor by opening the second switch after one of said making of the connection between the output of the DC voltage source and the DC output terminal and said waiting thereafter, and before said charging or discharging.

12. The method as claimed in claim 11 , further comprising waiting after said disconnecting and before said charging or discharging.

13. The method as claimed in claim 8 , wherein the first switch is externally controlled.

14. The DC ch

Assignees

• Böhm Markus
• Cherouvim Nicholas Demetris
• Reinschke Johannes
• Starkl Johnannes
• Siemens Ag

Inventors

• Böhm Markus
• Cherouvim Nicholas Demetris
• Reinschke Johannes
• Starkl Johnannes

Classifications

• H02J7/685

  using connection detecting circuits (H02J7/68 takes precedence) · CPC title

• H02J7/90

  Regulation of charging or discharging current or voltage · CPC title

• Y02T10/7072

  Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors · CPC title

• Y02T90/128

  Cross-Sectional Technologies · mapped topic

• B60L11/1809

  Operations & Transport · mapped topic