Protection device for a vehicle for preventing contact voltages

Patent metadata

Field	Value
Publication number	US-10046669-B2
Application number	US-201415027087-A
Country	US
Kind code	B2
Filing date	Sep 25, 2014
Priority date	Oct 2, 2013
Publication date	Aug 14, 2018
Grant date	Aug 14, 2018

Abstract

A vehicle has an electric or hybrid-electric traction drive supported by an ungrounded vehicle frame. The vehicle also has a current collector, which can be electrically connected to the traction drive and which can be brought in galvanic contact with a contact line of a grounded contact-line system to supply traction energy. The vehicle contains an electrical protection system for avoiding dangerous contact voltages on the vehicle frame or on a vehicle part connected to the vehicle frame in a conductive manner. The protection system has a first protection stage, a second protection stage, and a switching element, by which the protection system can be switched between the first and the second protection stages. The first protection stage provides greater safety from dangerous contact voltages than the second protection stage. Thus, a protection system can be provided which provides sufficient safety in all operating states of the vehicle.

First claim

The invention claimed is:

1. A vehicle, comprising:
an ungrounded vehicle frame;
a traction drive supported by said ungrounded vehicle frame and selected from the group consisting of an electric traction drive and a hybrid-electric traction drive;
a current collector being electrically connected to said traction drive and can be brought into galvanic contact with a contact line of a grounded contact line system to supply traction energy; and
an electrical protection system for preventing dangerous contact voltages on said ungrounded vehicle frame or on a vehicle part conductively connected thereto, said electrical protection system having a second protection stage, being constituted by electrically single-insulated mounting at least of said traction drive on said ungrounded vehicle frame, and a first protection stage, being additionally constituted by an electrically isolating DC-DC converter which is connected between said current collector and said traction drive, said electrical protection system further having a switching element by means of which said electrical protection system can be switched between said first protection stage and said second protection stage through an optional connection in circuit or bypassing of said DC-DC converter, wherein said first protection stage providing a higher degree of safety from the dangerous contact voltages than said second protection stage, and said traction drive being supplied with the traction energy from the contact line in both said first and second protection stages.

2. The vehicle according to claim 1 , wherein said electrical protection system has:
a sensor device for detecting an operating state of the vehicle; and
a control device interoperating with said sensor device and said switching element, said control device configured to automatically actuate said switching element depending on the operating state detected.

3. The vehicle according to claim 2 , wherein:
said sensor device has a speed measuring instrument for detecting a running speed of the vehicle; and
a first operating state assigned to said first protection stage is defined by running speeds up to a predefinable threshold value, whereas a second operating state assigned to said second protection stage is defined by the running speeds above the predefinable threshold value.

4. The vehicle according to claim 2 , wherein:
said sensor device has a current measuring instrument for measuring an intensity of a traction current arising from energy supplied from the contact line;
a first operating state assigned to said first protection stage is defined by traction currents up to a predefinable threshold value; and
a second operating state assigned to said second protection stage is defined by the traction currents above the threshold value.

5. The vehicle according to claim 2 , wherein said sensor device has at least one of a door close sensor for detecting if a vehicle door is closed, a seat occupancy sensor for detecting if a vehicle seat is occupied, or a seat belt sensor for detecting if a vehicle seat belt is buckled, wherein in contradistinction to a first operating state assigned to said first protection stage, a second operating state assigned to said second protection stage is defined by at least one of the vehicle door being closed from an inside, occupied vehicle seat or a buckled driver seat belt.

6. The vehicle according to claim 1 , further comprising:
an on-board operator control element;
a communication device for wireless data transmission; and
an operator control device, wherein said switching element being manually actuated by means of said on-board operator control element and/or being remotely actuated by means of said communication device for wireless data transmission and said operator control device interoperating therewith.

7. The vehicle according to claim 1 , further comprising an electrical energy store for traction supply of said traction drive, said electrical energy store being charged from the contact line when said DC-DC converter is connected in circuit.

8. The vehicle according to claim 1 , wherein said electrical protection device further having a monitoring device for detecting and indicating insulation faults in said electrically single insulated mounting between said traction drive and said ungrounded vehicle frame.

9. The vehicle according to claim 1 , wherein said switching element has a neutral mid-position in which neither said first protection stage nor said second protection stage of said electrical protection system is selected.

Assignees

• Siemens Ag
• Scania Cv Ab

Inventors

• Buehs Florian
• Dietrich Klaus
• Gerstenberg Frank
• Gruenjes Hasso Georg
• Lang Hans-Peter
• Lehmann Michael
• Lindstroem Johan
• Stark Thomas
• Saenger Goeran
• Thoren Christer

Classifications

• B60L2200/18

  Buses · CPC title

• B60L9/18

  fed from DC supply lines · CPC title

• B60L5/00

  Current collectors for power supply lines of electrically-propelled vehicles (current collectors in general H01R41/00) · CPC title

• B60L3/0069

  relating to the isolation, e.g. ground fault or leak current · CPC title

• B60L11/1809

  Operations & Transport · mapped topic