Voltage measurements of electrically conducting elements in systems for controlling electrical processes

• US 8,305,095 B2
• Filed: 06/02/2008
• Issued: 11/06/2012
• Est. Priority Date: 06/07/2007
• Status: Active Grant

• Current Assignee: Hitachi Energy Limited (Hitachi, Ltd.)
• Original Assignee: ABB Technology AG (ABB Limited)
• Inventors: Björklund, Hans, Nyberg, Krister
• Primary Examiner(s): Vazquez, Arleen M
• Assistant Examiner(s): Diaz Perez, Julio C
• Application Number:
  US12/663,440
• Publication Number:
  US 20100244865A1
• Time in Patent Office: 1,618 Days
• Field of Search: 324/120, 324/123.R, 361/78, 361/62, 361/115, 361/58, 361/93, 361/91, 361/64, 361/66
• US Class Current: 324/713
• CPC Class Codes: G01R 15/04 Voltage dividers
• CPC Class Codes: G01R 15/06 having reactive components, e.g. capacitive transformer
• CPC Class Codes: H02H 1/0007 concerning the detecting means in general G01R or other subclasses of G01; reed switches H01H71/2445

Abstract

A voltage measurement device for connection to a primary voltage dividing element provided between ground and an electrically conducting element in a system for controlling an electrical process and such a system. The device includes at least one first branch of secondary voltage dividing elements, where the branch is adapted to be connected in parallel with the primary voltage dividing element, and a first measuring unit connected to one of the secondary voltage dividing elements of the first branch and arranged to measure the voltage across this secondary voltage dividing element and provide a first voltage signal corresponding to a voltage of the electrically conducting element.

Claims

1. A voltage measurement device for connection to a primary voltage dividing element provided between ground and an electrically conducting element in a system for controlling an electrical process, the voltage measurement device comprising:

a first branch of secondary voltage dividing elements including two or more voltage dividing elements, wherein said first branch is adapted to be connected in parallel with said primary voltage dividing element;

a first measuring unit connected to one of the secondary voltage dividing elements of the first branch and arranged to measure a voltage across the one of the secondary voltage dividing elements and provide a first voltage signal corresponding to a voltage of the electrically conducting element;

a second branch of secondary voltage dividing elements including two or more voltage dividing elements, wherein said second branch is connected in parallel with said first branch; and

a second measuring unit connected to one of the secondary voltage dividing elements of the second branch and arranged to measure a voltage across the one of the secondary voltage dividing elements and provide a second voltage signal corresponding to the voltage of the electrically conducting element.

2. The voltage measurement device according to claim 1, further comprising:

an electro-optical conversion unit in each measuring unit, each electro-optical conversion unit being configured to convert the corresponding voltage signal from an electrical to an optical domain in order to be transmitted to a control station of the system.

3. The voltage measurement device according to claim 1, further comprising:

an A/D converter in each measuring unit, each A/D converter configured to convert the corresponding voltage signal from an analog to a digital representation.

4. The voltage measurement device according to claim 1, further comprising:

an amplifier in each measuring unit.

5. The voltage measurement device according to claim 1, further comprising:

a filter arranged between each branch and the primary voltage dividing element.

6. The voltage measurement device according to claim 1, further comprising:

a temperature determining module configured to determine an outdoor temperature and a temperature within the voltage measurement device; and

a voltage adjustment module configured to adjust voltage measurement values.

7. The voltage measurement device according to claim 1, wherein each measuring unit comprises a measuring channel to a control station of the system.

8. The voltage measurement device according to claim 7, further comprising:

inputs on each measuring channel for detection of low gas pressure.

9. The voltage measurement device according to claim 7, further comprising:

an internal supervision and detection module configured to supervise and detect failures on each measuring channel; and

a notification module configured to generate and send a notification of a detected failure to the control station.

10. The voltage measurement device according to claim 1, further comprising:

a power receiver configured to redundantly receive power from redundant battery systems in the system.

11. A system for controlling an electrical process, the system comprising:

at least one control station;

an electrically conducting element;

a primary voltage dividing element provided between the electrically conducting element and ground;

a voltage measurement device comprising at least one first branch of secondary voltage dividing elements including two or more voltage dividing elements, wherein said first branch is connected in parallel with said primary voltage dividing element;

a first measuring unit connected to one of the secondary voltage dividing elements of the first branch and arranged to measure the voltage across this secondary voltage dividing element and provide a first voltage signal corresponding to a voltage of the electrically conducting element to said control station;

a second branch of secondary voltage dividing elements including two or more voltage dividing elements and connected in parallel with said first branch; and

a second measuring unit connected to one of the secondary voltage dividing elements of the second branch and arranged to measure the voltage across this secondary voltage dividing element and provide a second voltage signal corresponding to the same voltage of the electrically conducting element.

12. The system according to claim 11, wherein said control station comprises control and protection devices configured to receive the first voltage signal.

13. The system according to claim 11, wherein said voltage measurement device is separated from the control station.