Switching apparatus and method for a segment of an electric power line

• US 6,396,172 B1
• Filed: 12/03/1999
• Issued: 05/28/2002
• Est. Priority Date: 12/04/1998
• Status: Expired due to Term

• Current Assignee: Hydro-Quebec (Province of Québec)
• Original Assignee: Hydro-Quebec (Province of Québec)
• Inventors: Couture, Pierre
• Primary Examiner(s): Ballato, Josie
• Assistant Examiner(s): DEBERADINIS, ROBERT L
• Application Number:
  US09/453,400
• Time in Patent Office: 907 Days
• Field of Search: 307/125,113,116,126,147,112 219/501
• US Class Current: 307/125
• CPC Class Codes: H02G 1/02 for overhead lines or cables
• CPC Class Codes: H02G 7/00 Overhead installations of electric lines or cables installations of bus-bars H02G5/00
• CPC Class Codes: H02G 7/16 Devices for removing snow or ice from lines or cables
• CPC Class Codes: H02G 7/20 Spatial arrangements or dispositions of lines or cables on poles, posts or towers
• CPC Class Codes: H02J 3/00 Circuit arrangements for ac mains or ac distribution networks

Abstract

The switching apparatus is intended to be used with a segment of an electric power line having several phase lines. Each of the phase lines has several conductors electrically insulated one from the other and connected in parallel. The conductors of each phase line are short-circuited among them at two extremities of the segment. The apparatus comprises pairs of switches connected in parallel, for selectively opening and closing the conductors of each phase line, a detecting device for detecting current operating conditions of the segment, and a controlling device for controlling the pairs of switches according to the current operating conditions of the segment. The present invention also relates to a switching method.

Claims

1. A switching apparatus for a segment of an electric power line having several phase lines, each of the phase lines having several conductors electrically insulated one from the other and connected in parallel for conducting a phase current, the conductors of each phase line being short-circuited among them at two ends of the segment, the apparatus comprising:

pairs of electromechanical and electronic switches connected in parallel, for selectively opening and closing the conductors of each phase line so as to conduct the corresponding phase current through one or several conductors;

detecting means for detecting current operating conditions of the segment of the electric power line; and

control means for controlling the pairs of electromechanical and electronic switches according to the current operating conditions of the segment, the switches of each pair being independently controlled by control signals.

2. An apparatus according to claim 1, wherein the electromechanical switches of a same phase line are integrated in an electromechanical switching device which comprises:

a housing;

first terminals mounted on the housing and connected respectively to first sections of the conductors of the phase line;

fixed conducting contacts connected to the first terminals;

second terminals mounted on the housing and connected respectively to second sections of the conductors of the phase line;

a mobile carriage capable of displacement with respect to the housing along a course, the carriage including mobile conducting contacts connected to the second terminals, the mobile conducting contacts having respectively partially discontinuous conducting surfaces disposed one with respect to the others so that all along the course at least one of the conductors of the phase line is closed by a connection between at least one of the mobile conducting contacts and at least one of the fixed conducting contacts;

guiding means for guiding the carriage along its course; and

motor means for moving the carriage along its course, the motor means being controlled by the control means.

3. An apparatus according to claim 2, wherein the guiding means comprise rails mounted on the housing, and linear bearings mounted on the carriage and capable of sliding along the rails.

4. An apparatus according to claim 2, comprising furthermore regulating means for regulating a movement of the carriage during its course, said regulating means comprising:

a flexible spring rod having a first extremity connected to the carriage and a second extremity provided with a positioning component; and

an elongated member mounted on the housing and provided with notches positioned in relation to the course of the carriage and capable of cooperating with the positioning component during the course of the carriage so as to stabilize said carriage in different operating positions.

5. An apparatus according to claim 2, comprising furthermore indicating means for indicating an actual operating position of the carriage, said indicating means comprising:

a flexible spring rod having a first extremity connected to the carriage and a second extremity provided with an indicating component; and

a part of an external wall of the housing, provided with holes positioned in relation to the course of the carriage and capable of cooperating with the indicating component during the course of the carriage so as to indicate to an observer external to the housing the actual operating position of the carriage.

6. An apparatus according to claim 2, wherein the motor means comprise:

a motor mounted on the housing and controlled by control means;

a speed reducer coupled to the motor;

a lead screw having a first extremity connected to the speed reducer, and a second extremity fixed to an anchorage point of the housing;

a barrel capable of moving along the lead screw, the barrel being linked to the carriage for moving said carriage when the motor is activated.

7. An apparatus according to claim 1, wherein the electromechanical switches of a same phase line are integrated in an electromechanical switching device which comprises:

a housing;

first terminals mounted on the housing and connected respectively to first sections of the conductors of the phase line;

a mobile carriage capable of displacement with respect to the housing along a course, the carriage including mobile conducting contacts connected to the first terminals;

second terminals mounted on the housing and connected respectively to second sections of the conductors of the phase line;

fixed conducting contacts connected to the second terminals, the fixed conducting contacts having respectively partially discontinuous conducting surfaces disposed one with respect to the others so that all along the course at least one of the conductors of the phase line is closed by a connection between at least one of the mobile conducting contacts and at least one of the fixed conducting contacts;

guiding means for guiding the carriage along its course; and

motor means for moving the carriage along its course, the motor means being controlled by the control means.

8. An apparatus according to claim 3, wherein the guiding means comprise rails mounted on the housing, and linear bearings mounted on the carriage and capable of sliding along the rails.

9. An apparatus according to claim 7 comprising furthermore regulating means for regulating a movement of the carriage during its course, said regulating means comprising:

a flexible spring rod having a first extremity connected to the carriage and a second extremity provided with a positioning component; and

an elongated member mounted on the housing and provided with notches positioned in relation to the course of the carriage and capable of cooperating with the positioning component during the course of the carriage so as to stabilize said carriage in different operating positions.

10. An apparatus according to claim 7, comprising furthermore indicating means for indicating an actual operating position of the carriage, said indicating means comprising:

a flexible spring rod having a first extremity connected to the carriage and a second extremity provided with an indicating component; and

a part of an external wall of the housing, provided with holes positioned in relation to the course of the carriage and capable of cooperating with the indicating component during the course of the carriage so as to indicate to an observer external to the housing the actual operating position of the carriage.

11. An apparatus according to claim 7, wherein the motor means comprise:

a motor mounted on the housing and controlled by the control means;

a speed reducer coupled to the motor;

a lead screw having a first extremity connected to the speed reducer, and a second extremity fixed to an anchorage point of the housing; and

a barrel capable of moving along the lead screw, the barrel being linked to the carriage for moving said carriage when the motor is activated.

12. An apparatus according to claim 1, wherein:

the detecting means comprise;

several load cells, at least one load cell being mounted for every phase line, each load cell comprising a load sensor for measuring a load value supported by the corresponding phase line, an inclination sensor for measuring its inclination with respect to a vertical axis, a temperature sensor for measuring an ambient temperature, and a radiofrequency transmitter for transmitting signals indicating the value of the load, the inclination and the ambient temperature; and

detecting means comprising;

a processor having first input ports for receiving signals indicating the operating positions of the switches, and second input ports for receiving signals indicating the voltages at the terminals of the pairs of switches;

a radiofrequency transmitter connected to the processor for transmitting signals indicating the operating positions of the switches, and of the voltages; and

electric power supply means for supplying the processor and the transmitter;

the control means comprise;

the processor which has furthermore outputs for transmitting the control signals;

a radiofrequency receiver connected to the processor for receiving radiofrequency control signals from which the control signals are produced;

an amplifier connected to the processor for controlling the motor means according to the control signals; and

the electric power supply means for supplying furthermore the receiver and the amplifier.

13. An apparatus according to claim 12, wherein the electric power supply means comprise:

a first electric power supply having a battery and a solar panel connected to the battery; and

an electric power supply connected in parallel to the first electric power supply, and having inputs connected to the conductors.

14. An apparatus according to claim 1, comprising respectively, in parallel with each pair of switches, a damping circuit, a voltage clamp and a thermal spark gap device.

15. A switching method for a segment of an electric power line having several phase lines, each of the phase lines having several conductors electrically insulated one from the other and connected in parallel for conducting a phase current, the conductors of each phase line being short-circuited among them at two ends of the segment, the method comprising the following steps:

(a) detecting current operating conditions of the segment of the electric power line; and

(b) controlling pairs of electromechanical and electronic switches connected in parallel according to operating conditions detected in step (a) for selectively opening and closing the conductors of each phase line so as to conduct the corresponding phase current through one or several conductors, the switches of each pair being independently controlled by control signals.

16. A method according to claim 15, wherein step (b) comprises the following steps:

(i) during a closing of a pair of switches, producing control signals causing a closing of the electronic switch before a closing of the electromechanical switch; and

(ii) during an opening of a pair of switches, producing control signals causing an opening of the electromechanical switch before an opening of the electronic switch.

17. A method according to claim 15, wherein step (a) comprises the following steps:

(i) detecting operating positions of the switches;

(ii) measuring voltages at the terminals of the pairs of switches;

(iii) measuring for each phase line a load value that is supported by means of load cells, inclinations of the load cells with respect to a vertical axis, and temperatures ambient to the load cells;

(iv) transmitting radiofrequency signals indicating the operating positions of the switches, the voltages, the load values, the inclinations and the ambient temperatures;

(v) following step (iv), receiving radiofrequency control signals; and

(vi) producing the control signals according to the radiofrequency control signals.

18. A method according to claim 15, wherein, in step (b), the pairs of electromechanical and electronic switches are controlled so as to conduct the phase current of each phase line through at least one of the corresponding electromechanical switches.

19. A method according to claim 18, wherein step (b) comprises the following steps:

(i) permanently opening electromechanical switches from predetermined pairs of switches associated to predetermined phase lines; and

(ii) using the electronic switches of the predetermined pairs of switches to open and close the corresponding conductors.