Patent Application
20190267199
The invention relates generally to a sensor assembly system for a high voltage disconnect switch and, more particularly, to a sensor assembly for detecting the position, speed, acceleration, temperature, and/or current of an attached disconnect switch blade for the purpose of ensuring that the switch blade has closed properly into its corresponding parting contacts, that the switch blade is closing with proper speed, and not operating at relatively high temperature due to poor contact engagement.
In electric power systems, disconnect switches are employed to isolate lines and apparatus to permit the inspection or repair of such apparatus or redirect power or other reasons. An example of such a disconnect switch, is a high voltage vertical break disconnect switch. This type of high voltage disconnect switch typically has a relatively long and somewhat flexible switch blade that is prone to suffer from wear, from improper installation, from weathering or from improper or incomplete operation, e.g. from ice build-up on the break jaws. This may cause the switch blade to not fully seat in its parting contacts, i.e., break jaws, making it unable to carry its rated current and causing damage to the parting contacts from overheating. From ground level, a utility operator may not be able to see whether proper closure of the disconnect switch has occurred, i.e., with full seating of a switch blade contact portion within the oppositely disposed break jaw contacts. Remote closure by a motor operator offers no ability to review the correctness of the switch closure before energization.
As a result, there has been a long-felt need in the electric utility industry that uses such high voltage disconnect switches—for analytics, verification, and status directly from a switch blade to be able to confirm proper operation. In this regard it has also been a long-felt need to determine if a subject high voltage disconnect switch is operating within desired specifications such as operating speed, temperature, and complete closure.
Some recently issued patents have dealt with this problem, such as U.S. Pat. No. 9,041,402 B2 by Patrick Lalonge, et al., issued May 26, 2015, and assigned to EHT International Inc. The Lalonge patent discloses a method for detecting an abnormality or malfunction of a switch in a high voltage electrical substation. The method comprises determining a position of an arm of the high voltage disconnect switch operatively connected to a motor. The motor is operated driving the arm of the high voltage disconnect switch. The torque of the motor, at a position, is determined for given position of the arm. The torque of the motor is compared to a predetermined torque threshold for the current position of the arm. An abnormal operation is determined based on the comparison. An apparatus for determining a malfunction of an arm of a disconnect switch is also disclosed which includes a memory and a torque comparison unit. A system for determining a malfunction of an arm of a disconnect switch is also disclosed comprising a position sensor, a torque determining module for determining a torque of the motor when the arm is at the current position, and an abnormality detecting module connected to the position sensor and torque determining module that compares the torque of the motor to a torque threshold previously associated with the current position of the arm to obtain a comparison result.
U.S. Pat. No. 9,052,363 B2 by Joseph R. Rostron, et al., issued Jun. 9, 2015, and assigned to Southern States LLC, discloses a high voltage switch blade closing detector and method. The Rostron patent discloses a blade closing detector and an electronic or visual indicator. In one embodiment one type of detector is disclosed using a gravity switch and a magnetic pickup to detect proper engagement between the blade and the switch. A second embodiment discloses a second type of detector using a sliding latch with a visual indicator rod to provide a visual indication of proper engagement of the blade within the jaws. A third embodiment discloses a detector using a magnetic switch with a pivot arm and a dome shaped visual indicator. The Rostron patent discloses that the detector may be used individually or in combination and may be augmented with communication equipment to transmit switch status to a remote location. The Rostron patent discloses the blade closing detector includes a first detector component having a first indicator actuation element carried by the blade arm, and a second detector component having a second indicator actuation element located near the jaws. The first and second detector components are positioned to cause the first indicator actuation element to become positioned adjacent to the second indicator actuation element when the blade is properly engaged in the jaws. Also, the first and second indicator actuation elements have an indication sensitivity causing an indicator actuation to be caused by the first and second indicator actuation elements when the blade arm comes into proper physical engagement with the jaws and no indication sensitivity when there is no such proper physical engagement. A visual indicator is disclosed which provides a visual distinction between a detector to show detector actuation versus no detector actuation.
Another such invention is disclosed in U.S. Pat. No. 9,071,110 B2 by Patrick Lalonge, et al, issued Jun. 30, 2015, and assigned to Energie H. T. International Inc. The Lahonge patent discloses a system and method for detecting an abnormal operation of a motor controlling an operating parameter of a machine. Both a torque of the motor and the operating parameter are monitored. A memory stores a plurality of predetermined torque values indicative of a normal operation of the motor. A plurality of operating parameter values are also stored in the memory with each operating parameter value having a corresponding predetermined torque value associated therewith. The predetermined torque value corresponding to the monitored operating parameter is retrieved from the memory and compared to the monitored torque value to detect abnormal operation of the motor.
In U.S. Pat. No. 9,666,393 B1 by Peter M. Kowalik, et al., issued May 30, 2017, and assigned to Cleaveland/Price Inc., the present assignee is disclosed a high voltage disconnect switch with a blade position detector and rollover indicator. The blade position and rollover indicator is operatively attached to an elongated movable switch-blade assembly of a horizontally mounted high voltage vertical break disconnect switch. The blade position detector and rollover indicator is gravity responsive and attached in predetermined position to the elongated disconnect blade assembly that reacts when the proper angle of closure of the blade is obtained in an intermediate closed switch position and finally when the proper angle of blade rollover is obtained in a fully closed switch position to provide in one embodiment a visual indication of full closure of the disconnect switch. The aforesaid U.S. Pat. No. 9,666,393 B1, by Peter M. Kowalik, et al., which is assigned to the present assignee, is herein incorporated by reference in its entirety as though fully set forth.
It is therefore an object of the present invention to devise a high voltage disconnect switch blade sensor assembly and system therefor that is simple to install on a high voltage switch blade and provides reliable analytics, verification, and status directly from the switch blade that confirms proper switch operation and this information is electronically displayed locally and transmitted by radio or optical fiber.
The present invention provides an improved and efficient sensor assembly system for detecting the proper closure of a high voltage disconnect switch blade within its parting contacts, and to ensure that the switch blade is closing with proper speed, and that the switch blade is not operating at excessively high temperature due to poor switch contact engagement. The present invention provides analytics, verification, and status from a sensor assembly attached to and carried only by the switch blade. It confirms proper operation of the disconnect switch without the use of a magnetic sensor and without sensing motor torque of an associated switch motor operator or requiring some other switch motor operator characteristic, while only requiring a single sensor assembly contained in a housing attached directly to the switch blade. The sensor assembly includes a self-contained sensor array including a number of sensors which are electronic or electromechanical. The self-contained sensor array preferably is miniaturized so that the sensors are microelectronic or microelectromechanical types. The sensors may be combined into what is known as a “System On Chip”. No other sensor components detached from the switch blade are required to sense switch operation. The sensor assembly of the present invention may be installed at the factory before shipment on the switch blade or is suitable to a retrofit installation in the field on an existing switch blade.
The high voltage disconnect switch blade sensor assembly of the present invention provides an electric utility operator the information necessary to ensure proper operation of a high voltage disconnect switch. Such a switch can operate between voltages such as 5 kV to 765 kV and carry currents from 600 amps to 5000 amps. Such a switch is employed to isolate lines and apparatus to permit the inspection or repair of such apparatus or redirect power or other reasons. The sensor assembly determines if the high voltage disconnect switch is operating within desired specifications. The sensor assembly can determine if the switch is moving at the expected rate, i.e., speed and/or acceleration and/or is in the proper position and/or is operating within a proper temperature range. If the switch is not moving at the expected rate or is not in the proper position or is operating beyond the proper temperature range or doesn't close properly, the sensor assembly will alert an operator, either by visual electronic notification or by transmission of electronic data back to a central network. It can also inform the operator that these sensed variables are within a normal range. The information is in six (6) forms, i.e., proper switch operation duration, proper switch blade travel, proper switch blade speed of operation, switch blade unexpected motion or acceleration during an operation, switch blade current, and switch blade temperature. This data that the sensor assembly provides ensures that the switch is operating within design specifications, which is an observation that is difficult from ground level.
The disconnect switch blade sensor assembly of the present invention is an electronic device that monitors position and operation of a disconnect switch blade. Due to the typical location of a human operator in relationship to the blade of the switch, it can be difficult or impossible to ensure that the switch is functioning properly. The present invention provides the human operator of the switch and/or SCADA (abbreviation for Supervisory Control and Data Acquisition Network) a clear confirmation the switch is operating properly.
The sensor assembly of the present invention, as mentioned, is contained in a housing that attaches directly to the blade of the switch—it can monitor proper switch operation duration, proper switch blade travel, proper switch blade speed of the operation, switch blade unexpected motion or acceleration during an operation, switch blade current, and switch blade temperature to determine if there are any issues with the switch's operation. Additionally, it detects in order to insure that the switch blade is properly seated into its pressure contacts for full switch closure and full electrical current carrying capability. The sensor assembly may be comprised of a plastic housing, power supply, self-contained sensor array, microcontroller, visual indicator, and a radio module. The components of the sensor assembly work together to obtain the status of the switch; and can relay the information back down to a ground-based transceiver that is connected to a SCADA system or substation and/or visually to the human switch operator on the ground via indicating lights.
The housing of the sensor assembly is preferably weather-sealed and may be made of a UV-resistant plastic, such as, UV stabilized high density polyethylene, referred to herein subsequently as HDPE. The housing desirably has a cavity on the back thereof to securely mount it to a switch blade. It may be mounted to the switch blade using two worm drive hose clamps. There are slots provided in the plastic housing for the clamps to pass through. An insulative material is used between the housing of the sensor assembly and the blade of the switch to minimize heat transfer from a hot switch blade. The sensor assembly is “calibrated”, once properly installed, by logging the initial position, speed, and acceleration characteristics of the switch blade. From this point the sensor assembly compares the operational characteristics to the initial calibration; if the operational characteristics of the switch are within a predetermined threshold the sensor assembly indicates proper operation of the switch.
As mentioned, it is difficult for a human electric utility operator to determine if a switch is operating properly, or if it's closing fully, from observing the switch at ground level. The sensor system assembly of the present invention determines if the switch is operating properly, by determining if the switch is moving at the expected rate, and can detect if the switch blade is properly seated into its pressure contacts, by monitoring the final position of the switch blade. Improper or unexpected movement of the switch detected by the sensor assembly can indicate excessive wear and tear on the equipment or tampering.
The sensor assembly of the present invention comprises several electrical components that work together. They include a power supply that may contain a battery, a solar panel, an inductive power supply, or some combination of them. The sensor assembly also includes a high-efficiency voltage regulation circuit, that provides a stable voltage to the internal electronics. The sensor assembly also includes a self-contained sensor array which may comprise a gyroscope, accelerometer, magnetometer, ultrasonic transducers, time-of-flight light sensors such as LIDAR (abbreviation for Laser Imaging, Detection and Ranging), cameras (for detecting position, motion, corona, or arcing), current sensors, (such as Rogowski coils, current transformers, or hall-effect sensors), environmental sensors, such as humidity, or barometric pressure sensors, and/or temperature sensors. The sensor array obtains data from the operational characteristics of the switch. These sensor assembly components measure the angular and rotational position and temperature of the blade of the switch blade. An on-board microcontroller is also included in the sensor assembly that reads the data from the sensors periodically and determines if the present operational characteristics of the switch are similar to those of a properly adjusted and functioning switch. The microcontroller can control daylight viewable indicator lights, such as red and green LED's, to indicate open and close status respectively of the switch. Also the sensor assembly may include a radio transceiver to transmit the information of the switch down to a ground based transceiver.
The microcontroller will process and prepare data from the sensor array for actuating on-board visual indicators and/or transmitting to the ground based transceiver. The sensor assembly processes the data and compares it to previously obtained reference data. The sensor data can be transmitted wirelessly to another remote device to process and aggregate the data. This data processing device is referred to as a ground based transceiver data processing device. The microcontroller in the sensor assembly will process and can packetize the data for transmitting by radio to the ground based transceiver data processing device. The ground based transceiver radio module provides a link to a SCADA system for transmitting information to a utility control room. The ground based transceiver data processing device may reduce the power and computational requirements of the sensor assembly, and aggregate sensor readings to diagnose trends. This serves to improve the reference data and operational characteristics among a population of switches. Based on the data collected by the ground based transceiver data processing device, it can provide local indication or transmit data back to a control room.
The power supply of the sensor assembly is maintained at high potential, i.e., high voltage, such as 115 kV. The “ground” of the electronics is at a high potential, such as 115 kV, compared to true/earth ground. This eliminates safety concerns and bulky insulated cables to true ground. Comparable products such as used in consumer electronics and the automotive industry rely on a power supply at true/earth ground potential, or are purely mechanical in nature.
Data processing through the use of a microcontroller or digital signal processor is not novel in and of itself. However, the analytics performed on blade positioning and movement by use of the sensor assembly of the present invention and the operation of the sensor assembly in collecting blade data to be processed by the sensor assembly microcontroller and/or the ground based transceiver microcontroller provides for a unique approach.
Indications of an open or closed switch are fairly common in the electric utility industry. An electronic indication maintained at actual line potential, based on the movement and positioning of the switch itself, is unique. Other prior art electronic switch position sensors such as that disclosed in the previously mentioned U.S. Pat. No. 9,041,402 B2 by Patrick Lalonge, et al., and assigned to EHT International Inc. rely on the positioning of the torsional pipe of the switch to determine information about the status and health of a switch, unlike the present invention which obtains formation from the switch blade itself which is more accurate. The previously mentioned U.S. Pat. No. 9,052,363 B2 by Joseph R. Rostron, et al. utilizes a detector mounted to the moving switch blade that reacts with another detector mounted to the jaw of the switch, and the two detectors when close to each other provide an indication of a properly closed switch. Conversely the present invention utilizes a novel method for indicating a properly closed switch via sophisticated accelerometers and other sensors mounted to the switch blade that indicates the position of the switch blade without the necessity of a second detector or detector component mounted to the jaw or any other part of the switch. This and other distinguishing features will be pointed out.
Radio systems maintained at high potential are common. The data being transmitted at that high potential by the sensor assembly of the present invention is also believed novel.
Ground level data processing units are very common, especially when connected to lower-powered devices. The ground based transceiver data processing unit of the present invention is believed novel based on the nature of its algorithms for indicating system health and operating parameters.
The sensor assembly of the present invention may incorporate the following additional features:
a. an industrial temperature sensor, to indicate the switch's operating temperature;
b. a current sensor, magnetically coupled to the switch or otherwise, to determine current flowing through the switch;
c. a calibration method for the sensor assembly, incorporating a push-button, radio command, or other external signal to the sensor assembly; and,
d. a sensor to monitor environmental information, such as humidity and/or barometric pressure.
The sensor assembly does not need to possess both a radio and local indication lights to fulfil its primary function.
The present invention as mentioned determines position data based on blade position rather than switch motor operator position. This provides the advantage of more accurately indicating proper operation and closure when compared to the previously described arrangement in U.S. Pat. No. 9,041,402 B2 by Patrick Lalonge, et al., and assigned to EHT International Inc. which monitors just the linkage system. The sensor assembly of the present invention as mentioned resides at line potential, and can be attached to any switch—whether automated through a motor operator or otherwise or manually operated.
These and other aspects of the present invention will be further understood from the entirety of the description, drawings and claims.
For a better understanding of the invention reference may be made to the accompanying drawings exemplary of the invention, in which:
Referring to
The rotatable insulator 42, is capable of rotary operative motion for driving the switch-blade assembly 50. To mechanically interconnect the operation of the elongated movable switch-blade assembly 50 with rotation of the rotatable insulator 42, the drive arrangement 44 also includes a movable blade-arm 56 which is mounted to the horizontally extending movable switch-blade assembly 50. At the upper end of the movable blade-arm 56, is pivotally connected a link 58 by a pivot pin 61.
At pin 60 a tongue member 62 operatively engages a movable tubular crank-member 64, which is rotated by the operating motion of the rotatable insulator 42. When the rotatable insulator 42 is initially rotated when the switch is in the full-open position and now closing (not shown in the drawings), the tubular crank-member 64 causes elongated switch-blade assembly 50 to vertically pivot about the hinge axis 66 causing the blade tip 54 to initially enter the break jaw contact assembly 34; then further rotation of the rotatable insulator 42 causes the blade tip 54 to rotate about its own longitudinal axis to a final horizontal position as shown in
The horizontal vertical break disconnect switch 13 described thus far is conventional and well known in the industry. As can be seen by reference to
With reference to
The operation of the sensor assembly 10 as shown in
With reference to
Once the initial calibration is complete the sensor assembly 10 monitors the operational characteristics of the switch 13 as follows:
The sensor assembly 10 determines if the switch 13 is moving at the expected velocity, and ensures that the switch blade 12 is properly seated into its pressure contacts, i.e., jaw fingers 36a, 36b. Improper or unexpected switch 13 movement can indicate excessive wear and tear on the equipment. Additionally, if a switch blade 12 is not properly seated into its pressure contacts upon switch energization, the switch contacts can be damaged, degrading the ampacity of the switch 13.
The sensor assembly power supply 16 keeps the sensor assembly 10 online. Instead of just a non-rechargeable battery 78 or a rechargeable battery 100, it could be powered by a solar panel, thermoelectric generator, an inductive power supply,—or some combination of them. The sensor assembly power supply 16 powers the entire sensor assembly 10, including sensor assembly microcontroller 20, sensor assembly visual indicator 24, and sensor assembly radio module 22. A sensor assembly power supply management system can be included in the sensor assembly microcontroller 20 to incorporate, manage, and charge various energy storage devices such as sensor assembly batteries 100 and capacitors 98.
The sensor array 18 may be comprised of many types of sensors to determine position, speed, angle or distance of the switch blade 12 relative to the break jaws or fingers 36a, 36b, for example. Examples of such sensors, include gyroscopes, magnetometers, accelerometers, ultrasonic transducers, time-of-flight light sensors, such as LIDAR, or cameras. The sensor assembly microcontroller 20, in one embodiment, can process the data from the sensors and communicates with the ground data processing device 26. The sensor assembly visual indicator 24 is optional, but if used, could be an onboard visual indicator, or a remote indication transmitted via wire or through a wireless communication device. The sensor assembly microcontroller 20 can manage the sensor assembly power supply 16, the sensor array 18, the sensor assembly radio module 22 and the sensor assembly visual indicator 24. Depending on the function of the sensor assembly 10, and the amount of data that is obtained from it, the ground data processing unit 26 may include the ground based microcontroller 90, such as shown in
A current sensor, not shown in the drawings, can be provided, magnetically coupled to the switch 13 or otherwise, to determine if current is flowing through the switch 13. Clamps 68a and 68b can be replaced or combined with a split-core direct current sensor or Rogowski coil to measure switch blade 12 currents and transmit values to the sensor assembly radio transceiver 22. A calibration method for the sensor assembly 10, incorporating a push-button, radio command, or other external signal to the sensor assembly 10 can be used for calibration and set up. A sensor to monitor environmental information, such as humidity and/or barometric pressure could be provided.
With reference to
With reference to
With reference to
Of course variations from the foregoing embodiments are possible without departing from the scope of the invention.
This is application claims the benefit of U.S. Provisional Application No. 62/634,468 filed Feb. 23, 2018 which is incorporated herein by reference in its entirety as though fully set forth.
| Number | Date | Country | |
|---|---|---|---|
| 62634468 | Feb 2018 | US |
