Motor operator for over-head air break electrical power distribution switches

• US 6,456,025 B2
• Filed: 03/08/2001
• Issued: 09/24/2002
• Est. Priority Date: 04/03/1998
• Status: Expired due to Term

• Current Assignee: S&C Electric Company
• Original Assignee: EnergyLine Systems, Inc.
• Inventors: Hammons, John, Klusmeyer, Terry R., Isaacson, Stephen F., Heckathorn, Jeff, Berkowitz, Donald S., Nelson, William Christian Tracy, Bik, Witold
• Primary Examiner(s): Ro, Bentsu
• Application Number:
  US09/802,780
• Publication Number:
  US 20010020834A1
• Time in Patent Office: 565 Days
• Field of Search: 318/256, 318/257, 318/264, 318/265, 318/266, 318/272, 318/283, 318/286, 318/432, 318/433, 318/466, 318/468, 307/112, 307/116, 307/125, 307/126, 307/139, 307/143
• US Class Current: 318/272
• CPC Class Codes: H01H 2003/266 having control circuits for motor operating switches, e.g. controlling the opening or closing speed of the contacts
• CPC Class Codes: H01H 2071/006 Provisions for user interfaces for electrical protection devices
• CPC Class Codes: H01H 33/36 using dynamo-electric motor
• CPC Class Codes: H02H 7/222 for switches

Abstract

A motor operator for an overhead power switch is disclosed including a microcontroller, a unique and powerful array of well-integrated sensors, a motor and drive developing substantial torque and speed and coupled to a switch actuator and responsive to the microcontroller, and a sophisticated program algorithm stored in memory at the actuator site for dynamically controlling, i.e., governing the various control modes as called for by changing conditions. The sensors include an encoder associated with the motor and drive that develops position information signals fed to the dynamic microcontroller to compute real time information including position, speed, and stopping distance used in conjunction with remote operate commands to open, close and monitor status of the switch in the various ways disclosed. Under the supervision of the microcontroller, a motor drive power switching circuit selectively applies a source of power, such as from an on site battery, to an electric motor to drive the switch toward open or closed position at different speeds, output force levels such as at different torques, and in continuous or incremental movements depending on conditions determined by the microcontroller in response to sensor inputs.

Claims

1. An operator for an overhead electrical power switch, in which operator comprises:

a controlled motor drive adapted to be coupled to an overheas electrical power switch;

motor drive position sensor producing a signal representing motor drive position; and

dynamic controller for controlling said motor drive in response to the signal produced by said motor drive position sensor, wherein said dynamic controller has a switch opening mode that includes first applying power to the motor drive to drive the switch closed and then applying power in a reverse direction to drive the switch open.

2. A method to detect the coupled state of an operator having a switch that is driven by a motor drive adapted to be coupled to the switch through an actuator, the method comprising the steps of:

when opening the switch from a closed position, initially controlling the motor drive to drive the switch in a closing direction in a first low torque mode of operation;

sensing if the motor drive exceeds a predetermined amount of travel beyond the closed position; and

indicating an operator disengaged condition if the motor drive exceeds the predetermined amount of travel.

3. The method of claim 2 further comprising the step of controlling the motor drive to drive the switch in a second high torque mode of operation in an opening direction reverse to the closing direction if the motor drive does not exceed the predetermined amount of travel in the sensing step.

4. An operator for an overhead electrical switch, in which the operator comprises:

a controlled motor drive adapted to be coupled to an overhead electrical power switch;

motor drive position sensor producing a signal representing motor drive position; and

a dynamic controller for controlling said motor drive in response to the signal produced by said motor drive position sensor, said dynamic controller having a switch opening mode that initially controls said motor drive to drive the switch in a closing direction in a first low torque mode of operation, senses if said motor drive exceeds a predetermined amount of travel beyond a predetermined closed position, indicating an operator disengaged condition said motor drive exceeds said predetermined amount of travel in said first low torque mode, and controlling said motor drive to drive the switch in a second high torque mode drive does not exceed said predetermined amount of travel in said first low torque mode of operation.

5. A digital controller for an electrical power switch driven by a motor drive that engages the electrical power switch, the digital controller comprising:

a first input adapted for receiving a switch command signal for commanding an open or closed state of a switch;

a second input adapted for receiving an electrical signal representing motor drive position;

a processor having switch opening and closing modes for turning on power to the electrical power switch to drive it in respective opening and closing directions toward its open or closed states, respectively;

a memory for storing stopping point positions for the motor drive and turning off power in response to reaching said stored motor stopping point position;

said switch opening mode comprising a first low torque mode for initially controlling said motor drive to drive the electrical power switch in the closing direction while sensing if the motor drive exceeds a predtermined amount of travel beyond a closed stored motor stopping position and indicating a motor drive disengaged condition if the motor drive exceeds said predetermined amount of travel in said first low torque mode, said switch opening mode further comprising a second high torque mode of operation and controlling said motor drive to drive the switch in the opening direction if the motor drive does not exceed the predetermined amount of travel in said first low torque mode of operation.