Switch, gas insulated switchgear, and method for controlling switch

Patent metadata

Field	Value
Publication number	US-12237652-B2
Application number	US-202017925270-A
Country	US
Kind code	B2
Filing date	Jul 6, 2020
Priority date	Jul 6, 2020
Publication date	Feb 25, 2025
Grant date	Feb 25, 2025

Abstract

A switch includes a fixed contact, a movable contact, a motor to drive the movable contact via a drive mechanism that converts rotational motion into linear motion, and a drive controller to control driving of the motor. The drive controller controls a rotation speed of the motor such that during an opening operation of the switch, a moving speed of the movable contact in a part of an entire moving range of the movable contact is lower than a moving speed of the movable contact during a closing operation of the switch. The part of the entire moving range includes an interrupting point at which an arc current is extinguished.

First claim

The invention claimed is:

1. A switch comprising:
a fixed contact;
a movable contact that is couplable to the fixed contact to complete a closing operation of the switch;
a motor to drive the movable contact via a drive mechanism that converts rotational motion into linear motion of the movable contact; and
a drive controller to drive and control the motor, wherein
the drive controller controls a rotation speed of the motor such that during an opening operation of the switch, a moving speed of the movable contact in a part of an entire moving range of the movable contact is lower than a moving speed of the movable contact during the closing operation of the switch from start to completion of the closing operation,
an interrupting point at which an arc current flowing between the movable contact and the fixed contact is extinguished is located in the part of the entire moving range,
a tip part of the movable contact is engaged with the fixed contact at start of the opening operation,
the drive controller controls the motor such that the motor rotates at a first rotation speed from start of the opening operation until the tip part of the movable contact reaches a first position at which the tip part has just separated from the fixed contact,
the drive controller controls the motor such that the motor rotates at a second rotation speed lower than the first rotation speed after the tip part of the movable contact passes through the first position until the tip part reaches a second position,
the interrupting point is located between the first position and the second position, and the part of the entire moving range of the movable contact is defined between the first position and the second position, and
the drive controller controls the motor such that the motor rotates at a third rotation speed higher than the second rotation speed after the tip part of the movable contact passes through the second position until the opening operation is completed.

2. The switch according to claim 1 , wherein
the drive controller controls the motor such that the first rotation speed and the third rotation speed are equal to a rotation speed of the motor during the closing operation of the switch.

3. The switch according to claim 1 , wherein
the motor is one of an induction motor and a universal motor, and
the drive controller includes:
a transformer to step down an input AC voltage;
a switching circuit to switch between direct connection of an AC power supply to the motor and connection of the AC power supply to the motor via the transformer; and
a controller to control a switching operation of the switching circuit.

4. The switch according to claim 3 , wherein
the controller controls the switching circuit to directly connect the AC power supply to the motor from start of the opening operation until the tip part of the movable contact reaches the first position,
the controller controls the switching circuit to connect the AC power supply to the motor via the transformer after the tip part of the movable contact passes through the first position until the tip part reaches the second position, and
the controller controls the switching circuit to directly connect the AC power supply to the motor after the tip part of the movable contact passes through the second position until the opening operation is completed.

5. The switch according to claim 1 , wherein
the motor is a universal motor, and
the drive controller includes:
a resistor to divide a DC voltage that is input to the resistor;
a switching circuit to switch between direct connection of an DC power supply to the motor and connection of the DC power supply to the motor via the resistor; and
a controller to control a switching operation of the switching circuit.

6. The switch according to claim 5 , wherein
the controller controls the switching circuit to directly connect the DC power supply to the motor from start of the opening operation until the tip part of the movable contact reaches the first position,
the controller controls the switching circuit to connect the DC power supply to the motor via the resistor after the tip part of the movable contact passes through the first position until the tip part reaches the second position, and
the controller controls the switching circuit to directly connect the DC power supply to the motor after the tip part of the movable contact passes through the second position until the opening operation is completed.

7. A gas insulated switchgear comprising the switch according to claim 1 as an earth switch.

8. A method for controlling a switch that includes:
a fixed contact;
a movable contact that is couplable to the fixed contact to complete a closing operation of the switch; and
a motor to drive the movable contact via a drive mechanism that converts rotational motion into linear motion of the movable contact,
the method comprising:
controlling the motor, during the closing operation of the switch, to rotate at a first rotation speed from start to completion of the closing operation; and
controlling the motor, during an opening operation of the switch, to rotate at a second rotation speed in a part of an entire moving range of the movable contact, the second rotation speed being lower than the first rotation speed, wherein
an interrupting point at which an arc current flowing between the movable contact and the fixed contact is extinguished is located in the part of the entire moving range,
a tip part of the movable contact is engaged with the fixed contact at start of the opening operation, and
the controlling the motor during the opening operation of the switch includes:
controlling the motor such that the motor rotates at the first rotation speed from start of the opening operation until the tip part of the movable contact reaches a first position at which the tip part has just separated from the fixed contact;
controlling the motor such that the motor rotates at the second rotation speed after the tip part of the movable contact passes through the first position until the tip part reaches a second position, wherein the interrupting point is located between the first position and the second position, and wherein the part of the entire moving range of the movable contact is defined between the first position and the second position; and
controlling the motor such that the motor rotates at a third rotation speed higher than the second rotation speed after the tip part of the movable contact passes through the second position until the opening operation is completed.

9. The method for controlling the switch according to claim 8 , wherein
the first rotation speed and the third rotation speed are equal to a rotation speed of the motor during the closing operation of the switch.

10. The method for controlling the switch according to claim 8 , wherein
the motor is one of an induction motor and a universal motor,
the switch further includes:
a transformer to step down an input AC voltage; and
a switching circuit to switch between direct connection of an AC power supply to the motor and connection of the AC power supply to the motor via the transformer,
the controlling the motor such that the motor rotates at the first rotation speed includes controlling the switching circuit to directly connect the AC power supply to the motor,
the controlling the motor such that the motor rotates at the second rotation speed includes controlling the switching circuit to connect the AC power supply to the motor via the transformer, and
the controlling the motor such that the motor rotates at the third rotation speed includes controlling the switching circuit to directly connect the AC power supply to

Assignees

• Mitsubishi Electric Corp

Inventors

• Nakano Mieko
• Nakauchi Shinichiro
• Nakamura Yasunori
• EDO Takahiro

Classifications

• H01H33/91

  the arc-extinguishing fluid being air or gas · CPC title

• H01H33/42

  Driving mechanisms · CPC title

• H01H33/36

  using dynamo-electric motor · CPC title

• H01H2003/266

  having control circuits for motor operating switches, e.g. controlling the opening or closing speed of the contacts · CPC title

• H01H11/0062

  Testing or measuring non-electrical properties of switches, e.g. contact velocity (monitoring contacts H01H1/0015; monitoring gas density H01H33/563; monitoring vacuum H01H33/668; calibrating H01H69/01; adjusting H01H71/74; testing of electrical properties G01R31/333) · CPC title