Switching circuit

• US 10,418,903 B2
• Filed: 02/01/2019
• Issued: 09/17/2019
• Est. Priority Date: 02/09/2018
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Yokoyama, Atsuko
• Primary Examiner(s): Berhane, Adolf D
• Application Number:
  US16/264,753
• Publication Number:
  US 20190252977A1
• Time in Patent Office: 228 Days
• CPC Class Codes: H02M 1/088 for the simultaneous control of series or parallel connected semiconductor devices
• CPC Class Codes: H02M 1/143 using compensating arrangements for reducing noise from the supply in transmission systems H04B15/005
• CPC Class Codes: H02M 1/32 Means for protecting converters other than automatic disconnection
• CPC Class Codes: H02M 3/158 including plural semiconductor devices as final control devices for a single load
• CPC Class Codes: H02M 7/537 using semiconductor devices only, e.g. single switched pulse inverters
• CPC Class Codes: H02M 7/5387 in a bridge configuration
• CPC Class Codes: H02P 27/06 using dc to ac converters or inverters H02P27/05 takes precedence

Abstract

A switching circuit includes: a DC electric power supply; a first switching element; a second switching element; a resistor that is connected to the DC electric power supply in series with the second switching element; a voltage sensor that detects a voltage applied to the resistor; and a control device, wherein: a current flowing through the first switching element is larger than a current flowing through the second switching element; and the control device is configured to: turn off the second switching element and then turn off the first switching element; and compute a voltage applied between the first collector and the first emitter by integrating a value proportional to a voltage that is detected by the voltage sensor after turning off the first switching element.

Claims

1. A switching circuit comprising:

a DC electric power supply;

a first switching element that is connected to the DC electric power supply, the first switching element including a first gate, a first collector that is connected to a positive electrode side of the DC electric power supply, and a first emitter that is connected to a negative electrode side of the DC electric power supply;

a second switching element that is connected to the DC electric power supply in parallel with the first switching element, the second switching element including a second gate, a second collector that is connected to the positive electrode side of the DC electric power supply, and a second emitter that is connected to the negative electrode side of the DC electric power supply;

a resistor that is connected to the DC electric power supply in series with the second switching element;

a voltage sensor that detects a voltage applied to the resistor; and

a control device, wherein;

a current flowing through the first switching element is larger than a current flowing through the second switching element; and

the control device is configured to;

from a state where a potential of the first gate of the first switching element and a potential of the second gate of the second switching element are the same and are equal to an on-potential, turn off the second switching element by setting the potential of the second gate of the second switching element equal to an off-potential and then turn off the first switching element by setting the potential of the first gate equal to an off-potential; and

after turning off the first switching element, compute a voltage applied between the first collector and the first emitter by integrating a value proportional to a voltage that is detected by the voltage sensor after turning off the first switching element.

2. The switching circuit according to claim 1, wherein the control device is configured to, based on a voltage that is detected by the voltage sensor before turning off the second switching element, compute a current flowing through the first switching element.

3. The switching circuit according to claim 1, wherein the control device is configured to compute a maximum value of a voltage applied between the first collector and the first emitter after turning off the first switching element.

4. The switching circuit according to claim 3, wherein the control device is configured to:

compute a voltage applied between the first collector and the first emitter of the first switching element at a predetermined timing, by integrating a value proportional to the voltage detected by the voltage sensor until the predetermined timing;

compute a correction coefficient based on the computed voltage and a voltage of the DC electric power supply; and

correct the maximum value based on the correction coefficient.