Control circuit for power converter

Patent metadata

Field	Value
Publication number	US-10374509-B2
Application number	US-201816194903-A
Country	US
Kind code	B2
Filing date	Nov 19, 2018
Priority date	Nov 21, 2017
Publication date	Aug 6, 2019
Grant date	Aug 6, 2019

Abstract

In a control circuit for controlling a power converter that includes a switch, a power supply circuit outputs electrical power, and a command generator generates a switching command that controls switching operations of the switch, based on the electrical power output from the power supply circuit. A failure mode determiner executes a determination of whether which of failure modes has occurred in the power supply circuit, and outputs a result of the determination. A switch controller selectively executes, based on the result of the determination, a first switch control task and a second switch control task. The first switch control task forcibly shuts down the switch independently of the switching command, and the second switch control task enables the switching operations of the switch to be continuously controlled based on the switching command.

First claim

What is claimed is:

1. A control circuit for controlling a power converter that includes a switch, the control circuit comprising:
a power supply circuit configured to output electrical power;
a command generator configured to generate a switching command that controls switching operations of the switch, based on the electrical power output from the power supply circuit;
a failure mode deter miner configured to:
perform a determination of whether which of failure modes has occurred in the power supply circuit; and
output a result of the determination; and

a switch controller configured to selectively execute, based on the result of the determination, a first switch control task and a second switch control task,
the first switch control task forcibly shutting down the switch independently of the switching command,
the second switch control task enabling the switching operations of the switch to be continuously controlled based on the switching command.

2. The control circuit according to claim 1 , wherein:
the power supply circuit is configured to generate, as the electrical power, an output voltage to the command generator;
the failure mode determiner is configured to:
measure the output voltage of the power supply circuit; and
determine whether a low voltage failure as one of the failure modes has occurred in the power supply circuit, the low voltage failure representing a failure where the measured output voltage is lower than a lower limit of a predetermined operation guarantee voltage range of the power supply circuit; and

the switch controller is configured to select the first switch control task to forcibly shut down the switch upon it being determined that the low voltage failure has occurred in the power supply circuit.

3. The control circuit according to claim 2 , wherein:
the failure mode determiner is configured to output a reset signal to the command generator to thereby shut down the command generator upon determining that the low voltage failure has occurred in the power supply circuit; and
the switch controller is configured to select the first switch control task to forcibly shut down the switch before shutdown of the command generator in response to an input of the reset signal to the command generator.

4. The control circuit according to claim 2 , wherein:
the power supply circuit is configured to generate, as the electrical power, an output voltage to the command generator based on an input voltage thereto;
the failure mode determiner is configured to:
measure the input voltage to the power supply circuit;
determine whether the measured input voltage is higher than a predetermined input voltage threshold; and
determine whether an overvoltage failure as one of the failure modes has occurred in the power supply circuit, the overvoltage failure representing a failure where the measured output voltage is higher than an upper limit of the predetermined operation guarantee voltage range of the power supply circuit; and

the switch controller is configured to:
select the first switch control task to forcibly shut down the switch upon it being determined that the overvoltage failure has occurred and that the measured input voltage is higher than the input voltage threshold; and
select the second switch control task to enable the switching operations of the switch to be continuously controlled upon it being determined that the overvoltage failure has occurred and that the measured input voltage is equal to or lower than the input voltage threshold.

5. The control circuit according to claim 2 , wherein:
the failure mode determiner is configured to:
measure a value of at least one of a first temperature parameter correlating with a temperature of the command generator and a second temperature parameter correlating with a temperature of the power supply circuit;
determine whether the measured value of the at least one of the first and second temperature parameters is higher than a predetermined upper limit for the at least one of the first and second temperature parameters; and
determine whether an overvoltage failure as one of the failure modes has occurred in the power supply circuit, the overvoltage failure representing a failure where the measured output voltage is higher than an upper limit of the predetermined operation guarantee voltage range of the power supply circuit; and

the switch controller is configured to:
select the first switch control task to forcibly shut down the switch upon it being determined that the overvoltage failure has occurred and the measured value of the at least one of the first and second temperature parameters is higher than the predetermined upper limit; and
select the second switch control task to enable the switching operations of the switch to be continuously controlled upon it being determined that the overvoltage failure has occurred and that the measured value of the at least one of the first and second temperature parameters is equal to or lower than the predetermined upper limit.

6. The control circuit according to claim 2 , wherein:
the power supply circuit is configured to generate, as the electrical power, an output voltage to the command generator based on an input voltage thereto;
the failure mode determiner is configured to:
measure the input voltage to the power supply circuit;
measure a value of at least one of a first temperature parameter correlating with a temperature of the command generator and a second temperature parameter correlating with a temperature of the power supply circuit; and
determine whether an overvoltage failure as one of the failure modes has occurred in the power supply circuit, the overvoltage failure representing a failure where the measured output voltage is higher than an upper limit of the predetermined operation guarantee voltage range of the power supply circuit; and

the switch controller is configured to selectively execute the first switch control task and the second switch control task in accordance with the measured input voltage and the measured value of the at least one of the first and second temperature parameters upon it being deter mined that the overvoltage failure has occurred.

7. The control circuit according to claim 1 , wherein:
the failure mode determiner is configured to:
determine whether an operation failure has occurred in the command generator; and

the switch controller is configured to select the first switch control task to forcibly shut down the switch upon it being determined that the operation failure has occurred in the command generator.

8. The control circuit according to claim 1 , wherein:
the power supply circuit comprises at least upstream and downstream power supply circuits connected to each other, a direct-current power source and the command generator are connected through the upstream and downstream power supply circuits;
the upstream power supply circuit is configured to generate a voltage;
the downstream power supply circuit is configured to step down the generated voltage to thereby generate, as the electrical power, an output voltage directly to the command generator;
the failure mode determiner is configured to execute the determination of whether which of the failure modes has occurred in the downstream power supply circuit.

9. The control circuit according to claim 1 , wherein:
the power supply circuit comprises a plurality of power supply circuits; and
the failure mode determiner is configured to execute the determination of whether which of the failure modes has occurred in at least one of the plurality of power supply circuits,
the control circuit further comprising:
a power supply shutdown unit configured to shut down at least one

Assignees

• Denso Corp
• Toyota Motor Co Ltd

Inventors

• Nishibata Koichi
• Shindo Yusuke
• Ose Tomohisa
• Fukuta Junichi
• Terao Yasuhiro
• Shigehara Eiichiro
• Hata Keisuke

Classifications

• H02H7/1227

  responsive to abnormalities in the output circuit, e.g. short circuit · CPC title

• H02H5/04

  responsive to abnormal temperature {(specially adapted for electric machines H02H7/0852)} · CPC title

• H02H7/1225

  responsive to internal faults, e.g. shoot-through (avoiding shoot-through H02M1/38) · CPC title

• H02H7/1222

  responsive to abnormalities in the input circuit, e.g. transients in the DC input · CPC title

• H02M1/32 Primary

  Means for protecting converters other than automatic disconnection · CPC title