Signal transmission circuit provided with logic circuit

Patent metadata

Field	Value
Publication number	US-10186953-B2
Application number	US-201715497319-A
Country	US
Kind code	B2
Filing date	Apr 26, 2017
Priority date	Apr 26, 2016
Publication date	Jan 22, 2019
Grant date	Jan 22, 2019

Abstract

A signal transmission circuit transmitting abnormality signals from a primary side circuit to a secondary side circuit is provided, in which the primary side circuit includes switching elements driven by drive circuits, the secondary circuit including a receiving unit receiving the abnormality signals transmitted from the primary side circuit.
The signal transmission circuit includes: a plurality of isolation elements that electrically isolate the primary side circuit and the secondary side circuit, and allows the abnormality signals to be transmitted therethrough; and a logic circuit that receives the abnormality signals from the isolation elements, outputting a predetermined signal indicating an occurrence of an abnormality when at least one of the switching elements shows the abnormality.
The isolation elements transmit the abnormality signals relative to a predetermined reference voltage in the secondary side circuit and the predetermined signal outputted by the logic circuit is received by the receiving unit.

First claim

What is claimed is:

1. A signal transmission circuit transmitting abnormality signals from a primary side circuit to a secondary side circuit, comprising:
a plurality of isolation elements that electrically isolate the primary side circuit and the secondary side circuit, and allows the abnormality signals to be transmitted therethrough, the primary side circuit including a plurality of switching elements and a plurality of drive circuits that drive the switching elements, the drive circuits each being isolated from each other, the secondary circuit including a receiving unit that receives the abnormality signals corresponding to respective switching elements, transmitted from the primary side circuit; and
a logic circuit that receives the abnormality signals from the isolation elements, the logic circuit being disposed in the secondary circuit, outputting a predetermined signal indicating an occurrence of an abnormality when at least one of the switching elements shows the abnormality, wherein:
the isolation elements transmit the abnormality signals relative to a predetermined reference voltage in the secondary side circuit,
the predetermined signal outputted by the logic circuit is received by the receiving unit,
the logic circuit has a plurality of logic elements,
the plurality of logic elements includes one or more first logic elements, each of the first logic element receives an output of a corresponding one isolation element, and an output of an adjacent one logic element,
the first logic element includes a second logic element of which the output is received by the receiving unit,
the plurality of logic elements includes a third logic element that receives outputs of two corresponding isolation elements,
the plurality of logic elements include a fourth logic element,
the first logic element is provided with a corresponding isolation element to form a first module,
a first isolation element among two isolation elements corresponding to the third logic element and the third logic element are formed in a second module,
a second isolation element and the fourth logic element are formed in a third module, and
the fourth logic element passes an output of the second isolation element to the third logic element without any changes.

2. The signal transmission circuit according to claim 1 , wherein
the second logic element in the plurality of logic elements has a shortest distance between a corresponding isolation element and the receiving unit.

3. The signal transmission circuit according to claim 1 , wherein:
inputs of the logic circuit are pulled-down or pulled-up, and
the logic circuit outputs the predetermined signal indicating an occurrence of an abnormality, when an open failure occurs in a connection between the isolation element and the logic element, or a connection between the logic elements.

4. The signal transmission circuit according to claim 1 , wherein
inputs of the logic circuit are pulled-down or pulled-up; and
the logic circuit outputs the predetermined signal indicating an occurrence of an abnormality, when an output of the isolation element is stopped.

5. The signal transmission circuit according to claim 1 , wherein
the isolation elements are configured of magnetically-coupled type isolation elements.

6. The signal transmission circuit according to claim 1 , wherein the plurality of switching elements configure an inverter having an upper arm switching elements and a lower arm switching element connected in series between a high voltage side and a low voltage side of the inverter;
the logic circuit includes:
a first logic circuit receiving the abnormality signals from the plurality of isolation elements corresponding to the upper arm switching element, outputting the predetermined signal indicating an occurrence of an abnormality when at least one of the upper arm switching elements shows the abnormality; and
a second logic circuit receiving the abnormality signals from the plurality of isolation elements corresponding to the lower arm switching element, outputting the predetermined signal indicating an occurrence of an abnormality when at least one of the lower arm switching elements shows the abnormality, an output of the first logic circuit and an output of the second logic circuit are connected to the receiving unit as an input thereof.

7. A signal transmission circuit transmitting abnormality signals from a primary side circuit to a secondary side circuit, comprising:
a plurality of isolation elements that electrically isolate the primary side circuit and the secondary side circuit, and allows the abnormality signals to be transmitted therethrough, the primary side circuit including a plurality of switching elements and a plurality of drive circuits that drive the switching elements, the drive circuits each being isolated from each other, the secondary circuit including a receiving unit that receives the abnormality signals corresponding to respective switching elements, transmitted from the primary side circuit; and
a logic circuit that receives the abnormality signals from the isolation elements, the logic circuit being disposed in the secondary circuit, outputting a predetermined signal indicating an occurrence of an abnormality when at least one of the switching elements shows the abnormality, wherein:
the isolation elements transmit the abnormality signals relative to a predetermined reference voltage in the secondary side circuit,
the predetermined signal outputted by the logic circuit is received by the receiving unit,
the logic circuit has a plurality of logic elements,
the plurality of logic elements includes one or more first logic elements, each of the first logic element receives an output of a corresponding isolation element, and an output of an adjacent logic element,
the first logic element includes a second logic element of which the output is received by the receiving unit,
the plurality of logic elements includes a third logic element that receives outputs of two corresponding isolation elements, and a fourth logic element that receives an output of the corresponding isolation element and an output of the second logic element,
the receiving unit serves as a control unit outputting a drive command signal that commands the drive circuits to drive the switching elements,
the isolation elements transmit the drive command signal to a corresponding drive circuit from the control unit, and
the isolation elements stop transmitting, in response to an output of a corresponding logic element, a drive command signal to a corresponding drive circuit from the control unit.

8. The signal transmission circuit according to claim 7 , wherein
each of the logic elements and the corresponding isolation element are formed in a module.

Assignees

• Denso Corp

Inventors

• Asako Yosuke
• Suzuki Tomotaka

Classifications

• H02P29/0241

  the fault being an overvoltage · CPC title

• H02P29/024

  Detecting a fault condition, e.g. short circuit, locked rotor, open circuit or loss of load · CPC title

• B60L3/003

  relating to inverters · CPC title

• B60L15/007

  Physical arrangements or structures of drive train converters specially adapted for the propulsion motors of electric vehicles · CPC title

• H03K17/61

  using transformer coupling · CPC title