Power conversion circuit having off-voltage control circuit
First Claim
1. A power conversion circuit, comprising:
- an upper arm connected to a high-voltage side;
a lower arm connected to a low-voltage side;
an upper-arm gate drive circuit configured to drive the upper arm, anda lower-arm gate drive circuit configured to drive the lower arm, whereinthe upper-arm gate drive circuit includes an upper-arm gate drive power supply and an upper-arm arm-drive circuit, and the lower-arm gate drive circuit includes a lower-arm gate drive power supply and a lower-arm arm-drive circuit,the upper-arm gate drive power supply and the lower-arm gate drive power supply supply a voltage to a control terminal of the corresponding upper or lower arm,the upper-arm arm-drive circuit and the lower-arm arm-drive circuit, receiving a control signal for controlling the corresponding upper or lower arm, output an arm drive signal according to the control signal,the lower-arm gate drive circuit further includes a signal output circuit and an off-voltage control circuit,the signal output circuit outputs a voltage adjustment signal responding to termination of turn-off operation of the lower arm and termination of turn-on operation of the upper arm,the off-voltage control circuit controls the output voltage of the lower-arm gate drive power supply, in response to the voltage adjustment signal from the signal output circuit, to generate a second voltage lower than a first voltage satisfying an off state of the lower arm during a time period from termination of turn-off operation of the lower arm until start of turn-on operation of the upper arm, and to generate the first voltage instead of the second voltage at and after termination of the turn-on operation of the upper arm.
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Accused Products
Abstract
In a power conversion circuit operating with high frequency, an off-voltage control circuit 101u of a lower-arm gate drive circuit 24u controls the output voltage of a gate drive power supply 103u to change the output voltage to a voltage lower than a predetermined off voltage during a time period from termination of turn-off operation of a lower arm 22u until start of turn-on operation of an upper arm 21u, and thereafter return the output voltage to the predetermined off voltage immediately after termination of the turn-on operation of the upper arm 21u. With this control, short-circuiting through the upper and lower arms occurring due to a high voltage change dv/dt can be avoided, and the life of a switching element constituting the power conversion circuit improves, increasing the reliability of the power conversion circuit.
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Citations
30 Claims
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1. A power conversion circuit, comprising:
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an upper arm connected to a high-voltage side; a lower arm connected to a low-voltage side; an upper-arm gate drive circuit configured to drive the upper arm, and a lower-arm gate drive circuit configured to drive the lower arm, wherein the upper-arm gate drive circuit includes an upper-arm gate drive power supply and an upper-arm arm-drive circuit, and the lower-arm gate drive circuit includes a lower-arm gate drive power supply and a lower-arm arm-drive circuit, the upper-arm gate drive power supply and the lower-arm gate drive power supply supply a voltage to a control terminal of the corresponding upper or lower arm, the upper-arm arm-drive circuit and the lower-arm arm-drive circuit, receiving a control signal for controlling the corresponding upper or lower arm, output an arm drive signal according to the control signal, the lower-arm gate drive circuit further includes a signal output circuit and an off-voltage control circuit, the signal output circuit outputs a voltage adjustment signal responding to termination of turn-off operation of the lower arm and termination of turn-on operation of the upper arm, the off-voltage control circuit controls the output voltage of the lower-arm gate drive power supply, in response to the voltage adjustment signal from the signal output circuit, to generate a second voltage lower than a first voltage satisfying an off state of the lower arm during a time period from termination of turn-off operation of the lower arm until start of turn-on operation of the upper arm, and to generate the first voltage instead of the second voltage at and after termination of the turn-on operation of the upper arm. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 27, 28)
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14. A power conversion circuit, comprising:
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an upper arm connected to a high-voltage side; a lower arm connected to a low-voltage side; an upper-arm gate drive circuit configured to drive the upper arm, and a lower-arm gate drive circuit configured to drive the lower arm, wherein the upper-arm gate drive circuit includes an upper-arm gate drive power supply and an upper-arm arm-drive circuit, and the lower-arm gate drive circuit includes a lower-arm gate drive power supply and a lower-arm arm-drive circuit, the upper-arm gate drive power supply and the lower-arm gate drive power supply supply a voltage to a control terminal of the corresponding upper or lower arm, the upper-arm arm-drive circuit and the lower-arm arm-drive circuit, receiving a control signal for controlling the corresponding upper or lower arm, output an arm drive signal according to the control signal, the upper-arm gate drive circuit further includes a signal output circuit and an off-voltage control circuit, the signal output circuit outputs a voltage adjustment signal corresponding to termination of turn-off operation of the upper arm and termination of turn-on operation of the lower arm, the off-voltage control circuit controls the output voltage of the upper-arm gate drive power supply, in response to the voltage adjustment signal from the signal output circuit, to generate a second voltage lower than a first voltage satisfying an off state of the upper arm during a time period from termination of turn-off operation of the upper arm until start of turn-on operation of the lower arm, and to generate the first voltage instead of the second voltage at and after termination of the turn-on operation of the lower arm. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26)
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29. The power conversion circuit of 14, wherein
each of the upper arm and the lower arm is constructed of a MOSFET.
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30. The power conversion circuit of 14, wherein
each of the upper arm and the lower arm is constructed of a wide bandgap semiconductor including silicon carbide or gallium nitride.
Specification