POWER CONVERSION DEVICE AND IN-VEHICLE POWER SUPPLY DEVICE EQUIPPED WITH SAME
First Claim
1. A power conversion device comprising:
- a DC/DC converter that includes;
an inverter unit having two serial semiconductor switching elements, for converting a DC power to an AC power;
a rectifier circuit for rectifying an AC output from the inverter unit; and
a smoothing circuit for smoothing a rectified voltage to output a DC power to a load; and
a control circuit for controlling the inverter unit,wherein the inverter unit includes capacitors connected respectively in parallel to the semiconductor switching elements, and an inductor, connected to a line of the AC output, which is made variable in its inductance according to a circuit current flowing through the DC/DC converter, so that the inductance decreases as the circuit current increases, andwherein the control circuit changes a dead time, which is a time period where both of said two serial semiconductor switching elements are made OFF, according to the circuit current,so as to cause the respective semiconductor switching elements to perform zero-voltage switching; and
at least in the range of the circuit current being equal to or less than a predetermined value, the control circuit controls the inverter unit using a PFM control.
1 Assignment
0 Petitions
Accused Products
Abstract
In a DC/DC converter that performs zero-voltage switching, capacitors are connected respectively in parallel to first and second MOSFETs that are included in an inverter unit in the primary-side of a transformer, and an inductor is connected to an AC output line. In a range of a current being more than a predetermined value, a control circuit controls the inverter unit using a PWM control with a fixed dead time, and in a light load range where the current is equal to or less than the predetermined value, the control unit changes the control to a PFM control and decreases a frequency so that the dead time becomes longer as the current decreases, to thereby keep a duty ratio without change.
16 Citations
21 Claims
-
1. A power conversion device comprising:
-
a DC/DC converter that includes;
an inverter unit having two serial semiconductor switching elements, for converting a DC power to an AC power;
a rectifier circuit for rectifying an AC output from the inverter unit; and
a smoothing circuit for smoothing a rectified voltage to output a DC power to a load; anda control circuit for controlling the inverter unit, wherein the inverter unit includes capacitors connected respectively in parallel to the semiconductor switching elements, and an inductor, connected to a line of the AC output, which is made variable in its inductance according to a circuit current flowing through the DC/DC converter, so that the inductance decreases as the circuit current increases, and wherein the control circuit changes a dead time, which is a time period where both of said two serial semiconductor switching elements are made OFF, according to the circuit current, so as to cause the respective semiconductor switching elements to perform zero-voltage switching; and
at least in the range of the circuit current being equal to or less than a predetermined value, the control circuit controls the inverter unit using a PFM control. - View Dependent Claims (2, 3, 4, 5, 6, 9, 10, 11)
-
-
7. A power conversion device, comprising:
-
a DC/DC converter that includes;
an inverter unit having two serial semiconductor switching elements, for converting a DC power to an AC power;
a rectifier circuit for rectifying an AC output from the inverter unit; and
a smoothing circuit for smoothing a rectified voltage to output a DC power to a load; anda control circuit for controlling the inverter unit, wherein the inverter unit includes capacitors connected respectively in parallel to the semiconductor switching elements, and an inductor connected to a line of the AC output, and wherein the control circuit changes a dead time, which is a time period where both of said two serial semiconductor switching elements are made OFF, according to a circuit current flowing through the DC/DC converter, so as to cause the respective semiconductor switching elements to perform zero-voltage switching;
at least in the range of the circuit current being equal to or less than a predetermined value, the control circuit controls the inverter unit using a PFM control; anda voltage between both ends of one of said two serial semiconductor switching elements is detected, and the control circuit adjusts switching of said two serial semiconductor switching elements according to the voltage detected. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21)
-
-
8. (canceled)
-
12. An in-vehicle power supply device which includes
a power conversion device and a battery for driving a motor for running, said power conversion device comprising: -
a DC/DC converter that includes;
an inverter unit having two serial semiconductor switching elements, for converting a DC power to an AC power;
a rectifier circuit for rectifying an AC output from the inverter unit; and
a smoothing circuit for smoothing a rectified voltage to output a DC power to a load; anda control circuit for controlling the inverter unit, wherein the inverter unit includes capacitors connected respectively in parallel to the semiconductor switching elements, and an inductor, connected to a line of the AC output, which is made variable in its inductance according to a circuit current flowing through the DC/DC converter, so that the inductance decreases as the circuit current increases, and the DC power is input to the inverter unit from the battery, wherein the control circuit changes a dead time, which is a time period where both of said two serial semiconductor switching elements are made OFF, according to the circuit current, so as to cause the respective semiconductor switching elements to perform zero-voltage switching; and
in the range of the circuit current being equal to or less than a predetermined value, the control circuit controls the inverter unit using a PFM control.
-
-
13. An in-vehicle power supply device which includes
a power conversion device and a battery for driving a motor for running, said power conversion device comprising: -
a DC/DC converter that includes;
an inverter unit having two serial semiconductor switching elements, for converting a DC power to an AC power;
a rectifier circuit for rectifying an AC output from the inverter unit; and
a smoothing circuit for smoothing a rectified voltage to output a DC power to a load; anda control circuit for controlling the inverter unit, wherein the inverter unit includes capacitors connected respectively in parallel to the semiconductor switching elements, and an inductor connected to a line of the AC output, and the DC power is input to the inverter unit from the battery, wherein the control circuit changes a dead time, which is a time period where both of said two serial semiconductor switching elements are made OFF, according to a circuit current flowing through the DC/DC converter, so as to cause the respective semiconductor switching elements to perform zero-voltage switching;
in the range of the circuit current being equal to or less than a predetermined value, the control circuit controls the inverter unit using a PFM control; and
a voltage between both ends of one of said two serial semiconductor switching elements is detected, and the control circuit adjusts switching of said two serial semiconductor switching elements according to the voltage detected.
-
Specification