Power supply device and method for controlling power supply circuit

Patent metadata

Field	Value
Publication number	US-10008940-B2
Application number	US-201615295384-A
Country	US
Kind code	B2
Filing date	Oct 17, 2016
Priority date	Oct 29, 2015
Publication date	Jun 26, 2018
Grant date	Jun 26, 2018

Abstract

A power supply device includes: a memory; and a processor coupled to the memory and the processor configured to: determine a duty ratio of a control signal of a switching element in a power supply circuit so that an output voltage of the power supply circuit approaches a target voltage; compute an acceptable range of a duty ratio based on an output current of the power supply circuit detected by a current detecting circuit; output the duty ratio when the duty ratio is inside the acceptable range; and stop the power supply circuit when the duty ratio is outside the acceptable range.

First claim

What is claimed is:

1. A power supply device comprising:
a memory; and
a processor coupled to the memory and the processor configured to:
determine a duty ratio of a control signal of a switching element in a power supply circuit so that an output voltage of the power supply circuit approaches a target voltage;
compute an acceptable range of a duty ratio based on an output current of the power supply circuit detected by a current detecting circuit;
output the duty ratio when the duty ratio is inside the acceptable range;

stop the power supply circuit when the duty ratio is outside the acceptable range;
multiply a wiring resistance of the power supply circuit by the output current of the power supply circuit detected by the current detecting circuit;
add an output value of the multiplying to the target voltage; and
divide an output value of the adding by an input voltage of the power supply circuit.

2. The power supply device according to claim 1 , wherein
the processor is configured to compute the acceptable range of the duty ratio based on the output current of the power supply circuit detected by the current detecting circuit and an input voltage of the power supply circuit.

3. The power supply device according to claim 1 , wherein
the processor is configured to compute the acceptable range of the duty ratio based on the output current of the power supply circuit detected by the current detecting circuit, an input voltage of the power supply circuit, and the target voltage.

4. The power supply device according to claim 1 , wherein
the processor is configured to compute the acceptable range of the duty ratio based on the output current of the power supply circuit detected by the current detecting circuit, an input voltage of the power supply circuit, the target voltage, and a wiring resistance of the power supply circuit.

5. The power supply device according to claim 1 , wherein the processor is configured to
output an upper limit of the acceptable range by multiplying the output value of the dividing by a first coefficient; and
output a lower limit of the acceptable range by multiplying the output value of the dividing by a second coefficient.

6. The power supply device according to claim 1 , wherein the processor is configured to
perform low-pass filtering on the duty ratio determined by the duty ratio determining,
output the duty ratio determined by the duty ratio determining when the duty ratio is inside the acceptable range, and
stop the power supply circuit when the duty ratio is outside the acceptable range.

7. The power supply device according to claim 1 , wherein the processor is configured to
output the duty ratio determined by the duty ratio determining when a duration time while the duty ratio determined by the duty ratio determining is outside the acceptable range is shorter than a threshold, and
stop the power supply circuit when the duration time while the duty ratio determined by the duty ratio determining is outside the acceptable range is greater than the threshold.

8. A method for controlling a power supply circuit, the power supply unit having a processor and a memory coupled to the processor, the method comprising:
determining a duty ratio of a control signal of a switching element in a power supply circuit so that an output voltage of the power supply circuit approaches a target voltage;
computing an acceptable range of a duty ratio based on an output current of the power supply circuit detected by a current detecting circuit; and
outputting the determined duty ratio when the duty ratio determined by the duty ratio determining is inside the acceptable range, and stopping the power supply circuit when the determined duty ratio is outside the acceptable range;
multiplying a wiring resistance of the power supply circuit by the output current of the power supply circuit detected by the current detecting circuit;
adding an output value of the multiplying to the target voltage; and
dividing an output value of the adding by an input voltage of the power supply circuit.

9. A non-transitory computer-readable recording medium that stores therein a program that causes a computer to execute a process comprising:
determining a duty ratio of a control signal of a switching element in a power supply circuit so that an output voltage of the power supply circuit approaches a target voltage;
computing an acceptable range of a duty ratio based on an output current of the power source circuit detected by a current detecting circuit;
outputting the determined duty ratio when the determined duty ratio is inside the acceptable range, and stopping the power source circuit when the determined duty ratio is outside the acceptable range;
multiplying a wiring resistance of the power supply circuit by the output current of the power supply circuit detected by the current detecting circuit;
adding an output value of the multiplying to the target voltage; and
dividing an output value of the adding by an input voltage of the power supply circuit.

Assignees

• Fujitsu Ltd

Inventors

• Sugawara Takahiko
• Yonezawa Yu
• Nakao Hiroshi
• Nakashima Yoshiyasu

Classifications

• H02M3/33507 Primary

  with automatic control of the output voltage or current, e.g. flyback converters (H02M3/33561, H02M3/33569 take precedence) · CPC title

• H02M2001/0009

  Electricity · mapped topic

• H02M1/08

  Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters · CPC title

• H02M1/36

  Means for starting or stopping converters · CPC title

• H02M1/0009

  Devices or circuits for detecting current in a converter · CPC title