PFC converter using a predetermined value that varies in synchronization with a phase of the input voltage
AssigneeMurata Manufacturing Co., Ltd.
InventorYoshiyuki Uno
Life of this patent
Estimating the term…
Abstract
A PFC converter that prevents and reduces switching losses by controlling ripple of inductor current and enables application for high power usage, includes a switching device that is turned off when an inductor current flowing through an inductor reaches a first threshold value, and turned on when the inductor current reaches a second threshold value. A switching control circuit sets a reference value of the inductor current using results from an input voltage detection circuit and an output voltage detection circuit. The first threshold value is produced by adding a predetermined value to the reference value, and the second threshold value is produced by subtracting the predetermined value from the reference value.
Claims8
A PFC converter comprising:
- a rectifier circuit that rectifies an AC voltage supplied from an AC input power supply;
- a series circuit that includes an inductor and a switching device, the series circuit being connected in a subsequent stage of the rectifier circuit;
- a rectifying-and-smoothing circuit connected in parallel to the switching device;
- an input voltage detector that detects an input voltage supplied from the rectifier circuit;
- an inductor current detector that detects a current flowing through the inductor;
- an output voltage detector that detects an output voltage of the rectifying-and-smoothing circuit;
- and
- a switching controller arranged and programmed to control the switching device so that an average value of the inductor current defines a shape similar to that of the input voltage;
- wherein
- the switching device is turned off when the inductor current reaches a first threshold value, and turned on when the inductor current reaches a second threshold value;
- the switching controller sets a reference value of the inductor current using results from the input voltage detector and the output voltage detector;
- the first threshold value is produced by adding a predetermined value to the reference value, and the second threshold value is produced by subtracting the predetermined value from the reference value;
- and
- the predetermined value varies in synchronization with a phase of the input voltage.
A PFC converter comprising:
- a first series circuit that is connected in parallel to a load and includes a first switching device and a first rectifier device;
- an inductor connected between a first input terminal of an AC input power supply and a connecting point of the first switching device and the first rectifying device;
- a second series circuit that is connected in parallel to the load and includes a second switching device and a second rectifying device, a connecting point of the second switching device and the second rectifying device being connected to a second input terminal of the AC input power supply;
- a smoothing circuit connected in parallel to the load;
- an input voltage detector that detects an input voltage supplied from the AC input power supply;
- an output voltage detector that detects an output voltage of the smoothing circuit;
- an inductor current detector that detects a current flowing through the inductor;
- and
- a switching controller arranged and programmed to control the first and second switching devices so that an average value of the inductor current defines a shape similar to that of the input voltage;
- wherein
- the first and second switching devices are turned off when the inductor current reaches a first threshold value, and turned on when the inductor current reaches a second threshold value;
- the switching controller sets a reference value of the inductor current using results from the input voltage detector and the output voltage detector;
- the first threshold value is produced by adding a predetermined value to the reference value, and the second threshold value is produced by subtracting the predetermined value from the reference value;
- and
- the predetermined value varies in synchronization with a phase of the input voltage.
Dependencies are inferred from the claim text.