Electronic apparatus and control method for high frequency AC to DC conversion

• US 9,312,750 B2
• Filed: 01/22/2014
• Issued: 04/12/2016
• Est. Priority Date: 01/22/2014
• Status: Active Grant

• Current Assignee: University of Hong Kong (Government of Hong Kong Special Administrative Region)
• Original Assignee: University of Hong Kong (Government of Hong Kong Special Administrative Region)
• Inventors: Kwan, Lee Chi, Kiratipongvoot, Sitthisak
• Primary Examiner(s): BERHANE, ADOLF D
• Application Number:
  US14/160,830
• Publication Number:
  US 20150207402A1
• Time in Patent Office: 811 Days
• Field of Search: 363 44- 48, 363/84, 363125-127
• US Class Current: 1/1
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02M 1/4241 using a resonant converter
• CPC Class Codes: H02M 1/4266 using passive elements
• CPC Class Codes: H02M 7/066 particular circuits having a special characteristic
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

A high-frequency ac-dc power converter takes an input ac signal and converts it to an output dc signal. The converter has at least two front-end rectifier diodes arranged as a full wave rectifier of the input ac signal. A first inductor positioned at the output of the full wave rectifier. An output capacitor is connected across a load for the converter. There are at least one additional inductor and one additional capacitor. A switching circuit selectively forms different (LC) resonant circuits with the inductors and capacitors during a cycle of the input ac signal to form a dc-dc power converter.

Claims

1. A high-frequency ac-dc power converter with an input ac signal and an output dc signal, comprising:

at least two front-end rectifier diodes arranged as a full wave rectifier of the input ac signal,

a first inductor with an input connected to the output of the full wave rectifier and an output connected to one end of a load for the converter,

an output capacitor connected across the load for the converter,

at least one additional inductor and one additional capacitor have one end connected to the junction between the first inductor and the load,

a switching circuit connected to the other ends of the additional inductor and capacitor for selectively forming different (LC) resonant circuits with the inductors and capacitors during predetermined parts of a cycle of the input ac signal to form a ac-dc power converter.

2. A high-frequency ac-dc power converter according to claim 1 wherein the LC resonant circuits are tuned to the frequency of the input voltage.

3. A high-frequency ac-dc power converter according to claim 1 wherein the capacitors of the LC resonant circuits are constructed by a switched capacitor bank and the resonant frequency is changed by controlling the switches of the capacitor bank.

4. A switched capacitor bank according to claim 3 wherein the value of the capacitors is arranged in a binary-weighted structure.

5. A high-frequency ac-dc power converter according to claim 1 wherein a switch S1 is turned on for the positive half cycle of the input ac signal and a switch S2 is turned on for the negative half-cycle thereof.

6. A high-frequency ac-dc power converter according to claim 1 wherein the connection of the LC resonant circuits and the dc-dc power converter is achieved by the control of a switch S4 for the positive half cycle of the input ac signal and a switch S3 for the negative half cycle thereof.

7. A high-frequency ac-dc converter 1 with an input ac signal and an output dc signal, comprising:

at least two front-end rectifier diodes arranged as a full wave rectifier of the input ac signal,

a first inductor with an input connected to the output of the full wave rectifier and an output connected to one end of a load for the converter,

an output capacitor connected across the load for the converter,

at least one additional inductor and one additional capacitor,

a switching circuit for selectively forming different (LC) resonant circuits with the inductors and capacitors during predetermined parts of a cycle of the input ac signal to form a ac-dc power converter; and

wherein the switching circuit comprises switches and a control for controlling the opening and closing of the switches, said control including a phase detector that detects the phase of the input ac signal, a PWM generator that drives the switching based on the phase of the input ac signal, and an output feedback loop with a compensator whose input is the difference between the output voltage and a reference, said compensator affecting the PWM generator operation.

8. A high-frequency ac-dc converter with an input ac signal and an output dc signal, comprising:

at least two front-end rectifier diodes arranged as a full wave rectifier of the input ac signal, a first inductor with an input connected to the output of the full wave rectifier and an output connected to one end of a load for the converter, an output capacitor connected across the load for the converter, at least one additional inductor and one additional capacitor, a switching circuit for selectively forming different (LC) resonant circuits with the inductors and capacitors during predetermined parts of a cycle of the input ac signal to form a ac-dc power converter; and

wherein the switching circuit comprises switches and a control for controlling the opening and closing of the switches, said control including a phase detector that detects the phase of the input ac signal, a PWM generator that drives the switching based on the phase of the input ac signal, and an output feedback loop with a compensator whose input is the difference between the output voltage and a reference, said compensator affecting the PWM generator operation.

9. A high-frequency ac-dc power converter with an input ac signal and an output dc signal, comprising:

at least two front-end rectifier diodes arranged as a full wave rectifier of the input ac signal,

a first inductor with an input connected to the output of the full wave rectifier and an output connected to one end of a load for the converter,

an output capacitor connected across the load for the converter,

at least one additional inductor and one additional capacitor,

a third diode connected in series with the at least one additional inductor across the load,

a switching circuit for selectively forming different (LC) resonant circuits with the inductors and capacitors during predetermined parts of a cycle of the input ac signal to form a ac-dc power converter

wherein the at least one additional capacitor is first and second capacitors with ends connected together and to the output of the first inductor, the other end of the first capacitor being connected through a switch S1 of the switching circuit to a negative terminal for the input ac signal and the other end of the second capacitor being connected through a switch S2 of the switching circuit to a positive terminal for the input ac signal,

wherein a switch S3 of the switching circuit is connected from the additional inductor where it connects to the third diode to the first capacitor where it connects to the switch S1 and a switch S4 of the switching circuit is connected from the additional inductor where it connects to the third diode to the second capacitor where it connects to the switch S2, and

wherein the switching circuit operates to close switches S1 and S4 and opens switches S2 and S3 during most of the positive cycle of the input ac signal, further opens switch S4 during the remaining portion of the positive cycle, closes switches S2 and S3 and opens switches S1 and S4 during most of the negative cycle of the input ac signal and further opens switch S3 during the remainder of the negative cycle of the input ac signal.

10. A high-frequency ac-dc power converter according to claim 9 wherein the opening and closing of switches is achieved with the use of a phase detector that detects the phase of the input ac signal, a PWM generator that drives the switching based on the phase of the input ac signal, and an output feedback loop with a compensator whose input is the difference between the output voltage and a reference, said compensator affecting the PWM generator operation.