Rectifier bridge circuit, corresponding apparatus and method

Patent metadata

Field	Value
Publication number	US-9979298-B2
Application number	US-201615157711-A
Country	US
Kind code	B2
Filing date	May 18, 2016
Priority date	Oct 15, 2015
Publication date	May 22, 2018
Grant date	May 22, 2018

Abstract

A rectifier bridge circuit includes a first SCR/IGBT switch and a second SCR/IGBT switch coupled to a circuit input to receive an ac input voltage. The first and second SCR/IGBT switches are alternatively switchable to generate a rectified voltage at a circuit output. Control currents coupled to control terminals of the first and second SCR/IGBT switches are power supply sourced from an auxiliary dc source generated by rectifying the ac input voltage. The control currents are generated by current sources coupled between the auxiliary dc source and the control terminals of the first and second SCR/IGBT switches. The current sources are selectively activatable to produce gating currents for switching on and off the first and second SCR/IGBT switches. A controller unit is provided to control the current sources via level shifter circuits. The control implements progressive conduction time of the first and second SCR/IGBT switches so as to provide inrush current limitation.

First claim

The invention claimed is:

1. A rectifier bridge circuit, comprising:
a first electronic switch having a control terminal,
a second electronic switch having a control terminal,
wherein the first and second electronic switches are coupled to a circuit input configured to receive an ac input voltage, said first and second electronic switches being alternatively switchable on and off to provide a rectified voltage at a circuit output, and
an auxiliary dc source circuit configured to provide a first control current from an auxiliary supply node to the control terminal of the first electronic switch and provide a second control current from said auxiliary supply node to the control terminal of the second electronic switch, said auxiliary dc source circuit comprising a capacitor having a first terminal directly connected to said auxiliary supply node and a second terminal directly connected to a ground node.

2. The rectifier bridge circuit of claim 1 , wherein the auxiliary supply node is connected to the circuit input via at least one diode operating to charge said capacitor by said ac input voltage.

3. The rectifier bridge circuit of claim 2 , wherein the auxiliary supply node is connected to the circuit input via a pair of diodes, said pair of diodes being components of a full-wave rectifier bridge coupled between the circuit input and anode terminals of the first and second electronic switches.

4. The rectifier bridge circuit of claim 1 , further including first and second current sources implemented as emitter-degenerated bipolar transistors, the first and second current sources coupled between the auxiliary supply node and the respective control terminals of the first and second electronic switches, wherein said first and second current sources are selectively activatable to produce a gating current for switching on and off the first and second electronic switches.

5. The rectifier bridge circuit of claim 4 , further including a controller circuit configured to selectively activate said first and second current sources, the controller circuit configured to progressively increase conduction times during which the first and second electronic switches are switched on thereby providing inrush current limitation.

6. The rectifier bridge circuit of claim 5 , further including first and second level shifters coupled between the auxiliary dc source circuit and the first and second current sources, respectively, wherein the first and second electronic switches are biased from the auxiliary dc source circuit.

7. The rectifier bridge circuit of claim 6 , wherein the first and second level shifters are configured to be driven by the controller circuit.

8. The rectifier bridge circuit of claim 1 , further including:
a power factor control circuit coupled to provide a power factor controlled voltage over a power factor controlled line,
a diode coupled between the power factor controlled line and the auxiliary supply node to transfer the power factor controlled voltage to said capacitor at the auxiliary supply node.

9. The rectifier bridge circuit of claim 1 , wherein the first and second electronic switches each comprise SCRs.

10. The rectifier bridge circuit of claim 1 , wherein the first and second electronic switches each comprise IGBTs.

11. A circuit, comprising:
a pair of ac input nodes;
a first SCR switch having an anode coupled to a first node of the pair of ac input nodes and a cathode coupled to a first output node;
a second SCR switch having an anode coupled to a second node of the pair of ac input nodes and a cathode coupled to the first output node;
a first current source generating a first current applied to a control node of the first SCR switch to turn on the first SCR switch;
a second current source generating a second current applied to a control node of the second SCR switch to turn on the second SCR switch;
wherein the first and second current sources are supplied power from a dc power supply node;
an auxiliary dc source circuit input from the pair of ac input nodes and configured to generate a dc supply voltage at said dc power supply node, wherein said auxiliary dc source circuit comprises a first diode coupled between the first node of the pair of ac input nodes and said dc power supply node and a second diode coupled between the second node of the pair of ac input nodes and said dc power supply node;
a first transistor having a source-drain path between the anode of the first SCR switch and a second output node;
a second transistor having a source-drain path between the anode of the second SCR switch and the second output node; and
a control circuit configured to generate first and second control signals for controlling actuation of the first and second current sources and further configured to generate third and fourth control signals for controlling actuation of the first and second transistors.

12. The circuit of claim 11 , wherein said first and second diodes are components of a rectifier bridge circuit which includes a third diode coupled between the anode of the first SCR switch and a second output node and a fourth diode coupled between the anode of the second SCR switch and the second output node.

13. The circuit of claim 11 , further comprising a control circuit configured to generate first and second control signals for controlling actuation of the first and second current sources so as to implement a progressive increase in conduction times during which the first and second SCR switches are turned on to provide inrush current limitation.

14. The circuit of claim 11 , further comprising a diode having an anode coupled to the output node and a cathode coupled to the dc power supply node.

15. The circuit of claim 11 , further comprising a power factor correction circuit coupled between the cathodes of the first and second SCR switches and the first output node.

16. The circuit of claim 11 , further comprising a transformer having a primary winding coupled in series with a switching circuit to the first output node, wherein a secondary winding of the transformer is configured to supply a load circuit.

17. A rectifier bridge circuit, comprising:
a first electronic switch having a control terminal,
a second electronic switch having a control terminal,
wherein the first and second electronic switches are coupled to a circuit input configured to receive an ac input voltage, said first and second electronic switches being alternatively switchable on and off to provide a rectified voltage at a circuit output,
an auxiliary dc source circuit comprising:
a first current source implemented as an emitter-degenerated bipolar transistor configured to provide a first control current to the control terminal of the first electronic switch; and
a second current source implemented as an emitter-degenerated bipolar transistor configured to provide a second control current to the control terminal of the second electronic switch,
wherein said first and second current sources are selectively activatable to produce a gating current for switching on and off the first and second electronic switches.

18. The rectifier bridge circuit of claim 17 , wherein the auxiliary dc source circuit further includes a capacitor coupled to the circuit input via at least one diode to be charged by said ac input voltage.

19. The rectifier bridge circuit of claim 18 , wherein the capacitor of the auxiliary dc source circuit is coupled to the circuit input via a pair of diodes, said pair of diodes being components of a full-wave rectifier bridge

Assignees

• St Microelectronics Srl
• St Microelectronics Tours Sas

Inventors

• Larosa Roberto
• Zoppi Giulio
• Gonthier Laurent

Classifications

• H02M1/36

  Means for starting or stopping converters · CPC title

• H02M7/125

  Avoiding or suppressing excessive transient voltages or currents · CPC title

• H02M7/062

  Avoiding or suppressing excessive transient voltages or currents · CPC title

• H02M1/081 Primary

  wherein the phase of the control voltage is adjustable with reference to the AC source · CPC title

• H02M1/08

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