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Power supplies having protection circuits

Imported: 23 Feb '17 | Published: 22 Oct '02

Paul George Bennett

USPTO - Utility Patents

Abstract

A power supply including an inverter receiving a DC input signal from a DC input source (

11). The inverter is comprised of two half bridges (S

1A, S

2A and S

1B, S

2B). Each inverter is driven by a signal source (

13A,

13B), which outputs an AC signal. The output from each inverter is input to a first stage harmonic filter. The power supply includes an output circuit that includes first and second rectifiers (D

1, D

2) arranged about a point so that if the inverter attempts to drive the point beyond a predetermined first and second voltage, the respective rectifier conducts in order to return at least one of power and current to the DC input source. The output from the first harmonic filter (L

1A, C

1; L

1B, C

1) is output to a second harmonic filter (L

2, C

2) and is then output from the power supply.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may be performed in a number of ways and specific related inventions will now be described, by way of example, with reference to the accompanying drawings, in which;

FIGS. 1 and 2 are circuit topologies practiced in the prior art, as described above;

FIG. 3 is a power supply circuit arranged in accordance with the principles of the present invention;

FIG. 4 illustrates a related invention in which circuits are connected in series to produce a combined output;

FIG. 5 is a related invention in which circuits are connected in parallel to produce a combined power output;

FIG. 6 is a related invention in which each half of a switching bridge is protected by a single clamping diode pair;

FIG. 7 is a related invention in which is a resonant circuit and single switch provide an output and in which a single diode clamping pair protects the circuit;

FIG. 8 is a three level implementation of the circuit of FIG. 7;

FIG. 9 is a related invention showing a half bridge inverter and a protection circuit;

FIGS. 10-12 illustrate alternative configurations for switching devices, depending upon the particular switching device;

FIG. 13 is a circuit having a capacitor in parallel with one of the clamping diodes;

FIG. 14 is a circuit having a capacitor in parallel with each of the clamping diodes;

FIG. 15 is a circuit having a voltage divided across a series of capacitors and diodes;

FIG. 16 is a circuit showing an inductance and RC circuit in the protection circuit;

FIG. 17 shows a MOSFET circuit for improving operation of the filter network;

FIG. 18 is a circuit for an alternative input circuit for an inverter for addressing device capacitance;

FIG. 19 shows an inverter circuit for addressing device capacitance implemented using multiple FETs;

FIG. 20 is an improvement to the input circuit of FIG. 18;

FIG. 21 shows an inverter having an additional LC series circuit;

FIG. 22 illustrates a power supply circuit for varying the clamping voltage;

FIGS. 23-26 illustrate alternative constant voltage sink arrangements for use with the inverter of FIG.

22.

FIGS. 27

a-

27

m illustrate waveforms taken from an exemplary half bridge inverter incorporating a protection circuit;

FIGS. 28

a-

28

f illustrate comparative waveforms from an exemplary half bridge inverter not incorporating a protection circuit;

FIG. 29 is a block diagram of a control circuit for a power supply;

FIG. 30 is a block diagram for a plasma system utilizing a protection circuit.

FIG. 31 is a matching network for the control circuit of FIG.

30.

Claims

1. A power supply circuit for supplying alternating power to a load, comprising:

2. The apparatus of claim 1 wherein the first harmonic filter includes an inductor and a capacitor in series, and the first harmonic filter is placed in parallel with one of the switches of the half-bridge.

3. The apparatus of claim 1 wherein the first harmonic filter includes an inductor and a capacitor, and the inductor is placed between an output of the switches of the half-bridge and an interconnection between the first and second rectifiers, and the capacitor further comprises a combined capacitance of a pair of capacitors each in parallel with the respective first and second rectifier.

4. The apparatus of claim 1 wherein the first and second rectifiers each further comprise a pair of diodes in series, and the first harmonic filter includes an inductor and a capacitor, and the inductor is placed between an output of the switches and an interconnection between the first and second diodes, and the capacitor further comprises a combined capacitance of a plurality of capacitors, where each capacitor corresponds to one of each respective pair of diodes, each in parallel with a corresponding, respective diode.

5. The apparatus of claim 1 further comprising:

6. The apparatus of claim 5 further comprising a pair of diodes, each diode being in parallel with a respective capacitor.

7. The apparatus of claim 5 wherein the switches each further comprise a pair of switches in series, and further comprising a capacitor in parallel with each switch.

8. A power supply circuit for supplying alternating power to a load, comprising:

9. The apparatus of claim 8 further comprising a second harmonic filter at the combined output of the first harmonic filters, the second harmonic filter removing harmonic components from the filtered AC signal to generate an output signal.

10. The apparatus of claim 9 further comprising a blocking capacitor at the output of the second harmonic filter for removing DC components from the output of the second harmonic filter.

11. The apparatus of claim 9 wherein the first harmonic filter includes an inductor and a capacitor in series, and the first harmonic filter is placed in parallel with one of the switches of the half-bridge.

12. The apparatus of claim 10 wherein the second harmonic filter includes an inductor and a capacitor in series, and the second harmonic filter is placed in parallel with one of the switches of the half-bridge.

13. The apparatus of claim 9 wherein the first harmonic filter includes an inductor and a capacitor, and the inductor is placed between an output of the switches and an interconnection between the first and second rectifiers, and the capacitor further comprises a combined capacitance of a pair of capacitors each in parallel with the respective first and second rectifier.

14. The apparatus of claim 13 wherein the second harmonic filter includes an inductor and a capacitor, and the inductor is placed between an output of the switches and an interconnection between the first and second rectifiers, and the capacitor further comprises a combined capacitance of a pair of capacitors each in parallel with the respective second and second rectifier.

15. The apparatus of claim 9 further comprising:

16. The apparatus of claim 15 further comprising a pair of diodes, each diode being in parallel with a respective capacitor.

17. The apparatus of claim 8 further comprising a signal generator generating switching signal to each half of the inverter.

18. The apparatus of claim 17 wherein the signal generator varies a relative phase of operation between the first and second bridge halves.

19. The apparatus of claim 8 wherein at least one of the voltage and current is fed back into the inverter.

20. A power supply circuit for supplying alternating power to a load, comprising:

21. The apparatus of claim 20 wherein each single ended inverter comprises:

22. The apparatus of claim 21 wherein the tank circuit further comprises:

23. The apparatus of claim 21 further comprising a blocking capacitor between the switch and the first harmonic filter.

24. The apparatus of claim 20 further comprising a second harmonic filter at the combined output of the first harmonic filters, the second harmonic filter removing harmonic components from the filtered AC signal to generate an output signal.

25. The apparatus of claim 24 further comprising a blocking capacitor at the output of the second harmonic filter for removing DC components from the output of the second harmonic filter.

26. The apparatus of claim 25 wherein the first harmonic filter includes an inductor and a capacitor in series, and the first harmonic filter is placed in parallel with one of the switches of the half-bridge.

27. The apparatus of claim 26 wherein the second harmonic filter includes an inductor and a capacitor in series, and the second harmonic filter is placed in parallel with one of the switches of the half-bridge.

28. The apparatus of claim 25 wherein the first harmonic filter includes an inductor and a capacitor, and the inductor is placed between an output of the switches and an interconnection between the first and second rectifiers, and the capacitor further comprises a combined capacitance of a pair of capacitors each in parallel with the respective first and second rectifier.

29. The apparatus of claim 28 wherein the second harmonic filter includes an inductor and a capacitor, and the inductor is placed between an output of the switches and an interconnection between the second and second rectifiers, and the capacitor further comprises a combined capacitance of a pair of capacitors each in parallel with the respective second and second rectifier.

30. The apparatus of claim 20 further comprising:

31. The apparatus of claim 29 further comprising a pair of diodes, each diode being in parallel with a respective capacitor.

32. The apparatus of claim 21 further comprising a signal generator generating switching signal to each half of the inverter.

33. The apparatus of claim 32 wherein the signal generator varies a relative phase of operation between the first and second bridge halves.

34. The apparatus of claim 21 wherein the voltage and/or current is fed back into the inverter.

35. A power supply circuit for supplying alternating power to a load, comprising:

36. The apparatus of claim 35 wherein at least one single ended inverter comprises:

37. The apparatus of claim 36 wherein the tank circuit further comprises:

38. The apparatus of claim 36 wherein the local voltage rail for a first bridge half has a corresponding local voltage rail for a second bridge half, wherein the local voltage rail for a first bride half and the corresponding local voltage rail of the second bridge half are interconnected.

39. The apparatus of claim 36 further comprising a blocking capacitor between each switch and the first harmonic filter.

40. The apparatus of claim 36 further comprising a second harmonic filter at the combined output of the first harmonic filters, the second harmonic filter removing harmonic components from the filtered AC signal to generate an output signal.

41. A power supply circuit for supplying alternating power to a load, comprising:

42. The apparatus of claim 41 wherein the at least one rectifier is a Zener diode.

43. The apparatus of claim 41 wherein the at least one rectifier comprises a pair of Zener diodes arranged back to back, and the breakdown voltages of each Zener diode determines the predetermined first and second voltages.

44. The apparatus of claim 42 further comprising a second harmonic filter at the output of the first harmonic filter, the second harmonic filter removing harmonic components from the filtered AC signal to generate an output signal.

45. The apparatus of claim 43 wherein the at least one Zener diode is inserted between a common voltage reference and the output of the first harmonic filter.

46. The apparatus of claim 42 wherein the at least one rectifier actuates a switch to enable the switch to conduct current and dissipate power.

47. The apparatus of claim 42 wherein the at least one rectifier interconnects two halves of a diode bridge.

48. A control system for a power generator, comprising:

49. The apparatus of claim 47 wherein the power amplifier comprises a plurality of power amplifiers arranged in parallel and the apparatus further comprises a combiner for combining the output signal of each of the plurality of inverters.

50. A plasma control system comprising:

51. The apparatus of claim 50 wherein the power supply further comprises:

52. The apparatus of claim 50 wherein the power supply further comprises:

53. A power supply circuit for supplying alternating power to a load, comprising:

54. The apparatus of claim 53 wherein the output circuit further comprises a harmonic filter.

55. The apparatus of claim 53 wherein the output circuit further comprises a harmonic filter including an inductor and a capacitor.

56. The apparatus of claim 53 wherein the return circuit comprises first and second rectifiers.

57. The apparatus of claim 53 wherein the inverter comprises a half bridge inverter.

58. The apparatus of claim 53 wherein the inverter comprises a full bridge inverter having two halves, and the halves are placed in one of series and parallel with the load.

59. The apparatus of claim 53 wherein the return circuit returns at least one of voltage and current to return to the inverter.

60. A power supply circuit for supplying alternating power to a load, comprising:

61. The apparatus of claim 60 the dissipation circuit comprises at least one Zener diode.

62. The apparatus of claim 60 wherein the dissipation circuit comprises a pair of Zener diodes arranged back to back, and the breakdown voltages of each Zener diode determines the predetermined first and second voltages.