Choke and EMI filter circuits for power factor correction circuits

• US 10,075,065 B2
• Filed: 04/13/2017
• Issued: 09/11/2018
• Est. Priority Date: 04/15/2016
• Status: Active Grant

• Current Assignee: Copeland Corporation LLC (Emerson Electric Company)
• Original Assignee: Emerson Climate Technologies Incorporated (Emerson Electric Company)
• Inventors: Marcinkiewicz, Joseph G., Bockhorst, Kraig
• Primary Examiner(s): Leja, Ronald W
• Application Number:
  US15/487,201
• Publication Number:
  US 20170302165A1
• Time in Patent Office: 516 Days
• Field of Search: 361 18
• CPC Class Codes: H02M 1/32 Means for protecting converters other than automatic disconnection
• CPC Class Codes: H02M 1/4208 Arrangements for improving power factor of AC input
• CPC Class Codes: H02M 1/4216 operating from a three-phase input voltage H02M1/4233 takes precedence
• CPC Class Codes: H02M 1/44 Circuits or arrangements for compensating for electromagnetic interference in converters or inverters
• CPC Class Codes: H02M 7/06 using discharge tubes without control electrode or semiconductor devices without control electrode
• 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 converter circuit is provided and includes: a first EMI filter connected to AC lines and includes one or more across-the-line capacitors; a charging circuit that receives power from the first EMI filter and limits an amount of current passing from the first EMI filter to a DC bus; and a PFC circuit of a compressor drive that provides PFC between an output of the charging circuit and a generated first DC voltage. The PFC circuit includes: a rectification circuit that rectifies the power from the AC lines or a charging circuit output; and a second EMI filter connected downstream from the rectification circuit and including a DC bus rated capacitor. The second EMI filter outputs a filtered DC signal based on a rectification circuit output. The PFC circuit, based on the second EMI filter output, outputs the first DC voltage to the DC bus to power the compressor drive.

Claims

1. A converter circuit comprising:

a first electromagnetic interference filter connected to alternating current (AC) lines and comprising one or more across-the-line capacitors, wherein the first electromagnetic interference filter comprises an across-the-line capacitor for each phase of an AC input signal;

a charging circuit configured to (i) receive power from the first electromagnetic interference filter, and (ii) limit an amount of current passing from the first electromagnetic interference filter to a direct current (DC) bus; and

a power factor correction circuit of a compressor drive, wherein the power factor correction circuit is configured to provide power factor correction between an output of the charging circuit and a generated first DC voltage, wherein the power factor correction circuit comprises

a rectification circuit configured to rectify the power from the AC lines or the output of the charging circuit depending on whether the rectification circuit is upstream or downstream from the charging circuit, and

a second electromagnetic interference filter connected downstream from the rectification circuit and comprising only a single DC bus rated capacitor, wherein the second electromagnetic interference filter is configured to output a filtered DC signal based on an output of the rectification circuit, a capacitance of each of the one or more across-the-line capacitors of the first electromagnetic interference filter is related to a capacitance of the single DC bus rated capacitor of the second electromagnetic interference filter, such that inclusion of the DC bus rated capacitor allows capacitances of each of the one or more across-the-line capacitors to be reduced while not reducing a level of electromagnetic interference filtering, and

wherein the power factor correction circuit is configured to, based on the output of the second electromagnetic interference filter, output the first DC voltage to the DC bus to power the compressor drive.

2. The converter circuit of claim 1, wherein the second electromagnetic interference filter comprises a plurality of DC bus rated capacitors connected in parallel.

3. The converter circuit of claim 1, further comprising a grounded electromagnetic interference filter comprising line-to-ground capacitors, wherein the grounded electromagnetic interference filter is connected upstream or downstream from the rectification circuit.

4. The converter circuit of claim 3, wherein the power factor correction circuit comprises the grounded electromagnetic interference filter.

5. The converter circuit of claim 1, further comprising a first protection circuit configured to provide surge protection, wherein the protection circuit is connected upstream or downstream from the rectification circuit and comprises at least one of a varistor or a gas discharge tube.

6. The converter circuit of claim 5, wherein the protection circuit is upstream from the rectification circuit to protect the rectification circuit from peak inverse voltage (PIV).

7. The converter circuit of claim 5, wherein:

the power factor correction circuit comprises the first protection circuit; and

the first protection circuit provides surge protection.

8. The converter circuit of claim 7, further comprising a second protection circuit connected upstream from the charging circuit, wherein the second protection circuit comprises surge protection.

9. The converter circuit of claim 8, wherein the second protection circuit is connected downstream from the first protection circuit.

10. The converter circuit of claim 1, further comprising a common mode choke, wherein the common mode choke is connected upstream or downstream from the rectification circuit.

11. The converter circuit of claim 10, wherein the power factor correction circuit comprises the common mode choke.

12. The converter circuit of claim 11, wherein the power factor correction circuit is connected downstream from the charging circuit.

13. The converter circuit of claim 1, wherein the converter circuit is void of a line-to-ground capacitor upstream from the rectification circuit.

14. The converter circuit of claim 1, wherein the rectification circuit comprises:

a first bridge rectifier configured to receive an AC voltage; and

a second bridge rectifier (i) receives the AC voltage, and (ii) bypasses at least one of the first bridge rectifier, a choke, and a diode of the power factor correction circuit to provide a rectified AC voltage out of the second bridge rectifier to the DC bus.

15. The converter circuit of claim 14, wherein the first bridge rectifier and the second bridge rectifier are each 3-phase bridge rectifiers.

16. The converter circuit of claim 14, wherein the power factor correction circuit comprises:

a power converter comprising a switch and configured to (i) receive an output of the first bridge rectifier, (ii) convert the output of the first bridge rectifier to a second DC voltage, and (iii) supply the second DC voltage to the DC bus; and

a control module configured to control operation of a driver to transition the switch between an open state and a closed state to adjust the first DC voltage on the DC bus, wherein the first DC voltage, depending on the AC voltage and the first DC voltage, is based on at least one of (i) the rectified AC voltage, and (ii) the second DC voltage.

17. The converter circuit of claim 1, further comprising a switched bridge circuit, wherein:

the rectification circuit comprises a bridge rectifier configured to receive an AC voltage;

the switched bridge circuit comprising a plurality of switches;

a driver generating control signals to control states of the plurality of switches; and

a control module configured to control operation of the driver.

18. The converter circuit of claim 17, wherein:

the switched bridge circuit comprises a plurality of diodes;

the plurality of switches include pairs of switches, wherein each of the pairs of switches include two switches connected in series, wherein the pairs of switches are connected in parallel between the DC bus and a reference terminal; and

each of the plurality of diodes is connected across a respective one of the plurality of switches.

19. The converter circuit of claim 1, further comprising a protection circuit configured to provide surge protection, wherein the protection circuit is connected downstream from the rectification circuit and comprises at least one of a varistor or a gas discharge tube.

20. The converter circuit of claim 1, wherein the converter circuit is void of an line-to-ground capacitor upstream of the rectification circuit.

21. A converter circuit comprising:

a first electromagnetic interference filter connected to alternating current (AC) lines and comprising one or more across-the-line capacitors;

a charging circuit configured to (i) receive power from the first electromagnetic interference filter, and (ii) limit an amount of current passing from the first electromagnetic interference filter to a direct current (DC) bus;

a power factor correction circuit of a compressor drive, wherein the power factor correction circuit is configured to provide power factor correction between an output of the charging circuit and a generated first DC voltage, wherein the power factor correction circuit comprises

a rectification circuit configured to rectify the power from the AC lines or the output of the charging circuit depending on whether the rectification circuit is upstream or downstream from the charging circuit, and

a second electromagnetic interference filter connected downstream from the rectification circuit and comprising one or more DC bus rated capacitors, wherein the second electromagnetic interference filter is configured to output a filtered DC signal based on an output of the rectification circuit, and

wherein the power factor correction circuit is configured to, based on the output of the second electromagnetic interference filter, output the first DC voltage to the DC bus to power the compressor drive; and

a third electromagnetic interference filter connected downstream from the first electromagnetic interference filter and comprising one or more across-the-line capacitors, wherein a capacitance of each of the one or more DC bus rated capacitors is greater than a capacitance of each of the one or more across-the-line capacitors of the third electromagnetic interference filter.

22. The converter circuit of claim 21, wherein a capacitance of each of the one or more DC bus rated capacitors is an order of magnitude greater than a capacitance of each of the one or more across-the-line capacitors of the third electromagnetic interference filter.

23. A converter circuit comprising:

a charging circuit configured to (i) receive power based on power from alternating current (AC) lines, and (ii) limit an amount of current passing to a direct current (DC) bus; and

a power factor correction circuit of a compressor drive, wherein the power factor correction circuit is configured to provide power factor correction between an output of the charging circuit and a generated first DC voltage, wherein the power factor correction circuit comprises

a rectification circuit configured to rectify the power from the AC lines or an output of the charging circuit depending on whether the rectification circuit is upstream or downstream from the charging circuit, and

a first electromagnetic interference filter comprising one or more DC bus rated capacitors, wherein the first electromagnetic interference filter is configured to output a filtered DC signal based on an output of the rectification circuit,

wherein the capacitance of each of the one or more DC bus rated capacitances is less than or equal to the capacitance of each across-the-line capacitor connected upstream from the charging circuit or the rectification circuit, and

wherein the power factor correction circuit is configured to, based on an output of the first electromagnetic interference filter, output the first DC voltage to the DC bus to power the compressor drive.

24. The converter circuit of claim 23, further comprising a first protection circuit configured to provide surge protection, wherein:

the charging circuit is configured to (i) receive the AC power based on an output of the first protection circuit; and

the first protection circuit comprises at least one of a varistor and a gas discharge tube.

25. The converter circuit of claim 24, further comprising a second protection circuit, (i) upstream from the rectification circuit, or (ii) included in the power factor correction circuit and downstream from the rectification circuit.

26. The converter circuit of claim 25, wherein the second protection circuit is connected downstream from the first protection circuit.

27. The converter circuit of claim 23, further comprising a first protection circuit configured to provide surge protection, wherein:

the charging circuit is configured to receive DC power from the rectification circuit;

the first protection circuit is upstream from the rectification circuit, connected between the rectification circuit and the charging circuit, or downstream from the charging circuit; and

the first protection circuit comprises at least one of a varistor and a gas discharge tube.

28. The converter circuit of claim 23, wherein the converter circuit is void of an across-the-line capacitor upstream from the power factor correction circuit.

29. The converter circuit of claim 23, wherein the converter circuit is void of a line-to-ground capacitor upstream from the power factor correction circuit.

30. The converter circuit of claim 23, further comprising a second electromagnetic interference filter connected upstream from the charging circuit.

31. The converter circuit of claim 23, wherein the rectification circuit comprises:

a first bridge rectifier configured to receive an AC voltage; and

a second bridge rectifier (i) receives the AC voltage, and (ii) bypasses at least one of the first bridge rectifier, a choke, and a diode of the power factor correction circuit to provide a rectified AC voltage out of the second bridge rectifier to the DC bus.

32. The converter circuit of claim 31, wherein the power factor correction circuit comprises:

a power converter comprising a switch and configured to (i) receive an output of the first bridge rectifier, (ii) convert the output of the first bridge rectifier to a second DC voltage, and (iii) supply the second DC voltage to the DC bus; and

a control module configured to control operation of a driver to transition the switch between an open state and a closed state to adjust the first DC voltage on the DC bus, wherein the first DC voltage, depending on the AC voltage and the first DC voltage, is based on at least one of (i) the rectified AC voltage, and (ii) the second DC voltage.

33. The converter circuit of claim 23, further comprising a common mode choke, wherein the common mode choke is connected upstream or downstream from the rectification circuit.

34. The converter circuit of claim 23, wherein the charging circuit is configured to (i) during a power up, increase resistance between the first electromagnetic interference filter and the power factor correction circuit from a first resistance to a second resistance, and (ii) subsequent to the power up, decrease the resistance between the first electromagnetic interference filter and the power factor correction circuit from the second resistance to the first resistance.

35. A converter circuit comprising:

a charging circuit configured to (i) receive power based on power from alternating current (AC) lines, and (ii) limit an amount of current passing to a direct current (DC) bus;

a power factor correction circuit of a compressor drive, wherein the power factor correction circuit is configured to provide power factor correction between an output of the charging circuit and a generated first DC voltage, wherein the power factor correction circuit comprises

a rectification circuit configured to rectify the power from the AC lines or an output of the charging circuit depending on whether the rectification circuit is upstream or downstream from the charging circuit, and

a first electromagnetic interference filter comprising one or more DC bus rated capacitors, wherein the first electromagnetic interference filter is configured to output a filtered DC signal based on an output of the rectification circuit; and

a second electromagnetic interference filter connected upstream from the charging circuit, wherein the second electromagnetic interference filter comprises at least one of an across-the-line capacitor, wherein the second electromagnetic interference filter is upstream from the charging circuit and downstream from the first electromagnetic interference filter,

wherein the converter circuit is void of an across-the-line capacitor downstream from the second electromagnetic interference filter and upstream from the rectification circuit, and

wherein the power factor correction circuit is configured to, based on an output of the first electromagnetic interference filter, output the first DC voltage to the DC bus to power the compressor drive.

36. A converter circuit comprising:

a charging circuit configured to (i) receive power based on power from alternating current (AC) lines, and (ii) limit an amount of current passing to a direct current (DC) bus; and

a power factor correction circuit of a compressor drive, wherein the power factor correction circuit is configured to provide power factor correction between an output of the charging circuit and a generated DC voltage, wherein the power factor correction circuit comprises

a rectification circuit configured to rectify the power from the AC lines or an output of the charging circuit depending on whether the rectification circuit is upstream or downstream from the charging circuit,

at least one of

a common mode choke, or

a grounded electromagnetic interference filter,

wherein the common mode choke or the grounded electromagnetic interference filter is configured to, based on an output of the rectification circuit, output the DC voltage for the DC bus to power the compressor drive; and

a first electromagnetic interference filter comprising one or more DC bus rated capacitors, wherein the first electromagnetic interference filter is configured to output a filtered DC signal based on an output of the rectification circuit,

wherein the power factor correction circuit is configured to, based on the output of the first electromagnetic interference filter, output the DC voltage to the DC bus to power the compressor drive, and

wherein at least one of (i) the converter circuit is void of an across-the-line capacitor upstream from the power factor correction circuit, or (ii) capacitance of each of the one or more DC bus rated capacitances is less than or equal to a capacitance of each across-the-line capacitor connected upstream from the charging circuit or the rectification circuit.

37. The converter circuit of claim 36, wherein the converter circuit is void of across-the-line capacitors.

38. The converter circuit of claim 36, further comprising a first protection circuit connected upstream from the charging circuit and configured to receive the AC power and provide surge protection.

39. The converter circuit of claim 38, wherein the first protection circuit comprises a metal oxide varistor.

40. The converter circuit of claim 36, wherein the charging circuit is configured to (i) during a power up, increase resistance between the first electromagnetic interference filter and the power factor correction circuit from a first resistance to a second resistance, and (ii) subsequent to the power up, decrease the resistance between the first electromagnetic interference filter and the power factor correction circuit from the second resistance to the first resistance.

41. A converter circuit comprising:

a charging circuit configured to (i) receive power based on power from alternating current (AC) lines, and (ii) limit an amount of current passing to a direct current (DC) bus; and

a power factor correction circuit of a compressor drive, wherein the power factor correction circuit is configured to provide power factor correction between an output of the charging circuit and a generated first DC voltage, wherein the power factor correction circuit comprises

a rectification circuit configured to rectify the power from the AC lines or an output of the charging circuit depending on whether the rectification circuit is upstream or downstream from the charging circuit, and

a first electromagnetic interference filter comprising one or more DC bus rated capacitors, wherein the first electromagnetic interference filter is configured to output a filtered DC signal based on an output of the rectification circuit, wherein capacitance of each of the one or more DC bus rated capacitors is less than or equal to a capacitance of each across-the-line capacitor connected upstream from the charging circuit or the rectification circuit, and

wherein the power factor correction circuit is configured to, based on an output of the first electromagnetic interference filter, output the first DC voltage to the DC bus to power the compressor drive.