POWER CONVERSION APPARATUS WITH LOW COMMON MODE NOISE AND APPLICATION SYSTEMS THEREOF

• US 20140140112A1
• Filed: 03/15/2013
• Published: 05/22/2014
• Est. Priority Date: 11/16/2012
• Status: Active Grant

• Current Assignee: Delta Electronics Incorporated
• Original Assignee: Delta Electronics Incorporated
• Inventors: Zhou, Jinping, Zhou, Min, Xie, Yicong
• Granted Patent: US 9,281,738 B2
• Time in Patent Office: Days
• US Class Current: 363/40
• CPC Class Codes: H02M 1/12 Arrangements for reducing harmonics from ac input or output
• CPC Class Codes: H02M 1/123 Suppression of common mode voltage or current
• CPC Class Codes: H02M 1/126 using passive filters
• CPC Class Codes: H02M 5/4585 having a rectifier with controlled elements
• CPC Class Codes: H02M 7/217 using semiconductor devices only
• CPC Class Codes: H02M 7/5387 in a bridge configuration

Abstract

A power conversion apparatus, comprising: a power conversion circuit comprising an AC source; a power conversion unit with DC terminals and AC terminals; a filter inductor unit including first and second terminals, the first terminals of the filter inductor unit being connected to the AC source, the second terminals of the filter inductor unit being connected to the AC terminals of the power conversion unit; a common mode noise suppression circuit comprising a capacitive impedance network including first and second terminals; an impedance balancing network including first and second terminals; the second terminals of the capacitive impedance network are connected to the first terminals of the impedance balancing network, the first terminals of the capacitive impedance network are connected to the first terminals of the filter inductor unit, and the second terminals of the impedance balancing network are connected to the DC terminals of the power conversion unit.

Claims

1. A power conversion apparatus with low common mode noise, comprising:

a power conversion circuit, the power conversion circuit comprising;

an AC source;

a power conversion unit with DC terminals and AC terminals; and

a filter inductor unit, the filter inductor unit including first terminals and second terminals, the first terminals of the filter inductor unit being connected to the AC source, and the second terminals of the filter inductor unit being connected to the AC terminals of the power conversion unit; and

a common mode noise suppression circuit, the common mode noise suppression circuit comprising;

a capacitive impedance network, including first terminals and second terminals;

an impedance balancing network, including first terminals and second terminals;

wherein the second terminals of the capacitive impedance network are connected to the first terminals of the impedance balancing network, the first terminals of the capacitive impedance network are connected to the first terminals of the filter inductor unit, and the second terminals of the impedance balancing network are connected to the DC terminals of the power conversion unit;

the impedance balancing network and the filter inductor unit are configured to have the same impedance characteristics in a preset frequency band of electromagnetic interference.

2. The power conversion apparatus according to claim 1, wherein the power conversion unit is a three-phase power conversion unit or a single-phase power conversion unit;

correspondingly the AC source is a three-phase AC source or a single-phase AC source.

3. The power conversion apparatus according to claim 1, wherein the filter inductor unit comprises the same number of filter inductor sub-units as that of terminals of the AC source;

first terminals of the filter inductor sub-units and the terminals of the AC source are connected in one-to-one correspondence, and second terminals of the filter inductor sub-units and the AC terminals of the power conversion unit are connected in one-to-one correspondence.

4. The power conversion apparatus according to claim 3, wherein the filter inductor sub-unit is an inductor element.

5. The power conversion apparatus according to claim 3, wherein the capacitive impedance network comprises the same number of capacitive branches as that of the filter inductor sub-units, first terminals of the capacitive branches and the first terminals of the filter inductor sub-units are connected in one-to-one correspondence, and second terminals of the capacitive branches are connected to the first terminals of impedance balancing network.

6. The power conversion apparatus according to claim 5, wherein the capacitive branch is a capacitor, or a capacitor connected in series with a resistor.

7. The power conversion apparatus according to claim 5, wherein an impedance of the impedance balancing network meets:

8. The power conversion apparatus according to claim 5, wherein each of the capacitive branches has the same structure and the same device parameters;

each of the filter sub-units has the same structure and the same device parameters; and

the power conversion unit is of symmetrical structure, and is of the same device parameters.

9. The power conversion apparatus according to claim 1, wherein the impedance balancing network is an inductive branch, and the inductive branch comprises at least one inductor.

10. The power conversion apparatus according to claim 9, wherein the inductive branch further comprises a damping resistor and a capacitor, and the damping resistor, the capacitor and the inductor are connected in series with each other.

11. The power conversion apparatus according to claim 9, wherein the inductor is a single inductor;

a terminal of the single inductor acts as the first terminal of the impedance balancing network.

12. The power conversion apparatus according to claim 9, wherein the inductor is a non-coupled inductor network or a coupled inductor network;

the non-coupled inductor network comprises at least two non-coupled inductors, the coupled inductor network comprises at least two coupled windings, a terminal of each of the two non-coupled inductors or coupled windings is connected into a common node which acts as the second terminal of the impedance balancing network, the other terminal of each of the two non-coupled inductors or coupled windings acts as the first terminal of the impedance balancing network.

13. The power conversion apparatus according to claim 1, wherein the DC terminals of the power conversion unit comprises two DC leads between which a DC voltage exists.

14. The power conversion apparatus according to claim 13, wherein the DC terminals of the power conversion unit further comprises two bus capacitors in series, the two bus capacitors in series are connected across between the two DC leads, and the common node of the two bus capacitors in series forms a midpoint of the DC terminals.

15. The power conversion apparatus according to claim 1, wherein the power conversion unit is a two-level rectifier or inverter circuit, or a multi-level rectifier or inverter circuit.

16. An energy conversion system, comprising:

an AC source;

a first power conversion unit with DC terminals and AC terminals;

a second power conversion unit with DC terminals and AC terminals;

a motor; and

a common mode noise suppression circuit;

wherein the AC source is coupled to the AC terminals of the first power conversion unit, the DC terminals of the first power conversion unit are coupled to the DC terminals of the second power conversion unit, the AC terminals of the second power conversion unit are electrically coupled to the motor, and the common mode noise suppression circuit is coupled to the first power conversion unit;

the first power conversion unit comprising;

a first power conversion circuit with DC terminals and AC terminals; and

a filter inductor unit, the filter inductor unit including first terminals and second terminals, the first terminals of the filter inductor unit being connected to the AC source, and the second terminals of the filter inductor unit being connected to the AC terminals of the first power conversion unit; and

the common mode noise suppression circuit comprising;

a capacitive impedance network, including first terminals and second terminals;

an impedance balancing network, including first terminals and second terminals;

wherein the second terminals of the capacitive impedance network are connected to the first terminals of the impedance balancing network, the first terminals of the capacitive impedance network are connected to the first terminals of the filter inductor unit, and the second terminals of the impedance balancing network are connected to the DC terminals of the first power conversion unit;

the impedance balancing network and the filter inductor unit are configured to have the same impedance characteristics in a preset frequency band of electromagnetic interference.

17. The energy conversion system according to claim 16, wherein the motor is a wind-powered generator.

18. A power quality device, comprising:

an inverter circuit unit connected to an AC source, for compensating the reactive power and/or harmonics generated by a nonlinear load that is electrically connected to the AC source, the inverter circuit unit comprising;

an inverter circuit, with DC terminals and AC terminals; and

a filter inductor unit, the filter inductor unit including first terminals and second terminals, the first terminals of the filter inductor unit being connected to the AC source, and the second terminals of the filter inductor unit being connected to the AC terminals of the inverter circuit; and

a common mode noise suppression circuit, comprising;

a capacitive impedance network, including first terminals and second terminals;

an impedance balancing network, including first terminals and second terminals;

wherein the second terminals of the capacitive impedance network are connected to the first terminals of the impedance balancing network, the first terminals of the capacitive impedance network are connected to the first terminals of the filter inductor unit, and the second terminals of the impedance balancing network are connected to the DC terminals of the inverter circuit;

the impedance balancing network and the filter inductor unit are configured to have the same impedance characteristics in a preset frequency band of electromagnetic interference.

19. An energy control system, comprising:

a DC source;

an AC source;

an inverter circuit unit, comprising;

an inverter circuit, with DC terminals and AC terminals; and

a filter inductor unit, the filter inductor unit including first terminals and second terminals, the first terminals of the filter inductor unit being connected to the AC source, and the second terminals of the filter inductor unit being connected to the AC terminals of the inverter circuit; and

a common mode noise suppression circuit, comprising;

a capacitive impedance network, including first terminals and second terminals;

an impedance balancing network, including first terminals and second terminals;

wherein the second terminals of the capacitive impedance network are connected to the first terminals of the impedance balancing network, the first terminals of the capacitive impedance network are connected to the first terminals of the filter inductor unit, the second terminals of the impedance balancing network are connected to the DC terminals of the inverter circuit, and the DC terminals of the inverter circuit are connected to the DC source;

the impedance balancing network and the filter inductor unit are configured to have the same impedance characteristics in a preset frequency band of electromagnetic interference band.