CN112564587A - Three-phase inverter common mode voltage suppression circuit - Google Patents
Three-phase inverter common mode voltage suppression circuit Download PDFInfo
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- CN112564587A CN112564587A CN202011326496.3A CN202011326496A CN112564587A CN 112564587 A CN112564587 A CN 112564587A CN 202011326496 A CN202011326496 A CN 202011326496A CN 112564587 A CN112564587 A CN 112564587A
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- 230000001629 suppression Effects 0.000 title claims abstract description 15
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- 239000003990 capacitor Substances 0.000 claims description 72
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- 230000006698 induction Effects 0.000 claims description 12
- 230000000087 stabilizing effect Effects 0.000 claims description 6
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P29/00—Arrangements for regulating or controlling electric motors, appropriate for both AC and DC motors
- H02P29/50—Reduction of harmonics
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/12—Arrangements for reducing harmonics from ac input or output
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P27/00—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage
- H02P27/04—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage
- H02P27/06—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage using dc to ac converters or inverters
- H02P27/08—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage using dc to ac converters or inverters with pulse width modulation
Abstract
The invention discloses a common-mode voltage suppression circuit of a three-phase inverter, belonging to the technical field of frequency converter application. The compensation voltage injected into the common mode path cancels the common mode voltage generated by the two-level voltage source inverter through the magnetizing inductance of the four-winding common mode transformer. The invention can reduce the magnetizing inductance of the common mode transformer, reduce the size, reduce the circuit volume and has good inhibition effect on the common mode voltage and the grounding leakage current peak value in the circuit.
Description
Technical Field
The invention belongs to the technical field of frequency converter application, and particularly relates to a common-mode voltage suppression circuit for an inverter part of a frequency converter.
Background
The variable frequency speed regulation is one of the most ideal speed regulation modes with good development prospect. The frequency converter has obvious contribution in the aspects of saving energy, reducing production cost, improving product quality, improving production efficiency and the like. The use of silicon carbide metal oxide semiconductor field effect transistors (SIC MOSFETs) in variable frequency drives is widespread for the purpose of achieving a miniaturized size and better system efficiency. Frequent opening of an integrated SIC switch in the variable-frequency drive and increase of the switching frequency aggravate common-mode noise and simultaneously cause increase of electromagnetic interference (EMI) problems in a drive system. Common mode noise in the drive system can result in the presence of ground leakage currents through various parasitic common mode paths that can lead to conducted electromagnetic interference problems through interaction with nearby systems, reduce machine insulation, and can cause shaft voltages that can reduce bearing life.
Inverter-powered drive systems operating by Pulse Width Modulation (PWM) technology generate high-frequency common-mode voltages that are accompanied by steep rise and fall time voltage rates of change (dv/dt). Such related problems can be mitigated or suppressed by control or various passive and active common mode attenuation techniques. Common mode voltage problems in two-level voltage source inverters are typically eliminated using pulse width modulation techniques, but absolute elimination of common mode voltage is not achieved. A three-phase four-leg inverter uses an additional leg to eliminate common mode voltage, but the additional branch added by the method increases the cost and increases the control complexity of the existing system. The simplest method for attenuating the common mode noise is to use a passive common mode filter, and the passive common mode attenuation method is simple and reliable, wherein the use of the common mode choke coil is the simplest method of the passive common mode attenuation methods, but the size of the common mode choke coil is increased at high switching frequency, the cost is increased, and in addition, the output response of the inverter is slowed down due to the increase of the size of the passive components.
Disclosure of Invention
In order to solve the defects of the prior art, the invention provides a common-mode voltage suppression circuit of a three-phase inverter, which utilizes active zero vector pulse width modulation of an active filtering and counteracting method, designs an active common-mode noise voltage eliminator (ACVC) on the basis of the method to attenuate pulse width modulation frequency, reduce magnetizing inductance and voltage stress of a common-mode transformer and improve common-mode performance.
The invention provides a common-mode voltage suppression circuit of a three-phase inverter, which comprises: line Impedance Stabilization Network (LISN), PWM inverter, first electric capacity, Line Impedance Stabilization Network (LISN) part respectively with first electric capacity and PWM inverter part link to each other, its effect respectively lies in suppressing the high frequency noise signal that comes from the electric wire netting and inverts the direct current into alternating current, its characterized in that still includes: the three-phase induction motor comprises a first inductor, a second inductor, a third inductor, an active common mode noise voltage eliminator and a three-phase induction motor; the first inductor, the second inductor and the third inductor are respectively connected with the PWM inverter and the active common mode noise voltage eliminator and are used for restraining high-frequency oscillation normal mode current; the active common mode noise voltage eliminator is respectively connected with an impedance stabilization network (LISN), a PWM inverter and a three-phase induction motor and used for restraining common mode voltage generated by the inverter.
Optionally, the active common mode noise voltage canceller includes: the circuit comprises a common-mode voltage sensing circuit, a four-winding common-mode transformer, an emitter follower circuit, a fifth capacitor and a sixth capacitor; the common-mode voltage sensing circuit is respectively connected with the first inductor, the second inductor, the third inductor and the emitter follower circuit and is used for sensing the common-mode voltage in the circuit; the four-winding common mode transformer is respectively connected with the emitter follower circuit and the three-phase induction motor and is used for generating magnetizing inductance to offset common mode voltage generated by the two-level voltage source inverter. The emitter follower circuit is respectively connected with the fifth capacitor, the sixth capacitor and the first capacitor and used as a voltage-controlled voltage source to inject compensation common-mode voltage.
Optionally, the common-mode voltage sensing circuit includes a first capacitor, a second capacitor, and a third capacitor, and one end of the first inductor, one end of the second inductor, and one end of the third inductor are respectively connected to the first capacitor, the second capacitor, and the third capacitor; and the base electrode of the emitter follower is connected with the other ends of the first capacitor, the second capacitor and the third capacitor.
Optionally, the four-winding common-mode transformer includes a primary winding, a secondary first winding, a second winding, and a third winding, and one end of a first capacitor, a second capacitor, and a third capacitor of the common-mode voltage sensing circuit is respectively connected to the homonymous ends of the secondary first winding, the second winding, and the third winding; three power ends of the three-phase induction motor are respectively connected with non-homonymous ends of a first winding, a second winding and a third winding on the secondary side; the emitter of the emitter follower is connected with the non-homonymous terminal of the primary winding L4; and one end of the fifth capacitor and one end of the sixth capacitor are connected with the same-name end of the primary winding.
Optionally, the emitter follower circuit includes a first triode and a second triode, and one end of the first triode, one end of the first capacitor and one end of the fifth capacitor are connected to a collector of the first triode; and the other ends of the first capacitor and the sixth capacitor are connected with the collector of the second triode.
When the circuit works, the sensing circuit consisting of the second capacitor, the third capacitor and the fourth capacitor senses the common-mode voltage, and an emitter follower circuit consisting of the first triode and the second triode is used as a voltage-controlled voltage source to inject the compensation common-mode voltage. The compensation voltage injected into the common mode path cancels the common mode voltage generated by the two-level voltage source inverter through the magnetizing inductance of the four-winding common mode transformer.
The first triode is NPN structure, the second triode is PNP structure, and the first triode and the second triode form a push-pull emitter follower.
The invention at least comprises the following beneficial effects:
1. active zero vector pulse width modulation by using an active filtering and offsetting method is adopted, and an active common mode noise voltage eliminator is added on the basis of the method, so that the magnetizing inductance of the common mode transformer is reduced, the size is reduced, the circuit volume is reduced, and the cost is reduced.
2. The circuit has obvious effect on inhibiting the common mode voltage and the grounding leakage current peak value in the circuit by the simultaneous action of the software module and the hardware module.
Drawings
The features and advantages of the present invention will be more clearly understood by reference to the accompanying drawings, which are illustrative and not to be construed as limiting the invention in any way, and in which:
fig. 1 is a schematic diagram of an embodiment of a common mode voltage suppression circuit according to the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
As shown in fig. 1, the present invention relates to a common mode voltage suppression circuit for a three-phase inverter, which is composed of a Line Impedance Stabilization Network (LISN)1, a PWM inverter 2, a first inductor L3, a second inductor L4, a third inductor L5, an active common mode noise voltage canceller 3, a four-winding Common Mode Transformer (CMT)4, a three-phase induction motor 5, a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6, a first triode T1, and a second triode T2: an input end of a Line Impedance Stabilizing Network (LISN)1 is respectively connected with a positive electrode and a negative electrode of a direct current bus, an output end of the Line Impedance Stabilizing Network (LISN)1 is respectively connected with one end of a first capacitor C1, one end of a fifth capacitor C5, one input end of a PWM inverter 2 and a collector of a first triode T1, the other end of the fifth capacitor C5 is respectively connected with a non-dotted terminal of a primary winding L4 of the four-winding common mode transformer 4 and one end of a sixth capacitor C6, the other output end of the Line Impedance Stabilizing Network (LISN)1 is respectively connected with the other end of a first capacitor C1, the other end of a sixth capacitor C6, the other input end of the PWM inverter 2 and a collector of a second triode T2, three output ends of the PWM inverter 2 are respectively connected with one ends of a first inductor L1, a second inductor L2 and a third inductor L3, a first inductor L1, a second inductor L2, The other end of the third inductor L3 is connected to one end of a second capacitor C2, a third capacitor C3, and a fourth capacitor C4, and the homonymous ends of the secondary side first winding L51, the second winding L52, and the third winding L53 of the four-winding common mode transformer 4, the other ends of the second capacitor C2, the third capacitor C3, and the fourth capacitor C4 are connected to the bases of a first triode T1 and a second triode T2, the non-homonymous ends of the secondary side first winding L51, the second winding L52, and the third winding L53 of the four-winding common mode transformer 4 are connected to three power supply terminals of the three-phase induction motor 5, and the non-homonymous end of the primary side winding L4 of the four-winding common mode transformer 4 is connected to the emitters of the first triode T1 and the second triode T2.
In this embodiment, three conventional inductors L1, L2, and L3 are added between the PWM inverter 2 and the active common mode voltage noise canceller 3 to suppress the high frequency oscillation normal mode current, whose inductance value is much smaller than that in the four-winding common mode transformer 4, and will not provide a significant attenuation to the common mode elements. When the circuit works, the sensing circuit consisting of the second capacitor C2, the third capacitor C3 and the fourth capacitor C4 senses the common-mode voltage, and an emitter follower circuit consisting of the first triode T1 and the second triode T2 is used as a voltage-controlled voltage source to inject the compensation common-mode voltage. The compensation voltage injected into the common mode path cancels the common mode voltage generated by the two-level voltage source inverter through the magnetizing inductance of the four-winding common mode transformer 4.
The inductance of the four-winding common-mode transformer 4 required for the common-mode voltage attenuation depends on the peak-to-peak value of the common-mode voltage and the switching frequency f of the power switch tubeswAnd power losses of the first transistor T1 and the second transistor T2, when an active zero vector pulse width modulation method is adopted, can be determined by the following formula:
in the formula LCMTIs the inductance value, V, of the four-winding common mode transformer 4cmFor the peak-to-peak value, P, of the common-mode voltage generated in the circuitdesThe power loss of the first transistor T1 and the second transistor T2, fswThe switching frequency of the power switch tube.
The design of the four-winding common mode transformer 4 magnetic core must ensure the saturation flux density (B) of the magnetic corem) In order to avoid magnetic saturation of the four-winding common-mode transformer 4 without exceeding the specified value of the pulse width modulation, the magnetic core should satisfy the following conditions in the active zero vector pulse width modulation method:
in the formula AcIs the cross-sectional area of the core, N is the number of turns of the core, VDCIs the value of the DC bus voltage, fswIs the switching frequency of the power switch tube, BmIs the magnetic saturation density of the magnetic core of the four-winding common mode transformer 4.
Claims (7)
1. A three-phase inverter common mode voltage suppression circuit, comprising: the circuit comprises a line impedance stabilizing network, a PWM inverter and a first capacitor, wherein the line impedance stabilizing network part is respectively connected with the first capacitor and the PWM inverter part and is used for inhibiting high-frequency noise signals from a power grid and inverting direct current into alternating current, and the circuit is characterized by further comprising: the three-phase induction motor comprises a first inductor, a second inductor, a third inductor, an active common mode noise voltage eliminator and a three-phase induction motor; the first inductor, the second inductor and the third inductor are respectively connected with the PWM inverter and the active common mode noise voltage eliminator and are used for restraining high-frequency oscillation normal mode current; the active common mode noise voltage eliminator is respectively connected with the impedance stabilizing network, the PWM inverter and the three-phase induction motor and used for restraining the common mode voltage generated by the inverter.
2. The three-phase inverter common mode voltage suppression circuit of claim 1, wherein the active common mode noise voltage canceller comprises: the circuit comprises a common-mode voltage sensing circuit, a four-winding common-mode transformer, an emitter follower circuit, a fifth capacitor and a sixth capacitor; the common-mode voltage sensing circuit is respectively connected with the first inductor, the second inductor, the third inductor and the emitter follower circuit and is used for sensing the common-mode voltage in the circuit; the four-winding common mode transformer is respectively connected with the emitter follower circuit and the three-phase induction motor and is used for generating magnetizing inductance to offset common mode voltage generated by the two-level voltage source inverter; the emitter follower circuit is respectively connected with the fifth capacitor, the sixth capacitor and the first capacitor and used as a voltage-controlled voltage source to inject compensation common-mode voltage.
3. The common-mode voltage suppression circuit of the three-phase inverter according to claim 1 or 2, wherein the emitter follower circuit comprises a first transistor and a second transistor, the common-mode voltage sensing circuit comprises a first capacitor, a second capacitor and a third capacitor, and one end of the first inductor, one end of the second inductor and one end of the third inductor are respectively connected with the first capacitor, the second capacitor and the third capacitor; and the base electrodes of the first triode and the second triode are connected with the other ends of the first capacitor, the second capacitor and the third capacitor.
4. The common-mode voltage suppression circuit of the three-phase inverter according to claim 3, wherein the four-winding common-mode transformer comprises a primary winding, a secondary winding, a first winding, a second winding and a third winding, and one end of a first capacitor, a second capacitor and a third capacitor of the common-mode voltage sensing circuit is respectively connected with the homonymous ends of the secondary winding, the second winding and the third winding; three power ends of the three-phase induction motor are respectively connected with non-homonymous ends of the first winding, the second winding and the third winding on the secondary side; the emitting electrodes of the first triode and the second triode are connected with the non-homonymous end of the primary winding; and one end of the fifth capacitor and one end of the sixth capacitor are connected with the same-name end of the primary winding.
5. The common-mode voltage suppression circuit of the three-phase inverter according to claim 4, wherein one end of the first capacitor and one end of the fifth capacitor are connected to a collector of the first triode; and the other ends of the first capacitor and the sixth capacitor are connected with the collector of the second triode.
6. The common-mode voltage suppression circuit for three-phase inverter as claimed in claim 4, wherein the inductance of the four-winding common-mode transformer depends on the peak-to-peak value of the common-mode voltage, the switching frequency f of the power switch tubeswAnd power losses of the first triode and the second triode can be determined by the following formula when an active zero vector pulse width modulation method is adopted:
in the formula LCMTInductance value, V, of a four-winding common mode transformercmFor the peak-to-peak value, P, of the common-mode voltage generated in the circuitdesIs the power loss of the first transistor and the second transistor, fswThe switching frequency of the power switching tube;
the design of the four-winding common mode transformer magnetic core must ensure the saturation flux density (B) of the magnetic corem) In order to avoid magnetic saturation of a four-winding common-mode transformer without exceeding a specified value of pulse width modulation, the magnetic core satisfies the following conditions in an active zero vector pulse width modulation method:
in the formula AcIs the cross-sectional area of the core, N is the number of turns of the core, VDCIs the value of the DC bus voltage, fswIs the switching frequency of the power switch tube, BmThe magnetic saturation density of the four-winding common mode transformer core.
7. The common-mode voltage suppression circuit for three-phase inverters according to claim 5, wherein said first transistor is NPN and said second transistor is PNP.
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| CN202011326496.3A CN112564587A (en) | 2020-11-23 | 2020-11-23 | Three-phase inverter common mode voltage suppression circuit |
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| CN202011326496.3A CN112564587A (en) | 2020-11-23 | 2020-11-23 | Three-phase inverter common mode voltage suppression circuit |
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Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101527505A (en) * | 2009-03-31 | 2009-09-09 | 西安交通大学 | Disturbance voltage attenuation device |
| CN108377666A (en) * | 2015-11-06 | 2018-08-07 | 国立大学法人北海道大学 | Power inverter |
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- 2020-11-23 CN CN202011326496.3A patent/CN112564587A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101527505A (en) * | 2009-03-31 | 2009-09-09 | 西安交通大学 | Disturbance voltage attenuation device |
| CN108377666A (en) * | 2015-11-06 | 2018-08-07 | 国立大学法人北海道大学 | Power inverter |
Non-Patent Citations (2)
| Title |
|---|
| JIANG YANSHU ET AL.: "A novel inverter output dv/dt suppression filter", 《 IECON"03. 29TH ANNUAL CONFERENCE OF THE IEEE INDUSTRIAL ELECTRONICS SOCIETY (IEEE CAT. NO.03CH37468)》 * |
| S. OGASAWARA ET AL.: "An active circuit for cancellation of common-mode voltage generated by a PWM inverter", 《IEEE TRANSACTIONS ON POWER ELECTRONICS》 * |
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Application publication date: 20210326 |