CN114448286A - Single-stage isolation bidirectional AC-DC converter topological structure and control method thereof - Google Patents
Single-stage isolation bidirectional AC-DC converter topological structure and control method thereof Download PDFInfo
- Publication number
- CN114448286A CN114448286A CN202210233966.4A CN202210233966A CN114448286A CN 114448286 A CN114448286 A CN 114448286A CN 202210233966 A CN202210233966 A CN 202210233966A CN 114448286 A CN114448286 A CN 114448286A
- Authority
- CN
- China
- Prior art keywords
- frequency
- converter
- power
- direct current
- alternating
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 230000002457 bidirectional effect Effects 0.000 title claims abstract description 62
- 238000002955 isolation Methods 0.000 title claims abstract description 47
- 238000000034 method Methods 0.000 title claims abstract description 16
- 238000006243 chemical reaction Methods 0.000 claims abstract description 24
- 239000003990 capacitor Substances 0.000 claims description 20
- 230000010363 phase shift Effects 0.000 claims description 14
- 238000010586 diagram Methods 0.000 description 11
- 230000005540 biological transmission Effects 0.000 description 6
- 230000000295 complement effect Effects 0.000 description 5
- 239000011159 matrix material Substances 0.000 description 4
- 239000004576 sand Substances 0.000 description 3
- 238000004146 energy storage Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
- 238000004804 winding Methods 0.000 description 2
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 229910052744 lithium Inorganic materials 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Images
Classifications
-
- 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
- H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
- H02M7/66—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output with possibility of reversal
- H02M7/68—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output with possibility of reversal by static converters
- H02M7/72—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output with possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M7/79—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output with possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
- H02M7/797—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output with possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
-
- 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
-
- 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
- H02M1/14—Arrangements for reducing ripples from dc input or output
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Inverter Devices (AREA)
Abstract
The invention relates to the technical field of power electronic converters, and provides a topological structure of a single-stage isolation bidirectional AC-DC converter and a control method thereof. Wherein, single-stage isolation bidirectional AC-DC converter topological structure includes: an AC-side filter; the alternating current side converter consists of two H half bridges which are reversely connected in series, and each H half bridge consists of two power switching devices which are connected in series in the same direction or in the same cathode in a reverse direction; a high-frequency transformer; a DC-side converter; and a DC side filter. The single-stage isolation bidirectional AC-DC converter topological structure provided by the invention realizes bidirectional AC-DC power conversion with low cost, high power density and high performance.
Description
Technical Field
The invention relates to the technical field of power electronic converters, in particular to a topological structure of a single-stage isolation bidirectional AC-DC converter and a control method thereof.
Background
With the development of energy storage technology, portable consumer applications based on energy storage elements such as lithium batteries and super capacitors have generated a great demand for AC-DC (alternating current-direct current) power converters with high cost performance, high power density, electrical isolation, and bidirectional power conversion.
Currently, for single-phase AC-DC power conversion applications, a typical bidirectional isolation AC-DC power converter includes two technical routes, i.e., power frequency isolation and high frequency isolation. The high-frequency isolation technology adopts a high-frequency alternating current chain to realize electrical isolation, and the passive device has the advantages of small volume and weight, high power density and suitability for portable consumer occasions.
In the prior art, bidirectional AC-DC power converters based on high-frequency isolation generally adopt an AC-DC two-stage power conversion topology and an AC-DC single-stage power conversion topology based on a matrix structure.
The AC-DC-DC power converter comprises two stages of power conversion, the number of required power switching devices is large, the cost is high, the loss is high, and the efficiency of the whole power converter is low.
The AC-DC single-stage power conversion topological structure based on the matrix structure has the advantages of single-stage power conversion and low power conversion loss because the AC end adopts a matrix converter circuit structure and is electrically isolated through a high-frequency transformer and the DC side adopts an H-bridge structure, but the number of switching devices is not reduced compared with the AC-DC-DC two-stage power conversion topological structure, the hardware cost of the whole machine is higher, and the control complexity is increased.
Disclosure of Invention
The invention provides a single-stage isolation bidirectional AC-DC converter topological structure and a control method thereof, which are used for overcoming the defects of high cost and low overall efficiency of a high-frequency isolation bidirectional AC-DC power converter in the prior art and realizing bidirectional AC-DC power conversion with low cost, high power density and high performance.
The invention provides a single-stage isolation bidirectional AC-DC converter topological structure, which comprises:
the AC side filter, one end of the said AC side filter is connected to AC power supply or load;
the AC side converter consists of two H half-bridges which are reversely connected in series, each H half-bridge consists of two power switching devices which are reversely connected in series in the same direction or in the same cathode, the anode end of one of the two power switching devices of the two H half-bridges is the power frequency output end of the AC side converter, the power frequency output end of the AC side converter is connected with the other end of the AC side filter, and the connecting end between the two power switching devices which are connected in series of the two H half-bridges is the high-frequency output end of the AC side converter;
the primary side of the high-frequency transformer is connected to an alternating-current side alternating-current link, the secondary side of the high-frequency transformer is connected to a direct-current side alternating-current link, and the alternating-current side alternating-current link is connected with the high-frequency output ends of the two alternating-current side converters;
one end of the direct current side converter is connected with a direct current side alternating current link;
and one end of the direct current side filter is connected with the other end of the direct current side converter, and the other end of the direct current side filter is connected with a direct current power supply.
According to the single-stage isolation bidirectional AC-DC converter topological structure provided by the invention, the AC link at the AC side and/or the AC link at the DC side are/is also connected with a low-frequency isolation capacitor in series, and the low-frequency isolation capacitor is used for separating a DC component, a power frequency component and a related low-frequency component from a high-frequency and low-frequency mixed pulse electric energy waveform generated by the AC side converter, so that only high-frequency pulse electric energy passes through the high-frequency transformer.
According to the single-stage isolation bidirectional AC-DC converter topological structure provided by the invention, the AC link at the AC side is also connected with a high-frequency inductor in series, and/or the AC link at the DC side is also connected with a high-frequency inductor in series.
According to the single-stage isolation bidirectional AC-DC converter topology structure provided by the invention, the power switch device is one of an IGBT power switch device, an IEGT power switch device or a MOSFET power switch device.
According to the single-stage isolation bidirectional AC-DC converter topology structure provided by the invention, the alternating-current side filter is one of an LC type filter, a CLC type filter or an RLC type filter.
According to the single-stage isolation bidirectional AC-DC converter topology structure provided by the invention, the DC side converter is composed of an H full bridge.
According to the single-stage isolation bidirectional AC-DC converter topology structure provided by the invention, the direct current side filter is one of a C-type filter, an LC-type filter or an LRC-type filter.
The invention also provides a control method of the single-stage isolation bidirectional AC-DC converter topological structure based on any one of the above, which comprises the following steps:
the adjustment of the power of the single-stage isolation bidirectional AC-DC converter and the control of the power flow direction are realized through bidirectional power conversion control;
the power switching device of the AC side converter and the power switching device of the DC side converter adopt the same high-frequency switching frequency; the alternating current side converter chops power frequency alternating current into high-frequency and low-frequency mixed pulse electric energy with adjustable duty ratio in a high-frequency chopping mode according to an alternating current modulation ratio instruction, and only the residual high-frequency pulse electric energy passes through the high-frequency transformer after the high-frequency and low-frequency mixed pulse electric energy passes through the low-frequency isolation capacitor; and the direct current side converter converts direct current into high-frequency pulse electric energy with adjustable duty ratio according to the direct current modulation ratio instruction.
According to the control method of the single-stage isolation bidirectional AC-DC converter topological structure, the bidirectional power conversion control comprises the following steps:
according to the original secondary side phase shift angle instruction, controlling the phase difference between the high-frequency pulse electric energy generated by the alternating current side converter and the high-frequency pulse electric energy generated by the direct current side converter, and realizing the adjustment of the power and the control of the power flow direction;
and/or changing the alternating current modulation ratio command and the direct current modulation ratio command to realize the adjustment of the power.
According to the control method of the topological structure of the single-stage isolation bidirectional AC-DC converter, the step of controlling the phase difference between the high-frequency pulse electric energy generated by the AC side converter and the high-frequency pulse electric energy generated by the DC side converter according to the primary and secondary side phase shift angle instruction comprises the following steps:
and when the power frequency voltage of the power frequency alternating current connection point of the alternating current side converter passes through zero, controlling the phase shift angle instruction of the original secondary side to invert, or controlling the output pulse of the direct current side converter to invert.
The single-stage isolation bidirectional AC-DC converter topological structure and the control method thereof realize bidirectional AC-DC power conversion with low cost, high power density and high performance.
Drawings
In order to more clearly illustrate the technical solutions of the present invention or the prior art, the drawings needed in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.
FIG. 1 is a circuit schematic of a single-stage isolated bidirectional AC-DC converter topology provided by the present invention;
fig. 2 is a schematic diagram of an H half-bridge structure of a single-stage isolated bidirectional AC-DC converter topology provided by the present invention, wherein (a) is a schematic diagram of a power switch device; (b) the H half-bridge structure schematic diagram is an H half-bridge structure schematic diagram formed by connecting two power switching devices in series in the same direction; (c) the H half-bridge structure schematic diagram is an H half-bridge structure schematic diagram formed by reversely connecting the common cathodes of two power switching devices in series;
FIG. 3 is a schematic diagram of a high-frequency and low-frequency mixed pulse electric energy waveform generated by an AC-side converter of a single-stage isolated bidirectional AC-DC converter topology structure provided by the invention;
FIG. 4 is a schematic diagram of waveforms of high-frequency pulse electric energy generated by a DC-side converter of the single-stage isolated bidirectional AC-DC converter topology provided by the present invention;
FIG. 5 is a schematic diagram of the operating waveform of the low-frequency isolation capacitor of the single-stage isolation bidirectional AC-DC converter topology provided by the invention;
FIG. 6 is a schematic diagram of a phase-shift control waveform of a control method of a single-stage isolated bidirectional AC-DC converter topology provided by the present invention;
fig. 7 is a block diagram of a system control device of a single-stage isolated bidirectional AC-DC converter topology according to the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings, 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.
In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "connected" and "connected" are to be interpreted broadly, e.g., as being fixed or detachable or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
The single-stage isolated bidirectional AC-DC converter topology and the control method thereof of the present invention are described below in conjunction with fig. 1-7.
Referring to fig. 1, in an embodiment of the present invention, a single-stage isolated bidirectional AC-DC converter topology includes:
the AC side filter, one end of the said AC side filter is connected to AC power supply or load;
the AC side converter consists of two H half-bridges which are reversely connected in series, each H half-bridge consists of two power switching devices which are reversely connected in series in the same direction or in the same cathode, the anode end of one of the two power switching devices of the two H half-bridges is the power frequency output end of the AC side converter, the power frequency output end of the AC side converter is connected with the other end of the AC side filter, and the connecting end between the two power switching devices which are connected in series of the two H half-bridges is the high-frequency output end of the AC side converter;
the primary side of the high-frequency transformer is connected to an alternating-current side alternating-current link, the secondary side of the high-frequency transformer is connected to a direct-current side alternating-current link, and the alternating-current side alternating-current link is connected with the high-frequency output ends of the two alternating-current side converters;
one end of the direct current side converter is connected with a direct current side alternating current link;
and one end of the direct current side filter is connected with the other end of the direct current side converter, and the other end of the direct current side filter is connected with a direct current power supply.
In the circuit structure, the alternating current side filter is used for filtering harmonic waves in alternating current side voltage and current so as to improve the quality of alternating current power. The AC side filter can be, but not limited to, LC type filter, CLC type filter or RLC type filter composed of inductor, capacitor and resistor, and the AC side filter given in the present embodiment is composed of inductor LacAnd CacComposition, capacitance CacThe filter can be used as an absorption capacitor of a power switch device of the alternating-current side converter while realizing filtering, and the turn-off voltage peak of the power switch device is reduced.
Referring to fig. 1 and fig. 2, in addition, the ac-side converter is composed of power switching devices, and performs a high-frequency switching operation (i.e., high frequency is relative to power frequency) in order by the power switching devices to chop the power frequency ac waveform into a high-frequency and low-frequency mixed pulse waveform, thereby realizing bidirectional power conversion between the power frequency ac and the high-frequency ac. In an embodiment of the invention, one H half-bridge is composed of two power switching devices T integrated with anti-parallel diodes1And T2The other H half-bridge is composed of two power switching devices T integrated with anti-parallel diodes3And T4In the same direction or in reverse series with a common cathode, i.e. power switching devices T2And T3Are connected in series in the reverse direction; each H half bridge comprises three connection points, namely a positive electrode point A, a negative electrode point B and an output electrode point C, when the two H half bridges are reversely connected in series, the points B of the two H half bridges are directly connected, the points A of the two H half bridges are power frequency output ends and are respectively connected with two connection ends at the other end of the alternating current side filter, the point C of the two H half bridges is a high-frequency output end,and the two ends of the alternating current link circuit on the alternating current side are respectively connected, and high-frequency and low-frequency mixed pulse waveforms are output.
In the embodiment of the present invention, the power switch device may be, but is not limited to, an IGBT power switch device, an IEGT power switch device, or a MOSFET power switch device. When the power switch device is an IGBT power switch device, the IGBT collector is taken as an anode, and the IGBT emitter is taken as a cathode; when the power switch device is a MOSFET power switch device, the drain electrode of the MOSFET is set as an anode, and the source electrode of the MOSFET is set as a cathode.
The topological structure of the alternating current side converter provided by the invention adopts two H half-bridges to be reversely connected in series to form a bidirectional power converter between the power frequency alternating current and the high frequency alternating current, and has the remarkable advantages of less switching devices, simplicity in control and low cost compared with the topological structure of a conventional matrix type converter and a conventional two-stage converter.
Referring to fig. 1, in the embodiment of the present invention, an ac link formed by a high-frequency transformer is mainly used for transmitting an ac power component, a primary side of the ac link is connected to an ac side ac link, and a secondary side of the ac link is connected to a dc side ac link.
And the alternating current link at the alternating current side and/or the alternating current link at the direct current side are/is also connected with a low-frequency isolation capacitor in series, and the low-frequency isolation capacitor is used for separating a direct current component, a power frequency component and a related low-frequency component from a high-frequency and low-frequency mixed pulse electric energy waveform generated by the alternating current side converter, so that only high-frequency pulse electric energy passes through the high-frequency transformer.
Thus, magnetic saturation of the high-frequency transformer due to direct-current components and low-frequency components in the alternating-current link is avoided. In this embodiment, the capacitance value of the low-frequency isolation capacitor should ensure that the power frequency capacitance is far greater than the high-frequency capacitance, and the high-frequency capacitance is as small as possible, and the low-frequency capacitance is as large as possible, so as to ensure that the high-frequency pulse electric energy component in the ac link passes through at a relatively low cost, and the low-frequency pulse electric energy component basically cannot pass through, thereby realizing isolation of the low-frequency component. Compared with a topological structure that only a direct current component is separated by a capacitor in a conventional bidirectional direct current converter so as to prevent magnetic saturation of the transformer, the bidirectional direct current converter utilizes a low-frequency isolation capacitor to separate a direct current component and a low-frequency alternating current component in an alternating current link, and only a high-frequency component of a high-frequency transformer is guaranteed, so that high-frequency pulse electric energy transmission is realized.
In addition, the alternating current side alternating current link is also connected with a high-frequency inductor in series, and/or the direct current side alternating current link is also connected with a high-frequency inductor in series.
The high-frequency inductor is connected in series in the alternating current link and used for adjusting the transmission power. In the invention, the high-frequency inductor can adopt the form of an independent inductor, can also be integrated with a transformer, or can be directly replaced by the leakage inductance of the transformer. The high-frequency inductor may be connected in series in the ac-side ac link circuit, in the dc-side ac link circuit, or in both the ac-side and dc-side ac link circuits. In certain applications, the high frequency inductor may be eliminated.
Specifically, in this embodiment, the ac-side ac link circuit is formed by connecting a high-frequency inductor, a primary side of a high-frequency transformer, and a low-frequency isolation capacitor in series, and the dc-side ac link circuit is formed by connecting a secondary side of the high-frequency transformer. The working frequency of the high-frequency transformer is high frequency, and the primary side and the secondary side of the high-frequency transformer are respectively and electrically connected with the alternating current side converter and the direct current side converter. The turn ratio of the primary winding and the secondary winding of the transformer is designed according to the amplitude of alternating voltage and direct voltage so as to realize the matching of alternating current and direct current voltage and improve the power conversion efficiency; the transformer transmits high-frequency alternating-current bidirectional power while realizing electrical isolation of an alternating-current side and a direct-current side; the leakage inductance of the transformer may be equivalent to a part of the high frequency inductance, or may replace the high frequency inductance.
Referring to fig. 1, in addition, in the embodiment of the present invention, the dc-side converter is composed of an H full bridge.
The middle point of the H full bridge is used as a high-frequency output end to be connected with a direct-current side alternating-current link circuit, a power switch device of the direct-current side converter acts through high-frequency switching, direct current is converted into high-frequency pulse electric energy, and bidirectional power conversion of high-frequency alternating current and direct current is achieved. Specifically, in this embodiment, the H full bridge is antiparallel from integratedPower switch device S of diode1、S2、S3、S4Wherein the power switch device may be, but is not limited to, an IGBT power switch device, an IEGT power switch device, or a MOSFET power switch device.
The dc-side filter is used to filter out ripples in the dc voltage and current, and the dc-side filter may be, but not limited to, one of a C-type filter composed of capacitors, inductors, and resistors, an LC-type filter, or an LRC-type filter.
Thus, based on the above embodiments, compared with the topology structure of the existing high-frequency isolated bidirectional AC-DC power converter, the topology structure of the single-stage isolated bidirectional AC-DC converter provided by the present invention realizes the bidirectional AC-DC power conversion with low cost, high power density and high performance.
Referring to fig. 3 to fig. 6, the present invention further provides a control method of the single-stage isolated bidirectional AC-DC converter, including:
the adjustment of the power of the single-stage isolation bidirectional AC-DC converter and the control of the power flow direction are realized through bidirectional power conversion control;
the power switching device of the AC side converter and the power switching device of the DC side converter adopt the same high-frequency switching frequency; the alternating current side converter chops power frequency alternating current into high-frequency and low-frequency mixed pulse electric energy with adjustable duty ratio in a high-frequency chopping mode according to an alternating current modulation ratio instruction, and only the residual high-frequency pulse electric energy passes through the high-frequency transformer after the high-frequency and low-frequency mixed pulse electric energy passes through the low-frequency isolation capacitor; and the direct current side converter converts direct current into high-frequency pulse electric energy with adjustable duty ratio according to the direct current modulation ratio instruction.
Specifically, referring to fig. 3, four power switches T of the ac-side converter1～T4And (3) chopping the power frequency alternating current waveform into a high-low frequency mixed pulse electric energy waveform with adjustable duty ratio by the action of a high-frequency switch.
The voltage on the AC side is positive (u)ac>0) Time, power switch device T3And T4Constant conductanceOn/off power switch device T1And T2At a switching frequency FsAnd switching and complementary conduction of the high-frequency switch. At T1Conduction, T2OFF state, high frequency output u of AC side converterABOutput a positive level "1"; at T1Off, T2On state, high-frequency output u of AC side converterABA zero level "0" is output.
The voltage on the AC side is negative (u)ac<0) Time, power switch device T1And T2Constant-conduction power switch device T3And T4At a switching frequency FsAnd switching and complementary conduction of the high-frequency switch. At T4Conduction, T3OFF state, high frequency output u of AC side converterABOutput negative level "-1"; at T4Off, T3On state, high-frequency output u of AC side converterABA zero level "0" is output.
Each switching period TsThe proportion of the duration of the positive level "1" or negative level "-1" in the whole switching period is the AC duty cycle dacOr an ac modulation ratio command. By adjusting the ac modulation ratio command per switching cycle, i.e. at uac>Under 0 condition, adjusting T1Conduction T2AC duty cycle d of turn-offacOr at uac<Under 0 condition, adjusting T4Conduction T3AC duty cycle d of turn-offacEach switching period T can be variedsMiddle uABAnd outputting the width of the high-frequency pulse, thereby adjusting the energy of each high-frequency pulse and finally realizing the adjustment of the transmission power. It is to be understood that the switching period TsTo the switching frequency FsThe reciprocal of (c).
In addition, referring to fig. 4, four power switches S of the dc-side converter1～S4The high-frequency switch acts to convert the direct current into high-frequency pulse electric energy with adjustable duty ratio.
At S1～S4At a switching frequency FsAt the time of switching of the high-frequency switch, S1And S2Complementary conduction, S3And S4And conducting complementarily. At S1And S4When conducting at the same time, the high frequency output terminal u of the DC side convertersOutput a positive level "1"; at S2And S3When conducting at the same time, the high frequency output terminal u of the DC side convertersOutput negative level "-1"; at S1And S3Or S2And S4When conducting at the same time, the high frequency output terminal u of the DC side convertersA zero level "0" is output. By S1～S4Sequential switching of switching devices, e.g. producing S by phase-shift modulation or PWM modulation1～S4High-frequency output end u of switch control pulse DC side convertersAnd outputting a rectangular pulse waveform.
In each switching period T of the DC-side convertersThe proportion of the duration of positive level "1" or negative level "-1" in half a switching period is defined as the DC duty cycle dacOr a dc modulation ratio command. The duty cycle of the positive level "1" and the duty cycle of the negative level "-1" may be the same or different. By adjusting the DC modulation ratio command per switching cycle, i.e. adjusting S1、S4、S2And S3By varying the on-time of u in each switching cyclesThe widths of the positive and negative levels of the rectangular pulses are output, so that the energy of each high-frequency pulse is adjusted, the adjustment of the transmission power is finally realized, and the control of the direct-current magnetic bias of the transformer can be realized.
In practical application, in order to prevent the two complementary conducting power switching devices from being instantaneously and simultaneously conducted due to irrational factors such as inconsistent switching speeds and the like to cause short circuit, dead time is increased between control pulses of the complementary conducting power switching devices. During the dead time, the complementary conducting power switches are all in an off state.
Referring to fig. 5, when the low-frequency isolation capacitor is connected in series in the ac link loop, the low-frequency isolation capacitor can mix the high-frequency and low-frequency pulse power waveform u generated by the ac side converterABThe direct current component, the power frequency component and the related low frequency component are separated,so that only high-frequency electric energy component u passing through high-frequency transformer in AC link of AC sidep. Wherein, the voltage u at two ends of the low-frequency isolation capacitorcIncluding dc components, power frequency components, and related low frequency components.
Referring to fig. 6, the method for controlling a single-stage isolated bidirectional AC-DC converter according to the present invention includes:
according to the original secondary side phase shift angle instruction, controlling the phase difference between the high-frequency pulse electric energy generated by the alternating current side converter and the high-frequency pulse electric energy generated by the direct current side converter, and realizing the adjustment of the power and the control of the power flow direction;
the phase difference between the high-frequency pulse electric energy generated by the AC side converter and the high-frequency pulse electric energy generated by the DC side converter can be controlled by adjusting the phase difference between the reference phase of the control pulse of each power switching device of the AC side converter and the reference phase of the control pulse of each power switching device of the DC side converter, so that the adjustment of the power and the control of the power flow direction are realized.
And/or changing the alternating current modulation ratio command and the direct current modulation ratio command to realize the adjustment of the power.
The pulse width of the positive and negative levels output by the high-frequency output end of the alternating-current side converter and the pulse width of the positive and negative levels output by the high-frequency output end of the direct-current side converter are respectively adjusted by changing the alternating-current modulation ratio instruction and the direct-current modulation ratio instruction, so that the adjustment of the power is realized.
Specifically, the step of controlling a phase difference between the high-frequency pulse electric energy generated by the ac-side converter and the high-frequency pulse electric energy generated by the dc-side converter according to the primary and secondary phase shift angle command includes:
and when the power frequency voltage of the power frequency alternating current connection point of the alternating current side converter passes through zero, controlling the phase shift angle instruction of the original secondary side to invert, or controlling the output pulse of the direct current side converter to invert.
Because the phase of the power frequency voltage at the zero crossing point is reversed in one power frequency period, namely the voltage amplitude is controlled byChanging positive into negative or from negative into positive, in order to implement forward or reverse unidirectional power conversion, the power frequency voltage u of power frequency AC connection point of AC side converterABWhen the zero-crossing occurs, the phase shift angle instruction of the primary side and the secondary side is controlled to be inverted, so that the phase shift angle instruction is changed from positive to negative or from negative to positive, or the direct current side converter is controlled to output pulse usThe phase inversion ensures that the high-frequency output pulse of the DC side converter is inverted by 180 degrees, thereby ensuring that u in the AC link is inverted in a single power frequency periodpAlways leading or lagging usThe phase of the power transmission is not changed, the direction of the power transmission is not changed, and the power is converted in a single direction. At upAnd usUnder the combined action of the two, a high-frequency alternating current i is generated in the alternating current linkpAnd high-frequency power conversion is realized.
In addition, referring to fig. 7, the present invention also provides a system control apparatus. The system control device comprises an alternating current side acquisition end 20, a direct current side acquisition end 30, a pulse generation end 40 and a main control end 10, wherein the main control end 10 is respectively connected with the alternating current side acquisition end 20, the direct current side acquisition end 30 and the pulse generation end 40.
The alternating current side acquisition end 20 acquires voltage and current of an alternating current side, the direct current side acquisition end 30 acquires voltage and current of a direct current side and feeds the voltage and the current back to the main control end 10, the main control end 10 calculates according to a control algorithm to obtain a control instruction, the control instruction comprises an alternating current modulation ratio instruction, a direct current modulation ratio instruction and a primary-secondary side phase shift angle instruction, and the system control device generates control pulses of a power switch device of an alternating current side converter and a power switch device of a direct current side converter according to the control instruction, so that power conversion control is realized.
Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (10)
1. A single-stage isolated bidirectional AC-DC converter topology, comprising:
the AC side filter, one end of the said AC side filter is connected to AC power supply or load;
the AC side converter consists of two H half-bridges which are reversely connected in series, each H half-bridge consists of two power switching devices which are reversely connected in series in the same direction or in the same cathode, the anode end of one of the two power switching devices of the two H half-bridges is the power frequency output end of the AC side converter, the power frequency output end of the AC side converter is connected with the other end of the AC side filter, and the connecting end between the two power switching devices which are connected in series of the two H half-bridges is the high-frequency output end of the AC side converter;
the primary side of the high-frequency transformer is connected to an alternating-current side alternating-current link, the secondary side of the high-frequency transformer is connected to a direct-current side alternating-current link, and the alternating-current side alternating-current link is connected with the high-frequency output ends of the two alternating-current side converters;
one end of the direct current side converter is connected with a direct current side alternating current link;
and one end of the direct current side filter is connected with the other end of the direct current side converter, and the other end of the direct current side filter is connected with a direct current power supply.
2. The single-stage isolated bidirectional AC-DC converter topology of claim 1, wherein a low frequency isolation capacitor is further connected in series with the AC-side AC link and/or the DC-side AC link for separating DC components, power frequency components, and related low frequency components from the high and low frequency hybrid pulsed power waveform generated by the AC-side converter such that only high frequency pulsed power passes through the high frequency transformer.
3. The single-stage isolated bidirectional AC-DC converter topology of claim 2, wherein the AC-side AC link is further connected in series with a high frequency inductor, and/or the DC-side AC link is further connected in series with a high frequency inductor.
4. A single-stage isolated bidirectional AC-DC converter topology according to any of claims 1-3, wherein the power switching devices are one of IGBT power switching devices, IEGT power switching devices, or MOSFET power switching devices.
5. A single stage isolated bidirectional AC-DC converter topology as recited in any of claims 1-3, wherein the AC side filter is one of an LC type filter, a CLC type filter, or an RLC type filter.
6. The single-stage isolated bidirectional AC-DC converter topology of any of claims 1-3, wherein the DC-side converter is comprised of an H full bridge.
7. The single stage isolated bidirectional AC-DC converter topology of any of claims 1 to 3, wherein the DC-side filter is one of a C-type filter, an LC-type filter, or an LRC-type filter.
8. The method for controlling the topology of the single-stage isolated bidirectional AC-DC converter according to claim 2, comprising:
the adjustment of the power of the single-stage isolation bidirectional AC-DC converter and the control of the power flow direction are realized through bidirectional power conversion control;
the power switching device of the AC side converter and the power switching device of the DC side converter adopt the same high-frequency switching frequency; the alternating current side converter chops power frequency alternating current into high-frequency and low-frequency mixed pulse electric energy with adjustable duty ratio in a high-frequency chopping mode according to an alternating current modulation ratio instruction, and only the residual high-frequency pulse electric energy passes through the high-frequency transformer after the high-frequency and low-frequency mixed pulse electric energy passes through the low-frequency isolation capacitor; and the direct current side converter converts direct current into high-frequency pulse electric energy with adjustable duty ratio according to the direct current modulation ratio instruction.
9. The method of controlling a single-stage isolated bidirectional AC-DC converter topology of claim 8, wherein the bidirectional power conversion control comprises:
according to the original secondary side phase shift angle instruction, controlling the phase difference between the high-frequency pulse electric energy generated by the alternating current side converter and the high-frequency pulse electric energy generated by the direct current side converter, and realizing the adjustment of the power and the control of the power flow direction;
and/or changing the alternating current modulation ratio command and the direct current modulation ratio command to realize the adjustment of the power.
10. The method of claim 9, wherein the step of controlling the phase difference between the high frequency pulsed electrical energy generated by the AC side converter and the high frequency pulsed electrical energy generated by the DC side converter based on the primary and secondary side phase shift angle commands comprises:
and when the power frequency voltage of the power frequency alternating current connection point of the alternating current side converter passes through zero, controlling the phase shift angle instruction of the original secondary side to invert, or controlling the output pulse of the direct current side converter to invert.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210233966.4A CN114448286A (en) | 2022-03-10 | 2022-03-10 | Single-stage isolation bidirectional AC-DC converter topological structure and control method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210233966.4A CN114448286A (en) | 2022-03-10 | 2022-03-10 | Single-stage isolation bidirectional AC-DC converter topological structure and control method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114448286A true CN114448286A (en) | 2022-05-06 |
Family
ID=81358656
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210233966.4A Pending CN114448286A (en) | 2022-03-10 | 2022-03-10 | Single-stage isolation bidirectional AC-DC converter topological structure and control method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114448286A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117240111B (en) * | 2023-09-15 | 2024-04-26 | 江南大学 | High-power factor high-frequency resonance isolation type AC/DC converter without direct current link in middle |
| WO2024187553A1 (en) * | 2023-03-10 | 2024-09-19 | 阳光电源股份有限公司 | Single-stage three-port magnetic integrated topology, and vehicle-mounted charger and control method therefor |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103595274A (en) * | 2013-11-27 | 2014-02-19 | 东南大学 | Method for controlling double-direction power flow high-frequency isolated active clamping rectifier |
| CN112564525A (en) * | 2020-11-23 | 2021-03-26 | 南京南瑞继保电气有限公司 | Multi-level converter topology suitable for medium-high voltage occasions and control method |
| CN112910272A (en) * | 2021-02-24 | 2021-06-04 | 北京晶电科技有限公司 | Isolation transformer |
-
2022
- 2022-03-10 CN CN202210233966.4A patent/CN114448286A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103595274A (en) * | 2013-11-27 | 2014-02-19 | 东南大学 | Method for controlling double-direction power flow high-frequency isolated active clamping rectifier |
| CN112564525A (en) * | 2020-11-23 | 2021-03-26 | 南京南瑞继保电气有限公司 | Multi-level converter topology suitable for medium-high voltage occasions and control method |
| CN112910272A (en) * | 2021-02-24 | 2021-06-04 | 北京晶电科技有限公司 | Isolation transformer |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2024187553A1 (en) * | 2023-03-10 | 2024-09-19 | 阳光电源股份有限公司 | Single-stage three-port magnetic integrated topology, and vehicle-mounted charger and control method therefor |
| CN117240111B (en) * | 2023-09-15 | 2024-04-26 | 江南大学 | High-power factor high-frequency resonance isolation type AC/DC converter without direct current link in middle |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107276418B (en) | Wide-range soft switching direct current conversion circuit and control method thereof | |
| US8559193B2 (en) | Zero-voltage-switching scheme for high-frequency converter | |
| CN110798074B (en) | Cascade type single-phase alternating current-to-direct current isolation converter | |
| CN103595274B (en) | Method for controlling double-direction power flow high-frequency isolated active clamping rectifier | |
| CN112928919B (en) | Isolated high-frequency resonant DC-DC converter with wide output voltage range and method | |
| CN114448286A (en) | Single-stage isolation bidirectional AC-DC converter topological structure and control method thereof | |
| CN110957922A (en) | Single-stage high-frequency isolated bidirectional direct-current converter and grid-connected energy storage system | |
| CN112688572A (en) | Bidirectional DC-DC converter | |
| CN110445387B (en) | Topological structure and control method of formation and grading power supply | |
| CN107947587A (en) | A kind of high-efficiency constant-flow Width funtion output circuit | |
| Pal et al. | A three-phase three-level isolated DC–AC converter with line frequency unfolding | |
| AU2021240158A1 (en) | Efficient electric power conversion | |
| Duan et al. | A novel high-efficiency inverter for stand-alone and grid-connected systems | |
| Jiang et al. | A novel single-phase soft-switching unipolar PWM inverter | |
| CN113992013B (en) | Current source direct current converter and control method | |
| CN113612401B (en) | Direct current conversion system and control method thereof | |
| CN214045457U (en) | Bidirectional DC-DC converter | |
| CN115833598A (en) | Input indirect series output parallel variable frequency modulation direct current converter topology and control method thereof | |
| CN210578299U (en) | Photovoltaic inverter based on gallium nitride device | |
| CN114157157A (en) | Three-level rectification DC/DC converter | |
| CN114157155A (en) | Three-level rectification DC/DC converter | |
| Das et al. | A soft-switched isolated single stage bidirectional three phase AC-DC converter | |
| CN114747113A (en) | Charging device and method for operating a charging device | |
| CN103840686A (en) | High-efficiency power supply converter with integrated functions of PFC and DC conversion | |
| CN114448285A (en) | Three-phase single-stage isolation bidirectional AC-DC converter topological structure and control method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20220506 |
|
| RJ01 | Rejection of invention patent application after publication |