CN109687717B - Power-adjustable LC input series output parallel direct current transformer and control method - Google Patents

Power-adjustable LC input series output parallel direct current transformer and control method Download PDF

Info

Publication number
CN109687717B
CN109687717B CN201910061399.7A CN201910061399A CN109687717B CN 109687717 B CN109687717 B CN 109687717B CN 201910061399 A CN201910061399 A CN 201910061399A CN 109687717 B CN109687717 B CN 109687717B
Authority
CN
China
Prior art keywords
tube
bridge arm
switching tube
converter
power
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.)
Active
Application number
CN201910061399.7A
Other languages
Chinese (zh)
Other versions
CN109687717A (en
Inventor
陈武
姚金杰
薛晨炀
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Southeast University
Original Assignee
Southeast University
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Southeast University filed Critical Southeast University
Priority to CN201910061399.7A priority Critical patent/CN109687717B/en
Publication of CN109687717A publication Critical patent/CN109687717A/en
Application granted granted Critical
Publication of CN109687717B publication Critical patent/CN109687717B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

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
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
    • H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
    • H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
    • H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
    • H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/33569—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having several active switching elements
    • H02M3/33576—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having several active switching elements having at least one active switching element at the secondary side of an isolation transformer
    • 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
    • H02M1/08—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters
    • H02M1/088—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters for the simultaneous control of series or parallel connected semiconductor devices
    • 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
    • H02M1/0067—Converter structures employing plural converter units, other than for parallel operation of the units on a single load
    • H02M1/0074—Plural converter units whose inputs are connected in series
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
    • Y02B70/10—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

The invention discloses a power-adjustable LC input-series output parallel direct current transformer and a control method thereof. The LC series resonance circuit works under the resonance frequency in an open loop mode to realize zero current switching. When power is transmitted in the forward direction, the upper tube of the auxiliary bridge arm module is continuously turned off and utilizes the diode to carry out follow current, and the lower tube is conducted at a certain duty ratio; and when power is transmitted reversely, the lower tube of the auxiliary bridge arm module is continuously turned off and utilizes the diode to carry out follow current, and the upper tube is conducted at a certain duty ratio. The power of the whole direct current transformer can be adjusted by adjusting the duty ratio of the upper tube or the lower tube of the auxiliary bridge arm module. Therefore, the purpose of adjustable power is achieved without frequency conversion.

Description

Power-adjustable LC input series output parallel direct current transformer and control method
Technical Field
The invention belongs to the technical field of power electronics, and particularly relates to a power-adjustable LC input-series output-parallel direct current transformer and a control method.
Background
As an important branch of power electronic integration technology, a multi-converter series-parallel system has been a hot spot of research in recent years. Because the multi-module series-parallel system has the advantages of reducing development difficulty, facilitating capacity expansion, realizing system redundancy, high reliability and the like, the multi-module series-parallel system is widely applied to systems such as distributed power generation, power electronic transformers, uninterruptible power supplies and the like. For a multi-converter series-parallel system, systems with different series-parallel combination modes are applied to different occasions. Take an ISOP (input-series output-parallel) system as an example, which is suitable for high-voltage input and large-current output occasions. Such as high-power dc switching power supplies in urban rail transit, electrified railways and marine power supply systems.
The LC resonance type direct current transformer formed by the series-parallel connection of the LC series resonance converter modules has a simple topological structure, works with a quasi-sinusoidal current waveform, is easy to realize soft switching, and has the advantages of high converter efficiency, convenient parameter design and mature control theory, thereby being widely used. In addition, the series resonant converter has the short-circuit self-protection characteristic, and when the load is in short circuit, the resonant inductor can prevent the current from suddenly increasing, so that the protection circuit has sufficient time to act. Because the resonant current is reduced along with the reduction of the load current, the circuit can still ensure higher efficiency under light load. The resonant capacitor has the function of blocking direct current, and can effectively block direct current components in resonant current, so that the problem of unbalanced volt/second caused by different switching speeds, unequal switching conduction time and unequal conduction voltage drops of power devices can be solved without additional control. In addition, capacitive filters are adopted for filtering on the load side, and the size and the cost of the converter are reduced. However, the main disadvantage of the series resonant converter is that the voltage transmission gain curve at idle is approximately horizontal, and the switching frequency needs to be changed greatly to adjust the output voltage, which is not favorable for the design of the filter.
Disclosure of Invention
The purpose of the invention is as follows: aiming at the characteristics that the voltage and the power of the LC resonance type direct current transformer are uncontrollable when the LC resonance type direct current transformer works at a resonance point in an open loop mode, but the efficiency is high, an auxiliary bridge arm module is added, and the purpose of adjusting the power of the direct current transformer can be realized without frequency conversion by adjusting the duty ratio of a switching tube of the auxiliary bridge arm module.
The technical scheme is as follows: in order to realize the purpose, the invention adopts the following technical scheme:
the power-adjustable LC input and the power-adjustable LC output based on the auxiliary bridge arm module are connected in series and output in parallel with a direct current transformer,
the DC-DC converter comprises N +1 DC-DC converters, wherein N is an integer and is more than or equal to 2:
the DC-DC converter comprises N LC series resonance converter modules and an auxiliary bridge arm module; the N LC series resonance converter modules are used as power transmission modules of the DC-DC converter;
the auxiliary bridge arm module is used for controlling the power of the DC-DC converter;
the input end of each LC series resonant converter module is respectively connected in parallel with a corresponding input voltage dividing capacitor CdiThe output ends of the two terminals are connected in parallel and then connected with the two sides of the load, and each LC series resonant converter has its ownThe controllers among the modules have no interconnection line, so that the independent control of each module is realized.
As a further preferable scheme of the power-adjustable LC input-series output-parallel direct current transformer based on the auxiliary bridge arm module, the LC series resonance converter module comprises an input voltage-dividing capacitor CdiConverter primary side, converter secondary side and output capacitor CoiThe input end of the primary side of the converter is connected in parallel with a corresponding input voltage-dividing capacitor CdiThe primary side of the converter is coupled with the secondary side of the converter through a magnetic circuit, and the output end of the secondary side of the converter is connected in parallel with an output capacitor CoiThen connected in parallel to the low voltage dc terminal, i ═ 1, 2.
As a further preferable scheme of the power-adjustable LC input-series output parallel direct current transformer based on the auxiliary bridge arm module of the present invention, the LC series resonant converter module includes a converter primary side full bridge circuit and a secondary side full bridge circuit, wherein the converter primary side full bridge circuit includes: first switch tube Qi1A second switch tube Qi2And a third switching tube Qi3And a fourth switching tube Qi4Primary side resonance inductance LriPrimary side resonance capacitor CriAnd a primary winding, a first switching tube Qi1To the fourth switching tube Qi4The first bridge arm and the second bridge arm are respectively arranged on a primary side full bridge circuit of the converter; the midpoint of the first bridge arm passes through the primary resonant inductor LriConnected with the same-name end of the primary winding, and the midpoint of the second bridge arm passes through the primary resonant capacitor CriIs connected with the other end of the primary winding;
the converter secondary side full bridge circuit comprises: fifth switch tube Qi5And a sixth switching tube Qi6Seventh switch tube Qi7The eighth switch tube Qi8And a secondary winding; fifth switch tube Qi5And a sixth switching tube Qi6Seventh switch tube Qi7The eighth switch tube Qi8The first bridge arm and the second bridge arm are respectively arranged on a secondary side full bridge circuit of the converter; the middle point of the first bridge arm is connected with the same name end of the secondary winding, and the middle point of the second bridge arm is connected with the other end of the secondary windingConnecting; 1, 2.
As a further preferable scheme of the power-adjustable LC input-series output-parallel direct current transformer based on the auxiliary bridge arm module, a first switching tube Q of an LC series resonant converter modulei1And a second switching tube Qi2The driving waveforms are complementary, the duty ratios are all fixed 50%, and the third switching tube Qi3And a fourth switching tube Qi4The driving waveforms are complementary and the duty ratio is fixed 50%, the first switch tube Qi1And a fourth switching tube Qi4The driving waveforms are the same, and the second switch tube Qi2And a third switching tube Qi3The driving waveforms are the same;
fifth switch tube Qi5And a sixth switching tube Qi6The drive waveforms are complementary and the duty ratio is fixed 50%, and a seventh switching tube Qi7And an eighth switching tube Qi8The driving waveforms are complementary, the duty ratio is fixed 50%, and the fifth switching tube Qi5And an eighth switching tube Qi8The sixth switching tube Q with the same driving waveformi6And a seventh switching tube Qi7The driving waveforms are the same;
first switch tube Qi1Drive waveform of (1) and fifth switching tube Qi5The same drive waveform is also used; first switch tube Qi1To the eighth switching tube Qi8Has the same switching frequency as the resonant frequency of the resonant cavity, is
Figure GDA0003046563070000031
As a further preferable scheme of the power-adjustable LC input-series output-parallel direct current transformer based on the auxiliary bridge arm module, the auxiliary bridge arm module comprises an input capacitor CaAn input inductor LaAnd a half bridge; wherein the upper tube and the lower tube of the half-bridge are connected with a diode in an anti-parallel mode, and the upper tube of the half-bridge is connected with an input voltage-dividing capacitor C of the LC series resonant converter moduledNLower tube connected to the input capacitor CaThe negative electrode of (1); input capacitance CaThe anode of the capacitor is connected in series with an input voltage-dividing capacitor C of the LC series resonant converter moduledNNegative pole of (1), input inductance LaA bridge terminating in a half-bridgeThe arm midpoint, the other end connected to the input capacitor CaThe positive electrode of (1).
As a further preferable scheme of the power-adjustable LC input-series output-parallel direct current transformer based on the auxiliary bridge arm module, when power is transmitted in the forward direction, an upper tube of the auxiliary bridge arm module always supplies a low-level signal and is in a normally-off state, an anti-parallel diode of the auxiliary bridge arm module is used for follow current, and the driving waveform of a lower tube is a square wave signal with adjustable duty ratio; when power is transmitted reversely, the lower tube of the auxiliary bridge arm module always supplies a low-level signal and is in a normally-off state, the anti-parallel diode of the auxiliary bridge arm module is used for freewheeling, and the driving waveform of the upper tube is a square wave signal with adjustable duty ratio.
A control method for a power-adjustable LC input-series output-parallel direct current transformer specifically comprises the following steps:
step 1, setting the switching frequency of each switching tube in the 1 st to N th LC series resonance converter modules to obtain the driving signal of the LC series resonance converter modules, so that the LC series resonance converter modules adopt a 50% duty ratio open-loop control mode;
step 2, setting the switching frequency of each switching tube of the auxiliary bridge arm module to be the same as the switching frequency of each switching tube in the LC series resonant converter module, and obtaining a driving signal of the switching tubes of the auxiliary bridge arm module;
and 3, performing power control on the input series output parallel direct current transformer.
As a further preferable scheme of the control method of the power-adjustable LC input series output parallel dc transformer of the present invention, in step 1: first switch tube Q of LC series resonance converter modulei1And a second switching tube Qi2The driving waveforms are complementary, the duty ratios are all fixed 50%, and the third switching tube Qi3And a fourth switching tube Qi4The driving waveforms are complementary and the duty ratio is fixed 50%, the first switch tube Qi1And a fourth switching tube Qi4The driving waveforms are the same, and the second switch tube Qi2And a third switching tube Qi3The driving waveforms are the same;
fifth switch tube Qi5And a sixth switching tube Qi6Are complementary and are duty-cycledAll the ratios are fixed 50%, and the seventh switch tube Qi7And an eighth switching tube Qi8The driving waveforms are complementary, the duty ratio is fixed 50%, and the fifth switching tube Qi5And an eighth switching tube Qi8The sixth switching tube Q with the same driving waveformi6And a seventh switching tube Qi7The driving waveforms are the same;
first switch tube Qi1Drive waveform of (1) and fifth switching tube Qi5The same drive waveform is also used; first switch tube Qi1To the eighth switching tube Qi8Has the same switching frequency as the resonant frequency of the resonant cavity, is
Figure GDA0003046563070000041
As a further preferable scheme of the control method of the power-adjustable LC input series output parallel dc transformer of the present invention, in step 2: when power is transmitted in the forward direction, an upper tube of the auxiliary bridge arm module always supplies a low-level signal and is in a normally-off state, an anti-parallel diode of the auxiliary bridge arm module is used for follow current, and the driving waveform of a lower tube is a square wave signal with adjustable duty ratio; when power is transmitted reversely, the lower tube of the auxiliary bridge arm module always supplies a low-level signal and is in a normally-off state, the anti-parallel diode of the auxiliary bridge arm module is used for freewheeling, and the driving waveform of the upper tube is a square wave signal with adjustable duty ratio.
As a further preferable scheme of the control method of the power-adjustable LC input series output parallel dc transformer of the present invention, step 3 specifically is:
step 3.1, judging the power transmission direction, and determining the working mode of the auxiliary bridge arm module;
step 3.2, sampling the output power of the input serial output parallel direct current transformer, then making a difference with the reference power to obtain a difference value, and obtaining the duty ratio of the upper tube or the lower tube of the auxiliary bridge arm module by the difference value sequentially passing through a PI regulator and an amplitude limiter;
and 3.3, feeding back the obtained duty ratio to the auxiliary bridge arm module to control the input and the series output of the parallel direct current transformer to output power.
Compared with the prior art, the invention has the advantages that,
1) the efficiency is high, and the output power can be adjusted without frequency conversion;
2) in the technical scheme, all the LC series resonance converter module switching tubes are driven to have a fixed duty ratio of 50%, PI regulation is performed only by sampling output power to obtain the duty ratio of the auxiliary bridge arm module switching tubes, and the control method is simple and easy to implement;
3) the modules have no interconnection line, so that the modularization degree is high;
4) the technical scheme has low cost and is convenient for further popularization and application.
Drawings
FIG. 1 is a schematic diagram of a main circuit of an ISOP DC transformer system according to the present invention;
FIG. 2 is a schematic diagram of a main circuit of an ISOP DC transformer system composed of two LC series resonant converter modules according to the present invention;
FIG. 3 is a typical drive for an LC series resonant converter module of the present invention;
FIG. 4 is a diagram of the main operating waveforms of an LC series resonant converter module of the present invention;
FIG. 5 is a waveform of output power variation of the system when the duty ratio of the switching tube of the auxiliary bridge arm module is changed according to the present invention;
FIG. 6 is a waveform of the output power variation of the system in the power reversal of the present invention.
Detailed Description
The technical solution of the present invention will be further explained with reference to the accompanying drawings and specific embodiments.
The following are only preferred embodiments of the present invention, it being noted that: it will be apparent to those skilled in the art that various modifications and adaptations can be made without departing from the principles of the invention and these are intended to be within the scope of the invention.
As shown in fig. 1, a power-adjustable LC input series output parallel dc transformer based on an auxiliary bridge arm module is characterized in that:
the DC-DC converter comprises N +1 DC-DC converters, wherein N is an integer and is more than or equal to 2:
the DC-DC converter comprises N LC series resonance converter modules and an auxiliary bridge arm module; the N LC series resonance converter modules are used as power transmission modules of the DC-DC converter;
the auxiliary bridge arm module is used for controlling the power of the whole converter;
the input end of each LC series resonance converter module is respectively connected with two ends of a corresponding input voltage-dividing capacitor in parallel, the output end of each LC series resonance converter module is connected with two sides of a load after being connected in parallel, each LC series resonance converter module is provided with a control loop, and the controllers among the modules are free of interconnection lines, so that the independent control of each module is realized.
The LC series resonant converter module comprises an input voltage-dividing capacitor CdiConverter primary side, converter secondary side and output capacitor CoiThe input end of the primary side of the converter is connected in parallel with a corresponding input voltage-dividing capacitor CdiThe primary side of the converter is coupled with the secondary side of the converter through a magnetic circuit, and the output end of the secondary side of the converter is connected in parallel with an output capacitor CoiThen connected in parallel to the low voltage dc terminal, i ═ 1, 2.
The LC series resonance converter module comprises a converter primary side full-bridge circuit and a secondary side full-bridge circuit, wherein the converter primary side full-bridge circuit comprises: first switch tube Qi1A second switch tube Qi2And a third switching tube Qi3And a fourth switching tube Qi4Primary side resonance inductance LriPrimary side resonance capacitor CriThe first switching tube to the fourth switching tube are connected with a diode in an anti-parallel mode and then are respectively arranged on a first bridge arm and a second bridge arm of a primary side full-bridge circuit of the converter; the midpoint of the first bridge arm passes through the primary resonant inductor LriConnected with the same-name end of the primary winding, and the midpoint of the second bridge arm passes through the primary resonant capacitor CriIs connected with the other end of the primary winding;
the converter secondary side full bridge circuit comprises: fifth switch tube Qi5And a sixth switching tube Qi6Seventh switchTube Qi7The eighth switch tube Qi8And a secondary winding; fifth switch tube Qi5And a sixth switching tube Qi6Seventh switch tube Qi7The eighth switch tube Qi8The first bridge arm and the second bridge arm are respectively arranged on a secondary side full bridge circuit of the converter; the midpoint of the first bridge arm is connected with the same-name end of the secondary winding, and the midpoint of the second bridge arm is connected with the other end of the secondary winding; 1, 2.
First switch tube Q of LC series resonance converter modulei1And a second switching tube Qi2The driving waveforms are complementary, the duty ratios are all fixed 50%, and the third switching tube Qi3And a fourth switching tube Qi4The driving waveforms are complementary and the duty ratio is fixed 50%, the first switch tube Qi1And a fourth switching tube Qi4The driving waveforms are the same, and the second switch tube Qi2And a third switching tube Qi3The driving waveforms are the same;
fifth switch tube Qi5And a sixth switching tube Qi6The drive waveforms are complementary and the duty ratio is fixed 50%, and a seventh switching tube Qi7And an eighth switching tube Qi8The driving waveforms are complementary, the duty ratio is fixed 50%, and the fifth switching tube Qi5And an eighth switching tube Qi8The sixth switching tube Q with the same driving waveformi6And a seventh switching tube Qi7The driving waveforms are the same;
first switch tube Qi1Drive waveform of (1) and fifth switching tube Qi5The same drive waveform is also used; the switching frequency of the switching tube is the same as the resonant frequency of the resonant cavity, and is
The auxiliary bridge arm module comprises an input capacitor CaAn input inductor LaAnd a half bridge; wherein the upper tube and the lower tube of the half-bridge are connected with a diode in an anti-parallel mode, and the upper tube of the half-bridge is connected with an input voltage-dividing capacitor C of the LC series resonant converter moduledNLower tube connected to the input capacitor CaThe negative electrode of (1); input capacitance CaThe anode of the resonant circuit is connected in series with the LC series resonant converterInput voltage-dividing capacitor C of moduledNNegative pole of (1), input inductance LaOne end of the input capacitor is connected to the middle point of the bridge arm of the half bridge, and the other end is connected to the input capacitor CaThe positive electrode of (1).
When power is transmitted in the forward direction, an upper tube of the auxiliary bridge arm module always supplies a low-level signal and is in a normally-off state, an anti-parallel diode of the auxiliary bridge arm module is used for follow current, and the driving waveform of a lower tube is a square wave signal with adjustable duty ratio; when power is transmitted reversely, the lower tube of the auxiliary bridge arm module always supplies a low-level signal and is in a normally-off state, the anti-parallel diode of the auxiliary bridge arm module is used for freewheeling, and the driving waveform of the upper tube is a square wave signal with adjustable duty ratio.
The invention also provides a control method of the power-adjustable LC input-series output parallel direct current transformer based on the auxiliary bridge arm module, which is characterized by comprising the following steps:
step 1, setting the switching frequency of each switching tube in the 1 st to N th LC series resonance converter modules to obtain the driving signal of the LC series resonance converter modules, so that the LC series resonance converter modules adopt a 50% duty ratio open-loop control mode;
step 2, setting the switching frequency of each switching tube of the auxiliary bridge arm module to be the same as the switching frequency of each switching tube in the LC series resonant converter module, and obtaining a driving signal of the switching tubes of the auxiliary bridge arm module;
and 3, performing power control on the ISOP direct current transformer.
In step 1: first switch tube Q of LC series resonance converter modulei1And a second switching tube Qi2The driving waveforms are complementary, the duty ratios are all fixed 50%, and the third switching tube Qi3And a fourth switching tube Qi4The driving waveforms are complementary and the duty ratio is fixed 50%, the first switch tube Qi1And a fourth switching tube Qi4The driving waveforms are the same, and the second switch tube Qi2And a third switching tube Qi3The driving waveforms are the same;
fifth switch tube Qi5And a sixth switching tube Qi6The drive waveforms are complementary and the duty ratio is fixed 50%, and a seventh switching tube Qi7And an eighth switching tube Qi8Drive theThe waveforms are complementary, the duty ratio is fixed 50%, and the fifth switching tube Qi5And an eighth switching tube Qi8The sixth switching tube Q with the same driving waveformi6And a seventh switching tube Qi7The driving waveforms are the same;
first switch tube Qi1Drive waveform of (1) and fifth switching tube Qi5The same drive waveform is also used; first switch tube Qi1To the eighth switching tube Qi8Has the same switching frequency as the resonant frequency of the resonant cavity, is
Figure GDA0003046563070000072
In step 2, the following steps are carried out: when power is transmitted in the forward direction, an upper tube of the auxiliary bridge arm module always supplies a low-level signal and is in a normally-off state, an anti-parallel diode of the auxiliary bridge arm module is used for follow current, and the driving waveform of a lower tube is a square wave signal with adjustable duty ratio; when power is transmitted reversely, the lower tube of the auxiliary bridge arm module always supplies a low-level signal and is in a normally-off state, the anti-parallel diode of the auxiliary bridge arm module is used for freewheeling, and the driving waveform of the upper tube is a square wave signal with adjustable duty ratio.
The step 3 specifically comprises the following steps:
step 3.1, judging the power transmission direction, and determining the working mode of the auxiliary bridge arm module;
step 3.2, sampling the output power of the ISOP direct current transformer, then making a difference with the reference power, and obtaining the duty ratio of the upper tube or the lower tube of the auxiliary bridge arm module by the difference value sequentially passing through a PI regulator and an amplitude limiter;
and 3.3, feeding back the obtained duty ratio to the auxiliary bridge arm module to control the power output of the direct current transformer.
Example (b):
the working principle of the technical solution of the present invention is illustrated below by taking an example of an iso p dc transformer (as shown in fig. 2) composed of two LC series resonant converter module modules and an auxiliary bridge arm module, and combining the simulation result. The simulation parameters are as follows:
simulation main parameters
Figure GDA0003046563070000081
Fig. 2 is a topology structure diagram of an ISOP dc transformer including two modules of an auxiliary bridge arm module, and referring to the control mode of fig. 3, a driving signal of the converter is given according to the control method provided in the foregoing, that is, the LC series resonant converter module adopts a 50% duty ratio open-loop control mode, and the auxiliary bridge arm module adopts a single-tube switching-on mode. Fig. 4 shows the main operating waveforms of the LC series resonant converter module with corresponding driving signals.
At the moment, power is transmitted in the forward direction, and the transmission power of the whole direct current transformer is changed by changing the duty ratio of the lower tube of the auxiliary bridge arm module.
As shown in fig. 5, when the time is 0.1s, the transmission power of the system jumps, and the jump of the transmission power is realized by changing the duty ratio of the lower tube of the auxiliary bridge arm module. Under the condition that the voltage of the low-voltage side is not changed, the output power of the system can be effectively adjusted by adjusting the duty ratio of the lower tube of the auxiliary bridge arm module.
As shown in fig. 6, at 0.1s, the transmission power direction of the system jumps, and the reverse power transmission mode is changed into the forward power transmission mode by changing the working mode of the auxiliary bridge arm module. Under the condition that the voltage of the low-voltage side is not changed, the direction of the output power of the system can be effectively adjusted by adjusting the working mode of the auxiliary bridge arm module.
In a word, the power-adjustable LC type input-series output-parallel (ISOP) direct current transformer based on the auxiliary bridge arm module is suitable for a medium-voltage direct current distribution network. The direct current transformer comprises a plurality of LC series resonance converter modules and an auxiliary bridge arm module, wherein an LC resonance circuit works under a resonance frequency to realize zero current switching. When power is transmitted in the forward direction, the upper tube of the auxiliary bridge arm module is continuously turned off and utilizes the diode to carry out follow current, and the lower tube is conducted at a certain duty ratio; and when power is transmitted reversely, the lower tube of the auxiliary bridge arm module is continuously turned off and utilizes the diode to carry out follow current, and the upper tube is conducted at a certain duty ratio. The power of the whole direct current transformer can be adjusted by adjusting the duty ratio of the upper tube or the lower tube of the auxiliary bridge arm module. Therefore, the purpose of adjustable power is achieved without frequency conversion.

Claims (5)

1. The power-adjustable LC input-series output parallel direct current transformer based on the auxiliary bridge arm module is characterized in that:
the DC-DC converter comprises N +1 DC-DC converters, wherein N is an integer and is more than or equal to 2:
the DC-DC converter comprises N LC series resonance converter modules and an auxiliary bridge arm module; the N LC series resonance converter modules are used as power transmission modules of the DC-DC converter;
the auxiliary bridge arm module is used for controlling the power of the DC-DC converter;
the input end of each LC series resonant converter module is respectively connected in parallel with a corresponding input voltage dividing capacitor CdiThe output ends of the two ends of the load are connected with the two sides of the load in parallel, each LC series resonance converter module is provided with a control loop, and controllers among the modules have no interconnection line, so that the independent control of each module is realized;
the LC series resonant converter module comprises an input voltage-dividing capacitor CdiConverter primary side, converter secondary side and output capacitor CoiThe input end of the primary side of the converter is connected in parallel with a corresponding input voltage-dividing capacitor CdiThe primary side of the converter is coupled with the secondary side of the converter through a magnetic circuit, and the output end of the secondary side of the converter is connected in parallel with an output capacitor CoiThen, the two ends of the low-voltage direct-current terminal are connected in parallel, i is 1,2,.
The LC series resonance converter module comprises a converter primary side full-bridge circuit and a secondary side full-bridge circuit, wherein the converter primary side full-bridge circuit comprises: first switch tube Qi1A second switch tube Qi2And a third switching tube Qi3And a fourth switching tube Qi4Primary side resonance inductance LriPrimary side resonance capacitor CriAnd a primary winding, firstSwitch tube Qi1To the fourth switching tube Qi4The first bridge arm and the second bridge arm are respectively arranged on a primary side full bridge circuit of the converter; the midpoint of the first bridge arm passes through the primary resonant inductor LriConnected with the same-name end of the primary winding, and the midpoint of the second bridge arm passes through the primary resonant capacitor CriIs connected with the other end of the primary winding;
the converter secondary side full bridge circuit comprises: fifth switch tube Qi5And a sixth switching tube Qi6Seventh switch tube Qi7The eighth switch tube Qi8And a secondary winding; fifth switch tube Qi5And a sixth switching tube Qi6Seventh switch tube Qi7The eighth switch tube Qi8The first bridge arm and the second bridge arm are respectively arranged on a secondary side full bridge circuit of the converter; the midpoint of the first bridge arm is connected with the same-name end of the secondary winding, and the midpoint of the second bridge arm is connected with the other end of the secondary winding; 1,2, N;
first switch tube Q of LC series resonance converter modulei1And a second switching tube Qi2The driving waveforms are complementary, the duty ratios are all fixed 50%, and the third switching tube Qi3And a fourth switching tube Qi4The driving waveforms are complementary and the duty ratio is fixed 50%, the first switch tube Qi1And a fourth switching tube Qi4The driving waveforms are the same, and the second switch tube Qi2And a third switching tube Qi3The driving waveforms are the same;
fifth switch tube Qi5And a sixth switching tube Qi6The drive waveforms are complementary and the duty ratio is fixed 50%, and a seventh switching tube Qi7And an eighth switching tube Qi8The driving waveforms are complementary, the duty ratio is fixed 50%, and the fifth switching tube Qi5And an eighth switching tube Qi8The sixth switching tube Q with the same driving waveformi6And a seventh switching tube Qi7The driving waveforms are the same;
first switch tube Qi1Drive waveform of (1) and fifth switching tube Qi5The same drive waveform is also used; first switch tube Qi1To the eighth switching tube Qi8Has the same switching frequency as the resonant frequency of the resonant cavity, is
Figure FDA0003046563060000021
The auxiliary bridge arm module comprises an input capacitor CaAn input inductor LaAnd a half bridge; wherein the upper tube and the lower tube of the half-bridge are connected with a diode in an anti-parallel mode, and the upper tube of the half-bridge is connected with an input voltage-dividing capacitor C of the LC series resonant converter moduledNLower tube connected to the input capacitor CaThe negative electrode of (1); input capacitance CaThe anode of the capacitor is connected in series with an input voltage-dividing capacitor C of the LC series resonant converter moduledNNegative pole of (1), input inductance LaOne end of the input capacitor is connected to the middle point of the bridge arm of the half bridge, and the other end is connected to the input capacitor CaThe positive electrode of (1);
when power is transmitted in the forward direction, an upper tube of the auxiliary bridge arm module always supplies a low-level signal and is in a normally-off state, an anti-parallel diode of the auxiliary bridge arm module is used for follow current, and the driving waveform of a lower tube is a square wave signal with adjustable duty ratio; when power is transmitted reversely, the lower tube of the auxiliary bridge arm module always supplies a low-level signal and is in a normally-off state, the anti-parallel diode of the auxiliary bridge arm module is used for freewheeling, and the driving waveform of the upper tube is a square wave signal with adjustable duty ratio.
2. The control method of the power-adjustable LC input-series output-parallel direct current transformer based on the auxiliary bridge arm module is characterized by comprising the following steps of:
step 1, setting the switching frequency of each switching tube in the 1 st to N th LC series resonance converter modules to obtain the driving signal of the LC series resonance converter modules, so that the LC series resonance converter modules adopt a 50% duty ratio open-loop control mode;
step 2, setting the switching frequency of each switching tube of the auxiliary bridge arm module to be the same as the switching frequency of each switching tube in the LC series resonant converter module, and obtaining a driving signal of the switching tubes of the auxiliary bridge arm module;
and 3, performing power control on the input series output parallel direct current transformer.
3. The control method of the power-adjustable LC input-series output-parallel direct current transformer based on the auxiliary bridge arm module as claimed in claim 2, wherein in step 1: first switch tube Q of LC series resonance converter modulei1And a second switching tube Qi2The driving waveforms are complementary, the duty ratios are all fixed 50%, and the third switching tube Qi3And a fourth switching tube Qi4The driving waveforms are complementary and the duty ratio is fixed 50%, the first switch tube Qi1And a fourth switching tube Qi4The driving waveforms are the same, and the second switch tube Qi2And a third switching tube Qi3The driving waveforms are the same;
fifth switch tube Qi5And a sixth switching tube Qi6The drive waveforms are complementary and the duty ratio is fixed 50%, and a seventh switching tube Qi7And an eighth switching tube Qi8The driving waveforms are complementary, the duty ratio is fixed 50%, and the fifth switching tube Qi5And an eighth switching tube Qi8The sixth switching tube Q with the same driving waveformi6And a seventh switching tube Qi7The driving waveforms are the same;
first switch tube Qi1Drive waveform of (1) and fifth switching tube Qi5The same drive waveform is also used; first switch tube Qi1To the eighth switching tube Qi8Has the same switching frequency as the resonant frequency of the resonant cavity, is
4. The control method of the power-adjustable LC input-series output-parallel direct current transformer based on the auxiliary bridge arm module is characterized in that in the step 2: when power is transmitted in the forward direction, an upper tube of the auxiliary bridge arm module always supplies a low-level signal and is in a normally-off state, an anti-parallel diode of the auxiliary bridge arm module is used for follow current, and the driving waveform of a lower tube is a square wave signal with adjustable duty ratio; when power is transmitted reversely, the lower tube of the auxiliary bridge arm module always supplies a low-level signal and is in a normally-off state, the anti-parallel diode of the auxiliary bridge arm module is used for freewheeling, and the driving waveform of the upper tube is a square wave signal with adjustable duty ratio.
5. The auxiliary bridge arm module-based control method for the power-adjustable LC input-series output-parallel direct current transformer according to claim 4, wherein the step 3 specifically comprises the following steps:
step 3.1, judging the power transmission direction, and determining the working mode of the auxiliary bridge arm module;
step 3.2, sampling the output power of the input serial output parallel direct current transformer, then making a difference with the reference power to obtain a difference value, and obtaining the duty ratio of the upper tube or the lower tube of the auxiliary bridge arm module by the difference value sequentially passing through a PI regulator and an amplitude limiter;
and 3.3, feeding back the obtained duty ratio to the auxiliary bridge arm module to control the input and the series output of the parallel direct current transformer to output power.
CN201910061399.7A 2019-01-23 2019-01-23 Power-adjustable LC input series output parallel direct current transformer and control method Active CN109687717B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201910061399.7A CN109687717B (en) 2019-01-23 2019-01-23 Power-adjustable LC input series output parallel direct current transformer and control method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201910061399.7A CN109687717B (en) 2019-01-23 2019-01-23 Power-adjustable LC input series output parallel direct current transformer and control method

Publications (2)

Publication Number Publication Date
CN109687717A CN109687717A (en) 2019-04-26
CN109687717B true CN109687717B (en) 2021-06-22

Family

ID=66193854

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201910061399.7A Active CN109687717B (en) 2019-01-23 2019-01-23 Power-adjustable LC input series output parallel direct current transformer and control method

Country Status (1)

Country Link
CN (1) CN109687717B (en)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3819159A1 (en) * 2019-11-11 2021-05-12 Fico Triad, S.A. Multi-port and multi-directional power conversion system for electric and/or hybrid vehicles
CN110868076B (en) * 2019-11-15 2021-08-10 中国舰船研究设计中心 DC-DC chopper device for ship regional power distribution
CN111614147A (en) * 2020-03-14 2020-09-01 青岛鼎信通讯股份有限公司 Working mode and control method for improving efficiency of charging station energy router system
CN111555629B (en) * 2020-05-14 2022-12-20 成都芯源系统有限公司 Resonant converter and control circuit and control method thereof
CN111786568A (en) * 2020-08-06 2020-10-16 石家庄通合电子科技股份有限公司 Bidirectional power converter, circuit and system
CN113014086B (en) * 2021-03-08 2022-02-01 东南大学 Direct-current transformer topological structure with high voltage transmission ratio and control method thereof
CN113037081B (en) * 2021-03-09 2022-03-22 东南大学 Modular high-voltage transmission ratio direct-current transformer topological structure and control method

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101536297A (en) * 2006-09-21 2009-09-16 伊顿工业公司 A switched mode power supply and method of production
US8300438B1 (en) * 2008-11-16 2012-10-30 Edward Herbert Power factor corrected 3-phase Ac-dc power converter using natural modulation
CN103312150A (en) * 2013-05-21 2013-09-18 东南大学 Voltage balancing control method of input-series and output-parallel combined converter
CN204392098U (en) * 2015-03-03 2015-06-10 张良华 A kind of Monophase electric power electronic transformer and application system thereof
CN107181413A (en) * 2017-07-15 2017-09-19 华北电力大学（保定） Mixed type direct current power electronic transformer
CN208063056U (en) * 2018-04-11 2018-11-06 南京南瑞继保电气有限公司 A kind of two-way DC converter of hybrid resonant type circuit and double active bridge circuits

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20140047981A (en) * 2012-10-15 2014-04-23 엘에스산전 주식회사 A dc-dc converter

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101536297A (en) * 2006-09-21 2009-09-16 伊顿工业公司 A switched mode power supply and method of production
US8300438B1 (en) * 2008-11-16 2012-10-30 Edward Herbert Power factor corrected 3-phase Ac-dc power converter using natural modulation
CN103312150A (en) * 2013-05-21 2013-09-18 东南大学 Voltage balancing control method of input-series and output-parallel combined converter
CN204392098U (en) * 2015-03-03 2015-06-10 张良华 A kind of Monophase electric power electronic transformer and application system thereof
CN107181413A (en) * 2017-07-15 2017-09-19 华北电力大学（保定） Mixed type direct current power electronic transformer
CN208063056U (en) * 2018-04-11 2018-11-06 南京南瑞继保电气有限公司 A kind of two-way DC converter of hybrid resonant type circuit and double active bridge circuits

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
全桥直流变压器/变换器ISOP组合式系统的研究;王子龙 等;《中国机电工程学报》;20141125 *
直流电网潮流控制与短路控制复合装置;叶晗 等;《电力系统自动化》;20181210 *

Also Published As

Publication number Publication date
CN109687717A (en) 2019-04-26

Similar Documents

Publication Publication Date Title
CN109687717B (en) Power-adjustable LC input series output parallel direct current transformer and control method
CN109687719B (en) Modulation method for CLLC bidirectional isolation type DC-DC converter
CN111446861B (en) DC/DC converter and control method thereof
CN110289765B (en) High-power-density DAB type direct current transformer submodule topology and control method thereof
CN110707931A (en) LLC resonant converter and control method
CN101534056B (en) Output adjustable structure-changeable direct current switch power supply
CN107017781B (en) The ISOP full-bridge direct current converter and its control method of asymmetrical PWM control
CN110277912B (en) Direct current boost conversion circuit
CN108736756B (en) Improved double-auxiliary resonant-pole three-phase soft switching inverter circuit
CN208939829U (en) A kind of controlled resonant converter
CN110365213B (en) Bidirectional direct current converter comprising two types of modules and control method thereof
CN211127589U (en) Single-stage high-frequency isolated bidirectional direct-current converter and grid-connected energy storage system
CN112054687A (en) Multi-path current-sharing LLC resonant converter
CN110601525A (en) Integrated vehicle-mounted charging conversion system of new energy automobile
CN108667301B (en) Full-bridge converter with follow current path
CN113437879B (en) Direct current converter and control method thereof
CN212627700U (en) Electric energy router
CN112421959B (en) Direct-current transformer topology and control method thereof
CN111669057B (en) DC boost converter and control method thereof
CN210724554U (en) Clamping type boosting power conversion circuit structure
CN112737316A (en) quasi-Z-source inverter and power supply system
CN1033121C (en) Constant-frequency zero-voltage edge resonance switch convertor
CN110957922A (en) Single-stage high-frequency isolated bidirectional direct-current converter and grid-connected energy storage system
CN111342664A (en) Integrated DC-DC converter and control method thereof
CN111030466A (en) Wide-voltage isolation type DC-DC converter with automatic current limiting function

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
GR01 Patent grant
GR01 Patent grant