CN114884318A - Control method of bidirectional buck-boost direct current converter based on duty ratio compensation - Google Patents

Control method of bidirectional buck-boost direct current converter based on duty ratio compensation Download PDF

Info

Publication number
CN114884318A
CN114884318A CN202210674786.XA CN202210674786A CN114884318A CN 114884318 A CN114884318 A CN 114884318A CN 202210674786 A CN202210674786 A CN 202210674786A CN 114884318 A CN114884318 A CN 114884318A
Authority
CN
China
Prior art keywords
compensation
duty ratio
boost
bridge arm
buck
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
Application number
CN202210674786.XA
Other languages
Chinese (zh)
Inventor
毕恺韬
庄煜
刘柳
李安龙
朱一昕
樊启高
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.)
Jiangnan University
Original Assignee
Jiangnan 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 Jiangnan University filed Critical Jiangnan University
Priority to CN202210674786.XA priority Critical patent/CN114884318A/en
Publication of CN114884318A publication Critical patent/CN114884318A/en
Pending legal-status Critical Current

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
    • 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
    • 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
    • H02M1/42—Circuits or arrangements for compensating for or adjusting power factor in converters or inverters
    • 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
    • H02M3/02—Conversion of dc power input into dc power output without intermediate conversion into ac
    • H02M3/04—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters
    • H02M3/10—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M3/145—Conversion of dc power input into dc power output without intermediate conversion into ac 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
    • H02M3/155—Conversion of dc power input into dc power output without intermediate conversion into ac 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
    • H02M3/156—Conversion of dc power input into dc power output without intermediate conversion into ac 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 with automatic control of output voltage or current, e.g. switching regulators
    • H02M3/157—Conversion of dc power input into dc power output without intermediate conversion into ac 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 with automatic control of output voltage or current, e.g. switching regulators with digital control
    • 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
    • H02M3/02—Conversion of dc power input into dc power output without intermediate conversion into ac
    • H02M3/04—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters
    • H02M3/10—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M3/145—Conversion of dc power input into dc power output without intermediate conversion into ac 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
    • H02M3/155—Conversion of dc power input into dc power output without intermediate conversion into ac 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
    • H02M3/156—Conversion of dc power input into dc power output without intermediate conversion into ac 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 with automatic control of output voltage or current, e.g. switching regulators
    • H02M3/158—Conversion of dc power input into dc power output without intermediate conversion into ac 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 with automatic control of output voltage or current, e.g. switching regulators including plural semiconductor devices as final control devices for a single load
    • H02M3/1582—Buck-boost converters
    • 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
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E70/00—Other energy conversion or management systems reducing GHG emissions
    • Y02E70/30—Systems combining energy storage with energy generation of non-fossil origin

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Dc-Dc Converters (AREA)

Abstract

The invention discloses a control method of a bidirectional buck-boost direct current converter based on duty ratio compensation, which relates to the technical field of power electronics, and comprises the following steps: when the bidirectional buck-boost direct-current converter works in a boost mode and a buck mode of a buck-boost mode, on the basis of a traditional phase-shift modulation strategy, the duty ratio of a conducting switch tube on the input side of an H-shaped bridge arm is positively compensated, and the duty ratio of a conducting switch tube on the output side of the H-shaped bridge arm is negatively compensated, so that the inductive current ripple when the converter works is reduced, and meanwhile, the power density of the whole converter is improved. The energy storage link of the new energy distribution power generation system such as light and wind has good application and development prospects.

Description

Control method of bidirectional buck-boost direct current converter based on duty ratio compensation
Technical Field
The invention relates to the technical field of power electronics, in particular to a control method of a bidirectional buck-boost direct-current converter based on duty ratio compensation.
Background
The energy storage is an important link in a photovoltaic and wind power generation system, and the energy storage battery is matched with renewable energy sources for use, so that the time, the strength and other aspects of the renewable energy source power generation can be matched with the power grid requirements, the randomness of the renewable energy source power generation is reduced, the voltage fluctuation of a direct-current micro-power grid is reduced, and the power generation quality is improved. The energy storage medium is usually connected with the high-voltage bus through the bidirectional DC/DC converter, so that bidirectional flow of energy between the energy storage medium and the direct-current bus can be realized, and control and efficient utilization of energy in a system can be realized.
At present, a common bidirectional DC/DC power converter device can be divided into two structures, namely an isolated topology and a non-isolated topology, according to whether electrical isolation exists between input and output. The non-isolated bidirectional power converter overcomes the defects of large size and low system efficiency of an isolated topology, and is commonly used in an energy storage system. The flying capacitor bidirectional buck-boost DC/DC converter reduces the voltage stress of the switching tube, increases the power density and has wider application range. However, the converter under the conventional modulation strategy still has large current ripple during operation, which may reduce the performance of the converter.
Disclosure of Invention
The invention provides a bidirectional buck-boost direct current converter control method based on duty ratio compensation aiming at the problems and the technical requirements, and the technical scheme of the invention is as follows:
a control method of a bidirectional buck-boost direct current converter based on duty ratio compensation is disclosed, the bidirectional buck-boost direct current converter comprises an H-shaped bridge arm, and the method comprises the following steps:
when the bidirectional buck-boost direct-current converter works in a boost mode and a buck mode of a buck-boost mode, on the basis of a traditional phase-shift modulation strategy, the duty ratio of a conducting switch tube on the input side of an H-shaped bridge arm is positively compensated, and the duty ratio of a conducting switch tube on the output side of the H-shaped bridge arm is negatively compensated, so that the inductive current ripple is reduced.
The further technical scheme is that the expression for carrying out positive and negative compensation on the duty ratio is as follows:
Figure BDA0003696036510000021
wherein d is 1 The duty ratio after positive compensation of the input side is recorded as a first duty ratio; d 2 Recording the duty ratio after the output side negative compensation as a second duty ratio; d b The duty ratio of a first switching tube at the input side of the H-shaped bridge arm is used as a reference duty ratio; λ is the compensation duty cycle.
The further technical scheme is that the method also comprises the following steps:
obtaining a first relation between the voltage gain and upper and lower limit values of the duty ratio and a compensation duty ratio according to the voltage gain and the first and second duty ratios of the bidirectional buck-boost direct current converter under the traditional phase-shift modulation strategy;
planning a voltage gain range according to the terminal voltage of the bidirectional buck-boost direct current converter;
under the linear control law of the duty ratio, combining the relation I of the voltage gain and a planning range to obtain the relation II of the upper and lower limit values of the duty ratio, the compensation duty ratio and the voltages at two sides of the bidirectional buck-boost direct current converter;
and determining the adjusting range of the compensation duty ratio according to the second relation and a preset condition.
The further technical scheme is that the method for obtaining the relation I comprises the following steps:
setting the upper and lower limit values of the duty ratio, substituting the voltage gain of the bidirectional buck-boost direct current converter under the traditional phase-shifting modulation strategy into the expressions of the first and second duty ratios to obtain:
Figure BDA0003696036510000022
wherein D is max And D min The upper limit value and the lower limit value of the duty ratio are respectively;
beta is the voltage gain of the bidirectional buck-boost direct-current converter under the traditional phase-shift modulation strategy, and the expression is as follows:
Figure BDA0003696036510000023
finishing to obtain:
Figure BDA0003696036510000024
the further technical scheme is that the range of voltage gain is planned according to the terminal voltage of the bidirectional buck-boost direct current converter, and the expression is as follows:
Figure BDA0003696036510000025
wherein, V 1min And V 1max The minimum value and the maximum value of the terminal voltage of the input side of the bidirectional buck-boost direct current converter are respectively; v 2 The voltage is the terminal voltage of the output side of the bidirectional buck-boost direct current converter.
The further technical scheme is that the expression of the relationship II is as follows:
Figure BDA0003696036510000031
wherein D is max And D min The upper limit value and the lower limit value of the duty ratio are respectively; v 1min And V 1max The minimum value and the maximum value of the terminal voltage of the input side of the bidirectional buck-boost direct current converter are respectively; v 2 The voltage is the terminal voltage of the output side of the bidirectional buck-boost direct current converter.
The further technical scheme is that the adjusting range of the compensation duty ratio is determined according to the second relation and a preset condition, and the adjusting range comprises the following steps:
and (5) finishing the second relation to obtain an adjusting range of the compensation duty ratio as follows:
Figure BDA0003696036510000032
wherein the left side of the second inequality satisfies the predetermined condition as: the maximum value of the compensation duty ratio is smaller than the duty ratio of the flying capacitor voltage, so that the flying capacitor voltage is half of the input side end voltage.
The further technical scheme is that the method also comprises the following steps:
the expression of the average value of the inductive current before and after duty cycle compensation is as follows:
Figure BDA0003696036510000033
wherein, I L Average value of inductor current before duty ratio compensation, I L_C Is the average value of the inductor current after duty ratio compensation, P s Input power, V, for a bidirectional buck-boost DC converter 1 For the voltage at the input side of a bidirectional buck-boost DC converter, d b Is a reference duty cycle, and lambda is a compensation duty cycle;
dividing the average value of the inductive current before and after duty ratio compensation to obtain a ratio formula as follows:
Figure BDA0003696036510000034
if the ratio of the average value of the inductive current before and after duty ratio compensation is greater than 1, the average value of the inductive current after duty ratio compensation is reduced under the same input power, and therefore it is determined that the ripple of the inductive current after compensation is reduced.
The further technical scheme is that the method also comprises the following steps:
respectively determining the state equation and the corresponding working time of each circuit after duty ratio compensation of the bidirectional buck-boost direct current converter in a boost mode and a buck mode;
and combining the state equation of each circuit of the bidirectional buck-boost direct current converter under the traditional phase-shift modulation strategy to obtain the voltage gain of the bidirectional buck-boost direct current converter after duty ratio compensation as follows:
Figure BDA0003696036510000041
wherein, V 2 For the voltage at the output side of a bidirectional buck-boost DC converter 1 For the voltage at the input side of a bidirectional buck-boost DC converter, d b λ is the compensation duty cycle.
The technical scheme is that two opposite bridge arms in the H-shaped bridge arms are respectively a first bridge arm and a second bridge arm, the first bridge arm and the second bridge arm respectively comprise first to fourth switching tubes which are sequentially connected in series, and the first bridge arm is arranged as an input side and the second bridge arm is arranged as an output side;
the method also comprises the following steps of after positive and negative compensation is carried out on the duty ratio:
when two-way buck-boost direct current converter works in the boost mode of the buck-boost mode, two working states are increased compared with the working state of the traditional phase-shift modulation strategy, and the two working states are respectively:
state one after compensation: the first switching tube and the second switching tube of the first bridge arm are conducted, the fourth switching tube of the second bridge arm is conducted, and the second switching tube of the second bridge arm is conducted in a follow current manner;
state two after compensation: the first switch tube and the second switch tube of the first bridge arm are conducted, the third switch tube of the second bridge arm is conducted, and the first switch tube of the second bridge arm is conducted in a follow current manner;
when two-way buck-boost direct current converter works in the buck-boost mode of the buck-boost mode, two working states are increased compared with the working state of the traditional phase-shift modulation strategy, and the two working states are respectively:
state three after compensation: a first switching tube of the first bridge arm is conducted, and a third switching tube of the first bridge arm is conducted with a first switching tube and a second switching tube of the second bridge arm in a follow current manner;
state four after compensation: the second switch tube of the first bridge arm is conducted, and the fourth switch tube of the first bridge arm is conducted with the first switch tube and the second switch tube of the second bridge arm in follow current.
The beneficial technical effects of the invention are as follows:
on the basis of a traditional phase-shift modulation strategy of the flying capacitor bidirectional buck-boost direct-current converter, the duty ratio of a conducting switch tube on the input side of an H-shaped bridge arm is positively compensated, the duty ratio of a conducting switch tube on the output side of the H-shaped bridge arm is negatively compensated, and the working state of the converter is increased; under the same power, the average value of the inductive current after duty ratio compensation is reduced, so that the power density of the system is more favorably improved; the application also provides a regulation range of the compensation duty ratio, and the maximum value of the compensation duty ratio is less than the duty ratio of the flying capacitor voltage, so that the flying capacitor voltage has certain regulation capacity and is half of the voltage of the input side; the control method provided by the application has good application and development prospects in the energy storage link of the new energy distribution power generation system such as light, wind and the like.
Drawings
Fig. 1 is a circuit diagram of a flying capacitor bidirectional buck-boost dc converter provided in the present application.
Fig. 2 is a diagram of driving and current ripple signals applied to a conventional phase-shift modulation strategy of a flying capacitor bidirectional buck-boost dc converter provided by the present application.
Fig. 3 is an equivalent circuit state diagram of the flying capacitor bidirectional buck-boost dc converter provided in the present application under a conventional phase-shift modulation strategy.
Fig. 4 is a flowchart of a control method of a bidirectional buck-boost dc converter based on duty compensation according to the present application.
Fig. 5 is a diagram of a duty cycle compensated drive square wave signal as provided herein.
Fig. 6 is a state diagram of the circuit that increases after duty cycle compensation as provided herein.
Fig. 7 is a graph comparing average inductor current before and after adding a compensation duty cycle to a converter provided by the present application.
Detailed Description
The following further describes the embodiments of the present invention with reference to the drawings.
As shown in fig. 1, a flying capacitor bidirectional buck-boost dc converter includes: h-shaped bridge arm, filter inductor L and resistor R L Two flying capacitors C f1 And C f2 Two filter capacitors C 1 And C 2 . Two opposite bridge arms in the H-shaped bridge arms are respectively a first bridge arm and a second bridge arm, the first bridge arm comprises first to fourth switching tubes S which are sequentially connected in series 11 -S 14 The second bridge arm comprises first to fourth switching tubes S which are sequentially connected in series 21 -S 24 The connecting bridge arm in the H-shaped bridge arm is provided with a filter inductor L and a resistor R which are connected in series L Since the specific connection manner of the H-type bridge arm switch tube is well known to those skilled in the art, it is not described in detail herein. Flying capacitor C f1 The positive pole of the first bridge arm is connected with a first switch tube S of the first bridge arm 11 And a second switching tube S 12 The negative pole is connected with the third switching tube S of the first bridge arm 13 And a fourth switching tube S 14 In the meantime. Similarly, another flying capacitor C f2 Two ends of the first switch tube and the second switch tube are respectively connected between the first switch tube and the second switch tube of the second bridge arm, and two ends of the third switch tube and the fourth switch tube are respectively connected between the first switch tube and the second switch tube of the second bridge arm. First switch tube S of first bridge arm 11 Upper end of and fourth switching tube S 14 Between the lower ends of the first and second filter capacitors C 1 And the upper end S of the first switch tube of the first bridge arm 11 And a fourth switching tube S 14 Between the lower ends of which a terminal voltage V is also formed 1 First switch tube S 11 Upper end of as terminal voltage V 1 The positive electrode of (1). First switch tube S of second bridge arm 21 Upper end of and fourth switching tube S 24 Between the lower ends of the first and second filter capacitors C 2 And the first switch tube S of the second bridge arm 21 Upper end of and fourth switching tube S 24 Between the lower ends of which a terminal voltage V is also formed 2 A first switch tube S 21 Upper end of as terminal voltage V 2 The positive electrode of (1). Fourth switch tube S of first bridge arm 14 And the lower end of the second bridge arm and a fourth switching tube S of the second bridge arm 24 Are connected at the lower end.
As shown in fig. 2, when the dc converter operates in a boost mode and a buck mode, the dc converter adopts a conventional phase shift modulation strategy, and has four operating states in a full duty cycle (i.e. 0-1), which is specifically shown in fig. 3. Wherein, the traditional phase shift modulation strategy is: first arm of the first bridgeA switch tube S 11 The driving signal and the second switch tube S of the first bridge arm 12 The drive signal of (1) phase-shifts 180 DEG, and a first switch tube S of a first bridge arm 11 The driving signal and a fourth switching tube S of the second bridge arm 24 The driving signals of the first bridge arm are the same, and the second switching tube S of the first bridge arm 12 And the third switching tube S of the second bridge arm 23 The drive signals of (a) are the same.
This application adds the compensation duty cycle on traditional phase shift modulation strategy's basis to further reduce the inductive current ripple, promote system power density simultaneously. In the following, taking the example that the dc converter transfers energy from left to right, the first bridge arm is an input side, and the second bridge arm is an output side, a control method of a bidirectional buck-boost dc converter based on duty compensation is provided, as shown in fig. 4, specifically including the following contents:
s1, when the bidirectional buck-boost direct current converter works in a boost mode and a buck mode of a buck-boost mode, on the basis of a traditional phase shift modulation strategy, performing positive compensation on the duty ratio of a conducting switch tube of a first bridge arm of an H-shaped bridge arm, and performing negative compensation on the duty ratio of a conducting switch tube of a second bridge arm of the H-shaped bridge arm, wherein the expression is as follows:
Figure BDA0003696036510000061
wherein d is 1 The duty ratio after positive compensation of the input side is recorded as a first duty ratio; d 2 Recording the duty ratio after the negative compensation of the output side as a second duty ratio; d b Is the first switching tube (i.e. S) at the input side of the H-shaped bridge arm 11 ) As a reference duty cycle; λ is the compensation duty cycle.
S2, two triangular carriers T with 180 degrees phase interval ri1 And T ri2 With a first duty cycle d in boost and buck modes, respectively 1 Second duty ratio d 2 And a reference duty cycle d b Comparing the modulated waves to obtain the H-shaped bridge arm input of the bidirectional buck-boost direct current converter in the boost mode and the buck mode of the buck-boost modeOutput side switching tube S 11 、S 12 、S 23 、S 24 As shown in fig. 5.
And S3, analyzing the working states of the direct current converter working in the voltage boosting mode and the voltage reducing mode of the voltage boosting mode and the voltage reducing mode to obtain the voltage gain of the bidirectional voltage boosting and reducing direct current converter after duty ratio compensation.
When the DC converter operates in the boost mode of the buck-boost mode after performing positive and negative compensation on the duty ratio, namely d b >At 0.5, compared with the working state of the traditional phase shift modulation strategy, two working states are added, namely:
state one after compensation: first and second switching tubes S of a first bridge arm 11 And S 12 Conducting the fourth switching tube S of the second bridge arm 24 On, the second switch tube D of the second bridge arm 22 The freewheeling is on as shown in fig. 6 (a).
State two after compensation: first and second switching tubes S of a first bridge arm 11 And S 12 Conducting the third switching tube S of the second bridge arm 23 Conducting the first switching tube D of the second bridge arm 21 The freewheeling is on as shown in fig. 6 (b).
When the bidirectional buck-boost DC converter operates in the buck-boost mode, i.e. d b <At 0.5, compared with the working state of the traditional phase shift modulation strategy, two working states are added, namely:
state three after compensation: first switch tube S of first bridge arm 11 Conducting the third switching tube D of the first bridge arm 13 And a first and a second switching tube D of a second bridge arm 21 、D 22 The freewheeling is on as shown in fig. 6 (c).
State four after compensation: second switch tube S of first bridge arm 12 On, the fourth switch tube D of the first bridge arm 14 And a first and a second switching tube D of a second bridge arm 21 、D 22 The freewheeling is on as shown in fig. 6 (d).
Respectively determining each circuit state equation and corresponding working time after duty ratio compensation of the bidirectional buck-boost direct current converter in the boost mode and the buck mode, wherein the circuit state equation comprises the following steps:
performing circuit analysis on the converter can obtain a state equation of the added circuit as follows:
Figure BDA0003696036510000071
wherein, V f1 And V f2 Are respectively two flying capacitors C f1 And C f2 The voltage of (c).
Duty ratio time analysis is performed on fig. 5, and the circuit state and the operating time thereof in the whole period shown in table 1 are obtained, where the operating time is obtained by adding or subtracting λ from the operating time corresponding to the original operating state.
TABLE 1 Duty ratio phase Shift Compensation Circuit State
Figure BDA0003696036510000072
And (3) obtaining the voltage gain of the bidirectional buck-boost direct-current converter after duty ratio compensation by combining the state equation of each circuit of the bidirectional buck-boost direct-current converter under the traditional phase-shift modulation strategy as shown in the formula (4).
Figure BDA0003696036510000081
Figure BDA0003696036510000082
S4, under the condition that a preset condition is met, designing an adjusting range of the compensation duty ratio, wherein the adjusting range comprises the following steps:
and S41, obtaining the relation I between the voltage gain and the upper and lower limit values of the duty ratio and the compensation duty ratio according to the voltage gain and the first and second duty ratios of the bidirectional buck-boost direct current converter under the traditional phase-shift modulation strategy.
In order to avoid the occurrence of narrow pulses in practical systemsThe duty ratio is usually set to an upper limit value D max And a lower limit value D min . Substituting the voltage gain of the bidirectional buck-boost direct-current converter under the traditional phase-shift modulation strategy into an expression (1) of the first duty ratio and the second duty ratio to obtain:
Figure BDA0003696036510000083
wherein, β is the voltage gain of the bidirectional buck-boost direct-current converter under the traditional phase-shift modulation strategy, and the expression is as follows:
Figure BDA0003696036510000084
the formula (5) is arranged to obtain:
Figure BDA0003696036510000085
s42, planning the range of voltage gain according to the terminal voltage of the bidirectional buck-boost direct current converter, wherein the expression is as follows:
Figure BDA0003696036510000086
wherein, V 1min And V 1max The minimum value and the maximum value of the terminal voltage of the input side of the bidirectional buck-boost direct-current converter are respectively.
S43, under the duty ratio linear control law, combining the relation equation (6) of the voltage gain and the planning range equation (7) to obtain a relation II of the upper and lower limit values of the duty ratio, the compensation duty ratio and the voltages at two sides of the bidirectional buck-boost direct current converter, wherein the expression is as follows:
Figure BDA0003696036510000091
and S44, determining the adjusting range of the compensation duty ratio according to the relation II (8) and a preset condition.
And (5) finishing the second relation to obtain an adjusting range of the compensation duty ratio as follows:
Figure BDA0003696036510000092
in an actual system, the flying capacitor voltage needs to be controlled independently to ensure that the flying capacitor voltage is always the voltage V at the input side 1 To make the converter always operate in three-level mode. The left side of the second inequality of equation (9) satisfies the predetermined condition: the maximum value of the compensation duty ratio is smaller than the duty ratio of the flying capacitor voltage, and the flying capacitor voltage is guaranteed to have certain adjusting capacity.
And S5, verifying the ripple state of the inductive current after duty ratio compensation.
When the energy is changed from V 1 To V 2 During transmission, the input power of the DC converter is controlled by the switching tube of the first bridge arm. Let the input power be P s The expression of the average value of the inductor current before and after duty cycle compensation is as follows:
Figure BDA0003696036510000093
wherein, I L Is the average value of the inductor current before duty ratio compensation, I L_C The average value of the inductance current after duty ratio compensation.
Dividing the average value of the inductive current before and after duty ratio compensation to obtain a ratio formula as follows:
Figure BDA0003696036510000094
this example shows I for two compensating duty cycles λ L And I L_C The numerical relationship of (a) is shown in FIG. 7. It can be seen from the figure that the ratio of the average value of the inductor current before and after duty compensation is greater than 1, which indicates that the average value of the inductor current after duty compensation is reduced under the same input power, so that it is determined that the ripple of the inductor current after compensation is reduced, which is more beneficial to improving the power density of the system. By using the control method provided by the application, light and wind can be controlledAnd the energy storage link of the new energy distribution power generation system has good application and development prospects.
What has been described above is only a preferred embodiment of the present application, and the present invention is not limited to the above embodiment. It is to be understood that other modifications and variations directly derivable or suggested by those skilled in the art without departing from the spirit and concept of the present invention are to be considered as included within the scope of the present invention.

Claims (10)

1. A control method of a bidirectional buck-boost direct current converter based on duty ratio compensation is disclosed, wherein the bidirectional buck-boost direct current converter comprises an H-shaped bridge arm, and the method comprises the following steps:
when the bidirectional buck-boost direct-current converter works in a boost mode and a buck mode of a buck-boost mode, on the basis of a traditional phase-shift modulation strategy, the duty ratio of a conducting switch tube on the input side of the H-shaped bridge arm is positively compensated, and the duty ratio of a conducting switch tube on the output side of the H-shaped bridge arm is negatively compensated, so that inductive current ripples are reduced.
2. The duty-cycle-compensation-based bidirectional buck-boost direct-current converter control method according to claim 1, wherein the positive and negative duty-cycle compensation expression is as follows:
Figure FDA0003696036500000011
wherein d is 1 The duty ratio after positive compensation of the input side is recorded as a first duty ratio; d 2 Recording the duty ratio after the output side negative compensation as a second duty ratio; d b The duty ratio of a first switching tube at the input side of the H-shaped bridge arm is used as a reference duty ratio; λ is the compensation duty cycle.
3. The duty cycle compensation based bidirectional buck-boost DC converter control method of claim 2, further comprising:
obtaining a first relation between the voltage gain and upper and lower limit values of the duty ratio and a compensation duty ratio according to the voltage gain and the first and second duty ratios of the bidirectional buck-boost direct current converter under a traditional phase-shift modulation strategy;
planning the range of the voltage gain according to the terminal voltage of the bidirectional buck-boost direct-current converter;
under the linear control law of the duty ratio, combining the relation I of the voltage gain and the planning range to obtain a relation II of the upper and lower limit values of the duty ratio, the compensation duty ratio and the voltages at two sides of the bidirectional buck-boost direct current converter;
and determining the adjusting range of the compensation duty ratio according to the second relation and a preset condition.
4. The duty cycle compensation based bidirectional buck-boost DC converter control method of claim 3, wherein the method of deriving the first relationship comprises:
setting the upper and lower limit values of the duty ratio, substituting the voltage gain of the bidirectional buck-boost direct current converter under the traditional phase shift modulation strategy into the expressions of the first and second duty ratios to obtain:
Figure FDA0003696036500000012
wherein D is max And D min The upper limit value and the lower limit value of the duty ratio are respectively;
beta is the voltage gain of the bidirectional buck-boost direct-current converter under the traditional phase-shift modulation strategy, and the expression is as follows:
Figure FDA0003696036500000021
finishing to obtain:
Figure FDA0003696036500000022
5. the duty cycle compensation-based bidirectional buck-boost direct current converter control method according to claim 3, wherein the range of the voltage gain is planned according to a terminal voltage of the bidirectional buck-boost direct current converter, and the expression is as follows:
Figure FDA0003696036500000023
wherein, V 1min And V 1max The minimum value and the maximum value of the terminal voltage of the input side of the bidirectional buck-boost direct current converter are respectively; v 2 The voltage is the terminal voltage of the output side of the bidirectional buck-boost direct current converter.
6. The duty cycle compensation-based bidirectional buck-boost direct current converter control method according to claim 3, wherein the expression of the second relation is as follows:
Figure FDA0003696036500000024
wherein D is max And D min The upper limit value and the lower limit value of the duty ratio are respectively; v 1min And V 1max The minimum value and the maximum value of the terminal voltage of the input side of the bidirectional buck-boost direct current converter are respectively; v 2 The voltage is the terminal voltage of the output side of the bidirectional buck-boost direct current converter.
7. The duty cycle compensation based bidirectional buck-boost DC converter control method of claim 6, wherein the determining the adjustment range of the compensation duty cycle according to the second relationship and a predetermined condition comprises:
and sorting the second relation to obtain the adjustment range of the compensation duty ratio as follows:
Figure FDA0003696036500000025
wherein the left side of the second inequality satisfies the predetermined condition: the maximum value of the compensation duty ratio is smaller than the duty ratio of the flying capacitor voltage, so that the flying capacitor voltage is half of the input side end voltage.
8. The duty cycle compensation based bidirectional buck-boost DC converter control method according to any one of claims 1-7, further comprising:
the expression of the average value of the inductive current before and after duty cycle compensation is as follows:
Figure FDA0003696036500000031
wherein, I L Is the average value of the inductor current before duty ratio compensation, I L_C Is the average value of the inductor current after duty ratio compensation, P s Input power, V, for a bidirectional buck-boost DC converter 1 For the voltage at the input side of a bidirectional buck-boost DC converter, d b Is a reference duty cycle, and lambda is a compensation duty cycle;
dividing the average value of the inductive current before and after the duty ratio compensation to obtain a ratio formula as follows:
Figure FDA0003696036500000032
and if the ratio of the average values of the inductive currents before and after the duty ratio compensation is greater than 1, the average value of the inductive current after the duty ratio compensation is reduced under the same input power, so that the reduction of the ripple of the inductive current after the duty ratio compensation is determined.
9. The duty cycle compensation based bidirectional buck-boost direct current converter control method of any one of claims 1-7, further comprising:
respectively determining state equations and corresponding working time of each circuit after duty ratio compensation of the bidirectional buck-boost direct current converter in a boost mode and a buck mode;
and combining the state equation of each circuit of the bidirectional buck-boost direct current converter under the traditional phase-shift modulation strategy to obtain the voltage gain of the bidirectional buck-boost direct current converter after duty ratio compensation as follows:
Figure FDA0003696036500000033
wherein, V 2 For the voltage at the output side of a bidirectional buck-boost DC converter 1 For the voltage at the input side of a bidirectional buck-boost DC converter, d b λ is the compensation duty cycle.
10. The duty-cycle-compensation-based bidirectional buck-boost direct-current converter control method according to any one of claims 1 to 7, wherein two opposite bridge arms in the H-shaped bridge arms are respectively a first bridge arm and a second bridge arm, the first bridge arm and the second bridge arm respectively comprise first to fourth switching tubes which are sequentially connected in series, and the first bridge arm is taken as an input side and the second bridge arm is taken as an output side;
the method further comprises the following steps of after positive and negative compensation is carried out on the duty ratio:
when two-way buck-boost direct current converter works in the boost mode of the buck-boost mode, two working states are increased compared with the working state of the traditional phase-shift modulation strategy, and the two working states are respectively:
state one after compensation: the first switching tube and the second switching tube of the first bridge arm are conducted, the fourth switching tube of the second bridge arm is conducted, and the second switching tube of the second bridge arm is conducted in a follow current manner;
state two after compensation: the first switch tube and the second switch tube of the first bridge arm are conducted, the third switch tube of the second bridge arm is conducted, and the first switch tube of the second bridge arm is conducted in a follow current manner;
when two-way buck-boost direct current converter works in the buck-boost mode of the buck-boost mode, two working states are increased compared with the working state of the traditional phase-shift modulation strategy, and the two working states are respectively:
state three after compensation: the first switching tube of the first bridge arm is conducted, and the third switching tube of the first bridge arm is conducted with the first switching tube and the second switching tube of the second bridge arm in a follow current manner;
state four after compensation: and the second switching tube of the first bridge arm is conducted, and the fourth switching tube of the first bridge arm is conducted with the first switching tube and the second switching tube of the second bridge arm in a follow current manner.
CN202210674786.XA 2022-06-15 2022-06-15 Control method of bidirectional buck-boost direct current converter based on duty ratio compensation Pending CN114884318A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210674786.XA CN114884318A (en) 2022-06-15 2022-06-15 Control method of bidirectional buck-boost direct current converter based on duty ratio compensation

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210674786.XA CN114884318A (en) 2022-06-15 2022-06-15 Control method of bidirectional buck-boost direct current converter based on duty ratio compensation

Publications (1)

Publication Number Publication Date
CN114884318A true CN114884318A (en) 2022-08-09

Family

ID=82682003

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210674786.XA Pending CN114884318A (en) 2022-06-15 2022-06-15 Control method of bidirectional buck-boost direct current converter based on duty ratio compensation

Country Status (1)

Country Link
CN (1) CN114884318A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115811230A (en) * 2022-12-06 2023-03-17 无锡钊源电力电子有限公司 MPC control method for flying capacitor three-level converter
CN117938026A (en) * 2024-03-25 2024-04-26 浙江电驱动创新中心有限公司 Optimized control method for narrow pulse of motor controller

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115811230A (en) * 2022-12-06 2023-03-17 无锡钊源电力电子有限公司 MPC control method for flying capacitor three-level converter
CN115811230B (en) * 2022-12-06 2023-06-27 无锡钊源电力电子有限公司 MPC control method for flying capacitor three-level converter
CN117938026A (en) * 2024-03-25 2024-04-26 浙江电驱动创新中心有限公司 Optimized control method for narrow pulse of motor controller

Similar Documents

Publication Publication Date Title
CN109889047B (en) Two-stage DC-DC converter suitable for wide input and output voltage range
CN114884318A (en) Control method of bidirectional buck-boost direct current converter based on duty ratio compensation
CN111010043B (en) Full-bridge LLC resonant converter fixed-frequency control method
CN111431415B (en) High-boost isolated DC converter with parallel input and series output
CN108880268B (en) Multi-mode control method of voltage source type semi-active bridge DC-DC converter
CN109842299B (en) Combined direct current conversion system and control method thereof
CN113346750A (en) Soft switching in-phase buck-boost converter based on coupling inductor and control method
CN109889036B (en) Tracking maximum efficiency point IPOS direct current charging power supply
CN111342664A (en) Integrated DC-DC converter and control method thereof
CN113541486B (en) Interleaved diode capacitor network high-gain ZVT (zero voltage zero volt) direct current converter and auxiliary circuit
CN114257097A (en) Multi-mode switching wide-output direct current converter and switching control thereof
CN113992010A (en) Wide-gain DC-DC converter and control method thereof
CN115347785B (en) High-efficiency photovoltaic converter without input filter
CN116054571A (en) Alternating parallel three-level soft switch direct current boost converter
CN113364294B (en) Low-voltage stress and low-input current ripple high-gain converter and control method
CN111669057B (en) DC boost converter and control method thereof
CN115664169A (en) Quasi-peak current control method for bidirectional four-switch Buck-Boost
CN212115161U (en) DCDC converter suitable for wide voltage input range
CN114825936A (en) Two-phase staggered flying capacitor bidirectional direct current converter based on coupling inductor
CN113992024A (en) Power segmented modulation method based on bridge arm multiplexing type isolation type DC-DC converter
CN113507229A (en) Wide-input step-down inversion system based on switched capacitor network and control method
CN113507212B (en) Double-active-bridge DC-DC converter based on three-winding coupling inductor and power control method
Wu et al. Modeling and Analysis of Partial Power Concept for Data Center Application
CN219247707U (en) Continuous mode control integrated PFC converter device
CN117856624B (en) Wide-range buck-boost direct current converter

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