CN115864857B - Converter and control method thereof - Google Patents
Converter and control method thereof Download PDFInfo
- Publication number
- CN115864857B CN115864857B CN202310148506.6A CN202310148506A CN115864857B CN 115864857 B CN115864857 B CN 115864857B CN 202310148506 A CN202310148506 A CN 202310148506A CN 115864857 B CN115864857 B CN 115864857B
- Authority
- CN
- China
- Prior art keywords
- unit
- current
- representing
- main power
- phase shift
- 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
Links
- 238000000034 method Methods 0.000 title claims abstract description 43
- 230000010363 phase shift Effects 0.000 claims abstract description 62
- 238000002955 isolation Methods 0.000 claims abstract description 45
- 230000003750 conditioning effect Effects 0.000 claims abstract description 44
- 238000012545 processing Methods 0.000 claims abstract description 36
- 230000005540 biological transmission Effects 0.000 claims abstract description 11
- 230000002457 bidirectional effect Effects 0.000 claims abstract description 8
- 239000003990 capacitor Substances 0.000 claims description 16
- 238000004891 communication Methods 0.000 claims description 9
- 230000003321 amplification Effects 0.000 claims description 3
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 3
- 230000000694 effects Effects 0.000 abstract description 7
- 238000010586 diagram Methods 0.000 description 15
- 230000006870 function Effects 0.000 description 11
- 230000008901 benefit Effects 0.000 description 6
- 238000006243 chemical reaction Methods 0.000 description 6
- HEZMWWAKWCSUCB-PHDIDXHHSA-N (3R,4R)-3,4-dihydroxycyclohexa-1,5-diene-1-carboxylic acid Chemical compound O[C@@H]1C=CC(C(O)=O)=C[C@H]1O HEZMWWAKWCSUCB-PHDIDXHHSA-N 0.000 description 5
- 238000004458 analytical method Methods 0.000 description 5
- 238000005070 sampling Methods 0.000 description 4
- 230000009471 action Effects 0.000 description 3
- 238000013459 approach Methods 0.000 description 3
- 230000001143 conditioned effect Effects 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 230000004044 response Effects 0.000 description 3
- 238000004364 calculation method Methods 0.000 description 2
- 230000000295 complement effect Effects 0.000 description 2
- 238000007599 discharging Methods 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 238000006467 substitution reaction Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000009977 dual effect Effects 0.000 description 1
- 238000004146 energy storage Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000001939 inductive effect Effects 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000010248 power generation Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
- 230000001131 transforming effect Effects 0.000 description 1
Images
Classifications
-
- 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
Landscapes
- Dc-Dc Converters (AREA)
- Control Of Ac Motors In General (AREA)
Abstract
The application provides a converter and a control method thereof, and relates to the technical field of converters. The converter comprises a main power unit, an analog signal conditioning unit, an isolation driving unit and a core processing unit, wherein the main power unit is respectively and electrically connected with the analog signal conditioning unit and the isolation driving unit; the main power unit is used for realizing power bidirectional transmission of the first port and the second port; the analog signal conditioning unit is used for collecting current signals and voltage signals when the main power unit operates; the core processing unit is used for determining a phase shift angle according to the current signal and the voltage signal and generating a driving signal according to the phase shift angle; the isolation driving unit is used for controlling the full bridge operation connected with the input port in the main power unit according to the driving signal. The converter and the control method thereof have the effects of simpler control and less occupation of hardware resources.
Description
Technical Field
The application relates to the technical field of converters, in particular to a converter and a control method thereof.
Background
At present, the double-active bridge type DCDC converter (DAB-DCDC) has the technical advantages of bidirectional electric energy circulation, input and output isolation and wide voltage transformation ratio, has important application in the fields of new energy power generation, direct current micro-grids, power electronic transformers and the like, and is a key technology for the key research of the electric energy conversion field.
The traditional control method adopted by the double-active bridge type DCDC converter comprises the following steps: single phase shift control, extended phase shift control, double phase shift control, and triple phase shift control. The four control modes adopt a double-side H-bridge duty ratio or phase shift angle control mode; existing control algorithms include: the control method is based on a small signal system model or a power equation to implement control.
However, the control method has a problem that the number of occupied pins is large, and control performance is limited.
Disclosure of Invention
The invention aims to provide a converter and a control method thereof, which are used for solving the problems of large occupied pin number, limited control performance and the like of a DCDC converter in the prior art.
In order to achieve the above purpose, the technical solution adopted in the embodiment of the present application is as follows:
in a first aspect, an embodiment of the present application provides a converter, where the converter includes a main power unit, an analog signal conditioning unit, an isolation driving unit, and a core processing unit, where the main power unit is electrically connected to the analog signal conditioning unit and the isolation driving unit, and the core processing unit is electrically connected to the analog signal conditioning unit and the isolation driving unit, respectively; wherein,,
the main power unit is used for realizing power bidirectional transmission of the first port and the second port;
the analog signal conditioning unit is used for collecting current signals and voltage signals when the main power unit operates;
the core processing unit is used for determining a phase shift angle according to the current signal, the voltage signal and a preset variational discipline function and generating a driving signal according to the phase shift angle;
wherein, the phase shift angle satisfies the formula:
alpha represents the phase shift angle, T s Represents a control period, m 1 And m is equal to 2 Representing a predetermined variational discipline function, C 1 Representing the capacitance of the output end capacitor, U 1 Representing input terminal voltage, U 2 Represents the output voltage, k represents the transformer turns ratio, i o Indicating the output current, L indicating the inductance value, i L Representing the current of the inductor,
representing a target output voltage value;
the isolation driving unit is used for controlling full-bridge operation connected with the input port in the main power unit according to the driving signal.
Optionally, the state equation of the main power unit during operation is:
wherein alpha represents a phase shift angle, C 1 Representing capacitance of capacitor, U 1 Representing input terminal voltage, U 2 Represents the output voltage, k represents the transformer turns ratio, i o Indicating the output current, L indicating the inductance value, i L Representing inductor current, T s The control period is indicated, and t is the time.
Optionally, the main power unit includes a first current transformer, a second current transformer, a third current transformer, a first full bridge, a second full bridge, a filter inductor, and a high-frequency transformer, where the first port, the first current transformer, the first full bridge, the filter inductor, the second current transformer, the high-frequency transformer, the second full bridge, the third current transformer, and the second port are electrically connected in sequence.
Optionally, the analog signal conditioning unit includes three paths of direct current acquisition circuits and two paths of direct current voltage acquisition circuits, the three paths of direct current acquisition circuits are respectively and electrically connected with the first current transformer, the second current transformer and the third current transformer, and the two paths of direct current voltage acquisition circuits are respectively and electrically connected with the first port and the second port.
Optionally, the core processing unit includes a program emulation and debug circuit, a core processor, a communication interface circuit, a power supply circuit, and a power-on reset circuit, where the core processor is electrically connected to the program emulation and debug circuit, the communication interface circuit, the power supply circuit, and the power-on reset circuit, respectively.
Optionally, the isolation driving unit includes a signal amplifying module, a logic gating module and a plurality of driving output modules, where the signal amplifying module is electrically connected with the core processing unit and the logic gating module respectively, and the logic gating module is also electrically connected with the plurality of driving output modules.
On the other hand, the embodiment of the application also provides a control method of a converter, which is applied to a core processing unit in the converter, the converter further comprises a main power unit, an analog signal conditioning unit and an isolation driving unit, the main power unit is respectively and electrically connected with the analog signal conditioning unit and the isolation driving unit, the core processing unit is respectively and electrically connected with the analog signal conditioning unit and the isolation driving unit, and the method comprises the following steps:
acquiring a current signal and a voltage signal transmitted by the analog signal conditioning unit;
determining a phase shift angle according to the current signal, the voltage signal and a preset variational discipline function, and generating a driving signal according to the phase shift angle;
wherein, the phase shift angle satisfies the formula:
alpha represents the phase shift angle, T s Represents a control period, m 1 And m is equal to 2 Representing a predetermined variational discipline function, C 1 Representing the capacitance of the output end capacitor, U 1 Representing input terminal voltage, U 2 Represents the output voltage, k represents the transformer turns ratio, i o Indicating the output current, L indicating the inductance value,i L representing the current of the inductor,
representing a target output voltage value; />
And transmitting the driving signal to the isolation driving unit so that the isolation driving unit drives the full bridge connected with the input port in the main power unit to work.
Optionally, the state equation of the main power unit during operation is:
wherein alpha represents a phase shift angle, C 1 Representing the capacitance of the output end capacitor, U 1 Representing input terminal voltage, U 2 Represents the output voltage, k represents the transformer turns ratio, i o Indicating the output current, L indicating the inductance value, i L Representing inductor current, T s The control period is indicated, and t is the time.
Compared with the prior art, the application has the following beneficial effects:
the application provides a converter and a control method thereof, wherein the converter comprises a main power unit, an analog signal conditioning unit, an isolation driving unit and a core processing unit, wherein the main power unit is respectively and electrically connected with the analog signal conditioning unit and the isolation driving unit, and the core processing unit is respectively and electrically connected with the analog signal conditioning unit and the isolation driving unit; the main power unit is used for realizing power bidirectional transmission of the first port and the second port; the analog signal conditioning unit is used for collecting current signals and voltage signals when the main power unit operates; the core processing unit is used for determining a phase shift angle according to the current signal and the voltage signal and generating a driving signal according to the phase shift angle; the isolation driving unit is used for controlling the full bridge operation connected with the input port in the main power unit according to the driving signal. In the application, only the full bridge connected with the input port in the main power unit needs to be controlled to work, and the full bridge connected with the output port can be in an off state, so that single-side phase shift control is realized, the control is simpler, the occupied hardware resources are fewer, namely, the occupied number of pins is fewer, and the control performance is improved.
In order to make the above objects, features and advantages of the present application more comprehensible, preferred embodiments accompanied with figures are described in detail below.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered limiting in scope, and that other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1 is a schematic circuit architecture diagram of a converter according to an embodiment of the present application.
Fig. 2 is a schematic circuit diagram of a main power unit according to an embodiment of the present application.
Fig. 3 is a schematic circuit diagram of a dc voltage acquisition circuit according to an embodiment of the present application.
Fig. 4 is a schematic circuit diagram of a dc current collecting circuit according to an embodiment of the present application.
Fig. 5 is a schematic block diagram of a core processing unit according to an embodiment of the present application.
Fig. 6 is a schematic block diagram of an isolated driving unit according to an embodiment of the present application.
Fig. 7 is a schematic circuit diagram of a signal amplifying module according to an embodiment of the present application.
Fig. 8 is a schematic circuit diagram of a portion of a logic gate module according to an embodiment of the present application.
Fig. 9 is another schematic circuit diagram of a logic gate module according to an embodiment of the present application.
Fig. 10 is a schematic circuit diagram of a driving output module according to an embodiment of the present application.
Fig. 11 is a schematic diagram of a single-sided phase shift control according to an embodiment of the present application.
Fig. 12 is a schematic diagram of an implementation principle of a control algorithm according to an embodiment of the present application.
Fig. 13 is an exemplary flowchart of a converter control method provided in an embodiment of the present application.
Icon:
110-a main power unit; 120-an analog signal conditioning unit; 130-isolating the drive unit; 140-a core processing unit; 111-a first current transformer; 112-a first full bridge; 113-filtering inductance; 114-a second current transformer; 115-high frequency transformer; 116-a second full bridge; 117-a third current transformer; 131-a signal amplification module; 132-logic gating module; 133-a drive output module; 141-program emulation and debug circuitry; 142-a core processor; 143-a communication interface circuit; 144-a power supply circuit; 145-a power-on reset circuit.
Detailed Description
For the purposes of making the objects, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments. The components of the embodiments of the present application, which are generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations.
Thus, the following detailed description of the embodiments of the present application, as provided in the accompanying drawings, is not intended to limit the scope of the application, as claimed, but is merely representative of selected embodiments of the application. All other embodiments, which can be made by one of ordinary skill in the art based on the embodiments herein without making any inventive effort, are intended to be within the scope of the present application.
It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further definition or explanation thereof is necessary in the following figures. Meanwhile, in the description of the present application, the terms "first", "second", and the like are used only to distinguish the description, and are not to be construed as indicating or implying relative importance.
It is noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions.
In the description of the present application, it should be noted that, the terms "upper," "lower," "inner," "outer," and the like indicate an orientation or a positional relationship based on the orientation or the positional relationship shown in the drawings, or an orientation or a positional relationship conventionally put in use of the product of the application, merely for convenience of description and simplification of the description, and do not indicate or imply that the apparatus or element to be referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present application.
Some embodiments of the present application are described in detail below with reference to the accompanying drawings. The following embodiments and features of the embodiments may be combined with each other without conflict.
As described in the background art, currently, the dual-active bridge DCDC converter generally adopts four control methods of single phase shift control, extended phase shift control, double phase shift control and triple phase shift control, and the objective disadvantages of the methods include:
1. the PWM driving pin occupies more hardware resources and limits the capability of a single processor to control a plurality of DAB-DCDC. In the four control methods, at least 4 pairs of PWM driving signals are needed, and 8 PWM special driving pins of the processor are occupied, so that more hardware resources are occupied.
2. The traditional control algorithm is used for controlling according to a small signal system model or a power transmission equation of DAB-DCDC, and the control performance is limited because the nonlinear characteristic of the system cannot be embodied.
3. The conventional control method focuses more on stable control of the output voltage, but focuses less on stable characteristics of the system, so that there is a problem in system stability.
4. The traditional control method is based on the voltage outer ring to implement closed-loop control, and less consideration is given to the current inner ring control for improving the system performance.
In view of the above, the present application provides a converter, which reduces the occupation of hardware resources by a single-side phase shift control method.
The following is an exemplary illustration:
as an implementation manner, referring to fig. 1, the converter includes a main power unit 110, an analog signal conditioning unit 120, an isolation driving unit 130, and a core processing unit 140, where the main power unit 110 is electrically connected to the analog signal conditioning unit 120 and the isolation driving unit 130, and the core processing unit 140 is electrically connected to the analog signal conditioning unit 120 and the isolation driving unit 130; the main power unit 110 is configured to implement bidirectional power transmission between the first port and the second port; the analog signal conditioning unit 120 is configured to collect a current signal and a voltage signal when the main power unit 110 is operating; the core processing unit 140 is configured to determine a phase shift angle according to the current signal and the voltage signal, and generate a driving signal according to the phase shift angle; the isolation driving unit 130 is used for controlling the full-bridge operation of the main power unit 110 connected to the input port according to the driving signal.
The main power unit 110 adopts a dual source bridge DCDC (DAB-DCDC) power conversion topology, so that bidirectional power transmission between the first port and the second port can be realized. For example, a first port may receive input power as an input port and a second port may output power as an output port; alternatively, the second port receives input power as an input port and the first port outputs power as an output port.
The current on the first port, the second port and the filter inductor (L in the figure) of the main power unit 110 is converted into 0-5A current through the current transformers CT1, CT2 and CT3 and then is input into the analog signal conditioning unit 120, and the voltage difference of the first port and the second port is input into the analog signal conditioning unit 120. The analog signal conditioning unit 120 inputs the conditioned voltage and current signals to the AD pin of the core processing unit 140. The core processing unit 140 performs phase shift angle calculation by adopting a nonlinear control algorithm according to the analog signal sampling value, outputs a high-frequency driving signal through a PWM driving pin, and the driving module is used for driving the single-side full bridge in the circuit of the main power unit 110 to work according to the high-frequency driving signal of the core processing unit 140.
The converter provided by the application can realize single-side phase shift control, so that the converter has the advantages of simple control realization and less hardware resource occupation; meanwhile, the control effect can be improved based on an asymptotic nonlinear control algorithm of the phase shift angle.
The following describes the hardware of the converter provided in the present application:
as an implementation manner, referring to fig. 2, the main power unit 110 includes a first current transformer 111, a second current transformer 114, a third current transformer 117, a first full bridge 112, a second full bridge 116, a filter inductor 113, and a high frequency transformer 115, where the first port, the first current transformer 111, the first full bridge 112, the filter inductor 113, the second current transformer 114, the high frequency transformer 115, the second full bridge 116, the third current transformer 117, and the second port are electrically connected in sequence. The first current transformer 111, the second current transformer 114, and the third current transformer 117 are used for transforming the large current in the main circuit into 0-5a direct current. The filter inductor 113 is used to realize smooth filtering of the current and reduce current surge. The high frequency transformer 115 is used to achieve buck-boost variation and power transfer. The first full bridge 112 and the second full bridge 116 are respectively composed of four power tubes, so as to realize phase-shifting control electric energy conversion.
Optionally, the analog signal conditioning unit 120 includes three paths of direct current collecting circuits and two paths of direct current voltage collecting circuits, the three paths of direct current collecting circuits are respectively electrically connected with the first current transformer 111, the second current transformer 114 and the third current transformer 117, and the two paths of direct current voltage collecting circuits are respectively electrically connected with the first port and the second port.
And the direct current acquisition circuit and the direct current voltage acquisition circuit both adopt an isolated sampling mode, so that the method has the technical advantages of strong and weak electric isolation, and the sampling is safer.
Fig. 3 is a schematic circuit diagram of a dc voltage acquisition circuit according to an embodiment of the present application. The voltage signal is converted into a current signal through a resistor R4, the current signal is input by a 1 pin of a Hall transformer U4, the current signal is output by a 3 pin according to a certain proportion, the output current signal is input into an operational amplifier through a resistor R8, a voltage signal of 0-3V is output after being conditioned by an operational amplifier U2B, and the voltage after being output is input into an AD pin of a core processing unit 140.
Fig. 4 is a schematic circuit diagram of a dc current collection circuit according to an embodiment of the present application. The 3 paths of direct current acquisition circuits all adopt closed-loop Hall current sensors CHCS_LTS to complete conversion from current signals to voltage signals, and the structures of the direct current acquisition circuits are the same, as shown in figure 4. R9, R12, R14, R16, U7B, C6 and C12 complete the differential conditioning function, and voltage signals can be conditioned to 0-3V by adjusting the ratio of R16 to R12. R13, C11 and U7A perform the voltage following function. The voltage following the output voltage is input to the AD pin of the core processing unit 140.
Referring to fig. 5, the core processing unit 140 includes a program emulation and debug circuit 141, a core processor 142, a communication interface circuit 143, a power supply circuit 144, and a power-on reset circuit 145, wherein the core processor 142 is electrically connected to the program emulation and debug circuit 141, the communication interface circuit 143, the power supply circuit 144, and the power-on reset circuit 145, respectively. Program emulation and debug circuitry 141 is used to perform the downloading and online debugging functions of the program of core processor 142. The core processor 142 is used for completing control algorithm calculation, the communication interface circuit 143 is used for realizing communication output and external interaction, the power supply circuit 144 is used for completing power supply required by the core processor 142 and the analog signal conditioning unit, and the power-on reset circuit 145 is used for completing the power-on reset function of the core processor 142.
As an implementation manner, referring to fig. 6, the isolation driving unit 130 includes a signal amplifying module 131, a logic gating module 132, and a plurality of driving output modules 133, where the signal amplifying module 131 is electrically connected to the core processing unit 140 and the logic gating module 132, and the logic gating module 132 is further electrically connected to the plurality of driving output modules 133.
Fig. 7 is a schematic circuit diagram of a signal amplifying module 131 provided in the embodiment of the present application, where a core processor 142 outputs 1 pair of PWM waves in total of EPWM1A and EPWM1B, and performs level conversion through a chip U3, so as to realize conversion from a 3.3V driving signal to a 5V level, and meanwhile, the chip U3 has a larger driving capability. The signal amplifying unit outputs two driving signals of EPWM1H, EPWM L and inputs the driving signals to the logic gate module 132.
The logic gating module 132 is shown in fig. 8 and 9. U8 and U9 are H-bridge gating control signals. The driving signal EPWM1H, EPWM L output by the signal amplifying module 131 and the H-bridge strobe signal io_h_ L, IO _h_r output by the core processing unit 140 are input to U6, U7, U10, U11 together, and input to optocouplers DB1, DB2, DB3, DB4 after being and operated, and input to driving signals Q1AT, Q1BT, Q2AT, Q2BT, respectively, and input to 4 driving output modules.
The 4 driving output modules have the same circuit structure, as shown in fig. 10, the logic gate module 132 outputs driving signals Q1AT, Q1BT, Q2AT, Q2BT to the driving output module 133 (only one driving output module 133 is shown in the figure, and the circuits of the remaining driving output modules are the same), and outputs 4 independent driving signals to connect the first full bridge 112 and the second full bridge 116 of the main power unit 110. U1 in the driving output module is a driving chip and can be well matched with the first full bridge 112 or the second full bridge 116.
In the conventional control manner, the DAB-DCDC performs power transmission control by simultaneously controlling the first full bridge 112 and the second full bridge 116, and in this application, a new way of single-side phase shift control is provided. The detailed implementation principle analysis is shown in fig. 11.
Because DAB-DCDC has the characteristic of symmetrical structure, the analysis is performed by taking the electric power input from the first port and the electric power output from the second port as examples, and the analysis processes of the input from the second port and the output from the first port are similar.
When electric power is input from the first port and output from the second port, the first full bridge 112 of the main power unit 110 operates in the phase-shift control mode, the driving signals of the second full bridge 116 are all low, and the second full bridge 116 operates in an uncontrollable rectifying state through the internal diode.
Referring to FIG. 1, Q1A and Q1A of the first full bridge 112 operate in a complementary state, Q1B/lag Q1A phase angle α, and Q1B operate in a complementary state.
In connection with fig. 11, there are four modes of operation for the first full bridge 112:
mode 1 (t) 0 ~t 1 ): inductive current forward state of charge
Q1A and Q1B/working at this time, U 1 The inductor L is input with voltage for charging, and the secondary side voltage U of the transformer is isolated 2 The voltage reduced to the primary side is KU 2 Therefore, the inductor Loutputs the filter capacitor C at this time 1 The method meets the following conditions:
mode 2 (t) 1 ~t 2 ): inductor current forward discharge state
At this time, Q1A stops working, the current on the inductor L cannot be suddenly changed, and the power on the inductor is supplied to the load by discharging through the body diode of Q1A/and Q1B/so that the inductor L outputs the filter capacitor C 1 The method meets the following conditions:
mode 3 (t) 2 ~t 3 ): inductor current reverse charge state
Q1B and Q1A/working at this time, U 1 The inductor L is input with voltage for charging, and the secondary side voltage U of the transformer is isolated 2 The voltage reduced to the primary side is KU 2 Therefore, the inductor Loutputs the filter capacitor C at this time 1 Satisfy the following requirements：
Mode 4 (t) 3 ~t 4 ): inductor current reverse discharge state
At this time, Q1A/stops working, the current on the inductor L cannot be suddenly changed, and the body diode of Q1A and Q1B discharge to supply power to the load, so that the inductor L outputs the filter capacitor C 1 The method meets the following conditions:
the above deduction process can show that the charging time of L can be changed by changing the phase shift angle alpha, so as to change the magnitude of the inductance energy storage. When L is smaller, the output voltage U is maintained in the discharging stage 2 The ability to stabilize is weak. Thus, the output voltage U can be varied by varying the phase shift angle α 2 Is of a size of (a) and (b).
Due to the fact that in one control period T S The working of the first half period and the second half period of the inner part has symmetrical characteristic, and if the phase shift angle alpha is introduced, the DAB-DCDC state equation can be obtained as follows:
wherein alpha represents a phase shift angle, C 1 Representing output endCapacitance of capacitor, U 1 Representing input terminal voltage, U 2 Represents the output voltage, k represents the transformer turns ratio, i o Indicating the output current, L indicating the inductance value, i L Representing inductor current, T s The control period is indicated, and t is the time.
Four conventional control methods adopted by DAB-DCDC are all to control power transmission by simultaneously controlling the first full bridge 112 and the second full bridge 116, so that 8 tubes need to be controlled simultaneously, and 4 pairs of PWM driving signals need to be used.
As can be seen from the principle analysis of the single-sided phase shift control provided by the present application, DAB-DCDC can only work in one state of electric power transmission (electric power is input from the first port to the second port and output from the second port to the first port), so that only one of the first full bridge 112 and the second full bridge 116 needs to be controlled to perform phase shift control, so that the output voltage can be changed, and the output power can be changed.
When the single-side phase shift control mode is adopted, the circuit form of the isolation driving unit 130 can be adopted, and the core processor outputs 1 pair of PWM driving signals of the EPWM1A and the EPWM1B to drive 8 power tubes of the first full bridge 112 and the second full bridge 116, so that the single-side phase shift control mode has the characteristic of simple structure.
In one implementation, the phase shift angle satisfies the formula:
wherein alpha represents a phase shift angle, T s Represents a control period, m 1 And m is equal to 2 Representing a predetermined variational discipline function, C 1 Representing the capacitance of the output end capacitor, U 1 Representing input terminal voltage, U 2 Represents the output voltage, k represents the transformer turns ratio, i o Indicating the output current, L indicating the inductance value, i L Representing the current of the inductor,
representing the target output voltage value.
The specific analysis is as follows:
the DAB-DCDC state equation obtained by the above deduction is as follows:
when taking out
At the time, can be obtained:
taking x 1 =U 2 ，x 2 =i L ，
From (1-3) and (1-4):
taking the target value of the output voltage as U 2ref =x ref The method can obtain:
taking the Lyapunov function
Can be represented by the formula (1-7)Obtaining:
taking the current inner loop target value
The method comprises the following steps:
substitution of formulas (1-9) into formulas (1-8) is available:
when taking out
When you can get->
。
The combination of formulas (1-6) can be obtained:
obtainable from formulae (1-11):
taking control input
The method comprises the following steps:
taking the Lyapunov function
Substitution of formulas (1-13) into formulas (1-12) can be obtained:
when taking out
When you can get->
。
The control inputs of DAB-DCDC are known from formulas (1-7) to (1-14):
obtainable from formulae (1-15):
due to
Thus, the phase shift control angle is obtained as follows: />
It should be noted that:
1. m is introduced into the control law 1 ，m 2 Two variable approach law functions, thereby ensuring
When the system is larger, the control output is stronger, and the convergence speed of the system is accelerated;
2. the control law alpha fully combines a nonlinear model structure of DAB-DCDC, and has better control effect;
3. the control law alpha contains the target value of the output voltage
In addition, the inductor current i is contained L Therefore, the voltage and current double closed-loop control effect is achieved, and the response speed is higher;
4. the coefficients that the control law alpha needs to determine include
；
5. The physical parameters involved in the control law alpha include C 1 、L；
6. State quantity (measurement quantity) related to control law α:
。
compared with the traditional single-voltage outer loop PI control mode, the Lyapunov-based variable approach nonlinear control method provided by the application comprises two physical parameters of voltage and inductance current, and meanwhile, all deduction processes are based on a nonlinear model of a system, so that the method has better dynamic regulation performance. The Lyapunov-based control method can ensure that the voltage overshoot phenomenon is basically avoided while the adjustment speed is very fast.
The implementation principle of the control algorithm is shown in fig. 12.
Through the converter that this application provided, have following effect at least:
1. compared with four traditional control modes, 8 power tubes can be controlled by only one pair of PWM driving signals, so that the control method has the advantages of simplicity in control realization and less occupation of hardware resources;
2. the asymptotic approach nonlinear control algorithm provided by the application can be effectively adapted to DAB-DCDC nonlinear characteristics, and has a better control effect compared with a traditional control mode based on a small signal model.
3. The control algorithm provided by the application is a nonlinear control method based on Lyapunov control stability theory, and can ensure the stability of a large range of a system while realizing the voltage stability control of the traditional control method, and the new control algorithm has stronger stability control capability.
4. The control algorithm provided by the application acquires the inductance current i L The real-time value can improve the control response speed of the system, and overcomes the defect that the traditional control method simply depends on the voltage outer ring control, so that the dynamic response of the system is quicker.
5. The driving circuit and the sampling circuit provided by the application have strong and weak electric isolation effects by adopting the measures such as the Hall sensor and the photoelectric isolation, have better safety and can be applied to high-power occasions.
Based on the above implementation manner, the embodiment of the present application further provides a control method of a converter, which is applied to a core processing unit 140 in the converter, where the converter further includes a main power unit 110, an analog signal conditioning unit 120, and an isolation driving unit 130, the main power unit 110 is electrically connected to the analog signal conditioning unit 120 and the isolation driving unit 130, the core processing unit 140 is electrically connected to the analog signal conditioning unit 120 and the isolation driving unit 130, respectively, and referring to fig. 13, the method includes:
s102, acquiring a current signal and a voltage signal transmitted by an analog signal conditioning unit;
s104, determining a phase shift angle according to the current signal and the voltage signal, and generating a driving signal according to the phase shift angle;
and S106, transmitting a driving signal to the isolation driving unit 130, so that the isolation driving unit 130 drives the full bridge connected with the input port in the main power unit 110 to work.
Wherein, the phase shift angle satisfies the formula:
wherein alpha represents a phase shift angle, T s Represents a control period, m 1 And m is equal to 2 Representing a predetermined variational discipline function, C 1 Representing the capacitance of the output end capacitor, U 1 Representing input terminal voltage, U 2 Represents the output voltage, k represents the transformer turns ratio, i o Indicating the output current, L indicating the inductance value, i L Representing the current of the inductor,
representing the target output voltage value.
The state equation of the main power unit 110 during operation is:
wherein alpha represents a phase shift angle, C 1 Representing the capacitance of the output end capacitor, U 1 Representing input terminal voltage, U 2 Represents the output voltage, k represents the transformer turns ratio, i o Indicating the output current, L indicating the inductance value, i L Representing inductor current, T s The control period is indicated, and t is the time.
In summary, the present application provides a converter and a control method thereof, where the converter includes a main power unit, an analog signal conditioning unit, an isolation driving unit, and a core processing unit, where the main power unit is electrically connected to the analog signal conditioning unit and the isolation driving unit, and the core processing unit is electrically connected to the analog signal conditioning unit and the isolation driving unit, respectively; the main power unit is used for realizing power bidirectional transmission of the first port and the second port; the analog signal conditioning unit is used for collecting current signals and voltage signals when the main power unit operates; the core processing unit is used for determining a phase shift angle according to the current signal and the voltage signal and generating a driving signal according to the phase shift angle; the isolation driving unit is used for controlling the full bridge operation connected with the input port in the main power unit according to the driving signal. In the application, only the full bridge connected with the input port in the main power unit needs to be controlled to work, and the full bridge connected with the output port can be in an off state, so that single-side phase shift control is realized, the control is simpler, the occupied hardware resources are fewer, namely, the occupied number of pins is fewer, and the control performance is improved. The foregoing description is only of the preferred embodiments of the present application and is not intended to limit the same, but rather, various modifications and variations may be made by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.
It will be evident to those skilled in the art that the present application is not limited to the details of the foregoing illustrative embodiments, and that the present application may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the application being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.
Claims (8)
1. The converter is characterized by comprising a main power unit, an analog signal conditioning unit, an isolation driving unit and a core processing unit, wherein the main power unit is respectively and electrically connected with the analog signal conditioning unit and the isolation driving unit, and the core processing unit is respectively and electrically connected with the analog signal conditioning unit and the isolation driving unit; wherein,,
the main power unit is used for realizing power bidirectional transmission of the first port and the second port;
the analog signal conditioning unit is used for collecting current signals and voltage signals when the main power unit operates;
the core processing unit is used for determining a phase shift angle according to the current signal, the voltage signal and a preset variational discipline function and generating a driving signal according to the phase shift angle;
wherein, the phase shift angle satisfies the formula:
alpha represents the phase shift angle, T s Represents a control period, m 1 And m is equal to 2 Representing a predetermined variational discipline function, C 1 Representing the capacitance of the output end capacitor, U 1 Representing input terminal voltage, U 2 Represents the output voltage, k represents the transformer turns ratio, i o Indicating the output current, L indicating the inductance value, i L Representing the current of the inductor,
representing a target output voltage value;
the isolation driving unit is used for controlling full-bridge operation connected with the input port in the main power unit according to the driving signal.
2. The converter of claim 1, wherein the state equation of the main power unit when operating is:
wherein alpha represents a phase shift angle, C 1 Representing the capacitance of the output end capacitor, U 1 Representing input terminal voltage, U 2 Represents the output voltage, k represents the transformer turns ratio, i o Indicating the output current, L indicating the inductance value, i L Representing inductor current, T s The control period is indicated, and t is the time.
3. The converter of claim 1, wherein the main power unit comprises a first current transformer, a second current transformer, a third current transformer, a first full bridge, a second full bridge, a filter inductance, and a high frequency transformer, the first port, the first current transformer, the first full bridge, the filter inductance, the second current transformer, the high frequency transformer, the second full bridge, the third current transformer, and the second port being electrically connected in sequence.
4. The converter of claim 3, wherein the analog signal conditioning unit comprises a three-way direct current acquisition circuit and two-way direct current voltage acquisition circuits, the three-way direct current acquisition circuits are respectively electrically connected with the first current transformer, the second current transformer and the third current transformer, and the two-way direct current voltage acquisition circuits are respectively electrically connected with the first port and the second port.
5. The converter of claim 1, wherein the core processing unit includes program emulation and debug circuitry, a core processor, communication interface circuitry, power supply circuitry, and power-on-reset circuitry, the core processor being electrically connected to the program emulation and debug circuitry, the communication interface circuitry, the power supply circuitry, and the power-on-reset circuitry, respectively.
6. The converter of claim 1, wherein the isolated drive unit includes a signal amplification module, a logic gating module, and a plurality of drive output modules, the signal amplification module being electrically connected to the core processing unit, the logic gating module, respectively, the logic gating module being further electrically connected to the plurality of drive output modules.
7. A method for controlling a converter, the converter further comprising a main power unit, an analog signal conditioning unit, and an isolation driving unit, wherein the main power unit is electrically connected to the analog signal conditioning unit and the isolation driving unit, and the core processing unit is electrically connected to the analog signal conditioning unit and the isolation driving unit, respectively, the method comprising:
acquiring a current signal and a voltage signal transmitted by the analog signal conditioning unit;
determining a phase shift angle according to the current signal, the voltage signal and a preset variational discipline function, and generating a driving signal according to the phase shift angle;
wherein, the phase shift angle satisfies the formula:
alpha represents the phase shift angle, T s Represents a control period, m 1 And m is equal to 2 Representing a predetermined variational discipline function, C 1 Representing the capacitance of the output end capacitor, U 1 Representing input terminal voltage, U 2 Represents the output voltage, k represents the transformer turns ratio, i o Indicating the output current, L indicating the inductance value, i L Representing the current of the inductor,
representing a target output voltage value;
and transmitting the driving signal to the isolation driving unit so that the isolation driving unit drives the full bridge connected with the input port in the main power unit to work.
8. The converter control method of claim 7, wherein the state equation of the main power unit in operation is:
wherein alpha represents a phase shift angle, C 1 Representing capacitance of capacitor, U 1 Representing input terminal voltage, U 2 Represents the output voltage, k represents the transformer turns ratio, i o Representing the output currentL represents inductance value, i L Representing inductor current, T s The control period is indicated, and t is the time.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310148506.6A CN115864857B (en) | 2023-02-22 | 2023-02-22 | Converter and control method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310148506.6A CN115864857B (en) | 2023-02-22 | 2023-02-22 | Converter and control method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115864857A CN115864857A (en) | 2023-03-28 |
| CN115864857B true CN115864857B (en) | 2023-05-16 |
Family
ID=85658667
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310148506.6A Active CN115864857B (en) | 2023-02-22 | 2023-02-22 | Converter and control method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115864857B (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110112922A (en) * | 2019-05-22 | 2019-08-09 | 湖南大学 | Based on double active bridging parallel operations of EPS control and its extracting method of phase shifting angle |
| CN110719030A (en) * | 2019-08-27 | 2020-01-21 | 河北工业大学 | Dual phase-shift modulation method for isolated bidirectional full-bridge DC-DC converter |
| CN210016405U (en) * | 2019-08-13 | 2020-02-04 | 电子科技大学中山学院 | Micro-grid double-active full-bridge bidirectional DC-DC converter |
| FR3124906A1 (en) * | 2021-07-05 | 2023-01-06 | Renault S.A.S | Method of controlling a reversible DC-DC converter. |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR102421163B1 (en) * | 2015-05-19 | 2022-07-14 | 엘지이노텍 주식회사 | Bi-directional dc-dc converter |
| US11121634B2 (en) * | 2018-12-07 | 2021-09-14 | Sharp Kabushiki Kaisha | Bidirectional DC-to-DC converter with inrush current suppression |
-
2023
- 2023-02-22 CN CN202310148506.6A patent/CN115864857B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110112922A (en) * | 2019-05-22 | 2019-08-09 | 湖南大学 | Based on double active bridging parallel operations of EPS control and its extracting method of phase shifting angle |
| CN210016405U (en) * | 2019-08-13 | 2020-02-04 | 电子科技大学中山学院 | Micro-grid double-active full-bridge bidirectional DC-DC converter |
| CN110719030A (en) * | 2019-08-27 | 2020-01-21 | 河北工业大学 | Dual phase-shift modulation method for isolated bidirectional full-bridge DC-DC converter |
| FR3124906A1 (en) * | 2021-07-05 | 2023-01-06 | Renault S.A.S | Method of controlling a reversible DC-DC converter. |
Non-Patent Citations (1)
| Title |
|---|
| 直流微电网双向全桥DC/DC变换器控制策略;朱胜杰 等;山东电力技术;第47卷(第09期);第1-6页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115864857A (en) | 2023-03-28 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108631357A (en) | A kind of mesohigh energy conversion system | |
| CN107070239B (en) | A kind of double active bridge DC/DC converter gamut soft switching control methods adjusted based on frequency | |
| CN105932883B (en) | Electric power electric transformer based on the direct AC-AC converters of energy injection type | |
| CN107623452B (en) | A kind of ultrasonic power and control method | |
| CN106981992A (en) | Isolation type bidirectional DC converter minimum reflux power phase-shifting control method | |
| CN106208715B (en) | A kind of distributed generation resource high voltage direct current access system and its control method | |
| CN107493015A (en) | A kind of two-way DC DC converters and its Poewr control method based on dual transformer structure | |
| CN108964476A (en) | The control method of isolation type bidirectional AC/DC converter based on double active bridges | |
| CN106076642B (en) | Electrostatic precipitation high-frequency and high-voltage power supply system and control method | |
| CN206658155U (en) | A kind of two-way full-bridge resonance DC/DC converter | |
| CN206790097U (en) | Realize the topological structure and system of bipolarity DC bus-bar voltage independent control | |
| CN106787768A (en) | A kind of two-way full-bridge resonance DC/DC converter and its control method | |
| CN107294389A (en) | One kind can freely commutate two-way DC/DC converters and its control method | |
| CN115864857B (en) | Converter and control method thereof | |
| CN109951082A (en) | The virtual current dead-beat control method of double active bridge DC converters | |
| CN110707935B (en) | Optimization control method of double-active full-bridge direct current converter | |
| CN209389939U (en) | Control circuit for resonant converter | |
| CN109302072B (en) | Series-input multi-port-output resonant DC converter and control method thereof | |
| CN111064370A (en) | LLC and DAB mixed bidirectional DC-DC converter | |
| CN205490225U (en) | Two -way ACDC circuit of high -frequency chopper isolated form | |
| Zhao et al. | Output capacitance effect on the voltage gain in the high step-up series resonant converter | |
| CN206775393U (en) | A kind of LLC resonant converter | |
| CN110995011B (en) | Bidirectional DC-DC converter based on alternating current switch switching | |
| CN207251276U (en) | A kind of charging unit | |
| CN207053406U (en) | A kind of electric power electric transformer of tandem mesohigh power network |
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 |