CN117277793A - Power supply system, DC/DC converter control method and control device - Google Patents
Power supply system, DC/DC converter control method and control device Download PDFInfo
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- CN117277793A CN117277793A CN202311560881.8A CN202311560881A CN117277793A CN 117277793 A CN117277793 A CN 117277793A CN 202311560881 A CN202311560881 A CN 202311560881A CN 117277793 A CN117277793 A CN 117277793A
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- 238000000034 method Methods 0.000 title claims abstract description 42
- 238000004146 energy storage Methods 0.000 claims abstract description 212
- 239000003990 capacitor Substances 0.000 claims abstract description 69
- 238000007665 sagging Methods 0.000 claims abstract description 29
- 238000007599 discharging Methods 0.000 claims description 51
- 230000008569 process Effects 0.000 claims description 11
- 101150117538 Set2 gene Proteins 0.000 description 12
- 230000033228 biological regulation Effects 0.000 description 12
- 101150055297 SET1 gene Proteins 0.000 description 11
- 230000002457 bidirectional effect Effects 0.000 description 6
- 238000004088 simulation Methods 0.000 description 6
- 238000011217 control strategy Methods 0.000 description 4
- 230000003247 decreasing effect Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 230000000630 rising effect Effects 0.000 description 2
- 208000033999 Device damage Diseases 0.000 description 1
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
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- 230000005611 electricity Effects 0.000 description 1
- 230000007274 generation of a signal involved in cell-cell signaling Effects 0.000 description 1
- 229910052744 lithium Inorganic materials 0.000 description 1
- 238000005065 mining Methods 0.000 description 1
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- 230000001172 regenerating effect Effects 0.000 description 1
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Classifications
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- 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
- H02M3/06—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using resistors or capacitors, e.g. potential divider
- H02M3/07—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using resistors or capacitors, e.g. potential divider using capacitors charged and discharged alternately by semiconductor devices with control electrode, e.g. charge pumps
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
- H02J7/007—Regulation of charging or discharging current or voltage
- H02J7/00712—Regulation of charging or discharging current or voltage the cycle being controlled or terminated in response to electric parameters
- H02J7/00714—Regulation of charging or discharging current or voltage the cycle being controlled or terminated in response to electric parameters in response to battery charging or discharging current
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
- H02J7/007—Regulation of charging or discharging current or voltage
- H02J7/00712—Regulation of charging or discharging current or voltage the cycle being controlled or terminated in response to electric parameters
- H02J7/007182—Regulation of charging or discharging current or voltage the cycle being controlled or terminated in response to electric parameters in response to battery voltage
-
- 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
- H02M1/0003—Details of control, feedback or regulation circuits
- H02M1/0038—Circuits or arrangements for suppressing, e.g. by masking incorrect turn-on or turn-off signals, e.g. due to current spikes in current mode control
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/08—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters
- H02M1/088—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters for the simultaneous control of series or parallel connected semiconductor devices
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/32—Means for protecting converters other than automatic disconnection
-
- 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
- H02M1/36—Means for starting or stopping 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
- 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
Abstract
The invention discloses a power supply system, a control method and a control device of a DC/DC converter, wherein the control method comprises the steps of generating a first output current according to an error between a charging current threshold value of an energy storage element and an energy storage side current; generating a second output current according to an error between the charge-discharge voltage threshold of the energy storage element and the energy storage side voltage; obtaining a third output current according to the busbar voltage and the sagging control curve; obtaining a reference current according to the first output current, the second output current and the third output current; generating a first output voltage according to the error between the reference current and the energy storage side current, obtaining a second output voltage according to the error between the bus voltage and the flying capacitor voltage, and generating a driving signal according to the first output voltage and the second output voltage. The invention can realize the voltage equalizing function of the flying capacitor, and the bus side adopts sagging control, so that the invention has the automatic current equalizing function when the multiple DC/DC converters on the bus side are connected in parallel.
Description
Technical Field
The invention belongs to the technical field of power electronics, and particularly relates to a power supply system, a DC/DC converter control method and a control device.
Background
Currently, in the field of engineering machinery vehicles (such as large heavy trucks) and trams, a great deal of transformation and upgrading to a pure electric drive system capable of changing oil to electricity are started, and new energy is accelerating to replace traditional fossil energy. The energy storage elements commonly used for the new energy vehicles are as follows: lead acid batteries, lithium batteries, supercapacitors, and the like. At present, parameters such as capacity, voltage class, current and the like of an energy storage element are gradually standardized, the rated voltage of the energy storage element is usually below 1000V, and along with the discharge of the energy storage element, the voltage of the energy storage element is gradually reduced, the minimum voltage of the discharge of the energy storage element is usually set to be 30% of the rated voltage, and the maximum feedback braking voltage is set to be 70% of the rated voltage. The power bus voltage of a construction machine vehicle or a tram is usually 1500-1800V, and the power bus voltage is allowed to fluctuate within a certain range, but the fluctuation range is too large to influence the operation of a load (mainly a motor). The bidirectional DC/DC is used as an intermediate voltage conversion medium of the direct current traction network and the energy storage element, so that the utilization rate of the energy storage element can be improved, and various complex control targets can be realized. In addition, the bidirectional DC/DC has wide application and market prospect in the energy storage field, the regenerative braking energy absorption and recycling field based on energy storage, the direct current micro-grid and the like.
The three-level topological structure is a topological structure of bidirectional DC/DC, and is mainly divided into a diode clamping type and a flying capacitor type. Typically, diode clamped three-level topologies are used in AC/DC systems, while flying capacitor three-level topologies are used in DC/DC systems. Compared with the diode clamping type, the flying capacitor type reduces two diodes, so that the self loss is reduced; the voltage resistance of the switching device is half of that of the two-level topological structure, so that the three-level topological structure is lower than that of the two-level topological structure from the cost; in addition, the three-level topological structure can output one level more. Therefore, under the same conditions, the output ripple current is twice smaller than that of the two-level topological structure, but the three-level topological structure is more complex than that of the two-level topological structure in the control strategy, because the three-level topological structure needs to control the voltage stability of the flying capacitor and is 1/2 of the bus voltage.
At present, control strategies aiming at a three-level bidirectional DC/DC topological structure and a general topological structure of a flying capacitor three-level structure are many, but the control strategies aiming at special requirements in the field of mining engineering vehicles or trams are not available, and the special requirements comprise relatively large load power; the inertia is relatively large in the starting or braking process, so that the DC/DC is easy to impact; the dynamic process is required to be stable and reliable. These special requirements also include parallel current sharing of multiple topologies, starting according to ramp voltage or ramp current to reduce starting shock, etc.
Hu (see Hu, yang Zhongping, advanced yellow, shi Jingjin, zhao) the three-level bidirectional DC converter for super capacitor energy storage system and control thereof [ J ]. Electrician technical school, 2015, 30 (8): 83-89), wherein the disclosed control strategy adopts a series structure of a voltage outer ring and a current inner ring, and the output current is controlled by means of the current inner ring, and the response speed of the inner ring is high, but the fluctuation is high, the precision is low, and the fluctuation of the control process is large and the precision is low when the output current is required to be controlled for large inertial load (such as slope current control and constant power control). Chen Ting (see, for example, chen Ting, cui Wenfeng, deng Yibai, qiao Zhijun, ruan Dianbo for application study of flying capacitor type three-level circuits in super capacitor energy feed systems) [ J ]. Infinite energy storage science and technology, 2020,9 (3): 935-941 ], wherein the working principle of flying capacitor type three-level topology is disclosed, but no specific control strategy is involved. Jin Ke (see Jin Ke, yang Mengxiong, ruan Xinbo. Three-level bidirectional converter [ J ]. Chinese Motor engineering report, 2006, 26 (18): 41-46.) adopts hardware implementation mode, and has no flexible software mode. In addition, the scheme does not consider the parallel current sharing condition of the bidirectional converter.
Disclosure of Invention
The invention aims to provide a power supply system, a DC/DC converter control method and a control device, which are used for solving at least one of the problems that the traditional control device or method is extremely easy to impact the DC/DC converter, the fluctuation of the dynamic control process is large, the precision is low and the current sharing when a plurality of bidirectional converters are connected in parallel cannot be realized.
The invention solves the technical problems by the following technical scheme: a control method of a DC/DC converter, the DC/DC converter adopting a flying capacitor type three-level topology structure, and having a first end connected to a bus and a second end connected to an energy storage element, the control method comprising the steps of:
acquiring bus voltage, energy storage side current, energy storage side voltage and flying capacitor voltage;
judging whether the device is in a charging mode or a discharging mode according to the bus voltage, the first voltage threshold and the second voltage threshold;
in a charging mode, obtaining a first output current according to an error between a charging current threshold of the energy storage element and an energy storage side current; in a discharging mode, obtaining a first output current according to an error between a discharging current threshold value of the energy storage element and an energy storage side current;
in a charging mode, obtaining a second output current according to an error between a charging voltage threshold of the energy storage element and an energy storage side voltage; in a discharging mode, obtaining a second output current according to an error between a discharging voltage threshold value of the energy storage element and an energy storage side voltage;
obtaining a third output current according to the busbar voltage and the busbar voltage sagging control curve;
obtaining a reference current according to the first output current, the second output current, the third output current, the energy storage side voltage and the bus voltage;
obtaining a first output voltage according to the error between the reference current and the energy storage side current;
obtaining a second output voltage according to an error between the bus voltage and the flying capacitor voltage, wherein the error is 0.5 times of the bus voltage;
and obtaining a driving signal according to the first output voltage and the second output voltage, and controlling the work of a switching tube in the DC/DC converter according to the driving signal.
Further, when the bus voltage is greater than the first voltage threshold, the device is in a charging mode; when the bus voltage is less than the second voltage threshold, the device is in a discharge mode, wherein the first voltage threshold is greater than the second voltage threshold.
Further, the upper limit value of the charging current threshold of the energy storage element is the rated charging current of the energy storage element, and the upper limit value of the discharging current threshold of the energy storage element is the rated discharging current;
the upper limit value of the charging voltage threshold of the energy storage element is a feedback energy charging limit value, and the upper limit value of the discharging voltage threshold of the energy storage element is a discharging voltage limit value of the energy storage element.
Further, in the charging mode, when the first voltage threshold value is less than the bus voltage and less than the third voltage threshold value, the device is in a sagging control stage, and the charging current of the energy storage element is increased along with the rising of the bus voltage; when the third voltage threshold value is smaller than the bus voltage, the product of the ratio between the bus voltage and the energy storage side voltage and the third output current is equal to the rated charging current, and the device is in a constant current control stage;
in a discharging mode, when the fourth voltage threshold value is smaller than the bus voltage and smaller than the second voltage threshold value, the device is in a sagging control stage, and the discharging current of the energy storage element is increased along with the decrease of the bus voltage; when the bus voltage is smaller than the fourth voltage threshold, the device is in a constant current control stage, and the discharge current of the energy storage element reaches the rated discharge current.
Further, obtaining a reference current according to the first output current, the second output current, the third output current, the energy storage side voltage and the bus voltage, specifically including:
calculating the ratio between the bus voltage and the energy storage side voltage, and then calculating the product of the ratio and the third output current to obtain a fourth output current;
in a charging mode, taking the minimum value of the first output current, the second output current and the fourth output current, and carrying out saturation treatment on the minimum value to obtain the reference current;
and in a discharging mode, taking the maximum value of the first output current, the second output current and the fourth output current, and carrying out saturation treatment on the maximum value to obtain the reference current.
Further, the direction of the energy storage side current in the charging mode is set to be positive, the direction of the energy storage side current in the discharging mode is set to be negative, and the specific process of the saturation treatment is as follows:
in the charging mode, when the minimum value is greater than the rated charging current, the reference current is equal to the rated charging current; when the minimum value is less than the rated charging current, the reference current is equal to the minimum value;
in the discharge mode, when the maximum value > rated discharge current, the reference current is equal to the maximum value; when the maximum value < rated discharge current, the reference current is equal to the rated discharge current.
Further, the switching tube of the DC/DC converter includes a switching tube S1, a switching tube S2, a switching tube S3, and a switching tube S4 sequentially connected from top to bottom, and the switching tube in the DC/DC converter is controlled to work according to the driving signal, which specifically includes:
in the charging mode, the driving signal controls the switching tube S1 and the switching tube S2 to be conducted, and the switching tube S3 and the switching tube S4 to be turned off;
in the charging mode, when the bus voltage is 0.5 times greater than the flying capacitor voltage, the driving signal controls the duty ratio of the switching tube S1 to be increased and the duty ratio of the switching tube S2 to be reduced;
in the charging mode, when the bus voltage is 0.5 times less than the flying capacitor voltage, the duty ratio of the switching tube S1 is controlled by the driving signal to be reduced, and the duty ratio of the switching tube S2 is controlled by the driving signal to be increased;
in the discharging mode, the driving signal controls the switching tube S1 and the switching tube S2 to be turned off, and the switching tube S3 and the switching tube S4 to be turned on;
in a discharging mode, when the bus voltage is 0.5 times greater than the flying capacitor voltage, the driving signal controls the duty ratio of the switching tube S4 to be increased and the duty ratio of the switching tube S3 to be reduced;
in the discharging mode, when the bus voltage is 0.5 times less than the flying capacitor voltage, the driving signal controls the duty ratio of the switching tube S4 to be reduced and the duty ratio of the switching tube S3 to be increased.
Further, before the device is started, the flying capacitor is charged, so that the voltage of the flying capacitor is close to 0.5 times of the bus voltage.
Based on the same conception, the invention also provides a DC/DC converter control device, the DC/DC converter adopts a flying capacitor type three-level topological structure, a first end of the DC/DC converter is connected with a bus, a second end of the DC/DC converter is connected with an energy storage element, and the control device comprises:
the energy storage side current control outer ring is used for obtaining a first output current according to an error between a charging current threshold value of the energy storage element and the energy storage side current in a charging mode; or obtaining a first output current according to the error between the discharge current threshold value of the energy storage element and the current at the energy storage side in the discharge mode;
the energy storage side voltage control outer ring is used for obtaining a second output current according to the error between the charging voltage threshold value of the energy storage element and the energy storage side voltage in the charging mode; or obtaining a second output current according to the error between the discharge voltage threshold value of the energy storage element and the voltage of the energy storage side in the discharge mode;
the bus voltage sagging control unit is used for obtaining a third output current according to the bus voltage and a bus voltage sagging control curve;
the reference current generation unit is used for obtaining a reference current according to the first output current, the second output current, the third output current, the energy storage side voltage and the bus voltage;
the energy storage side current control inner ring is used for obtaining a first output voltage according to the error between the reference current and the energy storage side current;
the flying capacitor voltage control unit is used for obtaining a second output voltage according to the error between the bus voltage and the flying capacitor voltage, which is 0.5 times of the bus voltage;
and the driving signal generating unit is used for generating a driving signal for controlling a switching tube in the DC/DC converter according to the first output voltage and the second output voltage.
Based on the same idea, the present invention also provides a power supply system comprising the DC/DC converter control device as described above.
Advantageous effects
Compared with the prior art, the invention has the advantages that:
according to the invention, sagging control is adopted at the bus side, so that the charging and discharging power of the energy storage element can be adjusted according to the bus voltage, and when a plurality of DC/DC converters at the bus side are connected in parallel, the automatic current equalizing function is realized; the invention realizes the voltage equalizing function of the flying capacitor by adjusting the error between the bus voltage and the flying capacitor voltage by 0.5 times, and the voltage equalizing target value is 1/2 of the bus voltage; compared with a series structure of the voltage outer ring and the current inner ring, the invention has the advantages that the current outer ring is connected with the voltage outer ring in parallel, the control process is more stable, and the precision is higher.
The invention has the constant voltage/constant current control automatic switching function, after each voltage threshold value is preset, when the charging reaches the corresponding voltage threshold value, the corresponding outer ring plays a role in determining, and the constant voltage/constant current control automatic switching is realized.
The invention can charge the flying capacitor before the device is started, so that the voltage of the flying capacitor is close to 0.5 times of the bus voltage, the independent control of starting current or starting voltage is realized, and the device damage caused by instant starting current impact or overvoltage of a switching tube is avoided.
Drawings
In order to more clearly illustrate the technical solutions of the present invention, the drawings that are needed in the description of the embodiments will be briefly described below, it being obvious that the drawing in the description below is only one embodiment of the present invention, and that other drawings can be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a flying capacitor type three level topology in an embodiment of the present invention;
FIG. 2 is a schematic diagram of a DC/DC converter control method in an embodiment of the invention;
FIG. 3 is a graph of control of bus voltage sag in an embodiment of the invention;
FIG. 4 is a simulation block diagram of a control method in an embodiment of the present invention;
FIG. 5 is a waveform of a bus voltage in a discharged state in an embodiment of the present invention; wherein a represents no-load starting, b represents bus loading, c represents a sagging control stage, and d represents a constant current control stage;
fig. 6 is a waveform of the output current of the battery in the discharging state in the embodiment of the present invention, wherein a represents no-load start, b represents bus loading, c represents a sagging control stage, and d represents a constant current control stage.
Detailed Description
The following description of the embodiments of the present invention will be made more apparent and fully by reference to the accompanying drawings, in which it is shown, however, only some, but not all embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
The technical scheme of the present application is described in detail below with specific examples. The following embodiments may be combined with each other, and some embodiments may not be repeated for the same or similar concepts or processes.
The invention provides a DC/DC converter control method and a control device, which are lower in self-loss of a flying capacitor type and lower in cost compared with a diode clamping type, and can output one level more. Therefore, the DC/DC converter of the present invention adopts a flying capacitor type three-level topology structure, and the first end of the DC/DC converter is connected to the bus, and the second end of the DC/DC converter is connected to the energy storage element, as shown in fig. 1. In FIG. 1, C fly In order to be a flying capacitor,u p for the voltage of the bus bar,i p for the bus-bar current,u b for the battery side voltage,i b for battery side current, the switching tubes S1 to S4 are connected in order from top to bottom. The positive direction of the voltage and current is shown in fig. 1, i.e., the current direction in the charging mode is positive, and the current direction in the discharging mode is negative. In this embodiment, the energy storage element is a battery pack, and each battery pack corresponds to one DC/DC converter.
As shown in fig. 2, the method for controlling a DC/DC converter according to the embodiment of the present invention includes the following steps:
step 1: obtaining bus voltageu p Energy storage side currenti b Voltage at energy storage sideu b Flying capacitor voltage U Cfly ；
Step 2: according to bus voltageu p First voltage thresholdU h1 Second voltage thresholdU l1 Judging whether the device is in a charging mode or a discharging mode;
step 3: in the charging mode, the energy storage element is charged with a threshold currentI set1 And energy storage side currenti b Error betweene i PI regulation is carried out to obtain a first output currenti bi ；
In the discharging mode, the energy storage element is discharged with a current threshold valueI set2 And energy storage side currenti b Error betweene i PI regulation is carried out to obtain a first output currenti bi ；
Step 4: in the charging mode, the energy storage element is charged with a threshold voltageU set1 Error with the energy storage side voltagee u PI regulation is carried out to obtain a second output currenti bu ；
In the discharging mode, the energy storage element is discharged by a voltage threshold valueU set2 Error with the energy storage side voltagee u PI regulation is carried out to obtain a second output currenti bu ；
Step 5: according to bus voltageu p Obtaining a third output current by using a busbar voltage sagging control curvei pref ；
Step 6: according to the first output currenti bi A second output currenti bu A third output currenti pref Voltage at energy storage sideu b Bus voltageu p Obtaining a reference currenti bref ；
Step 7: for reference currenti bref And energy storage side currenti b PI regulation is carried out on the error between the first output voltage and the second output voltage to obtain a first output voltageu 1 ；
Step 8: for 0.5 times of bus voltageu p And flying capacitor voltage U Cfly PI regulation is carried out on the error between the first output voltage and the second output voltage to obtain a second output voltageu 2 ；
Step 9: according to the first output voltageu 1 And a second output voltageu 2 A driving signal is obtained, and the operations of switching tubes S1 to S4 in the DC/DC converter are controlled according to the driving signal.
As can be seen from fig. 2, steps 3 to 5 and 8 are parallel steps. In this embodiment, PI adjustment is used for error adjustment.
In one embodiment of the invention, when the bus voltage isu p > first voltage thresholdU h1 When the device is in a charging mode; when the bus voltage isu p < second voltage thresholdU l1 When the device is in a discharge mode, wherein the first voltage threshold > the second voltage threshold.
In step 3, the energy storage side current is utilized to control the outer ring to charge the current threshold value of the energy storage element in the charging modeI set1 And energy storage side currenti b Error betweene i PI regulation is carried out to obtain a first output currenti bi The method comprises the steps of carrying out a first treatment on the surface of the In the discharging mode, the energy storage element is discharged with a current threshold valueI set2 And energy storage side currenti b Error betweene i PI regulation is carried out to obtain a first output currenti bi 。
I set Charge-discharge current curve of energy storage element, wherein the charge current threshold of energy storage element in charge modeI set1 Is thatI set A fraction of > 0, the energy storage element discharge current threshold in discharge modeI set2 Is thatI set The fraction of the total number of the,I set the upper limit value of (2) is the rated charging current of the energy storage element,I set the lower limit value of (2) is the rated discharge current. Charge-discharge curve of energy storage elementI set May be a ramp signal whenI set When the energy storage element is a slope signal, the energy storage element starts to chargeI set1 With the increase of the charging time, the charging current threshold value of the energy storage element is increased after a period of timeI set1 Reaching the upper limit value, namely the threshold value of the charging current of the energy storage elementI set1 Rated charging current for the energy storage element; when starting discharging, the discharge current threshold value of the energy storage elementI set2 With the increase of discharge time, the discharge current threshold value of the energy storage element is increased after a period of timeI set2 Reaching the upper limit, i.e. discharging the energy-storage elementCurrent threshold valueI set2 Is the rated discharge current of the energy storage element. Charge-discharge curve of energy storage elementI set Or square wave signal whenI set When the energy storage element is square wave signal, the threshold value of the charging current of the energy storage element is obtained during chargingI set1 Rated charging current for the energy storage element; during discharging, the energy storage element discharges the current threshold valueI set2 Is the rated discharge current of the energy storage element. At the time of starting, a current rising slope is set to control the current of the energy storage sidei b The corresponding rated value (i.e., rated charge current or rated discharge current) is slowly reached.The average value of the energy storage side current feedback signal is obtained, and because the speed of the control outer ring is relatively slow, the average value can be used for removing interference, and the control accuracy is improved. Error of energy storage side current control outer ringe i After PI control, a first output current is outputi bi When feeding back a signali b Below the charge-discharge threshold of the energy storage element,i bi become larger when the feedback signali b Above the charge-discharge threshold of the energy storage element,i bi and becomes smaller. In the charging mode, wheni b Reaching the threshold of the charging current of the energy storage elementI set1 In the time-course of which the first and second contact surfaces,i bi the energy storage side current control outer ring becomes smaller gradually, and then takes a decision function after Min () function (namely taking the minimum value); similarly, in the discharge mode, the energy storage element discharges the threshold value of the currentI set2 And feedback signali b All have negative values, when the feedback signali b Reaching the discharge current threshold of the energy storage elementI set2 ，i bi Will become larger and after Max () function (i.e. take the maximum value), the energy storage side current control outer loop will play a decisive role.
In step 4, the energy storage side voltage control outer ring charges the energy storage element with voltage in the charging modeThreshold valueU set1 Error with the energy storage side voltagee u PI regulation is carried out to obtain a second output currenti bu The method comprises the steps of carrying out a first treatment on the surface of the In the discharging mode, the energy storage element is discharged by a voltage threshold valueU set2 Error with the energy storage side voltagee u PI regulation is carried out to obtain a second output currenti bu 。
U set The voltage curve is charged and discharged for the energy storage element,U set the upper limit of (2) is the feedback energy charging limit,U set the lower limit value of (2) is the discharge voltage limit value of the energy storage element, and the charge voltage threshold value of the energy storage elementU set1 For the portion between the current voltage of the energy storage element and the feedback energy charging limit value, the energy storage element discharges the voltage threshold valueU set2 Is the fraction of the energy storage element between the present voltage and the discharge voltage limit. In this embodiment, the feedback energy charging limit is 70% of the rated voltage of the energy storage element, and the discharging voltage limit is 30% of the rated voltage of the energy storage element.Is the average value of the energy storage side voltage feedback signal,i bu and the control output of the outer loop is controlled for the voltage of the energy storage side. The working principle of the energy storage side voltage control outer ring is similar to that of the energy storage side current control outer ring, and when in a charging or discharging modeu b When the corresponding threshold value of the charge and discharge voltage of the energy storage element is reached, the outer ring of the voltage control on the energy storage side plays a role in determination.
In step 5, the sagging control unit of the bus voltage is utilized to control the sagging control unit according to the bus voltageu p Obtaining a third output current by using a busbar voltage sagging control curvei pref . As shown in fig. 3, the bus voltage sag control curve is controlled by a first voltage thresholdU h1 A third voltage thresholdU h2 Second voltage thresholdU l1 Fourth voltage thresholdU l2 To determine, wherein a third voltage thresholdU h2 > first voltage thresholdU h1 > second voltage thresholdU l1 > fourth voltage thresholdU l2 . The four voltage thresholds are determined according to the bus voltage working range corresponding to the vehicle, after the four voltage thresholds are determined, the bus voltage sagging control curve can be determined, meanwhile, the slope of the sagging control curve can be set according to the energy storage element SOC, and the energy storage element SOC balance when a plurality of DC/DC converters are connected in parallel is realized through controlling the slope difference. The busbar voltage sag control curve is divided into three phases: a charging stage, a discharging stage and a standby stage.
When the bus voltage isu p > first voltage thresholdU h1 When the bus is used for charging the energy storage element, the device is in a charging mode; when the bus voltage isu p < second voltage thresholdU l1 When the energy storage element discharges the bus, the device is in a discharge mode; when the second voltage thresholdU l1 < bus voltageu p < first voltage thresholdU h1 When the device is in a standby mode, the switching tubes S1-S4 are all turned off in the standby mode. The charging mode is divided into two phases, when the first voltage thresholdU h1 < bus voltageu p < third voltage thresholdU h2 In the droop control stage, the charging current of the energy storage element (i.e. the energy storage side current) increases with the rise of the bus voltagei b ) The current equalization can be basically achieved when a plurality of DC/DC converters are connected in parallel due to the droop control, namely the current output by each DC/DC converteri p Substantially equal; when the third voltage thresholdU h2 < bus voltageu p Bus voltage at the timeu p And energy storage side voltageu b Ratio between and third output currenti pref The product of%i pref ×u p )/u b Equal to rated charge current, the device is at constant currentIn the control stage, the charging current of the energy storage element reaches the rated charging current, and the bus voltage is increased at the moment, so that the charging current of the energy storage element is not increased.
The discharge mode is also divided into two phases, when the fourth voltage thresholdU l2 < bus voltageu p < second voltage thresholdU l1 The device is in a sagging control stage, and the sagging control stage is controlled according to the bus voltageu p Is reduced by the discharge current of the energy storage element (i.e. the energy storage side currenti b ) Increasing; when the bus voltage isu p < fourth voltage thresholdU l2 When the device is in a constant current control stage, the discharge current of the energy storage element reaches the rated discharge current.
In step 6, according to the first output currenti bi A second output currenti bu A third output currenti pref Voltage at energy storage sideu b Bus voltageu p Obtaining a reference currenti bref The method specifically comprises the following steps:
calculating bus voltageu p And energy storage side voltageu b The ratio of the current to the third output current is then calculatedi pref The product of the first and second output currents is obtainedi bp ；
In the charging mode, the first output current is takeni bi A second output currenti bu Fourth output currenti bp The minimum value min in (2) and carrying out saturation treatment on the minimum value to obtain a reference currenti bref The method comprises the steps of carrying out a first treatment on the surface of the In the discharging mode, take the first output currenti bi A second output currenti bu Fourth output currenti bp Maximum value max of (1) and saturation processing is carried out on the maximum value to obtain a reference currenti bref 。
In this embodiment, the specific process of the saturation treatment is that, assuming that the direction of the energy storage side current in the charging mode is positive and the direction of the energy storage side current in the discharging mode is negative:
in the charging mode, when the minimum value is greater than the rated charging current, the reference currenti bref Equal to the rated charge current; when the minimum value is less than the rated charging current, the reference currenti bref Is equal to the minimum value; in the discharge mode, when the maximum value is greater than the rated discharge current, the reference currenti bref Equal to the maximum value; when maximum value < rated discharge current, reference currenti bref Equal to the rated discharge current.
In step 7, the energy storage side current is utilized to control the inner loop to reference currenti bref And energy storage side currenti b PI regulation is carried out on the error between the first output voltage and the second output voltage to obtain a first output voltageu 1 。i bref The output from the outer loop control is the reference signal of the energy storage side current control inner loop,i b the signal is fed back for the instantaneous value of the energy storage side current.
Steps 8 and 9 are for flying capacitor voltage U Cfly Control and generation and distribution of driving signals are performed, and are also classified into a charge mode and a discharge mode. In step 8, the flying capacitor voltage control unit is utilized to control the voltage of the bus to be 0.5 timesu p And flying capacitor voltage U Cfly PI regulation is carried out on the error between the first output voltage and the second output voltage to obtain a second output voltageu 2 。
Under the charging mode, the switching tube S1 and the switching tube S2 are conducted, the switching tube S3 and the switching tube S4 are always turned off, which is equivalent to a BUCK circuit, and four working states are all available: when the duty ratio of the switching tube S1 and the switching tube S2 is increased, the charging current of the energy storage element is increased; when the duty ratio of the switching tube S1 and the switching tube S2 is reduced, the charging current of the energy storage element is reduced; when the duty ratio of the switching tube S1 becomes larger and the duty ratio of the switching tube S2 becomes smaller, the flying capacitorC fly Charging; when the duty ratio of the switching tube S1 becomes smaller and the duty ratio of the switching tube S2 becomes larger, the flying capacitorC fly And (5) discharging. Therefore, when 0.5 times the motherLine voltageu p Flying capacitor voltage U Cfly When the driving signal controls the duty ratio of the switching tube S1 to increase and the duty ratio of the switching tube S2 to decrease, so as to increase the flying capacitor voltage U Cfly The method comprises the steps of carrying out a first treatment on the surface of the When 0.5 times of bus voltageu p < flying capacitor voltage U Cfly When the driving signal controls the duty ratio of the switching tube S1 to decrease and the duty ratio of the switching tube S2 to increase, the flying capacitor voltage U is reduced Cfly 。
Similarly, in the discharging mode, the switching tube S1 and the switching tube S2 are always turned off, and the switching tube S3 and the switching tube S4 are turned on, which corresponds to a BOOST circuit, and has four working states: when the duty ratio of the switching tube S3 and the switching tube S4 becomes large, the discharge current of the energy storage element becomes larger; when the duty ratio of the switching tube S3 and the switching tube S4 becomes smaller, the discharge current of the energy storage element becomes smaller; when the duty ratio of the switching tube S4 becomes larger and the duty ratio of the switching tube S3 becomes smaller, the flying capacitorC fly When the duty ratio of the switching tube S4 becomes smaller and the duty ratio of the switching tube S3 becomes larger, the flying capacitor is chargedC fly And (5) discharging. Therefore, when 0.5 times of the bus voltageu p Flying capacitor voltage U Cfly When the driving signal controls the duty ratio of the switching tube S4 to be increased and the duty ratio of the switching tube S3 to be reduced, so as to increase the flying capacitor voltage; when 0.5 times of bus voltageu p < flying capacitor voltage U Cfly At this time, the driving signal controls the duty ratio of the switching tube S4 to decrease and the duty ratio of the switching tube S3 to increase, so as to decrease the flying capacitor voltage.
According to the first output voltageu 1 And a second output voltageu 2 And obtaining a driving signal, and controlling the work of the switching tubes S1-S4 in the DC/DC converter according to the driving signal. As shown in FIG. 2, when the bus voltage is 0.5 timesu p Flying capacitor voltage U Cfly At 0.5 times of bus voltageu p And flying capacitor voltage U Cfly Error betweene c Positive, second output voltageu 2 Positive, in charging mode, the first output voltageThe sum of the first output voltage and the second output voltage is increased, so that the duty ratio of the switching tube S1 is increased, the difference between the first output voltage and the second output voltage is reduced, and the duty ratio of the switching tube S2 is reduced; and (1) is the inversion (namely positive to negative), and in the discharging mode, the sum of the first output voltage and the second output voltage is increased, so that the duty ratio of the switching tube S4 is increased, the difference between the first output voltage and the second output voltage is reduced, and the duty ratio of the switching tube S3 is reduced. When 0.5 times of bus voltageu p < flying capacitor voltage U Cfly At 0.5 times of bus voltageu p And flying capacitor voltage U Cfly Error betweene c Negative, the second output voltageu 2 In the negative charging mode, the sum of the first output voltage and the second output voltage is reduced, so that the duty ratio of the switching tube S1 is reduced, the difference between the first output voltage and the second output voltage is increased, and the duty ratio of the switching tube S2 is increased; in the discharging mode, the sum of the first output voltage and the second output voltage is reduced, so that the duty ratio of the switching tube S4 is reduced, the difference between the first output voltage and the second output voltage is increased, and the duty ratio of the switching tube S3 is increased. The triangular wave in fig. 2 is a PWM modulated wave, and the modulation period of the PWM modulated wave corresponds to the switching frequency of the switching transistor.
The voltage control unit of the flying capacitor is outside the current loop and does not participate in current control, so that overcurrent is easily caused, particularly when the device is started, the flying capacitor needs to be charged before the device is started, and the voltage of the flying capacitor is as close as possibleu p And/2, starting, otherwise, starting the device instantaneously or over-voltage of a switching tube can damage the device.
In order to verify the effectiveness of the method, a simulation model is built by using a simulation platform matlab/simulink, as shown in fig. 4, wherein R1 is a load resistor, KM1 is a relay, and the method is used for simulating a load dynamic switching process. The control method needs to input 4 feedback signals, namely needs to sample bus voltageu p Energy storage side currenti b Voltage at energy storage sideu b Flying capacitor voltage U Cfly . Sampling value according to control methodThe multi-point average value is obtained, so that the influence of random error interference can be greatly reduced, and the control precision is improved. The simulation parameters are shown in table 1.
TABLE 1 simulation model parameter List
Taking a heavy truck as an example, since the truck DC/DC converter is mainly operated in a battery-to-bus discharge state, only the simulation waveforms in the discharge state are illustrated, as shown in fig. 5 and 6. Fig. 5 is a bus voltage waveform, and fig. 6 is a battery output current waveform. In the no-load starting stage a, the energy storage side current control outer ring plays a role in determination, and as can be seen from FIG. 6, the discharge current is negative, and rises according to a slope, after a period of time, when the bus voltage rises toU l1 The device enters a standby mode, the output current drops to 0, then KM1 is closed, the bus is suddenly loaded and started, the device enters a sagging control stage c, the sagging control stage c is characterized in that the battery discharge current is larger and larger along with the decrease of the bus voltage, the sagging control stage c in fig. 5 and 6 is characterized in that the bus voltage is decreased due to small battery capacity, the battery voltage is decreased along with the discharge process, the output power is also decreased, and the continuous decrease of the bus voltage occurs. As can be seen from fig. 5 and 6, the voltage of the bus bar can be maintained substantially stable during the sagging control phase c, and the discharge current of the battery gradually increases. When the discharge current of the battery reaches the rated discharge current, the constant-current control stage d is started, the output current of the battery is constant, and along with the reduction of the voltage of the battery, the discharge power of the battery and the voltage of a bus are accelerated to be reduced.
The embodiment of the invention also provides a DC/DC converter control device, the DC/DC converter adopts a flying capacitor type three-level topological structure, a first end of the DC/DC converter is connected with a bus, a second end of the DC/DC converter is connected with an energy storage element, and the control device comprises: the device comprises an energy storage side current control outer ring, an energy storage side voltage control outer ring, a busbar voltage sagging control unit, a reference current generation unit, an energy storage side current control inner ring, a flying capacitor voltage control unit and a driving signal generation unit.
The energy storage side current control outer ring is used for PI adjusting the error between the charging current threshold value of the energy storage element and the energy storage side current in a charging mode to obtain a first output current; or PI adjusting the error between the discharge current threshold value of the energy storage element and the current at the energy storage side in a discharge mode to obtain a first output current;
the energy storage side voltage control outer ring is used for PI adjusting the error between the threshold value of the charging voltage of the energy storage element and the energy storage side voltage in the charging mode to obtain a second output current; or PI adjusting the error between the discharge voltage threshold value of the energy storage element and the voltage of the energy storage side in the discharge mode to obtain a second output current;
the bus voltage sagging control unit is used for obtaining a third output current according to the bus voltage and a bus voltage sagging control curve;
the reference current generation unit is used for obtaining a reference current according to the first output current, the second output current, the third output current, the energy storage side voltage and the bus voltage;
the energy storage side current control inner ring is used for PI adjusting the error between the reference current and the energy storage side current to obtain a first output voltage;
the flying capacitor voltage control unit is used for PI adjusting the error between the bus voltage and the flying capacitor voltage which are 0.5 times, so as to obtain a second output voltage;
and the driving signal generating unit is used for generating a driving signal for controlling a switching tube in the DC/DC converter according to the first output voltage and the second output voltage.
The foregoing disclosure is merely illustrative of specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art will readily recognize that changes and modifications are possible within the scope of the present invention.
Claims (10)
1. A control method of a DC/DC converter, the DC/DC converter adopting a flying capacitor type three-level topology, and having a first end connected to a bus and a second end connected to an energy storage element, the control method comprising the steps of:
acquiring bus voltage, energy storage side current, energy storage side voltage and flying capacitor voltage;
judging whether the device is in a charging mode or a discharging mode according to the bus voltage, the first voltage threshold and the second voltage threshold;
in a charging mode, obtaining a first output current according to an error between a charging current threshold of the energy storage element and an energy storage side current; in a discharging mode, obtaining a first output current according to an error between a discharging current threshold value of the energy storage element and an energy storage side current;
in a charging mode, obtaining a second output current according to an error between a charging voltage threshold of the energy storage element and an energy storage side voltage; in a discharging mode, obtaining a second output current according to an error between a discharging voltage threshold value of the energy storage element and an energy storage side voltage;
obtaining a third output current according to the busbar voltage and the busbar voltage sagging control curve;
obtaining a reference current according to the first output current, the second output current, the third output current, the energy storage side voltage and the bus voltage;
obtaining a first output voltage according to the error between the reference current and the energy storage side current;
obtaining a second output voltage according to an error between the bus voltage and the flying capacitor voltage, wherein the error is 0.5 times of the bus voltage;
and obtaining a driving signal according to the first output voltage and the second output voltage, and controlling the work of a switching tube in the DC/DC converter according to the driving signal.
2. The method of claim 1, wherein the device is in a charging mode when the bus voltage > the first voltage threshold; when the bus voltage is less than the second voltage threshold, the device is in a discharge mode, wherein the first voltage threshold is greater than the second voltage threshold.
3. The control method of a DC/DC converter according to claim 1, wherein an upper limit value of the energy storage element charging current threshold is a rated charging current of the energy storage element; the upper limit value of the discharge current threshold of the energy storage element is the rated discharge current of the energy storage element;
the upper limit value of the charging voltage threshold of the energy storage element is a feedback energy charging limit value, and the upper limit value of the discharging voltage threshold of the energy storage element is a discharging voltage limit value of the energy storage element.
4. The control method of a DC/DC converter according to claim 2, wherein in the charging mode, when the first voltage threshold < bus voltage < third voltage threshold, the device is in a droop control stage, and as the bus voltage increases, the charging current of the energy storage element increases; when the third voltage threshold value is smaller than the bus voltage, the product of the ratio between the bus voltage and the energy storage side voltage and the third output current is equal to the rated charging current, and the device is in a constant current control stage;
in a discharging mode, when the fourth voltage threshold value is smaller than the bus voltage and smaller than the second voltage threshold value, the device is in a sagging control stage, and the discharging current of the energy storage element is increased along with the decrease of the bus voltage; when the bus voltage is smaller than the fourth voltage threshold, the device is in a constant current control stage, and the discharge current of the energy storage element reaches the rated discharge current.
5. The method for controlling a DC/DC converter according to any one of claims 1 to 4, wherein obtaining the reference current according to the first output current, the second output current, the third output current, the energy storage side voltage, and the bus voltage specifically includes:
calculating the ratio between the bus voltage and the energy storage side voltage, and then calculating the product of the ratio and the third output current to obtain a fourth output current;
in a charging mode, taking the minimum value of the first output current, the second output current and the fourth output current, and carrying out saturation treatment on the minimum value to obtain the reference current;
and in a discharging mode, taking the maximum value of the first output current, the second output current and the fourth output current, and carrying out saturation treatment on the maximum value to obtain the reference current.
6. The method according to claim 5, wherein the direction of the energy storage side current in the charging mode is positive, the direction of the energy storage side current in the discharging mode is negative, and the saturation process is as follows:
in the charging mode, when the minimum value is greater than the rated charging current, the reference current is equal to the rated charging current; when the minimum value is less than the rated charging current, the reference current is equal to the minimum value;
in the discharge mode, when the maximum value > rated discharge current, the reference current is equal to the maximum value; when the maximum value < rated discharge current, the reference current is equal to the rated discharge current.
7. The method for controlling a DC/DC converter according to any one of claims 1 to 4, wherein the switching tube of the DC/DC converter includes a switching tube S1, a switching tube S2, a switching tube S3, and a switching tube S4 sequentially connected from top to bottom, and the method specifically includes controlling the operation of the switching tube in the DC/DC converter according to the driving signal:
in the charging mode, the driving signal controls the switching tube S1 and the switching tube S2 to be conducted, and the switching tube S3 and the switching tube S4 to be turned off;
in the charging mode, when the bus voltage is 0.5 times greater than the flying capacitor voltage, the driving signal controls the duty ratio of the switching tube S1 to be increased and the duty ratio of the switching tube S2 to be reduced;
in the charging mode, when the bus voltage is 0.5 times less than the flying capacitor voltage, the duty ratio of the switching tube S1 is controlled by the driving signal to be reduced, and the duty ratio of the switching tube S2 is controlled by the driving signal to be increased;
in the discharging mode, the driving signal controls the switching tube S1 and the switching tube S2 to be turned off, and the switching tube S3 and the switching tube S4 to be turned on;
in a discharging mode, when the bus voltage is 0.5 times greater than the flying capacitor voltage, the driving signal controls the duty ratio of the switching tube S4 to be increased and the duty ratio of the switching tube S3 to be reduced;
in the discharging mode, when the bus voltage is 0.5 times less than the flying capacitor voltage, the driving signal controls the duty ratio of the switching tube S4 to be reduced and the duty ratio of the switching tube S3 to be increased.
8. The method according to any one of claims 1 to 4, wherein the flying capacitor is charged before the device is started, so that the voltage of the flying capacitor is approximately 0.5 times the bus voltage.
9. A DC/DC converter control device, the DC/DC converter adopting a flying capacitor type three-level topology, and having a first end connected to a bus and a second end connected to an energy storage element, the control device comprising:
the energy storage side current control outer ring is used for obtaining a first output current according to an error between a charging current threshold value of the energy storage element and the energy storage side current in a charging mode; or obtaining a first output current according to the error between the discharge current threshold value of the energy storage element and the current at the energy storage side in the discharge mode;
the energy storage side voltage control outer ring is used for obtaining a second output current according to the error between the charging voltage threshold value of the energy storage element and the energy storage side voltage in the charging mode; or obtaining a second output current according to the error between the discharge voltage threshold value of the energy storage element and the voltage of the energy storage side in the discharge mode;
the bus voltage sagging control unit is used for obtaining a third output current according to the bus voltage and a bus voltage sagging control curve;
the reference current generation unit is used for obtaining a reference current according to the first output current, the second output current, the third output current, the energy storage side voltage and the bus voltage;
the energy storage side current control inner ring is used for obtaining a first output voltage according to the error between the reference current and the energy storage side current;
the flying capacitor voltage control unit is used for obtaining a second output voltage according to the error between the bus voltage and the flying capacitor voltage, which is 0.5 times of the bus voltage;
and the driving signal generating unit is used for generating a driving signal for controlling a switching tube in the DC/DC converter according to the first output voltage and the second output voltage.
10. A power supply system, characterized in that the power supply system comprises the DC/DC converter control device according to claim 9.
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Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105024582A (en) * | 2015-07-27 | 2015-11-04 | 江苏大学 | Novel two-stage bidirectional energy storage converter control system and control method thereof |
| CN111628653A (en) * | 2020-06-30 | 2020-09-04 | 德尔福科技(苏州)有限公司 | Device and method for controlling voltage boosting and voltage reducing of bidirectional three-level DC-DC converter |
| US20200373839A1 (en) * | 2019-05-21 | 2020-11-26 | Huawei Technologies Co., Ltd. | Boost Converter and Control Method |
| JP2021093819A (en) * | 2019-12-10 | 2021-06-17 | 株式会社明電舎 | Control device of multilevel power converter |
| CN113270894A (en) * | 2021-06-29 | 2021-08-17 | 上海空间电源研究所 | Direct-current microgrid networking system based on spacecraft PCU system and control method |
| CN113328622A (en) * | 2021-06-04 | 2021-08-31 | 江南大学 | Control method of flying capacitor type three-level direct current buck converter |
| CN115118168A (en) * | 2022-07-20 | 2022-09-27 | 国网青海省电力公司西宁供电公司 | Buck type alternating current conversion device and control method |
| US20230291304A1 (en) * | 2022-03-11 | 2023-09-14 | Silergy Semiconductor Technology (Hangzhou) Ltd | Control circuit and control method for three-level dc-dc converter |
| CN116799841A (en) * | 2023-06-27 | 2023-09-22 | 上海电机学院 | Coordinated control method for multi-group energy storage sagging control based on consistency algorithm |
| CN116915048A (en) * | 2023-07-19 | 2023-10-20 | 深圳市盛弘新能源设备有限公司 | Loop controller, system, method and storage medium for three-level DC-DC converter |
-
2023
- 2023-11-22 CN CN202311560881.8A patent/CN117277793B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105024582A (en) * | 2015-07-27 | 2015-11-04 | 江苏大学 | Novel two-stage bidirectional energy storage converter control system and control method thereof |
| US20200373839A1 (en) * | 2019-05-21 | 2020-11-26 | Huawei Technologies Co., Ltd. | Boost Converter and Control Method |
| JP2021093819A (en) * | 2019-12-10 | 2021-06-17 | 株式会社明電舎 | Control device of multilevel power converter |
| CN111628653A (en) * | 2020-06-30 | 2020-09-04 | 德尔福科技(苏州)有限公司 | Device and method for controlling voltage boosting and voltage reducing of bidirectional three-level DC-DC converter |
| CN113328622A (en) * | 2021-06-04 | 2021-08-31 | 江南大学 | Control method of flying capacitor type three-level direct current buck converter |
| CN113270894A (en) * | 2021-06-29 | 2021-08-17 | 上海空间电源研究所 | Direct-current microgrid networking system based on spacecraft PCU system and control method |
| US20230291304A1 (en) * | 2022-03-11 | 2023-09-14 | Silergy Semiconductor Technology (Hangzhou) Ltd | Control circuit and control method for three-level dc-dc converter |
| CN115118168A (en) * | 2022-07-20 | 2022-09-27 | 国网青海省电力公司西宁供电公司 | Buck type alternating current conversion device and control method |
| CN116799841A (en) * | 2023-06-27 | 2023-09-22 | 上海电机学院 | Coordinated control method for multi-group energy storage sagging control based on consistency algorithm |
| CN116915048A (en) * | 2023-07-19 | 2023-10-20 | 深圳市盛弘新能源设备有限公司 | Loop controller, system, method and storage medium for three-level DC-DC converter |
Non-Patent Citations (1)
| Title |
|---|
| 陈宇飞: "直流母线接入的分布式混合储能系统功率控制研究", 中国优秀硕士学位论文全文数据库 工程科技Ⅱ辑, no. 05 * |
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