CN112968500A - Battery module terminal voltage regulating circuit and device - Google Patents
Battery module terminal voltage regulating circuit and device Download PDFInfo
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- CN112968500A CN112968500A CN202110344295.4A CN202110344295A CN112968500A CN 112968500 A CN112968500 A CN 112968500A CN 202110344295 A CN202110344295 A CN 202110344295A CN 112968500 A CN112968500 A CN 112968500A
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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
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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
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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
- H02J7/0047—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with monitoring or indicating devices or circuits
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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
- H02J7/02—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries for charging batteries from ac mains by converters
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Abstract
The invention relates to a terminal voltage regulating circuit of a battery module, which relates to the field of power supplies and comprises: the input end of the alternating current rectifying unit receives alternating current, and the output end of the alternating current rectifying unit is connected with a direct current bus and used for converting the alternating current into direct current bus voltage; a battery charging/discharging unit, a first end of which is connected with the direct current bus, a second end of which is connected with a battery module, and the battery charging/discharging unit is used for converting the direct current bus voltage at the first end into the direct current voltage at the second end to charge the battery module, or converting the direct current voltage at the second end into the direct current bus voltage at the first end; and the energy consumption discharge unit is connected with the direct current bus, and the battery module discharges electricity through the battery charge and discharge unit and the energy consumption discharge unit, so that the design is simple and standardized.
Description
Technical Field
The invention relates to the field of power supplies, in particular to a battery module terminal voltage regulating circuit.
Background
The large-scale series-parallel battery module is an indispensable system component in a plurality of current electrical fields, such as an energy supply unit of an electric automobile or an energy storage unit of a photovoltaic inversion system. Generally, a battery module (module) is formed by connecting a plurality of battery cells in series and parallel, and then an energy storage or power supply battery pack (package) is formed by connecting a plurality of battery modules in series and parallel to serve as an energy storage unit or an energy supply unit.
When a certain battery module in the battery pack needs to be replaced, the new battery module needs to adjust the capacity of the new battery module to a proper value before replacement so as to ensure the balance of the whole battery capacity. The battery module capacity is highly correlated with the battery module terminal voltage, so that in actual operation, adjusting the battery module terminal voltage can be regarded as adjusting the capacity. An Alternating Current (AC) rectifying unit is generally used to convert Alternating Current (AC) into Direct Current (DC) to charge the battery module, and a discharging unit is used to discharge the battery module to adjust the terminal voltage.
Specifically, referring to fig. 1, fig. 1 is a schematic diagram of a battery module terminal voltage regulating circuit according to an embodiment of the prior art. As shown in fig. 1, the battery module terminal voltage regulating circuit includes an alternating current rectifying unit 110 that converts Alternating Current (AC) into Direct Current (DC) to charge the battery module 130, and an inverter discharging unit 120 that converts Direct Current (DC) into Alternating Current (AC) to discharge the battery module 130, thereby regulating the terminal voltage of the battery module 130. However, since the inverter discharge is severely limited in some countries and regions of the world, the application is limited. The resistive load discharge mode with low cost is a popular choice in the industry, and particularly in the application occasions of high-power and large-current discharge, resistive discharge is the most effective and low-cost implementation scheme. There are disadvantages in control using the resistive discharge scheme. Specifically, please refer to fig. 2, fig. 2 is a schematic diagram of a battery module terminal voltage regulating circuit according to another embodiment of the prior art. The resistor R and the switch S1 are connected in series to form the discharge circuit 121, the discharge circuit 121 is switched on or off by controlling the switch S1 to be switched on or off, and the constant-resistance discharge of the battery module 130 is realized, but in the discharge process, the constant-current discharge condition required by common capacity detection or balance cannot be realized due to the change of the voltage of the battery module 130. Further, referring to fig. 3, fig. 3 is a schematic diagram of a battery module terminal voltage regulating circuit according to another embodiment of the prior art. As shown in fig. 3, the discharge unit 122 is formed by using the power device PD instead of the switch S1 in the discharge loop 121 of fig. 2, and the power device PD is controlled to operate in the linear region, so that constant current discharge can be achieved, but due to the dissipation power consumption limitation of the power device PD, the voltage variation that can be borne by the power device PD does not exceed 50V, that is, the voltage variation range of the battery module 130 during the discharge process does not exceed 50V, and different resistance values need to be used for different discharge currents, so that the battery module cannot be manufactured in large batch. Further, referring to fig. 4, fig. 4 is a schematic diagram of a battery module terminal voltage regulating circuit according to another embodiment of the prior art. A compromise method is adopted, a plurality of series branches formed by serially connecting resistors (R1 and R2 … … Rn) and switches (S1 and S2 … … Sn) are connected in parallel to form a discharge loop, and a power device PD is serially connected with the discharge loop to form a discharge unit 123, so that the resistors are switched, and the constant current realizable range of the system is expanded. However, if it is required to satisfy the requirement of a wide voltage range and a freely settable constant discharge current, only the DC/DC converter discharge unit 124 may be used as a discharge unit, specifically refer to the schematic diagram of the battery module terminal voltage regulating circuit in another embodiment of the prior art shown in fig. 5, but the requirement of high current and voltage control accuracy often cannot be satisfied by using the DC/DC converter discharge unit to discharge.
Disclosure of Invention
The invention provides a battery module terminal voltage regulating circuit, comprising: the input end of the alternating current rectifying unit receives alternating current, and the output end of the alternating current rectifying unit is connected with a direct current bus and used for converting the alternating current into direct current bus voltage; a battery charging/discharging unit, a first end of which is connected with the direct current bus, a second end of which is connected with a battery module, and the battery charging/discharging unit is used for converting the direct current bus voltage at the first end into the direct current voltage at the second end to charge the battery module, or converting the direct current voltage at the second end into the direct current bus voltage at the first end; and the energy consumption discharge unit is connected with the direct current bus, and the battery module discharges electricity through the battery charge and discharge unit and the energy consumption discharge unit.
Further, the energy consumption discharge unit includes: the direct current bus is connected with the first end of the discharging branch circuit and the first end of the DC/DC converter, and the second ends of the discharging branch circuit and the DC/DC converter are grounded.
The invention also provides a battery module terminal voltage adjusting device, which comprises: the input end of the alternating current rectifying unit receives alternating current, and the output end of the alternating current rectifying unit is connected with a direct current bus and used for converting the alternating current into direct current bus voltage; a battery charging/discharging unit, a first end of which is connected with the direct current bus, a second end of which is connected with a battery module, and the battery charging/discharging unit is used for converting the direct current bus voltage at the first end into the direct current voltage at the second end to charge the battery module, or converting the direct current voltage at the second end into the direct current bus voltage at the first end; the energy consumption discharge unit comprises at least one discharge branch formed by connecting a resistor and a switch in series and at least one DC/DC converter, the first end of the discharge branch and the first end of the DC/DC converter are both connected with the direct current bus, and the second ends of the discharge branch and the DC/DC converter are both grounded; and the control and sampling unit is connected with each discharging branch and the DC/DC converter in the energy consumption discharging unit, the alternating current rectifying unit and the battery charging and discharging unit and is used for outputting control signals to the switch in each discharging branch, the switch in the DC/DC converter, the switch in the alternating current rectifying unit and the switch in the battery charging and discharging unit so as to control the terminal voltage regulating circuit of the battery module to work in a charging mode or a discharging mode, the switch in the alternating current rectifying unit and the switch in the battery charging and discharging unit work in the charging mode to charge the battery module, and the switch in the battery charging and discharging unit, the switch in each discharging branch and the switch in the DC/DC converter work in the discharging mode to discharge the battery module.
Furthermore, the control and sampling unit is also connected with the battery module and used for sampling the terminal voltage of the battery module, when the terminal voltage of the battery module is lower than a charging threshold value, the control and sampling unit controls the terminal voltage regulating circuit of the battery module to work in a charging mode, and when the terminal voltage of the battery module is higher than a discharging threshold value, the control and sampling unit controls the terminal voltage regulating circuit of the battery module to work in a discharging mode so that the battery module is discharged through the battery charging and discharging unit and the energy consumption discharging unit.
Furthermore, the design power of one of the discharge branches is 1/n of the design power of the other discharge branches, wherein n is an integer greater than 1.
Furthermore, the design power of the discharge branch and the DC/DC converter is equal.
Furthermore, the control and sampling unit controls the number of the discharge branches which are connected in the energy consumption discharge unit to be sequentially reduced until only the DC/DC converter works alone to discharge until the discharge is finished.
Furthermore, the control and sampling unit controls to enable the discharging branches in the energy consumption discharging unit to be switched on or switched off so that the discharging power realized by all the discharging branches is gradually reduced until only the DC/DC converter works alone to discharge until the discharging is finished.
Furthermore, the switch in the discharge branch is a power device.
Furthermore, the power device in the discharge branch is controlled to work in a linear region during the process of turning off the discharge branch.
Drawings
Fig. 1 is a schematic diagram of a terminal voltage regulating circuit of a battery module according to an embodiment of the prior art.
Fig. 2 is a schematic diagram of a terminal voltage regulating circuit of a battery module according to another embodiment of the prior art.
Fig. 3 is a schematic diagram of a battery module terminal voltage regulating circuit according to another embodiment of the prior art.
Fig. 4 is a schematic diagram of a battery module terminal voltage regulating circuit according to another embodiment of the prior art.
Fig. 5 is a schematic diagram of a terminal voltage regulating circuit of a battery module according to another embodiment of the prior art.
Fig. 6 is a schematic diagram of a terminal voltage regulating circuit of a battery module according to an embodiment of the invention.
Fig. 7 is a schematic diagram of a terminal voltage regulating circuit of a battery module according to another embodiment of the invention.
Fig. 8 is a schematic diagram of a terminal voltage regulating device of a battery module according to an embodiment of the invention.
Fig. 9 is a schematic diagram illustrating a control principle of an embodiment of the terminal voltage regulating device of the battery module shown in fig. 8.
Fig. 10 is a schematic diagram illustrating a control principle of another embodiment of the terminal voltage regulating device of the battery module shown in fig. 8.
Fig. 11 is a schematic diagram of control waveforms of an embodiment of the terminal voltage regulating device of the battery module shown in fig. 8.
Fig. 12 is a schematic diagram of a control waveform of another embodiment of the terminal voltage regulating device of the battery module shown in fig. 8.
Detailed Description
The technical solutions in the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.
It is to be understood that the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the size and relative sizes of layers and regions may be exaggerated for clarity, and the same reference numerals denote the same elements throughout. It will be understood that when an element or layer is referred to as being "on" …, "adjacent to …," "connected to" or "coupled to" other elements or layers, it can be directly on, adjacent to, connected to or coupled to the other elements or layers or intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on …," "directly adjacent to …," "directly connected to" or "directly coupled to" other elements or layers, there are no intervening elements or layers present. It will be understood that, although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present invention.
Spatial relationship terms such as "under …", "under …", "below", "under …", "above …", "above", and the like, may be used herein for ease of description to describe the relationship of one element or feature to another element or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, then elements or features described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the exemplary terms "below …" and "below …" can encompass both an orientation of up and down. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatial descriptors used herein interpreted accordingly.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term "and/or" includes any and all combinations of the associated listed items.
The technical solutions in the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.
In an embodiment of the present invention, a battery module terminal voltage regulating circuit is provided, please refer to fig. 6, which shows a schematic diagram of a battery module terminal voltage regulating circuit according to an embodiment of the present invention, including: an AC rectifying unit 210 having an input terminal receiving an alternating current (AC In) and an output terminal connected to a DC BUS (DC BUS) for converting the alternating current into a DC BUS voltage Vbus; a battery charging/discharging unit 250 having a first end connected to the DC BUS (DC BUS) and a second end connected to the battery module 230, for converting the DC BUS voltage Vbus at the first end into a DC voltage (DC out) at the second end to charge the battery module 230, or converting the DC voltage (DC out) at the second end into the DC BUS voltage Vbus at the first end; and an energy consumption discharge unit 220 connected to the direct current BUS (DC BUS), wherein the battery module 230 discharges electricity through the battery charging and discharging unit 250 and the energy consumption discharge unit 220.
Thus, the accurate control of the constant current and voltage at the battery module end is undertaken by the battery charging and discharging unit 250, and since the voltage Vbus of the dc bus on the dc bus is substantially constant or changes only within a very small range (e.g., within 3V), the energy consumption discharging unit 220 only undertakes the function of adjusting the discharge power as required, and there is no need to deal with the difference in voltage levels of different battery modules, so the design is simple and standardized.
In an embodiment, the AC rectifying unit 210 may be any AC/DC converter as long as it can convert AC power into DC power, and the specific structure is not limited in this application.
In one embodiment, the battery charging/discharging unit 250 is a bidirectional DC/DC converter for converting the DC bus voltage Vbus and the DC voltage (DC out) to each other, and may be a bidirectional full-bridge converter, a buck-boost converter, or other converters capable of converting DC voltage bidirectionally.
Referring to fig. 7, fig. 7 is a schematic diagram of a battery module terminal voltage regulating circuit according to another embodiment of the present invention. Compared to the battery module terminal voltage regulating circuit shown in fig. 6, the energy consuming discharge unit 220 in the battery module terminal voltage regulating circuit shown in fig. 7 includes: at least one discharging branch 222 and at least one DC/DC converter 221, wherein the discharging branch 222 and the DC/DC converter 221 are connected in series by a resistor R and a switch S, a first end of the discharging branch 222 and a first end of the DC/DC converter 221 are both connected to the direct current BUS (DC BUS), and second ends of the discharging branch 222 and the DC/DC converter are both grounded, so as to form a parallel discharging structure. The control makes the switch in the discharging branch 222 turn on or off, so that the DC/DC converter 221 and the discharging branch 222 work cooperatively to discharge the battery module 230. During the discharging process, the DC/DC converter 221 operates to maintain the DC bus voltage Vbus at a constant value, or only vary within a very small range (e.g., within 3V), which is generally slightly higher than the constant voltage output of the ac rectifying unit 210. The DC/DC converter 221 and the discharging branch 222 work together, so that the discharging power can be linearly adjusted in the whole system range. In addition, because the direct-current bus voltage Vbus is basically constant, the resistance value of the resistor in the discharge branch 222 can be simply determined according to the power configuration of the resistor, and the resistor can be manufactured in large batch, without the need of managing the difference of the voltage levels of different battery modules.
In an embodiment, the specific structure of the DC/DC converter 221 is not limited in the present invention, as long as the conversion from DC power to DC power can be realized.
The invention also provides a device for regulating the terminal voltage of the battery module. Specifically, referring to the schematic diagram of the battery module terminal voltage adjusting device shown in fig. 8 according to an embodiment of the present invention, relative to the battery module terminal voltage adjusting circuit shown in fig. 7, the battery module terminal voltage adjusting device further includes: and the control and sampling unit 260, the control and sampling unit 260 is connected to each discharging branch 222 and the DC/DC converter 221 in the energy consumption discharging unit 220, the alternating current rectifying unit 210 and the battery charging and discharging unit 250, and is configured to output a control signal to the switch S in each discharging branch 222, the switch in the DC/DC converter 221, the switch in the alternating current rectifying unit 210 and the switch in the battery charging and discharging unit 250, so as to control the battery module terminal voltage regulating circuit to operate in a charging mode or a discharging mode, in the charging mode, the switch in the alternating current rectifying unit 210 and the switch in the battery charging and discharging unit 250 operate to charge the battery module 230, and in the discharging mode, the switch in the battery charging and discharging unit 250, the switch S in each discharging branch 222 and the switch in the DC/DC converter 221 operate to discharge the battery module 230.
In one embodiment, as shown in fig. 8, the control and sampling unit 260 is further connected to the battery module 230 and is configured to sample the terminal voltage of the battery module 230, when the terminal voltage of the battery module 230 is lower than a charging threshold, the control and sampling unit 260 controls the battery module terminal voltage regulating circuit to operate in a charging mode, and when the terminal voltage of the battery module 230 is higher than a discharging threshold, the control and sampling unit 260 controls the battery module terminal voltage regulating circuit to operate in a discharging mode so that the battery module 230 is discharged through the battery charging and discharging unit 250 and the energy consumption discharging unit 220.
The power levels of the discharge branch 222 and the DC/DC converter 221 may use different configurations, taking the number of the discharging branches 222 as 3 as an example, in one embodiment, the discharging branches 222 and the DC/DC converter 221 are equally distributed, i.e. using Pmax/4 as the design power of the discharging branch 222 and the DC/DC converter 221, wherein Pmax is the system design power, and at this time, the design power of the DC/DC converter 221 is only 25% of the system power, the design difficulty and cost of the DC/DC converter 221 can be reduced, and since the DC bus voltage Vbus on the DC bus is substantially constant, or only within a very small range (e.g., within 3V), the discharge branch 222 only performs the function of adjusting the discharge power as required, the voltage grades of different battery modules do not need to be managed, so the design is simple and the standardization can be realized. Of course, the above-mentioned "average" is not an absolute "average", i.e. the design powers of the discharging branch 222 and the DC/DC converter 221 are not exactly equal, and may have a deviation within 10%, and more preferably, may have a deviation within 5%.
In an embodiment, the design power of the DC/DC converter 221 is set to be between 103% and 105% of the design power of the smallest design power in the discharging branch 222, so as to reduce the fluctuation when the discharging power is switched, to achieve the continuous adjustable discharging power, and to reduce the influence on the load end when the discharging power is switched.
In another embodiment, the discharging branch 222 and the DC/DC converter 221 may be unevenly distributed, such as P1: p2: p3: PDC/DC ═ 1: 2: 4: 1, P1, P2, P3 and PDC/DC are the design powers of the first discharge branch, the second discharge branch, the third discharge branch and the DC/DC converter 221, respectively, the design can further reduce the design power of the DC/DC converter 221 to 12.5% of the system power, and further reduce the design difficulty and the system cost, and the discharge branch 222 still only takes the function of adjusting according to the required discharge power, and does not need to be different in voltage grade of different battery modules, so the design is simple and can be standardized.
In the discharging mode, the discharging branch 222 and the DC/DC converter 221 cooperate to discharge the battery module 230. The specific working principle is as follows:
in one embodiment, the designed power of the DC/DC converter 221 may be set aside by no more than 10%, so that the DC/DC converter will not operate in the load state of more than 90% or less than 10% during power switching, thereby improving the stability. In order to achieve the designed power of the DC/DC converter 221, a margin of no more than 10% is reserved, each discharging branch 222 needs to be switched, generally, as the discharging power decreases, the output power of the DC/DC converter 221 will decrease, and when a switching critical point (generally set to 10% of the designed power of the DC/DC converter 221) is reached, the discharging power borne by the discharging branch 222 is reduced. And so on until the battery module 230 reaches the discharge threshold. Taking the number of the discharging branches 222 as 3 and the system design power as 3000W as an example, in the first embodiment, the design is such that the first discharging branch P1A second discharge branch P2And a third discharge branch P3The design power of (1) is 750W, the design power of the DC/DC converter 221 is 800W, the direct current bus voltage Vbus on the direct current bus is 48V, and the first discharging branch P1A second discharge branch P2And a third discharge branch P3The resistance of the internal resistor is about 3 ohms, and the DC/DC converter 221 is the same as that of the internal resistorA resistive load with a resistance of about 2.9 ohms may be used. The control signal output by the initial discharge, control and sampling unit 260 controls the first discharge branch P1A second discharge branch P2And a third discharge branch P3The built-in switches are all turned on, and specifically, refer to a schematic control principle diagram of an embodiment of the device for regulating the terminal voltage of the battery module shown in fig. 8 shown in fig. 9. Before the time T1, the first discharging branch P1A second discharge branch P2And a third discharge branch P3The built-in switches are all turned on to discharge, the terminal voltage of the battery module 230 is gradually reduced, the discharge power is reduced, the DC/DC converter 221 gradually reduces the discharge power by adjusting the duty ratio, and when the discharge power of the DC/DC converter 221 is reduced to below 10% at the time of T1, the first discharge branch P is turned off1Internal switch, only the second discharge branch P2And a third discharge branch P3When the built-in switch is turned on to discharge, the discharge power of the DC/DC converter 221 is automatically increased to keep the DC bus voltage Vbus on the DC bus stable. And analogizing in sequence, when the discharging power of the DC/DC converter 221 is reduced to below 10% again by the time T2, the second discharging branch P is turned off2Internal switch, third discharge branch P only3When the built-in switch is turned on to discharge, the discharge power of the DC/DC converter 221 is automatically increased to keep the DC bus voltage Vbus on the DC bus stable. When the discharging power of the DC/DC converter 221 is reduced to below 10% again by the time T3, the third discharging branch P is turned off3In the internal switch, only the DC/DC converter 221 discharges, and at this time, the discharge power of the DC/DC converter 221 will automatically increase to keep the DC bus voltage Vbus on the DC bus stable, and as the discharge power decreases, the DC/DC converter 221 adjusts the duty ratio until the discharge is finished. Thus, the dc bus voltage Vbus on the dc bus is substantially constant or only varies within a very small range (e.g., within 3V), and the energy consumption discharge unit 220 only performs the function of adjusting the discharge power as required, and does not need to manage the voltage levels of different battery modules, so the design is simple and standardized, and there is no need to manage the voltage levels of different battery modulesThe voltage levels are different. That is, the control and sampling unit 260 controls to enable the number of the discharging branches 222 which are turned on in the energy consumption discharging unit 220 to be sequentially reduced until only the DC/DC converter 221 works alone to discharge until the discharging is finished. While avoiding direct bus voltage Vbus transients on the direct bus. In the second embodiment, the design is such that the first discharge branch P1A second discharge branch P2And a third discharge branch P3The design power of the first discharge branch P is 375W, 750W and 1500W respectively1A second discharge branch P2And a third discharge branch P3The resistance values of the resistors in the DC/DC converter 221 are respectively about 6 ohms, 3 ohms and 1.5 ohms, the design power of the DC/DC converter 221 is 400W, the DC/DC converter 221 can also use a resistive load, the load resistance value is about 5.9 ohms, and the direct-current bus voltage Vbus on the direct-current bus is 48V. The control signal output by the initial discharge, control and sampling unit 260 controls the first discharge branch P1A second discharge branch P2And a third discharge branch P3The built-in switches are all turned on, and specifically, refer to a schematic control principle diagram of another embodiment of the terminal voltage regulating device of the battery module shown in fig. 8 shown in fig. 10. Before the time T1, the first discharging branch P1A second discharge branch P2And a third discharge branch P3The built-in switches are all turned on to discharge, the terminal voltage of the battery module 230 is gradually reduced, the discharge power is reduced, the DC/DC converter 221 gradually reduces the discharge power by adjusting the duty ratio, and when the discharge power of the DC/DC converter 221 is reduced to below 10% at the time of T1, the first discharge branch P is turned off1Internal switch, second discharge branch P2And a third discharge branch P3The built-in switches are all turned on to discharge, and at this time, the discharge power of the DC/DC converter 221 is automatically increased to keep the DC bus voltage Vbus on the DC bus stable. By the time T2, when the discharge power of the DC/DC converter 221 is reduced below 10% again, the second discharge branch P is turned off2Internal switch, and simultaneously make the first discharge branch P1The inner switch is turned on, the first discharging branch P1And a third discharge branch P3Discharging is performed, and then the discharging power of the DC/DC converter 221 is self-dischargedAnd (4) dynamically lifting to keep the direct current bus voltage Vbus on the direct current bus stable. When the discharging power of the DC/DC converter 221 is reduced to below 10% again by the time T3, the switch in the first discharging branch P1 is turned off, and the third discharging branch P3When the built-in switch is turned on to discharge, the discharge power of the DC/DC converter 221 is automatically increased to keep the DC bus voltage Vbus on the DC bus stable. By the time T4, when the discharge power of the DC/DC converter 221 is reduced below 10% again, the third discharge branch P is turned off3Internal switch, and simultaneously make the first discharge branch P1And a second discharge branch P2The inner switch is turned on, the first discharging branch P1And a second discharge branch P2When discharging, the discharging power of the DC/DC converter 221 will be automatically increased to keep the DC bus voltage Vbus on the DC bus stable. By the time T5, when the discharge power of the DC/DC converter 221 is reduced below 10% again, the first discharge branch P is turned off1Internal switch, second discharge branch P2When discharging, the discharging power of the DC/DC converter 221 will be automatically increased to keep the DC bus voltage Vbus on the DC bus stable. By the time T6, when the discharge power of the DC/DC converter 221 is reduced below 10% again, the second discharge branch P is turned off2Internal switch, and simultaneously make the first discharge branch P1The internal switch is turned on, and the first discharging branch P1 discharges, so that the discharging power of the DC/DC converter 221 will automatically increase to keep the DC bus voltage Vbus on the DC bus stable. By the time T7, when the discharge power of the DC/DC converter 221 is reduced below 10% again, the first discharge branch P is turned off1And in the internal switch, at this time, only the DC/DC converter 221 discharges, the discharge power of the DC/DC converter 221 will be automatically increased to keep the DC bus voltage Vbus on the DC bus stable, and the DC/DC converter 221 adjusts the duty ratio as the discharge power decreases until the discharge is finished. Thus, the dc bus voltage Vbus on the dc bus is substantially constant or only varies within a very small range (e.g., within 3V), and the energy consumption discharge unit 220 only performs the function of adjusting the discharge power as required, without any need to deal with different battery modulesThe voltage levels of the banks are different, so that the design is simple and standardized without having to deal with the difference in voltage levels of the different battery modules. That is, the control and sampling unit 260 controls to turn on or off the discharging branches 222 in the energy consumption discharging unit 220 so as to gradually reduce the discharging power realized by all the discharging branches until only the DC/DC converter 221 works alone and discharges until the discharging is finished. While avoiding direct bus voltage Vbus transients on the direct bus.
In order to facilitate production and reduce the quantity of resistance materials, the design power of one discharge branch is 1/n of the design power of other discharge branches, wherein n is an integer greater than 1. As in the second embodiment, the first discharging branch P1Is designed to have the second discharge branch P 21/2, the first discharge branch P1Is designed to have the third discharge branch P 21/4, the second discharge branch P2And a third discharge branch P3The resistance in (1) is composed of n groups of first discharge branches P1Of (e.g. second discharge branch P)2The resistance in (1) is composed of 2 groups of first discharging branches P1The third discharge branch P3The resistance in (1) is composed of 4 groups of first discharge branches P1Is selected from the group consisting of (1). I.e. the interior of the discharge branch can also be standard modular for mass production.
For the embodiments shown in fig. 9 and 10, the switches in the discharge branch only have two operation modes of on and off, that is, the switches therein are turned off or on rapidly, because the dynamic response capability of the DC/DC converter 221 may be insufficient, a transient of the DC bus voltage Vbus on the DC bus may be caused, and if the high-frequency fluctuation of the transient exceeds 5% of the DC bus voltage Vbus, the transient may be coupled to the battery module side through the battery charging and discharging unit 250, which affects the discharge current collection accuracy and the capacity calculation accuracy in a short time. Please refer to fig. 11 for a schematic diagram of a control waveform of another embodiment of the terminal voltage regulating device of a battery module shown in fig. 8. In the first discharge branch P1When the internal switches are off, the DC/DC converter 221 has insufficient dynamic response capability, thus causing a momentary reduction in the DC bus voltage Vbus on the DC bus if the transient fluctuates at high frequencyOver 5% dc bus voltage Vbus, it is likely that the battery charging and discharging unit 250 will be coupled to the battery module side, affecting the discharging current collection accuracy and the capacity calculation accuracy in a short time. To avoid this, the switch in the discharging branch can be a power device and can operate in the linear region. And controlling the switch in the discharging branch circuit to work in a linear region in the process of turning off the discharging branch circuit, and reducing the transient of the direct current bus voltage Vbus on the direct current bus as much as possible. Referring to fig. 12, a schematic diagram of a control principle of another embodiment of the terminal voltage regulating device of the battery module shown in fig. 8 can be seen. After the first discharging branch P is turned off1In the process of (1), the first discharging branch P is controlled1When the internal switch works in a linear region, the working power of the DC/DC converter 221 changes slowly, and the DC bus voltage Vbus on the DC bus only generates a very small transient, which does not affect the collection precision and the calculation precision of the capacity of the control and sampling unit 260 for the discharge current, and ensures that the current control at the battery module end of the battery charging and discharging unit 250 meets the requirement of high precision in the whole process.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.
Claims (10)
1. A battery module terminal voltage regulating circuit, comprising:
the input end of the alternating current rectifying unit receives alternating current, and the output end of the alternating current rectifying unit is connected with a direct current bus and used for converting the alternating current into direct current bus voltage;
a battery charging/discharging unit, a first end of which is connected with the direct current bus, a second end of which is connected with a battery module, and the battery charging/discharging unit is used for converting the direct current bus voltage at the first end into the direct current voltage at the second end to charge the battery module, or converting the direct current voltage at the second end into the direct current bus voltage at the first end; and
and the energy consumption discharge unit is connected with the direct current bus, and the battery module discharges electricity through the battery charge and discharge unit and the energy consumption discharge unit.
2. The battery module terminal voltage regulation circuit of claim 1, wherein the dissipative discharge unit comprises: the direct current bus is connected with the first end of the discharging branch circuit and the first end of the DC/DC converter, and the second ends of the discharging branch circuit and the DC/DC converter are grounded.
3. A battery module terminal voltage adjusting device is characterized by comprising:
the input end of the alternating current rectifying unit receives alternating current, and the output end of the alternating current rectifying unit is connected with a direct current bus and used for converting the alternating current into direct current bus voltage;
a battery charging/discharging unit, a first end of which is connected with the direct current bus, a second end of which is connected with a battery module, and the battery charging/discharging unit is used for converting the direct current bus voltage at the first end into the direct current voltage at the second end to charge the battery module, or converting the direct current voltage at the second end into the direct current bus voltage at the first end;
the energy consumption discharge unit comprises at least one discharge branch formed by connecting a resistor and a switch in series and at least one DC/DC converter, the first end of the discharge branch and the first end of the DC/DC converter are both connected with the direct current bus, and the second ends of the discharge branch and the DC/DC converter are both grounded; and
the control and sampling unit is connected with each discharging branch and the DC/DC converter in the energy consumption discharging unit, the alternating current rectifying unit and the battery charging and discharging unit and used for outputting control signals to the switch in each discharging branch and the switch in the DC/DC converter, the switch in the alternating current rectifying unit and the switch in the battery charging and discharging unit so as to control the voltage regulating circuit at the end of the battery module to work in a charging mode or a discharging mode, the switch in the alternating current rectifying unit and the switch in the battery charging and discharging unit work in the charging mode to charge the battery module, and the switch in the battery charging and discharging unit, the switch in each discharging branch and the switch in the DC/DC converter work in the discharging mode to discharge the battery module.
4. The battery module terminal voltage regulating circuit of claim 3, wherein the control and sampling unit is further connected to the battery module for sampling the terminal voltage of the battery module, and when the terminal voltage of the battery module is lower than the charging threshold, the control and sampling unit controls the battery module terminal voltage regulating circuit to operate in the charging mode, and when the terminal voltage of the battery module is higher than the discharging threshold, the control and sampling unit controls the battery module terminal voltage regulating circuit to operate in the discharging mode so that the battery module is discharged through the battery charging and discharging unit and the energy consumption discharging unit.
5. The battery module terminal voltage regulating circuit according to claim 3, wherein the design power of one of the discharging branches is 1/n of the design power of the other discharging branches, wherein n is an integer greater than 1.
6. The battery module terminal voltage regulating circuit according to claim 3, wherein the designed power of the discharging branch and the DC/DC converter is equal.
7. The battery module terminal voltage regulating circuit according to claim 3, wherein the control and sampling unit controls to sequentially reduce the number of the discharge branches which are switched on in the energy consumption discharge unit until only the DC/DC converter works alone to discharge until the discharge is finished.
8. The battery module terminal voltage regulating circuit according to claim 3, wherein the control and sampling unit controls to turn on or off the discharging branches in the energy consumption discharging unit so as to gradually reduce the discharging power realized by all the discharging branches until only the DC/DC converter works alone and discharges until the end of discharging.
9. The battery module terminal voltage regulation circuit of claim 3, wherein the switch in the discharge branch is a power device.
10. The battery module terminal voltage regulating circuit according to claim 9, wherein the power device is controlled to operate in the linear region during the process of turning off the discharging branch.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110344295.4A CN112968500A (en) | 2021-03-31 | 2021-03-31 | Battery module terminal voltage regulating circuit and device |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110344295.4A CN112968500A (en) | 2021-03-31 | 2021-03-31 | Battery module terminal voltage regulating circuit and device |
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| CN112968500A true CN112968500A (en) | 2021-06-15 |
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| CN202110344295.4A Pending CN112968500A (en) | 2021-03-31 | 2021-03-31 | Battery module terminal voltage regulating circuit and device |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113783251A (en) * | 2021-08-26 | 2021-12-10 | 四川科陆新能电气有限公司 | Virtual internal resistance adjusting circuit for balancing between battery clusters |
| WO2023147751A1 (en) * | 2022-02-07 | 2023-08-10 | Oppo广东移动通信有限公司 | Adjustment circuit, apparatus, and method, electronic device, and readable storage medium |
-
2021
- 2021-03-31 CN CN202110344295.4A patent/CN112968500A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113783251A (en) * | 2021-08-26 | 2021-12-10 | 四川科陆新能电气有限公司 | Virtual internal resistance adjusting circuit for balancing between battery clusters |
| CN113783251B (en) * | 2021-08-26 | 2024-04-16 | 四川科陆新能电气有限公司 | Virtual internal resistance regulating circuit for balancing among battery clusters |
| WO2023147751A1 (en) * | 2022-02-07 | 2023-08-10 | Oppo广东移动通信有限公司 | Adjustment circuit, apparatus, and method, electronic device, and readable storage medium |
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