Disclosure of Invention
In view of the above, it is necessary to provide a battery charging/discharging circuit and a battery charging/discharging method capable of avoiding generation of a circulating current in a multi-machine parallel battery.
In a first aspect, the present application provides a charge-discharge circuit of a battery, where the charge-discharge circuit of the battery includes a controller and at least one charge-discharge module, the charge-discharge module is connected with the controller, and the charge-discharge module includes at least one charge-discharge unit;
the controller is used for controlling a first switch in the charging and discharging unit to be closed when the battery is charged by using the charging and discharging module so as to conduct a passage between an external power supply and the battery, and controlling the first switch to be opened when the external power supply is monitored to output a current not greater than a first preset current threshold value so as to enable a first diode in the charging and discharging unit to conduct the passage between the external power supply and the battery;
And the controller is used for controlling a target switch in the charging and discharging unit to be closed when the charging and discharging module is used for discharging the battery so as to conduct a passage between an external load and the battery, and controlling the target switch to be opened when the battery is monitored to output a current not greater than a second preset current threshold value so as to conduct a passage between the external load and the battery by a target diode in the charging and discharging unit.
In one embodiment, the charging and discharging unit comprises a first switch circuit, a second switch circuit and a first energy storage device; the first switch circuit comprises a first switch component and a second switch component, and the second switch circuit comprises a third switch component and a fourth switch component; one end of the first energy storage device is connected with the common end of the first switch assembly and the common end of the second switch assembly, and the other end of the first energy storage device is connected with the common end of the third switch assembly and the common end of the fourth switch assembly;
the controller is used for controlling a first switch in the first switch assembly to be closed when the battery is charged by using the charging and discharging module so as to conduct a passage between an external power supply and the battery, and controlling the first switch to be opened when the external power supply is monitored to output a current not greater than a first preset current threshold value so as to enable a first diode in the first switch assembly to conduct the passage between the external power supply and the battery;
The controller is used for controlling a third switch in the third component to be closed when the battery is discharged by using the charge-discharge module so as to conduct a passage between an external load and the battery, and controlling the third switch to be opened when the battery is monitored to output a current not greater than a second preset current threshold value so as to enable a third diode in the third component to conduct the passage between the external load and the battery; or, controlling a second switch in the second component to be closed so as to conduct a passage between an external load and the battery, and controlling the second switch to be opened when the battery is monitored to output a current not greater than a second preset current threshold value, so that a second diode in the second component conducts the passage between the external load and the battery.
In one embodiment, the first switch assembly includes the first switch and a first diode, the second switch assembly includes a second switch and a second diode, a third switch assembly includes the third switch and a third diode, and the fourth switch assembly includes a fourth switch and a fourth diode;
the controller is further configured to control the third switch and the fourth switch to be periodically closed when the battery is charged by using the charge-discharge module, so that a path between the battery and the external power supply is turned on when the third switch is closed and the fourth switch is opened, and a path between the first energy storage device and the battery is turned on when the fourth switch is closed and the third switch is opened;
The controller is further configured to control the fourth switch to be periodically closed when the battery is discharged by using the charge-discharge module, so that a path between the battery and the external load is turned on when the fourth switch is opened, and a path between the first energy storage device and the battery is turned on when the fourth switch is turned off;
or, the first switch and the second switch are controlled to be closed periodically, so that a passage between the battery and the external load is conducted when the first switch is closed and the second switch is opened, and a passage between the first energy storage device and the battery is conducted when the second switch is closed and the first switch is opened.
In one embodiment, the charge-discharge circuit further comprises a second energy storage device connected in parallel with the external power source or the external load.
In a second aspect, the present application further provides a method for charging and discharging a battery, the method being applied to the controller in the charging and discharging circuit of the battery according to the first aspect, the method comprising:
when the battery is charged by using the charging and discharging module, a first switch in the charging and discharging unit is controlled to be closed so as to conduct a passage between an external power supply and the battery, and when the external power supply is monitored to output a current not larger than a first preset current threshold value, the first switch is controlled to be opened so that a first diode in the charging and discharging unit conducts the passage between the external power supply and the battery;
When the battery is discharged by using the charging and discharging module, a target switch in the charging and discharging unit is controlled to be closed so as to conduct a passage between an external load and the battery, and when the battery is monitored to output a current not larger than a second preset current threshold value, the target switch is controlled to be opened so as to conduct a passage between the external load and the battery by a target diode in the charging and discharging unit.
In one embodiment, when the battery is charged by the charging and discharging module, the first switch in the charging and discharging unit is controlled to be closed to conduct a path between an external power source and the battery, and when the external power source is monitored to output a current not greater than a first preset current threshold, the first switch is controlled to be opened to enable the first diode in the charging and discharging unit to conduct the path between the external power source and the battery, including:
when the charging and discharging module is used for charging the battery, a first switch in the first switch assembly is controlled to be closed so as to conduct a passage between an external power supply and the battery, and when the external power supply is monitored to output current not larger than a first preset current threshold value, the first switch is controlled to be opened so that a first diode in the first switch assembly conducts the passage between the external power supply and the battery.
In one embodiment, when the battery is discharged by using the charging and discharging module, the controlling the target switch in the charging and discharging unit to be closed to conduct a path between an external load and the battery, and when it is monitored that the battery outputs a current not greater than a second preset current threshold, controlling the target switch to be opened to conduct a target diode in the charging and discharging unit to conduct a path between the external load and the battery, includes:
when the battery is discharged by using the charge-discharge module, a third switch in a third component is controlled to be closed so as to conduct a passage between an external load and the battery, and when the battery is monitored to output a current not greater than a second preset current threshold value, the third switch is controlled to be opened so as to conduct a passage between the external load and the battery by a third diode in the third component; or, controlling a second switch in the second component to be closed so as to conduct a passage between an external load and the battery, and controlling the second switch to be opened when the battery is monitored to output a current not greater than a second preset current threshold value, so that a second diode in the second component conducts the passage between the external load and the battery.
In one embodiment, the method further comprises:
when the charging and discharging module is used for charging the battery, the third switch and the fourth switch are controlled to be closed periodically, so that the passage between the battery and the external power supply is conducted when the third switch is closed and the fourth switch is opened, and the passage between the first energy storage device and the battery is conducted when the fourth switch is closed and the third switch is opened.
In one embodiment, the method further comprises:
when the charging and discharging module is used for discharging the battery, a fourth switch is controlled to be closed periodically, so that a passage between the battery and the external load is conducted when the fourth switch is opened, and a passage between a first energy storage device and the battery is conducted when the fourth switch is closed;
or, the first switch and the second switch are controlled to be closed periodically, so that a passage between the battery and the external load is conducted when the first switch is closed and the second switch is opened, and a passage between the first energy storage device and the battery is conducted when the second switch is closed and the first switch is opened.
In one embodiment, the method further comprises:
determining the first preset current threshold according to the voltages at two ends of the battery and the output voltage of the external power supply;
and determining the second preset current threshold according to the output voltage of the battery and the voltage of two ends of the external load.
The battery charging and discharging circuit comprises a controller and at least one charging and discharging module, wherein the charging and discharging module is connected with the controller, the charging and discharging module comprises at least one charging and discharging unit, the controller is used for controlling a first switch in the charging and discharging unit to be closed so as to conduct a passage between an external power supply and the battery when the charging and discharging module is used for charging the battery, controlling the first switch to be opened so as to conduct a passage between the external power supply and the battery by a first diode in the charging and discharging unit when the current which is not more than a first preset current threshold value is detected to be output by the external power supply, and controlling a target switch in the charging and discharging unit to be closed so as to conduct a passage between the external load and the battery when the current which is not more than a second preset current threshold value is detected to be output by the battery; because the current direction through the diode is a fixed current direction, when the current output by the external power supply is not greater than a first preset current threshold in the battery charging process, the first diode conducts a passage between the external power supply and the battery, or when the current output by the battery is not greater than a second preset current threshold in the battery discharging process, the target diode conducts a passage between the battery and an external load, and backflow in a charging and discharging circuit of the battery can be avoided.
Detailed Description
In order to make the objects, technical solutions and advantages of the present application more apparent, the present application will be further described in detail with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the present application.
Unless defined otherwise, technical or scientific terms used herein should be given the ordinary meaning as understood by one of ordinary skill in the art to which this application belongs. Reference to "a," "an," "the," and similar terms herein do not denote a limitation of quantity, but rather denote the singular or plural. The terms "comprising," "including," "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, article, or apparatus that comprises a list of steps or modules (elements) is not limited to only those steps or elements but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus. The term "plurality" as used herein means greater than or equal to two. "and/or" describes an association relationship of an association object, meaning that there may be three relationships, e.g., "a and/or B" may mean: a exists alone, A and B exist together, and B exists alone. The terms "first," "second," and the like, as used herein, merely distinguish similar objects and do not represent a particular ordering of objects.
It will be understood that the terms "first," "second," and the like, as used herein, may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another element.
It is to be understood that in the following embodiments, "connected" is understood to mean "electrically connected", "communicatively connected", etc., if the connected circuits, units, etc., have electrical signals or data transferred therebetween.
It is understood that "at least one" means one or more and "a plurality" means two or more. "at least part of an element" means part or all of the element.
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," and/or the like, specify the presence of stated features, integers, steps, operations, elements, components, or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or groups thereof. Also, the term "and/or" as used in this specification includes any and all combinations of the associated listed items.
The following describes the technical solutions of the present application and how the technical solutions of the present application solve the above technical problems in detail with specific embodiments. The following embodiments may be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments. Embodiments of the present application will be described below with reference to the accompanying drawings.
In one embodiment, as shown in fig. 1, there is provided a charge and discharge circuit of a battery, the charge and discharge circuit of the battery including: the device comprises a controller 01 and at least one charge-discharge module 02, wherein the charge-discharge module 02 is connected with the controller 01, and the charge-discharge module 02 comprises at least one charge-discharge unit; a controller 01, configured to control, when the battery 03 is charged by using the charge-discharge module 02, the first switch 1011 in the charge-discharge unit to be closed so as to conduct a path between the external power supply 04 (i.e., the external component 04 in the drawing) and the battery 03, and control, when it is monitored that the external power supply 04 outputs a current not greater than a first preset current threshold, the first switch to be opened so that the first diode 1012 in the charge-discharge unit conducts the path between the external power supply 04 and the battery 03; the controller 01 is configured to control, when the battery 03 is discharged by using the charge-discharge module 02, the target switch 103 in the charge-discharge unit to be closed so as to conduct a path between the external load 04 (i.e., the external component 04 shown in the drawing) and the battery 03, and when it is monitored that the battery 03 outputs a current not greater than a second preset current threshold, control the target switch 103 to be opened so as to enable the target diode 104 in the charge-discharge unit to conduct a path between the external load 04 and the battery 03.
In this embodiment of the present application, the charge-discharge circuit of the battery may include one charge-discharge module 02 or a plurality of charge-discharge modules 02, when the charge-discharge circuit of the battery includes a plurality of charge-discharge modules 02, the structures of the charge-discharge modules 02 are the same, and the charge-discharge modules 02 are connected in parallel, and each charge-discharge module 02 is connected with the controller 01, further, each charge-discharge module 02 may include one charge-discharge unit or a plurality of charge-discharge units, and when the charge-discharge module 02 includes a plurality of charge-discharge units, the structures of the charge-discharge units are the same, and the charge-discharge units are connected in parallel.
Illustratively, the charge-discharge circuit of the battery shown in fig. 1 includes 3 charge-discharge modules 02, each of the charge-discharge modules 02 includes 2 charge-discharge cells, and the charge-discharge cells may include a plurality of switches therein, and the controller 01 charges or discharges the battery 03 by controlling the on-off of the plurality of switches.
Further, in the embodiment of the present application, the controller 01 may monitor the current in the charging and discharging circuit through the current collecting component, when the charging and discharging module 02 is used to charge the battery 03, the controller 01 controls the first switch in the charging and discharging unit to be closed, and the external power source 04 and the battery 03 are conducted through the closed first switch and the first diode 1012 in the charging and discharging unit, and when it is monitored that the external power source 04 outputs a current not greater than the first preset current threshold, the first switch is controlled to be opened, and only the first diode 1012 is used to conduct the channel between the external power source 04 and the battery 03; when the battery 03 is discharged by using the charge-discharge module 02, the controller 01 controls the target switch 103 in the charge-discharge unit to be closed, and the path between the external load 04 and the battery 03 is made transparent through the closed target switch 103 and the target diode 104 in the charge-discharge unit, and when it is detected that the battery 03 outputs a current not greater than the second preset current threshold, the control target switch 103 is opened, and the path between the external load 04 and the battery 03 is turned on only through the target diode 104.
Optionally, the discharging modes for discharging the battery 03 using the charging and discharging module 02 include a plurality of discharging modes, and each discharging mode corresponds to a different target switch 103 and a target diode 104.
When the battery 03 is charged by the charge/discharge module 02, since current can only flow from the positive electrode of the first diode 1012 to the negative electrode of the first diode 1012, when only the first diode 1012 is turned on, current does not flow from the battery 03 to the external power source 04, i.e., no current backflow is generated, and when the current is greater than the first preset current threshold value, the first switch is closed, and when the current is greater than the first preset current threshold value, the path between the external power source 04 and the battery 03 is conducted through the first switch and the first diode 1012, so that the charging efficiency of the battery 03 can be improved; when the battery 03 is discharged by the charge/discharge module 02, since current can only flow from the positive electrode of the target diode 104 to the negative electrode of the target diode 104, when only the target diode 104 is on, current does not flow from the external load 04 to the battery 03, that is, no current backflow occurs, and when the current exceeds the second preset current threshold value, the target switch 103 is closed, and when the current exceeds the second preset current threshold value, the path between the external load 04 and the battery 03 is conducted through the target switch 103 and the target diode 104, so that the discharge efficiency of the battery 03 can be improved.
In the charge-discharge circuit of the battery, the charge-discharge circuit of the battery comprises a controller and at least one charge-discharge module, the charge-discharge module is connected with the controller, the charge-discharge module comprises at least one charge-discharge unit, the controller is used for controlling a first switch in the charge-discharge unit to be closed so as to conduct a passage between an external power supply and the battery when the charge-discharge module is used for charging the battery, controlling the first switch to be opened so as to conduct a passage between the external power supply and the battery by a first diode in the charge-discharge unit when the current output by the external power supply is not greater than a first preset current threshold value is monitored, and controlling a target switch in the charge-discharge unit to be closed so as to conduct a passage between the external load and the battery by the controller when the current output by the charge-discharge module is not greater than a second preset current threshold value is monitored. Because the current direction through the diode is a fixed current direction, when the current output by the external power supply is not greater than a first preset current threshold in the battery charging process, the first diode conducts a passage between the external power supply and the battery, or when the current output by the battery is not greater than a second preset current threshold in the battery discharging process, the target diode conducts a passage between the battery and an external load, and backflow in a charging and discharging circuit of the battery can be avoided.
On the basis of the above-described embodiments, as shown in fig. 2, in one embodiment, the charge and discharge unit includes a first switching circuit 10, a second switching circuit 20, and a first energy storage device 30; the first switch circuit 10 includes a first switch assembly 101 and a second switch assembly 102, and the second switch circuit 20 includes a third switch assembly 201 and a fourth switch assembly 202; one end of the first energy storage device 30 is connected with the common end of the first switch assembly 101 and the second switch assembly 102, and the other end of the first energy storage device 30 is connected with the common end of the third switch assembly 201 and the fourth switch assembly 202; a controller 01, configured to control, when the battery 03 is charged by using the charge-discharge module 02, the first switch 1011 in the first switch assembly 101 to be closed so as to conduct a path between the external power source 04 and the battery 03, and control, when it is monitored that the external power source 04 outputs a current not greater than a first preset current threshold, the first switch 1011 to be opened so that the first diode 1012 in the first switch assembly 101 is turned on the path between the external power source 04 and the battery 03; a controller 01, configured to control, when the battery 03 is discharged using the charge-discharge module 02, the third switch 2011 in the third component 201 to be closed so as to conduct a path between the external load 04 and the battery 03, and control, when it is monitored that the battery 03 outputs a current not greater than a second preset current threshold, the third switch 2011 to be opened so as to enable the third diode 2012 in the third component to conduct a path between the external load 04 and the battery 03; alternatively, the second switch 1021 in the second component is controlled to be closed to conduct the path between the external load 04 and the battery 03, and when it is monitored that the battery 03 outputs a current not greater than the second preset current threshold, the second switch 1021 is controlled to be opened to make the second diode 1022 in the second component conduct the path between the external load 04 and the battery 03.
In this embodiment of the present application, the first switch circuit 10 includes a first switch component 101 and a second switch component 102, the second switch circuit 20 includes a third switch component 201 and a fourth switch component 202, the controller 01 controls on/off of each switch component to charge or discharge the battery 03, and the first energy storage device 30 is connected to the first switch component 101, the second switch component 102, the third switch component 201 and the fourth switch component 202. Alternatively, the first switch assembly 101, the second switch assembly 102, the third switch assembly 201, and the fourth switch assembly 202 may be any one of a single pole double throw switch, a relay, and a field effect transistor (MOS) Semiconductor Field-Effect Transistor; the first energy storage device 30 may be a capacitor or an inductor.
Further, in this embodiment of the present application, the first switch assembly 101 may include a first switch 1011 and a first diode 1012, when the battery 03 is charged by using the charge-discharge module 02, if the charging current is small, a situation that the current flows from the battery 03 to the external power source 04 may occur, or a current of the battery 03 in any charge-discharge module 02 flows to the battery 03 in other charge-discharge module 02, that is, a backflow phenomenon occurs, so when the current output by the external power source 04 is not greater than the first preset current threshold, the controller 01 controls the first switch 1011 to be turned off, so that the current can only flow from the external power source 04 to the battery 03 through the first diode 1012.
In the embodiment of the present application, the discharge modes of the battery 03 include a step-up discharge mode and a step-down discharge mode. The third switch assembly may include a third switch 2011 and a third diode 2012, when the battery 03 is discharged in the boost discharging mode, if the discharge current is small, a current may flow from the external load 04 to the battery 03, that is, a backflow phenomenon may occur, so when the current output by the battery 03 is not greater than the second preset current threshold, the controller 01 controls the third switch 2011 to be turned off, so that the current may only flow from the battery 03 to the external load 04 through the third diode 2012. Alternatively, in this embodiment of the present application, the second switch assembly 102 may include the second switch 1021 and the second diode 1022, when the battery 03 is discharged in the buck discharging mode, if the discharge current is small, a situation that a current flows from the external load 04 to the battery 03 may also occur, that is, a backflow phenomenon occurs, so when the current output by the battery 03 is not greater than the second preset current threshold, the controller 01 controls the second switch 1021 to be turned off, so that the current can only flow from the battery 03 to the external load 04 through the second diode 1022.
Alternatively, when the first energy storage device 30 is an inductor, and the battery 03 is charged by the charging/discharging module 02 using the battery, the current passing through the inductor is the current output by the external load 04, the inductor may be represented as L, and the voltage across the inductor isWherein->For the current value at time t +.>Further, the first preset current threshold may be +.>Wherein, T is a preset period, D is a duty cycle, and the duty cycle is calculated by the controller according to the input value of the battery 03 and the output value of the external load 04.
Alternatively, when the first energy storage device 30 is an inductor, and the battery 03 is discharged by the charging and discharging module 02 using the battery, the current passing through the inductor is the current output by the external load 04, the inductor may be represented as L, and the voltage across the inductor isWherein->For the current value at time t +.>Further, the second preset current threshold may be +.>Wherein, T is a preset period, D is a duty cycle, and the duty cycle is calculated by the controller according to the output value of the battery 03 and the input value of the external load 04.
In the embodiment, when the charge and discharge module charges the battery, the controller controls the on-off of the first switch to avoid backflow in the charging process of the battery; when the charge and discharge module discharges the battery, the controller controls the on-off of the second switch 1021 or the third switch 2011 to avoid the backflow in the discharging process of the battery.
Based on the above embodiments, in one embodiment, the first switch assembly 101 includes a first switch 1011 and a first diode 1012, the second switch assembly 102 includes a second switch 1021 and a second diode 1022, the third switch assembly 201 includes a third switch 2011 and a third diode 2012, and the fourth switch assembly 202 includes a fourth switch 2021 and a fourth diode 2022; the controller 01 is further configured to control the third switch 2011 and the fourth switch 2021 to be periodically closed when the battery 03 is charged by using the charging and discharging module 02, so that the path between the battery 03 and the external power source 04 is turned on when the third switch 2011 is closed and the fourth switch 2021 is opened, and the path between the first energy storage device 30 and the battery 03 is turned on when the fourth switch 2021 is closed and the third switch 2011 is opened; the controller 01 is further configured to control the fourth switch 2021 to be periodically closed when the battery 03 is discharged by using the charge-discharge module 02, so that the fourth switch 2021 turns on a path between the battery 03 and the external load 04 when the fourth switch 2021 is opened, and to turn on a path between the first energy storage device 30 and the battery 03 when the fourth switch 2021 is closed; alternatively, the first switch 1011 and the second switch 1021 are controlled to be periodically closed, so that the path between the battery 03 and the external load 04 is turned on when the first switch 1011 is closed and the second switch 1021 is opened, and the path between the first energy storage device 30 and the battery 03 is turned on when the second switch 1021 is closed and the first switch 1011 is opened.
Optionally, in the embodiment of the present application, the switch component may be a MOS transistor, that is, a diode included in the switch component may be a body diode of the MOS transistor; the first energy storage device 30 is an inductor.
In the embodiment of the present application, when the charge-discharge module 02 is used to charge the battery 03, the controller 01 controls the third switch 2011 and the fourth switch 2021 to be periodically closed, and controls the second switch 1021 to be opened, so as to realize the buck charging of the external power supply 04 to the battery 03. As shown in fig. 3, when the third switch 2011 is closed and the fourth switch 2021 is opened, current flows from the positive electrode of the external power supply 04 to the first energy storage device 30 through the third switch 2011, flows to the positive electrode of the battery 03 sequentially through the first energy storage device 30 and the first switch assembly 101, and the negative electrode of the battery 03 is connected with the negative electrode of the external power supply 04 to form a loop, wherein when the current is greater than a first preset current threshold value, the first switch 1011 and the first diode 1012 in the first switch assembly 101 work together to conduct a path between the external power supply 04 and the battery 03, so that the transmission efficiency of the current is improved, and when the current is not greater than the first preset current threshold value, the first switch 1011 is opened, the first diode 1012 conducts a path between the external power supply 04 and the battery 03, so that a backflow phenomenon is avoided; as shown in fig. 4, when the third switch 2011 is turned off and the fourth switch 2021 is turned on, the inductance current will not change instantaneously, so that the inductance can be regarded as a small power supply, current flows from the inductance to the positive electrode of the battery 03 through the first switch component 101, and the negative electrode of the battery 03 is connected with the inductance through the fourth switch 2021 to form a loop, wherein when the current is greater than a first preset current threshold, the first switch 1011 and the first diode 1012 in the first switch component 101 work together to conduct the path between the inductance and the battery 03, so that the transmission efficiency of the current is improved, and when the current is not greater than the first preset current threshold, the first switch 1011 is turned off, the first diode 1012 conducts the path between the inductance and the battery 03, and a backflow phenomenon is avoided. It is obvious that the inductance voltage is smaller than the voltage of the external power supply 04, the step-down charging of the battery 03 can be achieved through the fast switching of the third switch 2011 and the fourth switch 2021, the duty ratio of the third switch 2011 and the fourth switch 2021 is determined according to the voltage required by the battery 03 and the voltage of the external power supply 04, and further the controller 01 controls the third switch 2011 and the fourth switch 2021 to be closed periodically according to the duty ratio.
In the embodiment of the present application, when the charge-discharge module 02 is used to boost and discharge the battery 03, the controller 01 controls the fourth switch 2021 to be periodically closed, and controls the second switch 1021 to be opened, so as to realize the boost and discharge of the battery 03 to the external load 04. As shown in fig. 5, when the fourth switch 2021 is turned off, current flows from the positive electrode of the battery 03 to the inductor through the first switch 1011, then flows to the positive electrode of the external load 04 through the third switch component 201, and the negative electrode of the battery 03 is connected with the negative electrode of the external load 04 to form a loop, wherein when the current output by the battery 03 is greater than a second preset current threshold value, the third switch 2011 and the third diode 2012 in the third switch component 201 work together to conduct the path between the battery 03 and the external load 04, so that the current transmission efficiency is improved, and when the current is not greater than the second preset current threshold value, the third switch 2011 is turned off, the third diode 2012 conducts the path between the inductor and the battery 03, so that the backflow phenomenon is avoided; as shown in fig. 6, when the fourth switch 2021 is closed, current flows from the positive electrode of the battery 03 to the inductor through the first switch 1011, and the inductor is connected to the negative electrode of the battery 03 through the fourth switch 2021, forming a loop, so that the battery 03 charges the inductor when the fourth switch 2021 is closed. Further, when the fourth switch 2021 is turned off, the external load 04 is charged together by the battery 03 and the inductor, thereby realizing boost discharge of the battery 03.
Alternatively, in the embodiment of the present application, when the battery 03 is subjected to buck discharge by using the charge-discharge module 02, the controller 01 controls the first switch 1011 and the second switch 1021 to be periodically closed, and controls the fourth switch 2021 to be opened, so as to realize buck discharge of the battery 03 to the external load 04. As shown in fig. 7, when the first switch 1011 is closed, current flows from the battery 03 to the inductor through the first switch 1011, then flows from the inductor to the positive electrode of the external load 04 through the third switch component 201, and the negative electrode of the external load 04 is connected with the negative electrode of the battery 03 to form a loop, wherein when the current output by the battery 03 is greater than a second preset current threshold value, the third switch 2011 and the third diode 2012 in the third switch component 201 work together to conduct the path between the battery 03 and the external load 04, thereby improving the transmission efficiency of the current, and when the current is not greater than the second preset current threshold value, the third switch 2011 is opened, and the third diode 2012 conducts the path between the inductor and the battery 03 to avoid the occurrence of a backflow phenomenon; as shown in fig. 8, when the second switch 1021 is closed, the inductance current will not change instantaneously, so the inductance can be regarded as a small power supply, the current flows from the inductance to the positive electrode of the external load 04 through the third switch assembly 201, and the negative electrode of the external load 04 is connected with the inductance through the second switch 1021 to form a loop, wherein when the current is greater than a second preset current threshold, the third switch 2011 and the third diode 2012 in the third switch assembly 201 work together to conduct the path between the inductance and the external load 04, thereby improving the transmission efficiency of the current, and when the current is not greater than the second preset current threshold, the third switch 2011 is opened, and the third diode 2012 conducts the path between the inductance and the external load 04, thereby avoiding the occurrence of a backflow phenomenon. It is obvious that the inductance voltage is smaller than the voltage of the external power supply 04, the voltage-reducing charging of the battery 03 can be achieved through the fast switching of the first switch 1011 and the second switch 1021, the duty ratio of the first switch 1011 and the second switch 1021 is determined according to the voltage required by the battery 03 and the voltage of the external power supply 04, and further the controller 01 controls the first switch 1011 and the second switch 1021 to be periodically closed according to the duty ratio.
Optionally, in the embodiment of the present application, as shown in fig. 9, the charging and discharging circuit further includes a second energy storage device 40, where the second energy storage device is connected in parallel with the external power source 04 or the external load 04. The second energy storage device 40 may be a capacitor, which may store electric energy to charge the battery 03 or the external load 04, and may also function as a protection circuit.
In this embodiment, the controller controls the on/off of the first switch, the second switch, the third switch and the fourth switch to realize buck charging, boost discharging and buck discharging of the battery, so that the application range and applicability of the charge-discharge module are ensured.
In one embodiment, as shown in fig. 10, there is provided a charge and discharge method of a battery, which is applied to a controller in a charge and discharge circuit of a battery as in the above embodiment, including:
s201, when the battery is charged by using the charging and discharging module, a first switch in the charging and discharging unit is controlled to be closed so as to conduct a passage between the external power supply and the battery, and when the fact that the external power supply outputs current not larger than a first preset current threshold value is monitored, the first switch is controlled to be opened so that a first diode in the charging and discharging unit conducts the passage between the external power supply and the battery.
And S202, when the battery is discharged by using the charge-discharge module, controlling a target switch in the charge-discharge unit to be closed so as to conduct a passage between the external load and the battery, and when the battery is monitored to output a current not greater than a second preset current threshold value, controlling the target switch to be opened so as to conduct a passage between the external load and the battery by a target diode in the charge-discharge unit.
The charge and discharge method of the battery provided in this embodiment may be used in the charge and discharge circuit embodiment of the battery, and its implementation principle and technical effects are similar and will not be described herein.
In an embodiment, an implementation manner of the foregoing S201 is provided, where the "when the battery is charged by using the charge-discharge module, controlling the first switch in the charge-discharge unit to be closed to conduct a path between the external power source and the battery, and controlling the first switch to be opened when it is monitored that the external power source outputs a current not greater than a first preset current threshold value, so that the first diode in the charge-discharge unit conducts the path between the external power source and the battery" includes: when the battery is charged by using the charging and discharging module, a first switch in the first switch assembly is controlled to be closed so as to conduct a passage between the external power supply and the battery, and when the external power supply is monitored to output current not larger than a first preset current threshold value, the first switch is controlled to be opened so that a first diode in the first switch assembly conducts the passage between the external power supply and the battery.
The charge and discharge method of the battery provided in this embodiment may be used in the charge and discharge circuit embodiment of the battery, and its implementation principle and technical effects are similar and will not be described herein.
In an embodiment, an implementation manner of the foregoing S202 is provided, where the "when the battery is discharged using the charge-discharge module, the controlling the target switch in the charge-discharge unit to be closed to conduct a path between the external load and the battery, and when it is monitored that the battery outputs a current not greater than the second preset current threshold, the controlling the target switch to be opened to conduct the target diode in the charge-discharge unit to conduct the path between the external load and the battery" includes: when the battery is discharged by using the charge-discharge module, a third switch in the third component is controlled to be closed so as to conduct a passage between the external load and the battery, and when the battery is monitored to output a current not greater than a second preset current threshold value, the third switch is controlled to be opened so as to conduct a passage between the external load and the battery by a third diode in the third component; or, controlling the second switch in the second component to be closed so as to conduct a passage between the external load and the battery, and controlling the second switch to be opened when the battery is monitored to output a current not greater than a second preset current threshold value so as to conduct a passage between the external load and the battery by a second diode in the second component.
The charge and discharge method of the battery provided in this embodiment may be used in the charge and discharge circuit embodiment of the battery, and its implementation principle and technical effects are similar and will not be described herein.
In one embodiment, the method for charging and discharging a battery further includes: when the battery is charged by using the charging and discharging module, the third switch and the fourth switch are controlled to be periodically closed, so that the passage between the battery and an external power supply is conducted when the third switch is closed and the fourth switch is opened, and the passage between the first energy storage device and the battery is conducted when the fourth switch is closed and the third switch is opened.
The charge and discharge method of the battery provided in this embodiment may be used in the charge and discharge circuit embodiment of the battery, and its implementation principle and technical effects are similar and will not be described herein.
In one embodiment, the method for charging and discharging a battery further includes: when the battery is discharged by using the charge-discharge module, the fourth switch is controlled to be periodically closed, so that a passage between the battery and an external load is conducted when the fourth switch is opened, and a passage between the first energy storage device and the battery is conducted when the fourth switch is closed; or the first switch and the second switch are controlled to be closed periodically, so that the passage between the battery and the external load is conducted when the first switch is closed and the second switch is opened, and the passage between the first energy storage device and the battery is conducted when the second switch is closed and the first switch is opened.
The charge and discharge method of the battery provided in this embodiment may be used in the charge and discharge circuit embodiment of the battery, and its implementation principle and technical effects are similar and will not be described herein.
In one embodiment, as shown in fig. 11, the method for charging and discharging a battery further includes:
s203, determining a first preset current threshold according to the voltage at two ends of the battery and the output voltage of the external power supply.
S204, determining a second preset current threshold according to the output voltage of the battery and the voltage of two ends of the external load.
The charge and discharge method of the battery provided in this embodiment may be used in the charge and discharge circuit embodiment of the battery, and its implementation principle and technical effects are similar and will not be described herein.
It should be understood that, although the steps in the flowcharts related to the embodiments described above are sequentially shown as indicated by arrows, these steps are not necessarily sequentially performed in the order indicated by the arrows. The steps are not strictly limited to the order of execution unless explicitly recited herein, and the steps may be executed in other orders. Moreover, at least some of the steps in the flowcharts described in the above embodiments may include a plurality of steps or a plurality of stages, which are not necessarily performed at the same time, but may be performed at different times, and the order of the steps or stages is not necessarily performed sequentially, but may be performed alternately or alternately with at least some of the other steps or stages.
The technical features of the above embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.
The above examples only represent a few embodiments of the present application, which are described in more detail and are not to be construed as limiting the scope of the present application. It should be noted that it would be apparent to those skilled in the art that various modifications and improvements could be made without departing from the spirit of the present application, which would be within the scope of the present application. Accordingly, the scope of protection of the present application shall be subject to the appended claims.