Large-current double-charging and double-discharging equipment

Abstract

The embodiment of the utility model discloses a large current pair charging and discharging device which comprises a plurality of batteries and further comprises a power grid interface module and a plurality of charging and discharging channels, the charging and discharging channels are sequentially connected in parallel, and the number of the charging and discharging channels is the same as that of the batteries; the charging input end of the power grid interface module is connected with a power grid, the charging output end of the power grid interface module is connected with the charging input ends of the charging and discharging channels which are connected in parallel, and the charging output ends of the charging and discharging channels are connected with corresponding batteries one by one; and each single charging and discharging channel is used for managing charging and discharging of the corresponding battery and is also used for being connected with other single charging and discharging channels, so that a channel loop is formed between the two single channels. Based on the equipment, the charging and discharging equipment can be subjected to calibration and aging test without adding extra equipment before charging and discharging the lithium ion battery.

Description

Technical Field

[0001] The present application relates to the field of battery capacity conversion, and in particular to a high-current charging and discharging device. Background Art

[0002] In recent years, my country's electric vehicle industry has developed rapidly. As the power source of future electric vehicles and energy storage, lithium batteries need to be formed and divided in capacity during the production process to ensure the quality and quality of the final power supply products. The general formation is only a charging process, and the battery cells do not need to be discharged, so a separate charging device can be used during the formation. Although the formation does not require discharge in general, the formation process of some battery cells requires more than one charging, and the capacity division process after the formation also requires the battery cells to be charged and discharged. This process requirement also leads to many battery manufacturers generally using charging and discharging devices with charging and discharging functions to complete the battery's formation and capacity division. It can achieve control of the battery's rapid charging and discharging process by adjusting the current size and direction. Existing charging and discharging devices are usually used for the maintenance and testing of battery packs. However, this charging and discharging device also faces the test of the test accuracy of the voltage and current of the battery charging and discharging, and the service life of the device itself.

[0003] In the prior art, the current calibration during charging is often performed by short-circuiting the output end of the charging and discharging device, and the current calibration during discharging is performed by connecting the output end of the charging and discharging device to a DC power supply; the voltage calibration during charging is performed by connecting the output end of the charging and discharging device to a resistive load; and the aging test is performed by connecting the output of the charging and discharging device to a resistive load or an electronic load.

[0004] However, the charging and discharging equipment can only perform current calibration on a single output terminal of the equipment at a time when charging or discharging, and an additional DC power supply is required when the charging and discharging equipment performs discharge current calibration, which limits the flexibility of the equipment and increases the energy consumption of the equipment; when the charging and discharging equipment performs voltage calibration, the additional connected resistance load will also consume additional energy; when the output of the charging and discharging equipment performs aging test, the additional resistance load will also consume additional energy. If an electronic load is used for aging test, an additional electronic load device is also required, which increases the complexity of the equipment. It can be seen that the charging and discharging equipment of the prior art has the disadvantages of limited flexibility, increased energy consumption and complex equipment. Utility Model Content

[0005] In this regard, for the aging and calibration process of lithium-ion battery charging and discharging equipment for power and energy storage, a high-current charging and discharging device is provided, including multiple batteries, a power grid interface module, and multiple charging and discharging channels, the charging and discharging channels are connected in parallel in sequence, and the number of the charging and discharging channels is the same as the number of the batteries;

[0006] The charging input end of the grid interface module is connected to the grid, the charging output end of the grid interface module is connected to the charging input ends of the plurality of parallel charging and discharging channels, and the charging output ends of the charging and discharging channels are connected one by one to the corresponding batteries;

[0007] A single charge and discharge channel is used to manage the charging and discharging of the corresponding battery, and is also used to connect with other single charge and discharge channels to form a channel loop between the two single channels.

[0008] It should be further explained that the grid interface module includes a bidirectional energy storage inverter PCS, a DC auxiliary power supply, and a DSP processor. The charging input end of the bidirectional energy storage inverter PCS is connected to the three-phase grid, and the charging output end of the bidirectional energy storage inverter PCS is connected to the charging input end of the charging and discharging channel. The bidirectional energy storage inverter PCS is used to convert the AC power output by the three-phase grid into a high-voltage DC source and then output it to the charging and discharging channel.

[0009] It should be further explained that the charging input end of the DC auxiliary power supply is connected to the single-phase power grid, and the charging output end of the DC auxiliary power supply is connected to the power module of the DSP processor. The DC auxiliary power supply is used to convert the AC power output from the single-phase power grid into a DC source and then power the DSP processor.

[0010] It should be further explained that the DSP processor is also connected to the charge and discharge channel, and the DSP processor is used to send control signals of forward and reverse switches to the charge and discharge channel.

[0011] It should be further explained that the charging and discharging channel includes two bidirectional LLC circuits connected in series and staggered in parallel and five buck-boost circuits connected in series and staggered in parallel;

[0012] The charging input end of the two interlaced parallel bidirectional LLC circuits is connected to the charging output end of the bidirectional energy storage converter PCS. The two interlaced parallel bidirectional LLC circuits are used to convert the high-voltage DC source output by the bidirectional energy storage converter PCS into a low-voltage DC source, and the charging output end of the two interlaced parallel bidirectional LLC circuits is output to the buck-boost circuit. The buck-boost circuit is used to convert the low-voltage DC source output by the two interlaced parallel bidirectional LLC circuits into a low-voltage high-current to charge the corresponding battery.

[0013] It should be further explained that a single bidirectional LLC circuit includes a switch circuit 601, an LLC resonant circuit 602, a rectifier circuit 603, and a Y capacitor;

[0014] The charging output end of the switch circuit 601 is connected to the charging input end of the LLC resonant circuit 602, the charging output end of the LLC resonant circuit 602 is connected to the charging input end of the rectifier circuit 603, and the charging output end of the rectifier circuit 603 is connected to the charging input end of the 5-way staggered parallel buck-boost circuit.

[0015] It should be further explained that the switch circuit 601 is a half-bridge circuit, and the switch circuit 601 includes two power MOS tubes Q1 and Q2 connected in series, and the gates of the power MOS tubes Q1 and Q2 are used to receive the control signals of the forward and reverse switches sent by the DSP processor;

[0016] The LLC resonant circuit 602 includes a capacitor C1, a capacitor C2, an inductor L2 and a first isolation transformer T1;

[0017] The rectifier circuit 603 is composed of a full-bridge circuit consisting of four power MOS tubes Q3, Q4, Q5 and Q6, and a capacitor C3. The capacitor C3 is connected in parallel with the full-bridge circuit to perform energy storage filtering on the output voltage of the full-bridge circuit.

[0018] It should be further explained that the switch circuit 601 is connected in parallel with the capacitor C1 and the capacitor C2, and the capacitor C1 is connected in series with the capacitor C2;

[0019] The switch circuit 601 is also connected in series with the Y capacitor. The switch circuit 601 is connected to a first end of the Y capacitor, and a second end of the Y capacitor is connected to the rectifier circuit 603 .

[0020] It should be further explained that a single buck-boost circuit includes a charging input side port X, a charging output side port Y, two power MOS tubes Q7 and Q8, an inductor L3 and a capacitor C9;

[0021] The power MOS tube Q7 and the power MOS tube Q8 are connected in series, the drain of the power MOS tube Q7 is connected to the charging input side port X, and the source of the power MOS tube Q7 is connected to the first end of the inductor L3, the second end of the inductor L3 is respectively connected to the positive electrode of the charging output side port Y and the first end of the capacitor C9, and the second end of the capacitor C9 is respectively connected to the negative electrode of the charging output side port Y and the source of the power MOS tube Q8.

[0022] It should be further explained that the device also includes a sampling module, which is connected between the positive electrode and the negative electrode of the charging output side port Y of the buck-boost circuit, and is used to obtain a sampling voltage value, a sampling current value, and detect the stability of the output voltage of the charging and discharging channel, the stability of the input current of the charging and discharging channel, the charging and discharging efficiency of the charging and discharging channel, and the temperature change of the charging and discharging channel.

[0023] Based on the above equipment, the present application can realize calibration and aging testing of the charging and discharging equipment itself before charging and discharging the lithium-ion battery without adding additional equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0025] Figure 1 It is a system block diagram of a high current charging and discharging device provided in an embodiment of the present application;

[0026] Figure 2 It is a connection diagram of two charging and discharging channels of the charging and discharging device provided in an embodiment of the present application;

[0027] Figure 3 It is a system block diagram of a single charging and discharging channel provided in an embodiment of the present application;

[0028] Figure 4 It is a schematic diagram of the charge and discharge channel calibration test process provided in an embodiment of the present application;

[0029] Figure 5 It is a structural schematic diagram of the charge and discharge channel aging test process provided in an embodiment of the present application;

[0030] Figure 6 It is a circuit schematic diagram of a two-way interlaced parallel bidirectional LLC circuit provided in an embodiment of the present application;

[0031] Figure 7 It is a circuit schematic diagram of a 5-way staggered parallel buck-boost circuit provided in an embodiment of the present application. Specific embodiments

[0032] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of this application.

[0033] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first" and "second" are used only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0034] In this application, the word "exemplary" is used to mean "used as an example, illustration, or description." Any embodiment described in this application as "exemplary" is not necessarily to be construed as being preferred or advantageous over other embodiments. The following description is given to enable any technician in the field to implement and use the present application. In the following description, details are listed for the purpose of explanation. It should be understood that a person of ordinary skill in the art can recognize that the present application can be implemented without using these specific details. In other instances, well-known structures and processes will not be elaborated in detail to avoid obscuring the description of the present application with unnecessary details. Therefore, the present application is not intended to be limited to the embodiments shown, but is consistent with the widest scope consistent with the principles and features disclosed in the present application.

[0035] In order to make the objectives, technical solutions and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0036] like Figure 1 As shown, an embodiment of the present application provides a high-current charging and discharging device, including multiple batteries, a power grid interface module, and multiple charging and discharging channels. The charging and discharging channels are connected in parallel in sequence, and the number of the charging and discharging channels is the same as the number of the batteries.

[0037] Exemplarily, the present embodiment includes four batteries, namely battery 1, battery 2, battery 3, and battery 4. Corresponding to the number of batteries, the present embodiment includes four charge and discharge channels, namely charge and discharge channel 1, charge and discharge channel 2, charge and discharge channel 3, and charge and discharge channel 4. These four charge and discharge channels are connected in parallel in sequence.

[0038] Taking the lithium-ion battery in charging mode as an example, in this mode, the current flows from the grid side to the grid interface module side. After conversion on the grid interface module side, the AC power at the output end of the grid side is converted into a high-voltage DC source and output to the charge and discharge channel side. The charge and discharge channel side converts the DC source at the output end of the grid interface module side into a low-voltage and high-current and outputs it to the battery side to charge the battery.

[0039] Taking the current flow direction of a lithium-ion battery in charging mode as an example, each port for outputting current is recorded as a charging output terminal, and each port for inputting current is recorded as a charging input terminal. That is to say, in this mode, the charging input terminal of the grid interface module is connected to the grid, and the charging output terminal of the grid interface module is connected to the charging input terminals of multiple parallel charging and discharging channels, and the charging output terminals of the charging and discharging channels are connected to the corresponding batteries one by one. Specifically, charging and discharging channel 1 is connected to battery 1, charging and discharging channel 2 is connected to battery 2, charging and discharging channel 3 is connected to battery 3, and charging and discharging channel 4 is connected to battery 4. Charging and discharging channel 1 outputs the low-voltage and high-current it converts to battery 1, charging and discharging channel 2 outputs the low-voltage and high-current it converts to battery 2, charging and discharging channel 3 outputs the low-voltage and high-current it converts to battery 3, and charging and discharging channel 4 outputs the low-voltage and high-current it converts to battery 4.

[0040] When the lithium-ion battery is in discharge mode, the device executes an energy conversion process opposite to that in charge mode according to the software program. The current flow direction in discharge mode is also opposite to that in charge mode. Therefore, the discharge output terminal in discharge mode is actually the charging input terminal in charge mode, and the discharge input terminal in discharge mode is actually the charging output terminal in charge mode.

[0041] In addition, when the lithium-ion battery is in charging mode and discharging mode, a single charging and discharging channel is also used to manage the charging and discharging of its corresponding battery. Exemplarily, charging and discharging channel 1 is used to control the charging and discharging switch of battery 1. The functions of the above-mentioned charging and discharging channels are merely exemplary and are not the only management functions that the charging and discharging channels can achieve for the battery.

[0042] The energy conversion process of the lithium-ion battery in the discharge mode is easily known to those skilled in the art based on the energy conversion process in the charging mode described above in this embodiment and common knowledge, and will not be further elaborated in this embodiment.

[0043] Combination Figure 1When the device is in the charge and discharge channel calibration test mode, that is, before charging and discharging the lithium-ion battery, a single charge and discharge channel is also used to connect with other single charge and discharge channels to form a channel loop between the two single channels.

[0044] Charge and discharge refers to the process in which a battery or energy storage system releases stored energy by transmitting current in the reverse direction, or stores energy in the battery by transmitting current to the battery. In related technologies, a battery is charged and discharged using a charging and discharging device, which usually has two channels, one for charging and one for discharging. During the charge and discharge process, calibration tests are required to ensure the accuracy of voltage and current.

[0045] For example, see Figure 2 The charge and discharge channel 1 is not only used to manage the charging and discharging of the battery 1, but also used to connect with the charge and discharge channel 2, that is, the positive poles of the charging output ends of the charge and discharge channel 1 and the charge and discharge channel 2 are connected to the positive poles, and the negative poles are connected to the negative poles, so that a channel loop is formed between the two single channels, and the corresponding processes are respectively executed according to the software program.

[0046] In the related art, when the battery is charging, it will receive the charging current at a certain voltage. When the battery is fully charged, the charging current will gradually decrease until it reaches zero. In order to keep the charging current constant, the charge and discharge channels will be set to maintain a constant output voltage so as to always provide a constant charging current during the charging process. When the battery is discharging, its internal chemical reaction will provide a certain voltage, but the battery voltage will gradually decrease during the discharge process. In order to maintain a constant discharge current, the charge and discharge channels will adjust the load voltage according to the state of the battery to ensure that a constant discharge current flows through the battery. Therefore, the charge and discharge channels work in constant voltage output in the charging mode, and the charge and discharge channels work in constant current input in the discharge mode. Therefore, it is only necessary to perform constant voltage and constant current checks on the charging output and discharge input of the two charging and discharging channels at different stages to achieve voltage and current calibration of the charging and discharging equipment itself.

[0047] In summary, when the charge and discharge channel is in the charge mode, the charge and discharge channel will be set to maintain a constant output voltage, and when the charge and discharge channel is in the discharge mode, the charge and discharge channel will adjust the load voltage.

[0048] Therefore, based on the functions that the above-mentioned charge and discharge channels already have in the charge mode and the discharge mode, in this embodiment, the working principle of the device in the charge and discharge channel calibration test mode is as follows: 1. Voltage calibration principle: When the charge output ends of the charge and discharge channel 1 and the charge and discharge channel 2 are connected together, they will form a closed loop. At this time, the grid interface module will provide a known constant voltage output and distribute the voltage to the charge and discharge channel 1 and the charge and discharge channel 2. Since they are connected together, the voltages of the charge and discharge channel 1 and the charge and discharge channel 2 will tend to be equal because they share the same voltage source. Therefore, by measuring the voltages of the charge and discharge channel 1 and the charge and discharge channel 2, calibration can be performed to determine whether they output a constant voltage; 2. Current calibration principle: Set the charge and discharge channel 1 to the charge mode and the charge and discharge channel 2 to the discharge mode, that is, the charge input end of the charge and discharge channel 1 is connected to the charge output end of the grid interface module, and a constant current input is obtained from the grid interface module. Since the charge and discharge channel 2 is in the discharge mode, the discharge input end of the charge and discharge channel 2 at this time is actually connected as a load to receive the current output of the charge and discharge channel 1. Therefore, by measuring the current of charge and discharge channel 1 and charge and discharge channel 2, calibration can be performed to determine whether they maintain a constant current.

[0049] Similarly, when the device is in the aging test mode, it is only necessary to check the stability of the voltage and current at different stages of the charging output and discharging input of the two charging and discharging channels to achieve the aging test of the charging and discharging device itself. This embodiment will not be elaborated on this. The number of single charging and discharging channels can be four or more. For the connection between single charging and discharging channels, it can be charging and discharging channel 1 connected to charging and discharging channel 2, or it can be charging and discharging channel 1 connected to charging and discharging channel 3. As long as two different single charging and discharging channels are connected, this embodiment is not limited here.

[0050] See also Figure 3 , combined with Figure 2, the process of performing the charge and discharge channel calibration test is as follows: first, connect the positive pole of the charge output terminal of the charge and discharge channel 1 and the charge and discharge channel 2 to the positive pole and the negative pole to the negative pole, then, connect the charge input terminal of the charge and discharge channel 1 and the charge input terminal of the charge and discharge channel 2 to the charge output terminal of the grid interface module, so that the high-voltage DC source converted by the grid interface module can be output to the charge and discharge channel 1 and the charge and discharge channel 2. At this time, the software program controls the charge and discharge channel 1 to be calibrated in the charge mode and controls the charge and discharge channel 2 to be calibrated in the discharge mode. The charge input terminal of the charge and discharge channel 1 is still the charge input terminal, and the charge input terminal of the charge and discharge channel 2 in the charge mode has actually been converted according to the mode. As the discharge output terminal in the discharge mode, the discharge input terminal of the charge and discharge channel 2 is also connected to the charge output terminal of the charge and discharge channel 1. At this time, since the grid interface module provides a known constant voltage output, the voltage is distributed to the charge and discharge channel 1 and the charge and discharge channel 2. Since they are connected together, the voltages of the charge and discharge channel 1 and the charge and discharge channel 2 will tend to be the same. Because they share the same voltage source, therefore, by sampling the voltage between the charging output terminal of the charging and discharging channel 1 and the discharging input terminal of the charging and discharging channel 2, it can be determined whether the charging and discharging channel 1 outputs a constant voltage; at the same time, since the charging and discharging channel 2 is in the discharging mode, the discharging input terminal of the charging and discharging channel 2 is actually connected as a load to receive the constant current output of the charging and discharging channel 1. Therefore, current sampling can also be performed between the charging output terminal of the charging and discharging channel 1 and the discharging input terminal of the charging and discharging channel 2 to determine whether the charging and discharging channel 2 outputs a constant current; if the calibration is not successful, the charging and discharging channel 1 is re-controlled to be calibrated in the charging mode, and the charging and discharging channel 2 is controlled to be calibrated in the discharging mode. If the calibration is successful, the control parameters of the successful calibration are solidified, and then the charging and discharging channel 2 is controlled to be calibrated in the charging mode, and the charging and discharging channel 1 is controlled to be calibrated in the discharging mode, so that it can be determined whether the charging and discharging channel 1 outputs a constant current and whether the charging and discharging channel 2 outputs a constant voltage. The specific principle of this embodiment will not be repeated here.

[0051] See also Figure 4 , combined with Figure 2, the process of the charge and discharge channel aging test is as follows: first, connect the positive pole of the charge output terminal of the charge and discharge channel 1 and the charge and discharge channel 2 to the positive pole and the negative pole to the negative pole, then, connect the charge input terminal of the charge and discharge channel 1 and the charge input terminal of the charge and discharge channel 2 to the charge output terminal of the grid interface module, so that the high-voltage DC source converted by the grid interface module can be output to the charge and discharge channel 1 and the charge and discharge channel 2. At this time, the first stage of the aging test begins. First, control the charge and discharge channel 1 to be calibrated in the charge mode, and control the charge and discharge channel 2 to be calibrated in the discharge mode. The voltage between the charge output terminal of the charge and discharge channel 1 and the discharge input terminal of the charge and discharge channel 2 is continuously sampled under high temperature conditions, that is, control the charge and discharge channel 1 to run at full power for n hours in the charge mode and the charge and discharge channel 2 to run at full power in the discharge mode, and then the charge and discharge channel 1 can be known. Voltage stability at different stages; at the same time, the current can also be continuously sampled under high temperature conditions between the charging output terminal of the charging and discharging channel 1 and the discharging input terminal of the charging and discharging channel 2, that is, the charging and discharging channel 1 is controlled to run at full power for n hours in the charging mode and the charging and discharging channel 2 is controlled to run at full power for n hours in the discharging mode, and the current stability of the charging and discharging channel 1 at different stages can be known; when the charging and discharging channel 1 is in the charging mode and the charging and discharging channel 2 is in the discharging mode and runs at full power for n hours, the first stage of the aging test is stopped, and then the second stage of the aging test is started, first control the charging and discharging channel 2 to run at full power for n hours in the charging mode and the charging and discharging channel 1 to run at full power for n hours in the discharging mode, and the voltage stability of the charging and discharging channel 2 at different stages, and the current stability of the charging and discharging channel 1 at different stages can be known, and the specific principles will not be further described in this embodiment. For the optional sampling parameters for the aging test of the charging and discharging channel, it can also be the temperature change of the charging and discharging channel, etc., which can be selected by those skilled in the art according to the specific situation, and this embodiment will not be further limited here.

[0052] See also Figure 5-Figure 7 Exemplarily, the grid interface module includes a bidirectional energy storage inverter PCS, a DC auxiliary power supply, and a DSP processor (Digital Signal Processor: a microprocessor specifically used to efficiently process digital signals). The charging input end of the bidirectional energy storage inverter PCS is connected to the three-phase grid, and the charging output end of the bidirectional energy storage inverter PCS is connected to the charging input end of the charging and discharging channel. The bidirectional energy storage inverter PCS is used to convert the alternating current output from the three-phase grid into a high-voltage direct current source and then output it to the charging and discharging channel.

[0053] The charging input end of the DC auxiliary power supply is connected to the single-phase power grid, and the charging output end of the DC auxiliary power supply is connected to the power module of the DSP processor. The DC auxiliary power supply is used to convert the AC power output from the single-phase power grid into a DC source to power the DSP processor.

[0054] The DSP processor is also connected to the charge and discharge channel, and the DSP processor is used to send control signals of the forward and reverse switches to the charge and discharge channel.

[0055] A single charge and discharge channel includes two bidirectional LLC circuits (Resonant Converters: resonant conversion circuit) connected in series and staggered in parallel and five buck-boost circuits (buck-boost: step-up and step-down DC conversion circuit).

[0056] The charging input end of the two interlaced parallel bidirectional LLC circuits is connected to the charging output end of the bidirectional energy storage converter PCS. The two interlaced parallel bidirectional LLC circuits are used to convert the high-voltage DC source output by the bidirectional energy storage converter PCS into a low-voltage DC source, and the charging output end of the two interlaced parallel bidirectional LLC circuits is output to the buck-boost circuit. The buck-boost circuit is used to convert the low-voltage DC source output by the two interlaced parallel bidirectional LLC circuits into a low-voltage high-current to charge the corresponding battery.

[0057] In addition, the device also includes a sampling module, which is connected between the positive electrode and the negative electrode of the charging output side port Y of the buck-boost circuit, and is used to obtain a sampling voltage value, a sampling current value, and detect the stability of the output voltage of the charging and discharging channel, the stability of the input current of the charging and discharging channel, the charging and discharging efficiency of the charging and discharging channel, and the temperature change of the charging and discharging channel.

[0058] A single bidirectional LLC circuit includes a switch circuit 601, an LLC resonant circuit 602, a rectifier circuit 603, and a Y capacitor.

[0059] The charging output end of the switch circuit 601 is connected to the charging input end of the LLC resonant circuit 602, the charging output end of the LLC resonant circuit 602 is connected to the charging input end of the rectifier circuit 603, and the charging output end of the rectifier circuit 603 is connected to the charging input end of the 5-way staggered parallel buck-boost circuit.

[0060] The switch circuit 601 is a half-bridge circuit, and includes two power MOS transistors Q1 and Q2 connected in series. The gates of the power MOS transistors Q1 and Q2 are used to receive the control signals of the forward and reverse switches sent by the DSP processor.

[0061] LLC resonant circuit 602 includes capacitor C1, capacitor C2, inductor L1 and isolation transformer T1; wherein, capacitor C1, capacitor C2 and inductor L1 have energy storage function, and provide energy source for primary loop ("primary loop" refers to the input side circuit of power transformer, also called "high voltage side", in power transformer, electric power is input from primary side, and is transformed by transformer, and is output to secondary side, that is, electric power is input from high voltage side, and is transformed by transformer, and is output to low voltage side) when Q1 is turned off and Q2 is turned on, and both are indispensable, and the same is true for the other bidirectional LLC circuit, which will not be elaborated in this embodiment.

[0062] The rectifier circuit 603 is composed of a full-bridge circuit consisting of four power MOS tubes Q3, Q4, Q5 and Q6, and a capacitor C3. The capacitor C3 is connected in parallel with the full-bridge circuit and is used to perform energy storage filtering on the output voltage of the full-bridge circuit. The function of the capacitor C3 is to perform energy storage filtering on the output voltage of a single bidirectional LLC circuit, and this capacitor cannot be missing.

[0063] The switch circuit 601 is connected in parallel with the capacitor C1 and the capacitor C2, and the capacitor C1 is connected in series with the capacitor C2;

[0064] The switch circuit 601 is also connected in series with the Y capacitor, the switch circuit 601 is connected to the first end of the Y capacitor, and the second end of the Y capacitor is connected to the rectifier circuit 603. The Y capacitor refers to a special type of capacitor, also known as a Y capacitor or a safety capacitor, which is generally used to eliminate interference and filter in electrical equipment. In this embodiment, the function of the Y capacitor is to reduce the common-mode interference brought by the secondary circuit of the first isolation transformer to the primary circuit, and also reduce the interference of the circuit to the outside.

[0065] See also Figure 7 , taking a single buck-boost circuit closest to the output terminal Y as an example, the single buck-boost circuit includes a charging input side port X, a charging output side port Y, two power MOS tubes Q7 and Q8, an inductor L3 and a capacitor C9;

[0066] The power MOS tube Q7 and the power MOS tube Q8 are connected in series, the drain of the power MOS tube Q7 is connected to the charging input side port X, and the source of the power MOS tube Q7 is connected to the first end of the inductor L3, the second end of the inductor L3 is respectively connected to the positive electrode of the charging output side port Y and the first end of the capacitor C9, and the second end of the capacitor C9 is respectively connected to the negative electrode of the charging output side port Y and the source of the power MOS tube Q8. Among them, the inductor L3 is an energy storage inductor, and the capacitor C9 is an energy storage filter capacitor. This article uses specific examples to illustrate the principles and embodiments of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea; at the same time, for those skilled in the art, according to the idea of ​​the present application, there will be changes in the specific embodiments and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A high current charging and discharging device, comprising a plurality of batteries, characterized in that: It also includes a grid interface module and a plurality of charging and discharging channels, wherein the charging and discharging channels are sequentially connected in parallel, and the number of the charging and discharging channels is the same as the number of the batteries; The charging input end of the grid interface module is connected to the grid, the charging output end of the grid interface module is connected to the charging input ends of the plurality of parallel charging and discharging channels, and the charging output ends of the charging and discharging channels are connected one by one to the corresponding batteries; A single charge and discharge channel is used to manage the charging and discharging of the corresponding battery, and is also used to connect with other single charge and discharge channels to form a channel loop between the two single channels.

2. A high current charging and discharging device as claimed in claim 1, characterized in that: The grid interface module includes a bidirectional energy storage converter PCS, a DC auxiliary power supply, and a DSP processor. The charging input end of the bidirectional energy storage converter PCS is connected to the three-phase grid, and the charging output end of the bidirectional energy storage converter PCS is connected to the charging input end of the charging and discharging channel. The bidirectional energy storage converter PCS is used to convert the alternating current output by the three-phase grid into a high-voltage direct current source and then output it to the charging and discharging channel.

3. A high current charging and discharging device as claimed in claim 2, characterized in that: The charging input end of the DC auxiliary power supply is connected to the single-phase power grid, and the charging output end of the DC auxiliary power supply is connected to the power module of the DSP processor. The DC auxiliary power supply is used to convert the AC power output by the single-phase power grid into a DC source and then power the DSP processor.

4. A high current charging and discharging device as claimed in claim 3, characterized in that: The DSP processor is also connected to the charge and discharge channel, and the DSP processor is used to send control signals of forward and reverse switches to the charge and discharge channel.

5. A high current charging and discharging device as claimed in claim 2, characterized in that: The charge and discharge channel includes two bidirectional LLC circuits connected in series and staggered in parallel and five buck-boost circuits connected in series and staggered in parallel; The charging input end of the two interlaced parallel bidirectional LLC circuits is connected to the charging output end of the bidirectional energy storage converter PCS. The two interlaced parallel bidirectional LLC circuits are used to convert the high-voltage DC source output by the bidirectional energy storage converter PCS into a low-voltage DC source, and the charging output end of the two interlaced parallel bidirectional LLC circuits is output to the buck-boost circuit. The buck-boost circuit is used to convert the low-voltage DC source output by the two interlaced parallel bidirectional LLC circuits into a low-voltage high-current to charge the corresponding battery.

6. A high current charging and discharging device as claimed in claim 5, characterized in that: A single bidirectional LLC circuit comprises a switch circuit, an LLC resonant circuit, a rectifier circuit, and a Y capacitor; The charging output end of the switch circuit is connected to the charging input end of the LLC resonant circuit, the charging output end of the LLC resonant circuit is connected to the charging input end of the rectifier circuit, and the charging output end of the rectifier circuit is connected to the charging input end of the 5-way staggered parallel buck-boost circuit.

7. A high current charging and discharging device as claimed in claim 6, characterized in that: The switch circuit is a half-bridge circuit, and includes two power MOS tubes Q1 and Q2 connected in series, and the gates of the power MOS tubes Q1 and Q2 are used to receive the control signals of the forward and reverse switches sent by the DSP processor; The LLC resonant circuit includes a capacitor C1, a capacitor C2, an inductor L2 and a first isolation transformer T1; The rectifier circuit is composed of a full-bridge circuit consisting of four power MOS tubes Q3, Q4, Q5 and Q6, and a capacitor C3. The capacitor C3 is connected in parallel with the full-bridge circuit and is used for energy storage filtering of the output voltage of the full-bridge circuit.

8. A high current charging and discharging device as claimed in claim 7, characterized in that: The switch circuit is connected in parallel with the capacitor C1 and the capacitor C2, and the capacitor C1 is connected in series with the capacitor C2; The switch circuit is also connected in series with the Y capacitor. The switch circuit is connected to a first end of the Y capacitor, and a second end of the Y capacitor is connected to the rectifier circuit 603 .

9. A high current charging and discharging device as claimed in claim 5, characterized in that: The single buck-boost circuit includes a charging input port X, a charging output port Y, two power MOS tubes Q7 and Q8, an inductor L3 and a capacitor C9; The power MOS tube Q7 and the power MOS tube Q8 are connected in series, the drain of the power MOS tube Q7 is connected to the charging input side port X, and the source of the power MOS tube Q7 is connected to the first end of the inductor L3, the second end of the inductor L3 is respectively connected to the positive electrode of the charging output side port Y and the first end of the capacitor C9, and the second end of the capacitor C9 is respectively connected to the negative electrode of the charging output side port Y and the source of the power MOS tube Q8.

10. A high current charging and discharging device as claimed in claim 9, characterized in that: The device also includes a sampling module, which is connected between the positive electrode and the negative electrode of the charging output side port Y of the buck-boost circuit, and is used to obtain a sampling voltage value, a sampling current value, and detect the stability of the output voltage of the charging and discharging channel, the stability of the input current of the charging and discharging channel, the charging and discharging efficiency of the charging and discharging channel, and the temperature change of the charging and discharging channel.

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