Multi-level charging and discharging device and high-power charging and discharging equipment

Abstract

The invention discloses a multi-level charging and discharging device and high-power charging and discharging equipment, which are applied to the technical field of charging and discharging equipment and are used for solving the problem that the charging and discharging device in the prior art cannot be compatible with different types of loads. Specifically, the positive output end of a first power conversion module in a power module group is connected with the positive end of a first load interface and the positive end of a second load interface, and the negative output end of the first power conversion module is connected with the negative end of the first load interface and the neutral line end of the second load interface; the positive output end of the second power conversion module is connected with the positive end of the first load interface and the neutral line end of the second load interface, and the negative output end of the second power conversion module is connected with the negative end of the first load interface and the negative end of the second load interface; the first load interface is connected with an external neutral-line-free load and provides two-level output; and the second load interface is connected with an external load with a neutral line, provides three-level output, and is compatible with charging and discharging of different types of loads.

Description

Technical Field

[0001] This application relates to the field of charging and discharging equipment technology, and in particular to a multi-level charging and discharging device and a high-power charging and discharging device. Background Technology

[0002] With the continuous advancement of power electronics technology, various power supply systems have been widely used in key fields such as industry, communications, and data centers. Uninterruptible power supplies (UPS) and high-voltage direct current (HVDC) power supplies, as important devices for ensuring power continuity and improving energy efficiency, are applied in different scenarios. UPSs are generally divided into two types: with and without a neutral line. UPSs with a neutral line achieve voltage balance through the neutral line and are suitable for three-phase unbalanced loads; while UPSs without a neutral line are typically used in applications where size and cost are more critical.

[0003] Currently, charging and discharging devices are typically designed for specific types of loads, such as only being compatible with UPS systems with a neutral line or only supporting UPS systems and HVDC systems without a neutral line. However, in practical applications, due to the diverse load types in different user scenarios, if the charging and discharging device cannot be compatible with these different types of loads, it will result in poor device versatility and limited applicability, thereby affecting the system's flexibility and deployment efficiency. Summary of the Invention

[0004] This application provides a multi-level charging and discharging device and a high-power charging and discharging device to solve the problem that existing charging and discharging devices cannot be compatible with different types of loads.

[0005] The technical solution provided in this application is as follows: On one hand, this application provides a multilevel charging and discharging device, including: at least one power module group, a first load interface, a second load interface, and a control module; wherein, the power module group includes two power conversion modules; The input terminal of each power conversion module in the power module group is connected to an external battery cluster; the positive output terminal of the first power conversion module in the power module group is connected to the positive terminal of the first load interface and the positive terminal of the second load interface, and the negative output terminal of the first power conversion module in the power module group is connected to the negative terminal of the first load interface and the neutral terminal of the second load interface, respectively; the positive output terminal of the second power conversion module in the power module group is connected to the positive terminal of the first load interface and the neutral terminal of the second load interface, respectively, and the negative output terminal of the second power conversion module in the power module group is connected to the negative terminal of the first load interface and the negative terminal of the second load interface, respectively. The first load interface is used to connect to an external load without a neutral line; the second load interface is used to connect to an external load with a neutral line. The control module is connected to the control terminal of each power conversion module, and the control module is used to generate drive signals for each power conversion module. The power conversion module is used to charge and discharge the battery pack between the battery pack and an external load without a neutral line, or to charge and discharge the battery pack between the battery pack and an external load with a neutral line, under the drive of a drive signal.

[0006] Optionally, the power conversion module includes: a first capacitor, a second capacitor, a first inductor, a first continuous current module, and a second continuous current module; The first terminal of the first capacitor serves as the first input terminal of the power conversion module, and the second terminal of the first capacitor serves as the second input terminal of the power conversion module; the first terminal of the second capacitor serves as the positive output terminal of the power conversion module, and the second terminal of the second capacitor serves as the negative output terminal of the power conversion module. The first terminal of the first inductor is connected to the first terminal of the first capacitor, and the second terminal of the first inductor is connected to the first terminal of the first continuous current module and the first terminal of the second continuous current module respectively; the second terminal of the first continuous current module is connected to the first terminal of the second capacitor; the second terminal of the second continuous current module is connected to the second terminal of the first capacitor and the second terminal of the second capacitor respectively; the control terminal of the first continuous current module and the control terminal of the second continuous current module are respectively connected to the control module. The first continuous current module is used to connect or disconnect the connection between the first terminal of the second capacitor and the second terminal of the first inductor under the control of the drive signal; it is also used to provide a continuous current branch with the direction from the first terminal of the first continuous current module to the second terminal of the first continuous current module. The second continuous current module is used to connect or disconnect the connection between the second terminal of the second capacitor and the second terminal of the first inductor under the control of the drive signal; it is also used to provide a continuous current branch with the direction from the second terminal of the second continuous current module to the first terminal of the second continuous current module.

[0007] Optionally, the power conversion module may also include: a third capacitor; The first terminal of the third capacitor serves as the third input terminal of the power conversion module. The first terminal of the third capacitor is also connected to the first terminal of the second capacitor. The second terminal of the third capacitor is connected to the first terminal of the first capacitor.

[0008] Optionally, the first continuous current module includes a first controllable switch and a first diode; the second continuous current module includes a second controllable switch and a second diode. The first terminal of the first controllable switch is connected to the first terminal of the third capacitor and the first terminal of the second capacitor, respectively; the second terminal of the first controllable switch is connected to the second terminal of the first inductor and the first terminal of the second controllable switch, respectively; the cathode of the first diode is connected to the first terminal of the first controllable switch, and the anode of the first diode is connected to the second terminal of the first controllable switch. The first terminal of the second controllable switch is connected to the second terminal of the first capacitor and the second terminal of the third capacitor, respectively; the control terminals of the first and second controllable switches are connected to the control module, respectively; the negative terminal of the second diode is connected to the first terminal of the second controllable switch, and the positive terminal of the second diode is connected to the second terminal of the second controllable switch.

[0009] Optionally, the first continuous current module includes a first MOSFET; the second continuous current module includes a second MOSFET. The drain of the first MOSFET is connected to the first terminal of the third capacitor and the first terminal of the second capacitor, respectively. The source of the first MOSFET is connected to the second terminal of the first inductor and the drain of the second MOSFET, respectively. The source of the second MOSFET is connected to the second terminal of the first capacitor and the second terminal of the third capacitor, respectively. The gates of the first MOSFET and the second MOSFET are connected to the control module, respectively.

[0010] Optionally, the multilevel charging and discharging device further includes: a first battery cluster interface and a second battery cluster interface; The positive terminal of the first battery cluster interface is connected to the first input terminal of each power conversion module, and the negative terminal of the first battery cluster interface is connected to the second input terminal of each power conversion module; or, the positive terminal of the first battery cluster interface is connected to the third input terminal of each power conversion module, and the negative terminal of the first battery cluster interface is connected to the first input terminal of each power conversion module. The positive terminal of the second battery cluster interface is connected to the first input terminal of the first power conversion module in each power module group, the negative terminal of the second battery cluster interface is connected to the first input terminal of the second power conversion module in each power module group, and the neutral terminal of the second battery cluster interface is connected to the second input terminal of the first power conversion module and the third input terminal of the second power module in each power module group.

[0011] Optionally, the multilevel charging and discharging device also includes: a third battery cluster interface; The positive terminal of the third battery cluster interface is connected to the third input terminal of each power conversion module, the negative terminal of the third battery cluster interface is connected to the second input terminal of each power conversion module, and the neutral terminal of the third battery cluster interface is connected to the first input terminal of each power conversion module.

[0012] Optionally, the multilevel charging and discharging device includes multiple power module groups, and when a load is connected to the first load interface, the control module is specifically used for: An interleaved parallel control method is used to generate the drive waveforms input to each power conversion module.

[0013] Optionally, the multi-level charging and discharging device includes multiple power module groups, and when a load is connected to the second load interface, the control module is specifically used for: An interleaved parallel control method is used to generate the drive waveforms input to each power module group.

[0014] On the other hand, this application provides a high-power charging and discharging device, including: multiple battery clusters and multiple of the above-mentioned multilevel charging and discharging devices; Multiple battery clusters are connected one-to-one with multiple multilevel charging and discharging devices. External loads are connected to the first charging interface of each multilevel charging and discharging device, or external loads are connected to the second charging interface of each multilevel charging and discharging device.

[0015] The beneficial effects of this application are as follows: This application achieves a two-level output for the first load interface by configuring the positive output terminal of the power conversion module in the power module group to be connected to the positive terminal of the first load interface, and the negative output terminal of the power conversion module in the power module group to be connected to the negative terminal of the first load interface, thus meeting the wiring requirements for loads without a neutral line. Furthermore, by configuring one power conversion module in the power module group to connect its positive output terminal to the positive terminal of the second load interface and its negative output terminal to the neutral line of the second load interface; and another power conversion module to connect its negative output terminal to the negative terminal of the second load interface and its positive output terminal to the neutral line of the second load interface, the voltage at the neutral line of the second load interface is superimposed to obtain a third level, thus achieving a three-level output for the second load interface, meeting the wiring requirements for loads with a neutral line. Under the drive of the control module for each power module group, the multi-level charging and discharging device can be compatible with different types of loads for charging and discharging, improving the utilization rate of the multi-level charging and discharging device and the flexibility of its application scenarios.

[0016] Other features and advantages of this application will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the application. The objectives and other advantages of this application may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings. Attached Figure Description

[0017] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 A functional structure diagram of the multilevel charging and discharging device in the embodiments of this application; Figure 2This is a simplified structural diagram of a multilevel charging and discharging device for power supply without a neutral load, as shown in the embodiments of this application. Figure 3 This is a simplified structural diagram of a multilevel charging and discharging device powered by a neutral load, as shown in the embodiments of this application. Figure 4 This is a schematic diagram of the first circuit structure of the power conversion module in the embodiments of this application; Figure 5 This is a schematic diagram of a second circuit structure of the power conversion module in an embodiment of this application; Figure 6 This is a schematic diagram of a third circuit structure of the power conversion module in an embodiment of this application; Figure 7 This is a schematic diagram of the fourth circuit structure of the power conversion module in the embodiments of this application; Figure 8 This is a schematic diagram of the fifth circuit structure of the power conversion module in the embodiments of this application; Figure 9 This is a schematic diagram of a first wiring method for the first battery cluster interface in an embodiment of this application; Figure 10 This is a schematic diagram of a second wiring method for the first battery cluster interface in an embodiment of this application; Figure 11 This is a wiring diagram of the second battery cluster interface in an embodiment of this application; Figure 12 This is a wiring diagram of the third battery cluster interface in an embodiment of this application; Figure 13 This is a functional structure diagram of a high-power charging and discharging device including multiple interfaces with centerline battery clusters in the embodiments of this application; Figure 14 This is a functional structure diagram of a high-power charging and discharging device including multiple interfaces without a centerline in the embodiments of this application.

[0018] Icons: 100 - Multilevel charging and discharging device; 110 - Power module group; 111 - Power conversion module; 112 - First on / off continuous current module; 113 - Second on / off continuous current module; 114 - First controllable switch; 115 - Second controllable switch; 120 - First load interface; 130 - Second load interface; 140 - Control module; 150 - First battery cluster interface; 160 - Second battery cluster interface; 170 - Third battery cluster interface; 200 - High-power charging and discharging equipment; 210 - Battery cluster with neutral line; 220 - Battery cluster without neutral line; C1 - First capacitor; C2 - Second capacitor; C3 - Third capacitor; L1 - First inductor; D1 - First diode; D2 - Second diode; Q1 - First MOSFET; Q2 - Second MOSFET. Detailed Implementation

[0019] To make the objectives, technical solutions, and beneficial effects of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] To facilitate a better understanding of this application by those skilled in the art, the technical terms used in this application will be briefly introduced below.

[0021] A neutral-line load is a load that needs to be connected to the neutral line and requires three voltage levels (such as +V, 0, -V) for power supply; neutral-line loads include neutral-line UPS loads.

[0022] A neutral-less load is a load that does not require a connection to the neutral line and needs to be powered by two voltage levels (such as +V and -V); neutral-less loads include neutral-less UPS loads and HVDC loads.

[0023] A battery cluster with a neutral point is a battery cluster that needs to be connected to the neutral line terminal.

[0024] A neutral-line-less battery cluster is a battery cluster that has no internal neutral point and does not need to be connected to a neutral line.

[0025] It should be noted that the terms "first," "second," etc., used in this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that the embodiments described herein can be implemented in an order other than that illustrated or described herein. Furthermore, the term "and / or" used in this application describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0026] After introducing the technical terms used in this application, the technical solutions provided by the embodiments of this application will be described in detail below.

[0027] This application provides a multilevel charging and discharging device, see reference. Figure 1 As shown, the multilevel charging and discharging device 100 provided in this application embodiment includes at least: at least one power module group 110, a first load interface 120, a second load interface 130, and a control module 140; wherein, the power module group 110 includes two power conversion modules 111; The input terminal of each power conversion module 111 in the power module group 110 is connected to an external battery cluster; the positive output terminal of the first power conversion module 111 in the power module group 110 is connected to the positive terminal of the first load interface 120 and the positive terminal of the second load interface 130, respectively; the negative output terminal of the first power conversion module 111 in the power module group 110 is connected to the negative terminal of the first load interface 120 and the neutral terminal of the second load interface 130, respectively; the positive output terminal of the second power conversion module 111 in the power module group 110 is connected to the positive terminal of the first load interface 120 and the neutral terminal of the second load interface 130, respectively; the negative output terminal of the second power conversion module 111 in the power module group 110 is connected to the negative terminal of the first load interface 120 and the negative terminal of the second load interface 130, respectively. The first load interface 120 is used to connect to an external load without a neutral line; the second load interface 130 is used to connect to an external load with a neutral line. The control module 140 is connected to the control terminal of each power conversion module 111, and the control module 140 is used to generate drive signals for each power conversion module 111. The power conversion module 111 is used to charge and discharge the battery pack with an external load without a neutral line, or to charge and discharge the battery pack with an external load with a neutral line, under the drive of a drive signal.

[0028] exist Figure 1 In the multilevel charging and discharging device 100 shown, each power conversion module 111 in the power module group 110 can be an isolated DC-DC converter or a non-isolated DC-DC converter. The control module 140 includes a drive circuit and a controller. The configuration of the drive circuit is determined by the number and type of switching devices in the power conversion module 111. The first load interface 120 corresponds to the parallel connection of the outputs of all power conversion modules 111 in the circuit, and the first load interface 120 outputs two levels (e.g., +V, -V). The second load interface 130 corresponds to the parallel connection of the outputs of all power module groups 110 in the circuit. The outputs of the power conversion modules 111 in the power module group 110 are connected in series. The negative output terminal of one power conversion module 111 in each power module group 110 is connected to the positive output terminal of another power conversion module 111. A third level is obtained by voltage superposition and connected to the neutral line terminal of the first load interface 120. The second load interface 130 outputs three levels (e.g., +V, 0, -V).

[0029] Thus, by configuring the positive output terminal of the power conversion module 111 in the power module group 110 to be connected to the positive terminal of the first load interface 120, and the negative output terminal of the power conversion module 111 in the power module group 110 to be connected to the negative terminal of the first load interface 120, a two-level output of the first load interface 120 is achieved, meeting the wiring requirements for loads without a neutral line; by configuring the positive output terminal of one power conversion module 111 in the power module group 110 to be connected to the positive terminal of the second load interface 130, and the negative output terminal to be connected to the neutral line terminal of the second load interface 130; another power... The negative output terminal of the power conversion module 111 is connected to the negative terminal of the second load interface 130, and the positive output terminal is connected to the neutral terminal of the second load interface 130. The voltage at the neutral terminal of the second load interface 130 is superimposed to obtain a third level, realizing the three-level output of the second load interface 130, which meets the wiring requirements of the load with neutral line. Under the drive of the control module 140 to each power module group 110, the multi-level charging and discharging device 100 can be compatible with different types of loads for charging and discharging, improving the utilization rate of the multi-level charging and discharging device 100 and the flexibility of application scenarios.

[0030] Specifically, multilevel charging and discharging devices connect to different types of loads, and the power module groups operate in different ways.

[0031] When the multilevel charging and discharging device is connected to an external load without a neutral line via the first load interface, the simplified structure of the multilevel charging and discharging device is as follows: Figure 2 As shown, taking charging a load without a neutral line via a battery cluster as an example, the control module 140 can control at least one power conversion module 111 in the circuit to operate.

[0032] When a power conversion module 111 is working in the control circuit of the control module 140, the control module 140 can generate a corresponding drive signal to the control terminal of the power conversion module 111 according to the charging parameters of the load, so that the power conversion module 111 charges the load through the battery pack.

[0033] When multiple power conversion modules 111 are working in the control circuit of the control module 140, the control module 140 is used to generate drive waveforms input to each power conversion module 111 using an interleaved parallel control method.

[0034] In practical applications, the control module 140 generates corresponding drive signals based on the load's charging parameters and the preset phase difference between the drive signals of each power conversion module 111. These signals are then input to the control terminals of each power conversion module 111, allowing the power conversion modules 111 to charge the load through the battery cluster in an alternating manner. This ensures that the switching actions within each parallel power conversion module 111 are staggered by a fixed phase difference, causing the pulsating currents of each module to cancel each other out when superimposed, thus reducing output ripple. With reduced output ripple, the requirements for filter inductors / capacitors are significantly relaxed, allowing for a reduction in the size of passive components during the design phase.

[0035] When the multilevel charging and discharging device is connected to an external neutral-load via a second load interface, the simplified structure of the multilevel charging and discharging device is as follows: Figure 3 As shown, taking charging a load with a neutral line via a battery cluster as an example, the control module 140 can control at least one power module group 110 in the circuit to operate.

[0036] When one power module group 110 is working in the control circuit of the control module 140, the control module 140 can generate a corresponding drive signal to the control terminals of the two power conversion modules 111 according to the charging parameters of the load. The drive signals of the two power conversion modules 111 in the power module group 110 are the same, that is, the outputs of the two power conversion modules 111 are consistent, so that the voltage of the negative output terminal of one power conversion module 111 and the positive output terminal of the other power conversion module 111 at the neutral line terminal of the second load port is superimposed to 0V, thereby providing a terminal for the load with neutral line and outputting a third level.

[0037] When multiple power module groups 110 are working in the control circuit of the control module 140, the control module 140 is used to generate drive waveforms input to each power module group 110 using an interleaved parallel control method.

[0038] In practical applications, the control module 140 can generate corresponding drive signals based on the load's charging parameters and a preset phase difference between the drive signals of each power module group 110. These signals are then input to the control terminals of each power conversion module 111, allowing the power conversion modules 111 to charge the load through the battery clusters in an alternating manner. The drive signals of two power conversion modules 111 within a power module group 110 remain identical, while a preset phase difference exists between the drive signals of each power module group 110. This ensures that the switching actions of the parallel power conversion module groups 111 are staggered by a fixed phase difference, causing the pulsating currents of each power conversion module group 111 to cancel each other out when superimposed, thus reducing output ripple. Reduced output ripple also allows for a reduction in the size of passive components during the design phase.

[0039] In practical implementation, the power conversion module in a multi-level charging and discharging device has various structures to achieve its function; see [reference needed]. Figure 4 As shown, the power conversion module includes: a first capacitor C1, a second capacitor C2, a first inductor L1, a first continuous current module 112, and a second continuous current module 113. The first terminal of the first capacitor C1 serves as the first input terminal of the power conversion module, and the second terminal of the first capacitor C1 serves as the second input terminal of the power conversion module; the first terminal of the second capacitor C2 serves as the positive output terminal of the power conversion module, and the second terminal of the second capacitor C2 serves as the negative output terminal of the power conversion module. The first terminal of the first inductor L1 is connected to the first terminal of the first capacitor C1. The second terminal of the first inductor L1 is connected to the first terminal of the first continuous current module 112 and the first terminal of the second continuous current module 113. The second terminal of the first continuous current module 112 is connected to the first terminal of the second capacitor C2. The second terminal of the second continuous current module 113 is connected to the second terminal of the first capacitor C1 and the second terminal of the second capacitor C2. The control terminal of the first continuous current module 112 and the control terminal of the second continuous current module 113 are connected to the control module 140. The first continuous current module 112 is used to connect or disconnect the connection between the first terminal of the second capacitor C2 and the second terminal of the first inductor L1 under the control of the drive signal; it is also used to provide a continuous current branch with the direction from the first terminal of the first continuous current module 112 to the second terminal of the first continuous current module 112. The second continuous current module 113 is used to connect or disconnect the connection between the second terminal of the second capacitor C2 and the second terminal of the first inductor L1 under the control of the drive signal; it is also used to provide a continuous current branch with the direction from the second terminal of the second continuous current module 113 to the first terminal of the second continuous current module 113.

[0040] exist Figure 4In the power conversion module shown, when the battery pack discharges to an externally connected load, the first inductor L1 acts as a power inductor, the first capacitor C1 acts as an input energy storage capacitor, and the second capacitor C2 acts as an output energy storage capacitor. Under the control of a PWM-type drive signal, the second on-off continuous current module 113 periodically connects or disconnects the connection between the second terminal of the second capacitor C2 and the second terminal of the first inductor L1. The first on-off continuous current module 112 disconnects the connection between the first terminal of the second capacitor C2 and the second terminal of the first inductor L1, and provides a freewheeling branch with a direction from the first terminal of the first on-off continuous current module 112 to the second terminal of the first on-off continuous current module 112. At this time, the power conversion module operates in BOOST discharge boost mode. When an externally connected load is charging the battery pack, the first inductor L1 acts as a power inductor, the first capacitor C1 acts as an output energy storage capacitor, and the second capacitor C2 acts as an input energy storage capacitor. Under the control of a PWM drive signal, the first on-off continuous current module 112 periodically connects or disconnects the connection between the first terminal of the second capacitor C2 and the second terminal of the first inductor L1. The second on-off continuous current module 113 disconnects the connection between the second terminal of the second capacitor C2 and the second terminal of the first inductor L1, and provides a freewheeling branch with a direction from the second terminal of the second on-off continuous current module 113 to the first terminal of the second on-off continuous current module 113. At this time, the power conversion module operates in BUCK charging buck mode.

[0041] In one possible implementation, see [reference] Figure 5 As shown, when the power conversion module includes a first capacitor C1, a second capacitor C2, a first inductor L1, a first continuous current module 112, and a second continuous current module 113, the following connection method can also be adopted: The first terminal of the first capacitor C1 serves as the first input terminal of the power conversion module, and the second terminal of the first capacitor C1 serves as the second input terminal of the power conversion module; the first terminal of the second capacitor C2 serves as the positive output terminal of the power conversion module, and the second terminal of the second capacitor C2 serves as the negative output terminal of the power conversion module. The first terminal of the first inductor L1 is connected to the second terminal of the first capacitor C1. The second terminal of the first inductor L1 is connected to the first terminal of the first continuous current module 112 and the first terminal of the second continuous current module 113. The second terminal of the first continuous current module 112 is connected to the first terminal of the first capacitor C1 and the first terminal of the second capacitor C2. The second terminal of the second continuous current module 113 is connected to the second terminal of the second capacitor C2. The control terminal of the first continuous current module 112 and the control terminal of the second continuous current module 113 are connected to the control module 140. The first continuous current module 112 is used to connect or disconnect the connection between the first terminal of the second capacitor C2 and the second terminal of the first inductor L1 under the control of the drive signal; it is also used to provide a continuous current branch with the direction from the first terminal of the first continuous current module 112 to the second terminal of the first continuous current module 112. The second continuous current module 113 is used to connect or disconnect the connection between the second terminal of the second capacitor C2 and the second terminal of the first inductor L1 under the control of the drive signal; it is also used to provide a continuous current branch with the direction from the second terminal of the second continuous current module 113 to the first terminal of the second continuous current module 113.

[0042] exist Figure 5 In the power conversion module shown, when the battery pack discharges to an externally connected load, the first inductor L1 is a power inductor, the first capacitor C1 is an input energy storage capacitor, and the second capacitor C2 is an output energy storage capacitor. Under the control of a PWM-type drive signal, the first on-off continuous current module 112 periodically connects or disconnects the connection between the first terminal of the second capacitor C2 and the second terminal of the first inductor L1. The second on-off continuous current module 113 disconnects the connection between the second terminal of the second capacitor C2 and the second terminal of the first inductor L1, and provides a freewheeling branch with the direction from the second terminal of the second on-off continuous current module 113 to the first terminal of the second on-off continuous current module 113. At this time, the power conversion module operates in BOOST discharge boost mode. When an externally connected load is charging the battery pack, the first inductor L1 acts as a power inductor, the first capacitor C1 acts as an output energy storage capacitor, and the second capacitor C2 acts as an input energy storage capacitor. Under the control of a PWM drive signal, the second on-off continuous current module 113 periodically connects or disconnects the connection between the second terminal of the second capacitor C2 and the second terminal of the first inductor L1. The first on-off continuous current module 112 disconnects the connection between the first terminal of the second capacitor C2 and the second terminal of the first inductor L1, and provides a freewheeling branch with a direction from the first terminal of the first on-off continuous current module 112 to the second terminal of the first on-off continuous current module 112. At this time, the power conversion module operates in BUCK charging buck mode.

[0043] In one possible implementation, see [reference] Figure 6 As shown, the power conversion module also includes: a third capacitor C3; The first terminal of the third capacitor C3 serves as the third input terminal of the power conversion module. The first terminal of the third capacitor C3 is also connected to the first terminal of the second capacitor C2. The second terminal of the third capacitor C3 is connected to the first terminal of the first capacitor C1.

[0044] exist Figure 6 In the power conversion module shown, when the battery cluster discharges to an externally connected load, the power conversion module has two alternating BOOST discharge boost modes.

[0045] First BOOST discharge boost mode: First inductor L1 is a power inductor, third capacitor C3 is an input energy storage capacitor, and second capacitor C2 is an output energy storage capacitor. Under the control of a PWM type drive signal, the first on-off continuous current module 112 periodically connects or disconnects the connection between the first terminal of the second capacitor C2 and the second terminal of the first inductor L1. The second on-off continuous current module 113 disconnects the connection between the second terminal of the second capacitor C2 and the second terminal of the first inductor L1, and provides a continuous current branch with the direction from the second terminal of the second on-off continuous current module 113 to the first terminal of the second on-off continuous current module 113.

[0046] Second BOOST discharge boost mode: First inductor L1 is a power inductor, first capacitor C1 is an input energy storage capacitor, second capacitor C2 is an output energy storage capacitor, and second on / off continuous current module 113, under the control of PWM type drive signal, periodically connects or disconnects the connection between the second terminal of second capacitor C2 and the second terminal of first inductor L1. First on / off continuous current module 112 disconnects the connection between the first terminal of second capacitor C2 and the second terminal of first inductor L1, and provides a continuous current branch with the direction from the first terminal of first on / off continuous current module 112 to the second terminal of first on / off continuous current module 112.

[0047] In this way, the first BOOST discharge boost mode and the second BOOST discharge boost mode operate alternately, and the first inductor L1 can operate alternately in both forward and reverse directions, increasing the utilization rate of the magnetic flux of the first inductor L1. Furthermore, when the voltage output from the battery cluster to the power conversion module changes, a higher output voltage can be maintained to the load by adjusting the drive signal.

[0048] Correspondingly, when an externally connected load is charging the battery pack, the power conversion module has two alternating BUCK charging buck modes.

[0049] First BUCK charging buck mode: First inductor L1 is a power inductor, second capacitor C2 is an output energy storage capacitor, and third capacitor C3 is an input energy storage capacitor. Under the control of a PWM type drive signal, the first on-off continuous current module 112 periodically connects or disconnects the connection between the first terminal of the second capacitor C2 and the second terminal of the first inductor L1. The second on-off continuous current module 113 disconnects the connection between the second terminal of the second capacitor C2 and the second terminal of the first inductor L1, and provides a freewheeling branch with the direction from the second terminal of the second on-off continuous current module 113 to the first terminal of the second on-off continuous current module 113.

[0050] Second BUCK charging buck mode: First inductor L1 is a power inductor, first capacitor C1 is an output energy storage capacitor, second capacitor C2 is an input energy storage capacitor, and second on / off continuous current module 113, under the control of PWM type drive signal, periodically connects or disconnects the connection between the second terminal of second capacitor C2 and the second terminal of first inductor L1. First on / off continuous current module 112 disconnects the connection between the first terminal of second capacitor C2 and the second terminal of first inductor L1, and provides a continuous current branch with the direction from the first terminal of first on / off continuous current module 112 to the second terminal of first on / off continuous current module 112.

[0051] In one possible implementation, see [reference] Figure 7 As shown, the first continuous current module 112 includes a first controllable switch 114 and a first diode D1; the second continuous current module 113 includes a second controllable switch 115 and a second diode D2. The first terminal of the first controllable switch 114 is connected to the first terminal of the third capacitor C3 and the first terminal of the second capacitor C2, respectively. The second terminal of the first controllable switch 114 is connected to the second terminal of the first inductor L1 and the first terminal of the second controllable switch 115, respectively. The negative terminal of the first diode D1 is connected to the first terminal of the first controllable switch 114, and the positive terminal of the first diode D1 is connected to the second terminal of the first controllable switch 114. The first terminal of the second controllable switch 115 is connected to the second terminal of the first capacitor C1 and the second terminal of the third capacitor C3, respectively; the control terminals of the first controllable switch 114 and the second controllable switch 115 are connected to the control module 140, respectively; the negative terminal of the second diode D2 is connected to the first terminal of the second controllable switch 115, and the positive terminal of the second diode D2 is connected to the second terminal of the second controllable switch 115.

[0052] In practical applications, the first controllable switch 114 is used to connect or disconnect the connection between the first terminal of the second capacitor C2 and the second terminal of the first inductor L1 under the control of the drive signal; the first diode D1 is used to provide a freewheeling branch with the direction from the first terminal of the first on-off freewheeling module 112 to the second terminal of the first on-off freewheeling module 112; the second controllable switch 115 is used to connect or disconnect the connection between the second terminal of the second capacitor C2 and the second terminal of the first inductor L1 under the control of the drive signal; the second diode D2 is used to provide a freewheeling branch with the direction from the second terminal of the second on-off freewheeling module 113 to the first terminal of the second on-off freewheeling module 113. The first controllable switch 114 and the second controllable switch 115 can be switching devices such as IGBTs, MOSFETs, and thyristors. Adding an additional diode in reverse parallel to each controllable switch can improve the reliability of the freewheeling.

[0053] In one possible implementation, see [reference] Figure 8As shown, the first on / off continuous current module 112 includes a first MOSFET Q1; the second on / off continuous current module 113 includes a second MOSFET Q2; The drain of the first MOSFET Q1 is connected to the first terminal of the third capacitor C3 and the first terminal of the second capacitor C2, respectively. The source of the first MOSFET Q1 is connected to the second terminal of the first inductor L1 and the drain of the second MOSFET Q2, respectively. The source of the second MOSFET Q2 is connected to the second terminal of the first capacitor C1 and the second terminal of the third capacitor C3, respectively. The gates of the first MOSFET Q1 and the second MOSFET Q2 are connected to the control module 140, respectively.

[0054] In practical applications, since the MOSFET has an internal anti-parallel body diode, the external diode can be omitted. The body diode of the first MOSFET Q1 provides a freewheeling branch from the first terminal of the first on-off freewheeling module 112 to the second terminal of the first on-off freewheeling module 112; and the second MOSFET Q2 provides a freewheeling branch from the second terminal of the second on-off freewheeling module 113 to the first terminal of the second on-off freewheeling module 113.

[0055] In one possible implementation, see [reference] Figure 9 and Figure 10 As shown, the multilevel charging and discharging device also includes: a first battery cluster interface 150 and a second battery cluster interface 160; The positive terminal of the first battery cluster interface 150 is connected to the first input terminal of each power conversion module 111, and the negative terminal of the first battery cluster interface 150 is connected to the second input terminal of each power conversion module 111; or, the positive terminal of the first battery cluster interface 150 is connected to the third input terminal of each power conversion module 111, and the negative terminal of the first battery cluster interface 150 is connected to the first input terminal of each power conversion module 111. The positive terminal of the second battery cluster interface 160 is connected to the first input terminal of the first power conversion module 111 in each power module group 110, the negative terminal of the second battery cluster interface 160 is connected to the first input terminal of the second power conversion module 111 in each power module group 110, and the neutral terminal of the second battery cluster interface 160 is connected to the second input terminal of the first power conversion module 111 and the third input terminal of the second power module in each power module group 110.

[0056] In practical applications, the first battery cluster interface 150 is connected to each power conversion module 111 in the same way. The first battery cluster interface 150 corresponds to the access of the neutralless battery cluster, and when the first battery cluster interface 150 is connected to the battery cluster, the multilevel charging and discharging device can only supply power to the external neutralless load.

[0057] according to Figure 9As shown in the connection diagram, the first battery cluster interface 150 is connected to the battery cluster without a neutral wire. When each power conversion module operates in discharge mode, the first inductor L1 is a power inductor, the first capacitor C1 serves as the input energy storage capacitor, and the second capacitor C2 serves as the output energy storage capacitor. The second MOSFET Q2 is periodically turned on under the control of a PWM drive signal, while the first MOSFET Q1 is turned off, and its body diode provides freewheeling. In this mode, the power conversion module operates in BOOST discharge boost mode. When each power conversion module operates in charging mode, the first inductor L1 is a power inductor, the first capacitor C1 serves as the output energy storage capacitor, and the second capacitor C2 serves as the input energy storage capacitor. The first MOSFET Q1 is periodically turned on under the control of a PWM drive signal, while the second MOSFET Q2 is turned off, and its body diode provides freewheeling. In this mode, the power conversion module operates in BUCK charging buck mode.

[0058] according to Figure 10 As shown in the connection diagram, the first battery cluster interface 150 is connected to the battery cluster without a neutral wire. When each power conversion module operates in discharge mode, the first inductor L1 is a power inductor, the third capacitor C3 serves as the input energy storage capacitor, and the second capacitor C2 serves as the output energy storage capacitor. The first MOSFET Q1 is periodically turned on under the control of a PWM drive signal, while the second MOSFET Q2 is turned off, with its body diode providing a freewheeling branch. In this mode, the power conversion module operates in BOOST discharge boost mode. When each power conversion module operates in charging mode, the first inductor L1 is a power inductor, the third capacitor C3 serves as the output energy storage capacitor, and the second capacitor C2 serves as the input energy storage capacitor. The second MOSFET Q2 is periodically turned on under the control of a PWM drive signal, while the first MOSFET Q1 is turned off, with its body diode providing a freewheeling branch. In this mode, the power conversion module operates in BUCK charging buck mode.

[0059] In practical applications, the second battery cluster interface 160 corresponds to the access of the battery cluster with a neutral line, and when the second battery cluster interface 160 is connected to the battery cluster with a neutral line, the multilevel charging and discharging device can only supply power to the external load with a neutral line.

[0060] according to Figure 11As shown in the connection diagram, the second battery cluster interface 160 is connected to the battery cluster with a neutral line. When each power conversion module group operates in discharge mode, the first inductor L1 and the second inductor L2 are power inductors, the third capacitor C3 and the fourth capacitor C4 serve as input energy storage capacitors, and the second capacitor C2 and the fifth capacitor C5 serve as output energy storage capacitors. The first MOSFET Q1 and the fourth MOSFET Q4 are periodically turned on under the control of a PWM drive signal, while the second MOSFET Q2 and the third MOSFET Q3 are both turned off. The body diodes of the second MOSFET Q2 and the third MOSFET Q3 provide freewheeling branches. At this time, the power conversion module group operates in BOOST discharge boost mode. When each power conversion module operates in charging mode, the first inductor L1 and the second inductor L2 are power inductors, the third capacitor C3 and the fourth capacitor C4 serve as output energy storage capacitors, and the second capacitor C2 and the fifth capacitor C5 serve as input energy storage capacitors. The second MOSFET Q2 and the third MOSFET Q3 are periodically turned on under the control of a PWM drive signal, while the first MOSFET Q1 and the fourth MOSFET Q4 are both turned off, and the body diodes of the first MOSFET Q1 and the fourth MOSFET Q4 freewheel. At this time, the power conversion module group operates in BUCK charging buck mode.

[0061] In one possible implementation, see [reference] Figure 12 As shown, the multi-level charging and discharging device also includes: a third battery cluster interface 170; The positive terminal of the third battery cluster interface 170 is connected to the third input terminal of each power conversion module 111, the negative terminal of the third battery cluster interface 170 is connected to the second input terminal of each power conversion module 111, and the neutral terminal of the third battery cluster interface 170 is connected to the first input terminal of each power conversion module 111.

[0062] exist Figure 12 As shown in the connection method, the third battery cluster interface 170 corresponds to the connection of a battery cluster with a neutral wire. When the third battery cluster interface 170 is connected to the battery cluster, the multi-level charging and discharging device can only supply power to external loads without a neutral wire. When each power conversion module 111 is operating in discharge mode, the power conversion module 111 can alternately operate in the first BOOST discharge boost mode and the second BOOST discharge boost mode. When each power conversion module 111 is operating in charging mode, the power conversion module 111 can alternately operate in the first BUCK charging buck mode and the second BUCK charging buck mode.

[0063] Based on the above embodiments, this application provides a high-power charging and discharging device, which includes at least: multiple battery clusters and multiple of the above-mentioned multilevel charging and discharging devices; Multiple battery clusters are connected one-to-one with multiple multilevel charging and discharging devices. External loads are connected to the first charging interface of each multilevel charging and discharging device, or external loads are connected to the second charging interface of each multilevel charging and discharging device.

[0064] Specifically, for applications requiring high power output, multi-level charging and discharging devices can be used in parallel. For the structure of high-power charging and discharging equipment when multiple battery clusters are all neutral-lined, please refer to [reference needed]. Figure 13 As shown, multiple battery clusters 210 with a centerline simultaneously provide high-power output to the load through corresponding multi-level charging and discharging devices 100. When multiple battery clusters are without a centerline, the structure of the high-power charging and discharging device is described in [reference needed]. Figure 14 As shown, multiple battery clusters 220 without a neutral wire simultaneously provide high-power output to the load through corresponding multi-level charging and discharging devices 100. Thus, by using the multi-level charging and discharging devices 100 in parallel, not only can high-power output be provided to different types of loads, but also, in the event of a battery cluster or multi-level charging and discharging device 100 failure, the other battery clusters and multi-level charging and discharging devices 100 connected in parallel do not affect the power supply to the load, improving the stability and reliability of the high-power charging and discharging equipment 200. Furthermore, since there is a one-to-one correspondence between the battery clusters and the multi-level charging and discharging devices 100, by adjusting the control parameters of the multi-level charging and discharging devices 100, battery clusters with different SOC values ​​can supply power to the same load.

[0065] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0066] Obviously, those skilled in the art can make various modifications and variations to the embodiments of this application without departing from the spirit and scope of the embodiments of this application. Therefore, if these modifications and variations to the embodiments of this application fall within the scope of the claims of this application and their equivalents, this application also intends to include these modifications and variations.

Claims

1. A multi-level charging and discharging device, characterized in that, include: The system includes at least one power module group, a first load interface, a second load interface, and a control module; wherein the power module group includes two power conversion modules. The input terminal of each power conversion module in the power module group is connected to an external battery cluster; the positive output terminal of the first power conversion module in the power module group is connected to the positive terminal of the first load interface and the positive terminal of the second load interface, respectively, and the negative output terminal of the first power conversion module in the power module group is connected to the negative terminal of the first load interface and the neutral terminal of the second load interface, respectively; the positive output terminal of the second power conversion module in the power module group is connected to the positive terminal of the first load interface and the neutral terminal of the second load interface, respectively, and the negative output terminal of the second power conversion module in the power module group is connected to the negative terminal of the first load interface and the negative terminal of the second load interface, respectively. The first load interface is used to connect to an external load without a neutral line; the second load interface is used to connect to an external load with a neutral line. The control module is connected to the control terminal of each power conversion module, and the control module is used to generate drive signals for each power conversion module. The power conversion module is used to charge and discharge the battery cluster with an external load without a neutral line, or to charge and discharge the battery cluster with an external load with a neutral line, under the drive of the drive signal.

2. The multi-level charging and discharging device as described in claim 1, characterized in that, The power conversion module includes: a first capacitor, a second capacitor, a first inductor, a first continuous current module, and a second continuous current module; The first terminal of the first capacitor serves as the first input terminal of the power conversion module, and the second terminal of the first capacitor serves as the second input terminal of the power conversion module; the first terminal of the second capacitor serves as the positive output terminal of the power conversion module, and the second terminal of the second capacitor serves as the negative output terminal of the power conversion module. The first terminal of the first inductor is connected to the first terminal of the first capacitor, and the second terminal of the first inductor is connected to the first terminal of the first continuous current module and the first terminal of the second continuous current module, respectively; the second terminal of the first continuous current module is connected to the first terminal of the second capacitor; the second terminal of the second continuous current module is connected to the second terminal of the first capacitor and the second terminal of the second capacitor, respectively; the control terminal of the first continuous current module and the control terminal of the second continuous current module are respectively connected to the control module. The first on / off continuous current module is used to connect or disconnect the connection between the first terminal of the second capacitor and the second terminal of the first inductor under the control of the drive signal; it is also used to provide a continuous current branch with the direction from the first terminal of the first on / off continuous current module to the second terminal of the first on / off continuous current module. The second on / off continuous current module is used to connect or disconnect the connection between the second terminal of the second capacitor and the second terminal of the first inductor under the control of the drive signal; it is also used to provide a continuous current branch with the direction from the second terminal of the second on / off continuous current module to the first terminal of the second on / off continuous current module.

3. The multi-level charging and discharging device as described in claim 2, characterized in that, The power conversion module further includes: a third capacitor; The first terminal of the third capacitor serves as the third input terminal of the power conversion module, and the first terminal of the third capacitor is also connected to the first terminal of the second capacitor; the second terminal of the third capacitor is connected to the first terminal of the first capacitor.

4. The multi-level charging and discharging device as described in claim 3, characterized in that, The first continuous current module includes a first controllable switch and a first diode; the second continuous current module includes a second controllable switch and a second diode. The first terminal of the first controllable switch is connected to the first terminal of the third capacitor and the first terminal of the second capacitor, respectively; the second terminal of the first controllable switch is connected to the second terminal of the first inductor and the first terminal of the second controllable switch, respectively; the cathode of the first diode is connected to the first terminal of the first controllable switch, and the anode of the first diode is connected to the second terminal of the first controllable switch. The first terminal of the second controllable switch is connected to the second terminal of the first capacitor and the second terminal of the third capacitor, respectively; the control terminals of the first and second controllable switches are connected to the control module, respectively; the negative terminal of the second diode is connected to the first terminal of the second controllable switch, and the positive terminal of the second diode is connected to the second terminal of the second controllable switch.

5. The multi-level charging and discharging device as described in claim 3, characterized in that, The first on / off continuous current module includes a first MOSFET; the second on / off continuous current module includes a second MOSFET. The drain of the first MOS transistor is connected to the first terminal of the third capacitor and the first terminal of the second capacitor, respectively; the source of the first MOS transistor is connected to the second terminal of the first inductor and the drain of the second MOS transistor, respectively; the source of the second MOS transistor is connected to the second terminal of the first capacitor and the second terminal of the third capacitor, respectively; and the gates of the first MOS transistor and the second MOS transistor are connected to the control module, respectively.

6. The multilevel charging and discharging device according to any one of claims 1-5, characterized in that, Also includes: First battery cluster interface and second battery cluster interface; The positive terminal of the first battery cluster interface is connected to the first input terminal of each of the power conversion modules, and the negative terminal of the first battery cluster interface is connected to the second input terminal of each of the power conversion modules; or, the positive terminal of the first battery cluster interface is connected to the third input terminal of each of the power conversion modules, and the negative terminal of the first battery cluster interface is connected to the first input terminal of each of the power conversion modules. The positive terminal of the second battery cluster interface is connected to the first input terminal of the first power conversion module in each of the power module groups, the negative terminal of the second battery cluster interface is connected to the first input terminal of the second power conversion module in each of the power module groups, and the neutral terminal of the second battery cluster interface is connected to the second input terminal of the first power conversion module and the third input terminal of the second power module in each of the power module groups.

7. The multi-level charging and discharging device as described in claim 6, characterized in that, Also includes: Third battery cluster interface; The positive terminal of the third battery cluster interface is connected to the third input terminal of each of the power conversion modules, the negative terminal of the third battery cluster interface is connected to the second input terminal of each of the power conversion modules, and the neutral terminal of the third battery cluster interface is connected to the first input terminal of each of the power conversion modules.

8. The multilevel charging and discharging device as described in claim 7, characterized in that, The multilevel charging and discharging device includes multiple power module groups, and when a load is connected to the first load interface, the control module is specifically used for: An interleaved parallel control method is used to generate the drive waveforms input to each power conversion module.

9. The multi-level charging and discharging device as described in claim 7, characterized in that, The multilevel charging and discharging device includes multiple power module groups, and when a load is connected to the second load interface, the control module is specifically used for: An interleaved parallel control method is used to generate the drive waveforms input to each power module group.

10. A high-power charging and discharging device, characterized in that, include: Multiple battery clusters and multiple multilevel charging and discharging devices as described in any one of claims 1-9; The battery clusters are connected one-to-one with the multilevel charging and discharging devices, and the external load is connected to the first charging interface of each multilevel charging and discharging device, or the external load is connected to the second charging interface of each multilevel charging and discharging device.

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