A multi-voltage platform automatic switching circuit and a control driving circuit

Abstract

The application discloses a multi-voltage platform automatic switching circuit and a control driving circuit. The automatic switching circuit comprises a power module for providing electric energy; a multi-path DC / DC conversion module for converting a direct-current voltage of the power module into multi-path direct-current outputs of different levels; an automatic switching and control module comprising a switch network matrix connected with the multi-path direct-current outputs, different types of switches in the switch network matrix being used to automatically control each path of the direct-current outputs, so that total voltage output is switched between different voltage working modes; and a load module comprising a power terminal powered by the total voltage. The application solves the problems of the existing multi-grade direct-current voltage output platform, such as difficult selection, high cost, single function, and low switching reliability.

Description

Technical Field

[0001] This application relates to the field of power control, and in particular to an automatic switching circuit and control drive circuit for multiple voltage platforms. Background Technology

[0002] Currently, there are generally three main solutions used in commercially available energy storage battery systems to obtain a multi-level DC voltage output platform: Option 1 involves configuring n battery clusters and connecting them in series with multiple switches to achieve the required highest voltage platform. The total voltage platform of the battery system is adjusted by gradually increasing or decreasing the number of switches in series, which is an n-level voltage platform. Option 2 involves configuring a battery cluster and an unconventional DC / DC converter connected in series. The unconventional DC / DC converter then boosts or bucks the battery cluster to achieve the required voltage platform. Option 3 involves configuring a battery cluster and n conventional DC / DC converters. The input of each DC / DC converter is connected to the battery cluster, and the positive and negative terminals of the output are connected in series through a switch to form a high-voltage output.

[0003] Option 1 has the following main drawbacks: it requires a large number of batteries, resulting in high costs, especially for lithium-ion battery clusters, where the price of a single cluster is relatively high; it can lead to uneven performance among the n battery clusters, causing battery consistency issues, i.e., when the voltage shifts, some battery clusters are separated from the circuit (not participating in the discharge operation), and their lifespan will be inconsistent with that of the online battery clusters, and the difference will become greater and greater as the number of charge and discharge cycles increases.

[0004] Option 2 has the following main drawbacks: difficulty in selection, conventional DC / DC boost voltage limits are all within 1500V, making it difficult to meet the needs of higher voltage platforms (such as above 2000Vdc); customized models are costly and have the drawback of being unable to meet the requirements of high voltage and instantaneous high current in parallel (limited output power, which leads to a decrease in output current capability when the voltage increases), and their size is unconventional, resulting in low utilization of installation space.

[0005] Scheme 3 has the following main shortcomings: it simply controls the on and off of various switches through software, resulting in low reliability of voltage platform switching. It lacks hardware-level safety and reliability design, and is prone to major problems such as abnormal short circuits and abnormal open circuits during the switching process. In severe cases, it may cause large-scale damage to the system or casualties. It also has few voltage switching levels, generally two levels, namely single voltage and n times voltage, lacking levels in the range of 2 times to n-1 times. Summary of the Invention

[0006] The purpose of this application is to provide an automatic switching circuit and control drive circuit for multiple voltage platforms, which can solve many problems of existing multi-level DC voltage output platforms, such as difficulty in selection, high cost, single function, and low switching reliability.

[0007] In a first aspect, embodiments of this application provide an automatic switching circuit for multiple voltage platforms, the circuit comprising: The power module is used to provide electrical energy; A multi-channel DC / DC converter module is used to convert the DC voltage of the power supply module into multiple DC outputs of different levels; The automatic switching and control module includes a switch network matrix connected to the multiple DC outputs. The switch network matrix automatically controls each DC output through different types of switches to switch the total output voltage between different voltage operating modes. The load module includes a power terminal powered by the total voltage.

[0008] In some possible embodiments, the circuit further includes: A charger, connected in parallel with the power terminal, is used to provide a reverse charging voltage for the power module.

[0009] In some possible embodiments, the multi-channel DC / DC converter module includes n parallel front-end branches, wherein: Each front-end branch includes a DC / DC converter. The input of each DC / DC converter is connected to the power module, and the output is connected in reverse parallel to a diode and in series with a branch switch.

[0010] In some possible embodiments, the multiplexed DC / DC converter module further includes: A capacitor bank is connected in parallel at the output of each DC / DC converter.

[0011] In some possible embodiments, the switch network matrix includes switches of the following types: n serial circuit breakers, n interlocking contactors, n-1 serial contactors, and n-1 parallel circuit breakers; wherein: The input terminals of n serial circuit breakers are connected in series with n DC outputs one-to-one; The main contacts of n interlocking contactors are connected in parallel one-to-one with the output terminals of n serial circuit breakers; The main contacts of any serial contactor are connected in series with the main contacts of two adjacent interlocking contactors, one end at a time. The positive and negative terminals of the input and output terminals of any parallel circuit breaker are connected in parallel one-to-one with the positive and negative terminals of the two adjacent DC outputs.

[0012] In some possible embodiments, each DC / DC converter output in the multi-channel DC / DC converter module is connected in series with a branch switch. The branch switch, interlock contactor, and serial contactor each include a corresponding normally open state feedback contact. When the branch switch, interlock contactor, and serial contactor are closed, the corresponding normally open state feedback contact is normally closed to form a self-locking mode.

[0013] The interlocking contactor, serial contactor, serial circuit breaker, and parallel circuit breaker each include a corresponding normally closed contact for status feedback. When the serial circuit breaker is closed, the normally closed contact of the state feedback of the interlocking contactor that has an interlocking relationship with the serial circuit breaker is normally closed, forming an interlocking mode between the serial circuit breaker and the interlocking contactor. When the interlock contactor is closed, the normally closed contact of the status feedback of the series circuit breaker that has an interlock relationship with the interlock contactor is normally closed, forming an interlock mode between the interlock contactor and the series circuit breaker. When the serial contactor is closed, the normally closed contact of the state feedback of the parallel circuit breaker, which is interlocked with the serial contactor, is normally closed, forming an interlocking mode between the serial contactor and the parallel circuit breaker. When the parallel circuit breaker is closed, the normally closed contact of the state feedback of the serial contactor, which is interlocked with the parallel circuit breaker, is normally closed, forming an interlocking mode between the parallel circuit breaker and the serial contactor.

[0014] In some possible embodiments, the n serial circuit breakers each include a corresponding first shunt coil, and by simultaneously energizing or de-energizing the first shunt coils, a synchronous mode in which the n serial circuit breakers are simultaneously turned on or off is formed. The n-1 parallel circuit breakers each include a corresponding second shunt coil. By simultaneously energizing or de-energizing the second shunt coils, a synchronous mode is formed in which the n-1 serial circuit breakers are simultaneously turned on or off.

[0015] In some possible embodiments, the serial circuit breaker and the interlocking contactor that are connected are interlocked. The serial contactor and the parallel circuit breaker that are connected to the adjacent front-end branch are interlocked. Secondly, embodiments of this application provide a control drive circuit, including... The control unit is used to control the multiple DC / DC conversion modules to perform DC voltage conversion, and to control the switches in the switch network matrix through various control branches; Multiple control branches are provided, and any one type of control branch is connected to a switch of a certain type in the switch network matrix. Any one type of control branch is used to automatically control the DC outputs of the multi-channel DC / DC converter module by controlling the on / off state of the corresponding type of switch, so that the total output voltage switches between different voltage operating modes.

[0016] In some possible embodiments, the multiple control branches include: The first type of control branch is used to control the on / off state of n branch switches respectively; the second type of control branch is used to control the on / off state of n interlock contactors respectively; the third type of control branch is used to control the on / off state of n-1 serial contactors respectively; the fourth type of control branch is used to control the on / off state of n serial circuit breakers respectively; the fifth type of control branch is used to control the on / off state of n-1 parallel circuit breakers respectively; the sixth type of control branch is used to simultaneously control the de-energization of n serial circuit breakers; and the seventh type of control branch is used to simultaneously control the de-energization of n-1 parallel circuit breakers. The control interface of any switch is connected to the corresponding branch of one type of control branch, and the branch is connected upward to the control port of the control unit and downward to the ground terminal of the control unit.

[0017] In some possible embodiments, any one of the first type of control branch, the second type of control branch, and the third type of control branch includes a primary branch. Each primary branch is connected in series with the control interface of the corresponding switch and two secondary branches. One of the secondary branches is connected to the control port of the control unit, and the other secondary branch is connected in series with the normally open contact of the status feedback of the corresponding switch and then connected to the power supply terminal of the control unit.

[0018] In some possible embodiments, any one of the second, third, fourth, and fifth type control branches includes a primary branch, and each primary branch is connected in series with the control interface of the corresponding switch and the normally closed contact of the state feedback of the switch that is interlocked with the switch.

[0019] In some possible embodiments, both the sixth and seventh type control branches include two primary branches. One primary branch is connected in series with the control coil of an intermediate relay and then connected upward to the control port of the control unit and downward to the ground terminal of the control unit. The other primary branch is connected upward to the power supply terminal of the control unit and downward to the main contact of an intermediate relay and multiple secondary branches. One of the secondary branches is connected in series with the shunt coil of the corresponding switch and then downward to the ground terminal of the control unit.

[0020] In some possible embodiments, the control unit is a programmable controller and is powered by an external power source or drawn from a battery pack via a switch. The power supply port of the control unit consists of a power supply terminal and a ground terminal.

[0021] In some possible embodiments, the different voltage operating modes may include any one or more of the following operating modes: A series output mode where at least one DC output is connected in series among multiple DC outputs; Parallel mode of output after at least one DC output is connected in parallel in a multi-channel DC output; A mixed-connection mode in which k DC outputs are connected in parallel and then connected in series, where k are positive integers greater than 1 and not greater than n, and n is the total number of DC outputs.

[0022] In some possible embodiments, the control unit first controls all switches to be in the off state, and after determining the target switch to be turned on in the current voltage operating mode, it turns on the target switch through corresponding multiple control branches according to the following turn-on sequence for different types of switches: Serial circuit breaker, parallel circuit breaker, serial contactor, interlocking contactor, branch switch.

[0023] The multi-channel DC / DC converter module in the automatic switching circuit of the multi-voltage platform in this application converts the DC voltage of the power supply module into DC outputs of different levels; the automatic switching and control module automatically controls the connection and disconnection of each DC / DC output, realizing automatic switching of different voltages, and truly solving many problems of existing multi-level DC voltage output platforms such as difficulty in selection, high cost, single function, and low switching reliability.

[0024] Other features and advantages of this application will be set forth in the description which follows, 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

[0025] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of an automatic switching circuit for multiple voltage platforms provided in an embodiment of this application; Figure 2 A schematic diagram of an automatic switching circuit for multiple voltage platforms when n is 3, provided in an embodiment of this application; Figure 3A This is a schematic diagram of the control drive circuit provided in an embodiment of this application; Figure 3B This is a schematic diagram of the control unit pins in the control drive circuit provided in the embodiments of this application; Figure 4 This is a schematic diagram illustrating the reliability design of the control drive circuit in an embodiment of this application; Figure 5 This is a schematic diagram of the equivalent circuit corresponding to the third voltage level in the series mode of the multi-voltage operation mode in the embodiments of this application; Figure 6 This is a schematic diagram of the equivalent circuit corresponding to the second voltage level in the series mode of the multi-voltage operation mode in the embodiments of this application; Figure 7 This is a schematic diagram of the equivalent circuit corresponding to the first voltage level in the series mode of the multi-voltage operation in the embodiments of this application; Figure 8 This is a schematic diagram of the equivalent circuit corresponding to the third voltage level in the parallel mode of the multi-voltage operation mode in the embodiments of this application; Figure 9 This is a schematic diagram of the equivalent circuit corresponding to the second voltage level in the parallel mode of the multi-voltage operation mode in the embodiments of this application; Figure 10 This is a diagram of the electrical main circuit architecture of the hybrid mode in the embodiments of this application; Figure 11 This is a schematic diagram of the equivalent circuit corresponding to the mixed-connection mode of the multi-voltage operating mode in the embodiments of this application; Figure 12 This is a schematic diagram of the smallest unit of electrical energy output as exemplified in the embodiments of this application; Figure 13 This is a schematic diagram illustrating voltage decomposition as exemplified in an embodiment of this application; Figure 14 This is a schematic diagram illustrating current decomposition as exemplified in an embodiment of this application; Figure 15 This is a schematic diagram of the independent discharge output of a small-capacity supercapacitor bank in an embodiment of this application. Detailed Implementation

[0027] To further illustrate the technical solutions provided in the embodiments of this application, a detailed description is provided below in conjunction with the accompanying drawings and specific implementation methods. Although the embodiments of this application provide method operation steps as shown in the following embodiments or drawings, more or fewer operation steps may be included in the method based on conventional or non-inventive effort. For steps that do not logically have a necessary causal relationship, the execution order of these steps is not limited to the execution order provided in the embodiments of this application. In actual processing or when the control device executes the method, it may be executed sequentially or in parallel according to the method shown in the embodiments or drawings.

[0028] In view of the many problems existing in the related technologies, such as difficulty in selection, high cost, single function and low switching reliability of multi-voltage output platforms, this application proposes an automatic switching circuit and control drive circuit for multi-voltage platforms.

[0029] Other features and advantages of this application will be set forth in the description which follows, 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.

[0030] The automatic switching circuit and control drive circuit of the multi-voltage platform in the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0031] like Figure 1 As shown in the figure, this application embodiment provides a multi-voltage platform automatic switching circuit, the circuit including: The power module 10 is used to provide electrical energy to power the automatic switching circuit of the multi-voltage platform. The power module can be a battery cluster including multiple batteries. The multi-channel DC / DC converter module 20 is used to convert the DC voltage of the power supply module into multiple DC outputs of different levels. The multi-channel DC / DC converter module may include n DC / DC converters, where n is a positive integer greater than 1. The input terminals of the n DC / DC converters are connected in parallel to form a single input terminal of the automatic switching circuit. In the embodiments of this application, the DC / DC converter may be, but is not limited to, an isolated bidirectional DC / DC converter. The automatic switching and control module 30 includes a switch network matrix connected to the multiple DC outputs. It automatically controls each DC output through different types of switches in the switch network matrix, allowing the total output voltage to switch between different voltage operating modes. The switch matrix network comprises several automatic switches connected in series and parallel to form a switch network matrix. The state of the switches in the switch network matrix can control the on / off state of each DC / DC converter output, thereby controlling whether each DC / DC converter output is powered, and the connection relationship with other powered DC / DC converters when powered. This enables the multi-voltage platform to operate in multiple voltage operating modes. The voltage range operating modes can include: a series mode where at least one DC output from multiple DC outputs is connected in series, i.e., a mode where at least one DC / DC converter from n DC / DC converters is connected in parallel; a parallel mode where at least one DC output from multiple DC outputs is connected in parallel, i.e., a mode where at least one DC / DC converter from n DC / DC converters is connected in parallel; and a mixed mode where every k DC outputs from multiple DC outputs are connected in parallel and then connected in series, i.e., a mode where every k DC / DC converter from n DC / DC converters is connected in parallel and then connected in series, where k are positive integers greater than 1 and not greater than n, and n is the total number of DC outputs. The load module 40 includes a power terminal powered by the total voltage.

[0032] The multi-voltage platform automatic switching circuit provided in this application uses a battery cluster + n conventional DC / DC converters and several automatic switches connected in series and parallel to form a switch network matrix. By controlling the switch network matrix, it operates in multiple voltage working modes and automatically builds the required voltage platform circuit. In addition to satisfying the multi-voltage platform switching function (series mode), the multi-voltage working mode also has the multi-power platform switching function (parallel mode) and the boost and power parallel switching function (hybrid mode), which truly solves many problems of existing multi-voltage DC output platforms, such as difficulty in selection, high cost, single function, and low switching reliability.

[0033] In some possible embodiments, the circuit further includes a charger connected in parallel with the power terminal for providing a reverse charging voltage to the power module.

[0034] The DC / DC converter in this embodiment is an isolated bidirectional DC / DC converter. The multi-voltage platform automatic switching circuit is a bidirectional charging and discharging circuit, meaning it can convert the electrical energy of the battery pack into a specified voltage or power platform to supply power to the load in the forward direction (discharging direction), and can also connect to a charger to charge the battery pack in the reverse direction (charging direction). The following embodiments illustrate the principle and function of the multi-voltage platform automatic switching circuit with the discharging direction as the positive direction, that is, with the end connected to the battery pack as the circuit input terminal and the end connected to the load as the circuit output terminal.

[0035] In related technologies, the high-voltage output platform has poor power stability. That is, under the condition that the output voltage of each DC / DC converter is constant, its output current is prone to deviation and fluctuation, which causes the power of the total voltage platform to vary due to the change of the current limit of a single DC / DC converter. In the embodiment of this application, the multi-channel DC / DC conversion module includes n parallel front-end branches, wherein: each front-end branch includes a DC / DC converter, the input terminal of each DC / DC converter is connected to the power supply module, and the output terminal is respectively connected in reverse parallel to a diode and in series with a branch switch. Then the multi-channel DC / DC conversion module includes n diodes and n branch switches KM1-KMn.

[0036] In some possible embodiments, the multi-channel DC / DC converter module further includes a capacitor bank connected in parallel at the output of each DC / DC converter. This capacitor bank is a small-capacity supercapacitor bank, such as tens of farads. By adding n small-capacity supercapacitor banks, the problems of current instability and difficulty in handling instantaneous high current parallel operation of a single DC / DC converter in series mode are effectively solved.

[0037] The switch network matrix in this embodiment includes switches of the following types: n serial circuit breakers QF11~QFnn, n interlocking contactors KM11~KMnn, n-1 serial contactors KM12~KM(n-1)n, and n-1 parallel circuit breakers QF12~QF(n-1)n; wherein: The input terminals of n serial circuit breakers are connected in series with n DC outputs one-to-one; The main contacts of n interlocking contactors are connected in parallel one-to-one with the output terminals of n serial circuit breakers; The main contacts of any serial contactor are connected in series with the main contacts of two adjacent interlocking contactors, one end at a time. The positive and negative terminals of the input and output terminals of any parallel circuit breaker are connected in parallel one-to-one with the positive and negative terminals of the two adjacent DC outputs.

[0038] like Figure 2As shown, taking n=3 as an example, the actual number is not limited to the number of multi-channel DC / DC converters. The total input terminal of the multi-voltage platform automatic switching circuit provided in this application embodiment is connected to a battery cluster, and the total output terminal is connected to a DC load, charger or other grid-connected object. The main body of the multi-voltage platform automatic switching circuit consists of 3 DC / DC converters, 3 diodes (D1-D3), 3 branch switches (contactors KM1-KM3), 3 small-capacity supercapacitor groups (C1-C3, tens of farads), and the core switch network matrix (several control switches connected in series and parallel). The switch network matrix consists of 3 serial circuit breakers (QF11 / QF22 / QF33), 3 interlocking contactors (KM11 / KM22 / KM33), 2 serial contactors (KM12 / KM23), and 2 parallel circuit breakers (QF12 / QF23).

[0039] The electrical connection relationships of all components in the multi-voltage platform automatic switching circuit provided in this application embodiment are as follows: 1. Main Input Terminal The input terminals of n DC / DC converters are connected in parallel to form a single circuit, which constitutes the total input terminal of the multi-voltage platform automatic switching circuit.

[0040] 2. Front-end branch

[0041] Each DC / DC converter output is independent and has no common ground relationship with each other (floating ground design), and is independently connected to other components; each DC / DC converter output is connected in reverse parallel with a diode and in series with a branch switch, and then connected in parallel with a small-capacity supercapacitor bank to form the front-end branch.

[0042] 3. Main output terminal

[0043] The switching network matrix has n (e.g., 3) input terminals and 1 output terminal. The n input terminals are connected one-to-one with the n front-end branches, and the 1 output terminal is the total output terminal of the automatic switching circuit, which is connected to the DC grid bus. 4. Switch combination In the front-end branch, the input terminals of n branch switches are connected in series with n front-end branches one-to-one. The internal component connection relationship of the switch network matrix is ​​as follows: the main contacts (A+ / A-) of n interlocking contactors are connected in parallel with the output terminals (+ / -) of n serial circuit breakers one-to-one; the main contacts (A+ / A-) of n-1 serial contactors are connected in series with the main contacts (A+ / A-) of n interlocking contactors end-to-end; and the positive and negative terminals of the input and output terminals of n-1 parallel circuit breakers are connected in parallel with the positive and negative terminals of n front-end branches one-to-one.

[0044] The component selection requirements and functional descriptions for the multi-voltage platform automatic switching circuit used in this application embodiment are as follows: n-channel DC / DC converters (exemplary, DC / DC1-DC / DC3) ): It can provide power of kW or above, with the low-voltage side voltage range matching the upper and lower limits of the battery cluster voltage, and the high-voltage side voltage range matching the operating voltage platform. It is bidirectional, enabling the conversion of electrical energy between two directions; It has electrical isolation function, completely isolating the input and output terminals from the potential relationship; It has communication and interaction functions, and can receive command data from various controllers and make timely responses such as voltage or power adjustment.

[0045] Diodes (D1-D3, for example): The reverse protection diode is used to conduct when a reverse electromotive force spike occurs at the output of the DC / DC converter, providing a path for reverse current and preventing damage to the device.

[0046] Small-capacity supercapacitor banks (exemplary, C1-C3): It features high power density and fast charging and discharging speed. It can be connected in parallel with the output of a DC / DC converter to provide complementary power output, handle small-capacity power regulation, and improve the output power stability of the DC / DC converter. It is capable of high-power pulse discharge applications by disconnecting the branch switch or closing the branch switch in conjunction with the DC / DC converter after being fully charged.

[0047] Branch switches KM1-KMn (exemplarily, KM1-KM3): It has one control interface (specifically a control coil) and one normally open contact for status feedback. Its current carrying capacity and withstand voltage meet the requirements of all circuit operating modes. The control circuit connects and disconnects the DC / DC converter on the branch from the circuit network, synchronously realizing the parallel output of the DC / DC converter and the supercapacitor bank or the independent output of the supercapacitor bank.

[0048] Serial circuit breakers QF11~QFnn (exemplary, QF11 / QF22 / QF33): It has one control interface (specifically, electric operation opening and closing control, including the closing coil), one shunt trip control (including the shunt coil) and one status feedback normally closed contact, and its current carrying capacity and withstand voltage meet the requirements of all circuit operating modes. The switching states of the serial contactors are interlocked. Taking KM11 and QF11 as an example, when KM11 is closed, QF11 is open, and when QF11 is closed, KM11 is open. The two can be open at the same time but cannot be turned on at the same time to prevent abnormal short circuits during circuit switching. When used in conjunction with interlocking contactors, serial contactors, and parallel circuit breakers, it enables multiple voltage operating modes for switching circuits.

[0049] Interlocking contactors KM11~KMnn (exemplary, KM11 / KM22 / KM33): It has one control interface (specifically a control coil), one normally open status feedback contact, and one normally closed status feedback contact. Its current carrying capacity and withstand voltage meet the requirements of all circuit operating modes. It forms an interlock relationship with the switching state of the serial circuit breaker; It can be used in conjunction with serial circuit breakers, serial contactors, and parallel circuit breakers to achieve multiple voltage operating modes for switching circuits.

[0050] Serial contactors KM12~KM(n-1)n (exemplary, KM12 / KM23) ) ： It has one control interface (specifically a control coil), one normally open status feedback contact, and one normally closed status feedback contact. Its current carrying capacity and withstand voltage meet the requirements of all circuit operating modes. The switching states of the parallel circuit breakers are interlocked. Taking KM12 and QF12 as an example, when KM12 is closed, QF12 is open, and when QF12 is closed, KM12 is open. The two can be open at the same time but cannot be closed at the same time to prevent abnormal short circuits from occurring during circuit switching. It can be used in conjunction with serial circuit breakers, serial contactors, and parallel circuit breakers to achieve multiple voltage operating modes for switching circuits.

[0051] Parallel circuit breakers QF12~QF(n-1)n (exemplarily, QF12 / QF23): It has one control interface (specifically, electric operation opening and closing control, including the closing coil), one shunt trip control (including the shunt coil) and one status feedback normally closed contact, and its current carrying capacity and withstand voltage meet the requirements of all circuit operating modes. It can be used in conjunction with interlocking contactors, serial contactors, and serial circuit breakers to achieve various operating modes of switching circuits.

[0052] In some possible embodiments, the aforementioned branch switch, interlock contactor, and serial contactor each include a corresponding normally open state feedback contact. When the branch switch, interlock contactor, or serial contactor is closed, the corresponding normally open state feedback contact is normally closed to form a self-locking mode. When any branch switch, interlock contactor, or serial contactor is closed under the control of the control drive circuit, the corresponding normally open state feedback contact is normally closed to prevent the corresponding switch from opening due to instability of the switch closure, thus forming a self-locking mode of the switch.

[0053] In some possible embodiments, the interlocking contactor, serial contactor, serial circuit breaker, and parallel circuit breaker described above each include a corresponding normally closed contact for state feedback, wherein: When the serial circuit breaker is closed, the normally closed contact of the state feedback of the interlocking contactor that has an interlocking relationship with the serial circuit breaker is normally closed, forming an interlocking mode between the serial circuit breaker and the interlocking contactor. When the interlock contactor is closed, the normally closed contact of the status feedback of the series circuit breaker that has an interlock relationship with the interlock contactor is normally closed, forming an interlock mode between the interlock contactor and the series circuit breaker. When the serial contactor is closed, the normally closed contact of the state feedback of the parallel circuit breaker, which is interlocked with the serial contactor, is normally closed, forming an interlocking mode between the serial contactor and the parallel circuit breaker. When the parallel circuit breaker is closed, the normally closed contact of the state feedback of the serial contactor, which is interlocked with the parallel circuit breaker, is normally closed, forming an interlocking mode between the parallel circuit breaker and the serial contactor.

[0054] By designing the normally closed contact of the state feedback of the above-mentioned type of switch, when the switch with which it is interlocked is closed, the corresponding normally closed contact of the state feedback is closed, thereby keeping the switch in the normally open state and thus forming an interlocking mode.

[0055] In some possible embodiments, each of the n serial circuit breakers includes a corresponding first shunt coil. Simultaneous energizing or de-energizing of these first shunt coils creates a synchronous mode where the n serial circuit breakers are simultaneously switched on or off. Similarly, each of the n-1 parallel circuit breakers includes a corresponding second shunt coil. Simultaneous energizing or de-energizing of these second shunt coils also creates a synchronous mode where the n-1 serial circuit breakers are simultaneously switched on or off. By simultaneously switching the corresponding switches on or off in the synchronous mode, rapid de-energizing of both the serial and parallel circuit breakers can be achieved.

[0056] In some possible embodiments, the serial circuit breaker and the interlocking contactor that are connected are interlocked; the serial contactor and the parallel circuit breaker that are connected to an adjacent front-end branch are interlocked. As mentioned above, both can be disconnected simultaneously but cannot be connected simultaneously to prevent abnormal short circuits during circuit switching.

[0057] Based on the multi-voltage platform automatic switching circuit provided in the embodiments of this application, a control drive circuit for controlling the above-mentioned multi-voltage platform automatic switching circuit is provided, such as... Figure 3A and Figure 3B As shown, the circuit includes: The control unit 301 is used to control the multi-channel DC / DC conversion module to perform DC voltage conversion, and to control the switches in the switch network matrix through multiple control branches. The control unit can communicate with n DC / DC converters in the multi-channel DC / DC conversion module through multiple communication ports, and issue control commands through the communication ports to control the DC / DC converters to perform DC voltage conversion. It is also connected to multiple control branches through multiple control ports, and controls the switching on or off of the switches in the switch network matrix through the high and low levels output by the control ports. The control unit is a programmable controller (PLC or microcontroller, etc.) with a certain number of communication ports and control ports. It can be powered by an external power supply or by drawing power from the battery pack in the power module through a switch. Its power supply port is composed of a power supply terminal and a ground terminal (common terminal). Multiple control branches 302, any type of control branch connects to a type of switch in the switch network matrix, any type of control branch is used to automatically control the DC outputs of the multi-channel DC / DC converter module by controlling the on and off of the corresponding type of switch, so that the total output voltage switches between different voltage operating modes.

[0058] As mentioned earlier, multiple control branches are used to control the following types of switches: branch switches, serial circuit breakers, interlocking contactors, serial contactors, and parallel circuit breakers. Each type of switch has a control interface (control coil, closing coil, shunt coil) and status feedback contacts (normally closed contact NC or normally open contact NO). Figure 2 The bidirectional DC / DC converters used in this system all have communication interfaces, and these interfaces are compatible with... Figure 3A and Figure 3B The central control unit and control branch are matched and connected. Figure 3B The control unit's multiple communication ports are respectively connected to Figure 2 All bidirectional DC / DC converters in the system are connected and communicate with each other. Through communication, voltage or power adjustment commands are issued. Each DC / DC converter receives the command and responds quickly and converts the output power to the specified voltage platform. Figure 3B The control unit's multi-channel control port / power supply port are respectively connected to Figure 2 All the control branches of the switches are connected, and the high and low level states of each control port are controlled by the built-in software program, thereby driving the various control coils, closing coils and shunt coils on the control branches to go up and down, so as to realize the switching action.

[0059] In some possible embodiments, the multiple control branches include: The first type of control branch is used to control the on / off state of n branch switches respectively; The second type of control branch is used to control the on / off state of n interlocking contactors respectively; A third type of control branch used to control the on / off state of n-1 serial contactors respectively; A fourth type of control branch used to control the on / off state of n serial circuit breakers respectively; The fifth type of control branch is used to control the opening and closing of n-1 parallel circuit breakers respectively; The sixth type of control branch is used to simultaneously control the power outage of n serial circuit breakers, thereby achieving rapid power outage when n serial circuit breakers malfunction. The seventh type of control branch is used to simultaneously control the power outage of n-1 parallel circuit breakers, thereby achieving rapid power outage when n-1 parallel circuit breakers malfunction. The control interface of any switch is connected to the corresponding branch of one type of control branch, and the branch is connected upward to the control port of the control unit and downward to the ground terminal of the control unit.

[0060] like Figure 3A The diagram shows the control drive circuit when n is 3.

[0061] The reliability design of the control drive circuit in this application focuses on the hardware level, and the following reliability design is mainly implemented at the hardware level.

[0062] While controlling the on / off states of branch switches, interlocking contactors, and serial contactors through the first, second, and third type control branches, a self-locking mode can also be achieved through the combination of self-locking switches on the control branches. In some possible embodiments, any one of the first, second, and third type control branches includes a primary branch. Each primary branch is connected in series with the control interface of the corresponding switch and two secondary branches. One of the secondary branches is connected to the control port of the control unit, and the other secondary branch is connected in series with the normally open contact of the status feedback of the corresponding switch and then connected to the power supply terminal of the control unit.

[0063] In the embodiments of this application, the devices that act as self-locking switches include normally open contacts for state feedback of branch switches (such as...). Figure 3A KM1_NO / KM2_NO / KM3_NO), the normally open contact of the interlock contactor's status feedback (such as...) Figure 3A KM11_NO / KM22_NO / KM33_NO), the normally open contact of the serial contactor's status feedback (such as KM11_NO / KM22_NO / KM33_NO), and the normally open contact of the serial contactor's status feedback (such as KM11_NO / KM22_NO / KM33_NO). Figure 3A (KM12_NO / KM23_NO in the data), see the specific distribution location. Figure 4 The solid coil markings.

[0064] The self-locking switch design is primarily implemented for contactor-type switches. The working mechanism of contactor-type control switches involves applying a driving voltage to the control coil to activate the main contacts via a single-pole operation. This driving voltage typically originates from the control level generated by the control port of the control unit. However, unstable driving levels can cause the contactor's main contacts to disconnect, leading to abnormal circuit breakage. To avoid this type of fault, this embodiment adds a secondary branch to the control coil drive branch of the contactor-type control switch. This secondary branch connects the normally open contact of the contactor's status feedback in series and is connected upwards to the power supply terminal of the control unit. This creates a redundant design where two secondary branches simultaneously drive the contactor coil.

[0065] Taking the branch containing the KM1 control coil in the first type of control branch as an example, this branch has two secondary branches. The first secondary branch is directly connected to the control port, and the second secondary branch is connected to the power supply end after being connected in series with the normally open contact KM1_NO of KM1's status feedback. In this way, KM1 can first achieve the conduction of KM1's main contact (the first secondary branch) through the driving level of the control port, and simultaneously close its normally open contact KM1_NO of its status feedback, forming the conduction of the second secondary branch. In this way, when the first secondary branch becomes unstable, the second secondary branch can serve as a substitute, greatly improving the stability of the switch conduction.

[0066] It should be noted that circuit breaker-type control switches have an internal locking structure. After the closing coil is turned on, the position of the double-pole main contacts will be locked, preventing the contact from disengaging due to unstable coil drive.

[0067] In this embodiment, the second, third, fourth, and fifth control branches not only control the on / off states of interlocked contactors, serial contactors, serial circuit breakers, and parallel circuit breakers, but also enable a self-locking mode through combinations of interlocked switches on the control branches. In some possible embodiments, any one of the second, third, fourth, and fifth control branches includes a primary branch, and each primary branch is connected in series with the control interface of the corresponding switch and the normally closed contact of the switch that has an interlocking relationship with the switch.

[0068] In the embodiments of this application, the devices that act as interlocking switches include the normally closed contacts of the serial circuit breaker (such as...). Figure 3A The normally closed contacts of the interlock contactors (such as QF11_NC / QF22_NC / QF33_NC) and the status feedback contacts of the interlock contactors (e.g.) Figure 3A KM11_NC / KM22_NC / KM33_NC in the circuit breaker), the normally closed contact of the status feedback of the parallel circuit breaker (such as KM11_NC / KM22_NC / KM33_NC in the circuit breaker), and the status feedback contact of the parallel circuit breaker (such as KM11_NC / KM22_NC / KM33_NC in the circuit breaker). Figure 3A KM12_NC / KM23_NC), the normally closed contact of the serial contactor's status feedback (such as KM12_NC / KM23_NC), and the normally closed contact of the serial contactor's status feedback (such as KM12_NC / KM23_NC). Figure 3A (KM12_NC / KM23 in the data), see the specific distribution location. Figure 4 The part marked with a dashed circle.

[0069] This application embodiment forms two sets of interlocking combinations: one set is the interlocking between the serial circuit breaker and the interlocking contactor; the other set is the interlocking between the parallel circuit breaker and the serial contactor. The specific interlocking mechanism is as follows: Taking the control coil branch of the second type of control branch KM1 and the closing coil branch of the fourth type of control branch QF11 as examples, the normally closed state feedback contact QF11_NC of QF11 is connected in series on the first-level branch where the control coil of KM11 is located, and the normally closed state feedback contact KM11_NC of KM11 is connected in series on the first-level branch where the closing coil of QF11 is located. This ensures that the branch where the closing coil of QF11 is located can only be turned on when KM11 is in the open state (KM11_NC is closed) (the closing coil energizes QF11 to turn on). Similarly, the branch where the control coil of KM11 is located can only be turned on when QF11 is in the open state (QF11_NC is closed) (the control coil energizes KM11 to turn on). The two can be turned off at the same time but cannot be turned on at the same time. The premise for one to be turned on is that the other is turned off.

[0070] The above interlocking design can prevent electrical short circuits caused by the simultaneous conduction of the serial circuit breaker and the interlocking contactor when switching circuits at the hardware level. Then, the same interlocking design is implemented at the software level (the control unit detects the status of all switches and sets the switch logic interlock). This achieves dual interlocking function of hardware and software, maximizing reliability.

[0071] In this application embodiment, for the sixth and seventh type control branches, a synchronous switch combination design on the control branches is used to achieve a synchronous mode for the rapid power-off of serial circuit breakers and parallel circuit breakers. As mentioned above, both serial and parallel circuit breakers include shunt coils. Both the sixth and seventh type control branches include two primary branches. One primary branch is connected in series with the control coil of an intermediate relay and then connected upwards to the control port of the control unit and downwards to the ground terminal of the control unit. The other primary branch is connected upwards to the power supply terminal of the control unit and downwards in series with the main contact of an intermediate relay and multiple secondary branches. One of the secondary branches is connected in series with the shunt coil of the corresponding switch and then downwards to the ground terminal of the control unit.

[0072] The devices that act as synchronous switches are mainly intermediate relays KA1 / KA2. The explanation of intermediate relays KA1 / KA2 is as follows: It has one control coil, whose current carrying capacity and withstand voltage meet the requirements of all circuit operating modes; Simultaneously, the shunt coils in the multi-channel shunt trip control are energized synchronously to achieve synchronous operation of all series or parallel circuit breakers, preventing unbalanced distribution of cutting current or cutting voltage caused by large operating time differences (the latter operating with lag is subject to overload current or overload voltage, affecting its lifespan).

[0073] For the specific distribution locations of intermediate relays KA1 / KA2, please refer to [link / reference]. Figure 4In the section with dual coil markings, the main contacts of KA1 are connected in series in the main circuit of the branch containing the shunt coils of the three series circuit breakers, while the main contacts of KA2 are connected in series in the main circuit of the branch containing the shunt coils of the two parallel circuit breakers. The synchronization mode mechanism is illustrated below, using the control branch containing KA1 as an example: By driving KA1 to conduct through the control port, the shunt coils of the three series circuit breakers can be indirectly energized synchronously. After synchronous energization, the main contacts of the three series circuit breakers are driven to trip synchronously. This avoids the large time difference caused by driving each one individually. The benefit of this is that when the control unit detects a serious fault, it will immediately control all circuit breakers in the circuit to trip under load. The smaller the tripping time difference, the shorter the unbalanced time of the shared current load or voltage load borne by each circuit breaker, and the smaller the impact on the lifespan.

[0074] The following example uses n=3, combined with Figure 3A This application describes the connection relationships of the seven types of control branches provided in its embodiments: 1. Type I control branch The first type of control branch includes three primary branches. Each primary branch is connected in series with the control coil of one branch switch (KM1 / KM2 / KM3) and two secondary branches. One secondary branch is directly connected to the control port of the control unit (control 1 / control 2 / control 3). The other secondary branch is connected in series with the normally open contact of the corresponding branch switch (KM1_NO / KM2_NO / KM3_NO) and then connected to the power supply terminal of the control unit. Each primary branch is connected to the ground terminal of the control unit.

[0075] 2. Second type of control branch

[0076] The second type of control branch includes three primary branches. Each primary branch is connected in series with the control coil of an interlocking contactor (KM11 / KM22 / KM33), a normally closed contact for status feedback of a corresponding serial circuit breaker (QF11_NC / QF22_NC / QF33_NC), and two secondary branches. One secondary branch is directly connected to the control port of the control unit (control 4 / control 5 / control 6). The other secondary branch is connected in series with the normally open contact for status feedback of the corresponding interlocking contactor (KM11_NO / KM22_NO / KM33_NO) and then connected to the power supply terminal of the control unit. Each primary branch is connected to the ground terminal of the control unit.

[0077] 3. Third-class control branch

[0078] The third type of control branch includes two primary branches. Each primary branch is connected in series with the control coil of a serial contactor (KM12 / KM23) + a normally closed contact (QF12_NC / QF23_NC) for status feedback of the corresponding parallel circuit breaker + two secondary branches. One secondary branch is directly connected to the control port (control 7 / control 8) of the control unit. The other secondary branch is connected in series with the normally open contact (KM12_NO / KM23_NO) for status feedback of the corresponding serial contactor and then connected to the power supply terminal of the control unit. Each primary branch is connected to the ground terminal of the control unit.

[0079] 4. Category IV control branch

[0080] The fourth type of control branch includes three primary branches. Each primary branch is connected in series with the closing coil of a serial circuit breaker (QF11 / QF22 / QF33) and the status feedback normally closed contact of a corresponding interlock contactor (KM11_NC / KM22_NC / KM33_NC). Each primary branch is directly connected to the control port of the control unit (control 9 / control 10 / control 11) and the grounding terminal of the control unit.

[0081] 5. Fifth type of control branch

[0082] The fifth type of control branch includes two primary branches. Each primary branch is connected in series with the closing coil of a parallel circuit breaker (QF12 / QF23) and the normally closed contact of the corresponding serial contactor (KM12_NC / KM23_NC). Each primary branch is directly connected to the control port (control 12 / control 13) of the control unit and to the grounding terminal of the control unit.

[0083] 6. Category 6 control branch

[0084] The sixth type of control branch includes two primary branches. One primary branch connects upward to the control port (control 14) of the control unit, the control coil of an intermediate relay (KA1) connected in series, and downward to the grounding terminal of the control unit. The other primary branch connects upward to the power supply terminal of the control unit, the main contact of an intermediate relay (KA1) connected in series, and connects to three secondary branches. Each secondary branch connects in series with the shunt coil of a series circuit breaker (QF11 / QF22 / QF33) and downward to the grounding terminal of the control unit.

[0085] 7. Category 7 control branch

[0086] The seventh type of control branch includes two primary branches. One primary branch connects upward to the control port (control 15) of the control unit, the control coil of an intermediate relay (KA2) connected in series, and downward to the grounding terminal of the control unit. The other primary branch connects upward to the power supply terminal of the control unit, the main contact of an intermediate relay (KA2) connected in series, and connects to two secondary branches. Each secondary branch connects in series with the shunt coil of a parallel circuit breaker (QF12 / QF23) and downward to the grounding terminal of the control unit.

[0087] The control unit in this embodiment has multiple communication ports, multiple control ports, and a human-machine interface, and has software programming and program upgrade functions; it has on-site interface operation input or background remote communication input (the specific input form is not limited), and executes switching of multiple voltage platform working modes, including at least one of series mode, parallel mode and mixed mode.

[0088] In some possible embodiments, the multi-voltage operating modes implemented by the control unit controlling the switch combination via a control port include: A series output mode where at least one DC output is connected in series among multiple DC outputs; Parallel mode of output after at least one DC output is connected in parallel in a multi-channel DC output; A mixed-connection mode in which k DC outputs are connected in parallel and then connected in series, where k are positive integers greater than 1 and not greater than n, and n is the total number of DC outputs.

[0089] In order to safely switch to the multi-voltage platform operating mode, when the control unit controls the switch by outputting a high or low level through the control port, it first controls all switches to be in the off state, and after determining the target switch to be turned on in the current voltage operating mode, it turns on the target switch through the corresponding multi-type control branches according to the following turn-on sequence for different types of switches: Serial circuit breaker, parallel circuit breaker, serial contactor, interlocking contactor, branch switch.

[0090] The following uses n as an example to illustrate the functional mechanism of the control unit of this application in controlling the automatic switching circuit of multiple voltage platforms to realize the above three working modes: 1. Series mode This mode is based on the electrical isolation characteristics (no potential relationship) of the inputs and outputs of the three selected DC / DC converters, which allows the positive and negative terminals of their outputs to be connected in series without causing an electrical short circuit. Based on this, by controlling the on / off combinations of four types of switches (serial contactor, interlocking contactor, serial circuit breaker, and parallel circuit breaker) in the switch network matrix, a three-level boost function of the switching circuit can be achieved.

[0091] Series mode, third gear: ① First, control all switches to be in the open state; ② Then, control the three series circuit breakers to conduct sequentially (QF11 conducts + QF22 conducts + QF33 conducts) and the two series contactors to conduct sequentially (KM12 conducts + KM23 conducts); ③ Finally, control the three branch switches to conduct sequentially (KM1 conducts + KM2 conducts + KM3 conducts); At this point, the third gear boost circuit is complete. The specific equivalent circuit is as follows... Figure 5 As shown, the achieved overall boost ratio coefficient is k 3 Its functional mechanism is as follows: Voltage (i.e., battery cluster voltage). These are the input voltages of the three DC / DC converters, and α, β, and γ are the boost ratio coefficients of the three DC / DC converters, respectively.

[0092] ; Total output voltage These are the output voltages of the three DC / DC converters. It is the total boost ratio coefficient of the switching circuit, the sum of the boost ratio coefficients of the three DC / DC converters, and the highest boost ratio of the automatic switching circuit.

[0093] Series mode, second stage: ① First, control all switches to be in the open state; ② Then, control the two series circuit breakers to conduct sequentially (QF11 conducts + QF22 conducts), the two series contactors to conduct sequentially (KM12 conducts + KM23 conducts), and the one interlock contactor to conduct (KM33 conducts); ③ Finally, control the two branch switches to conduct (KM1 conducts + KM2 conducts); At this point, the second stage boost circuit is complete. The specific equivalent circuit is as follows... Figure 6 As shown, the achieved boost ratio coefficient is Its functional mechanism is as follows: ; Total output voltage These are the output voltages of the three DC / DC converters. It is the total boost ratio coefficient of the automatic switching circuit, which is the sum of the boost ratio coefficients of the two DC / DC converters. It is not limited to the combination of DC / DC1 converter and DC / DC2 converter. The automatic switching circuit can realize any combination of two DC / DC converters.

[0094] Series mode, first gear: ① First, control all switches to be in the open state; ② Then, control one series circuit breaker to be turned on (QF11 turned on), two series contactors to be turned on sequentially (KM12 turned on + KM23 turned on), and two interlock contactors to be turned on sequentially (KM22 turned on + KM33 turned on); ③ Finally, control one branch switch (KM1) to be turned on; at this point, the third gear boost circuit is complete. The specific equivalent circuit is as follows: Figure 7 As shown, the achieved boost ratio coefficient is k 1 Its functional mechanism is as follows: This is the branch output current of the DC / DC1 converter (in conjunction with a supercapacitor bank). The total output power of the automatic switching circuit is equal to the branch output power of the DC / DC1 converter. : ; First-gear boost ratio k 1 It is equal to the boost ratio coefficient of one of the DC / DC converters, not limited to DC / DC1. The automatic switching circuit can realize the individual output voltage of any one DC / DC converter, and it is the lowest boost ratio of the automatic switching circuit.

[0095] 2. Parallel mode

[0096] This mode is based on the fact that the three selected DC / DC converters have output voltage regulation function. According to the voltage regulation command issued by the control unit, the three DC / DC converters must output the same voltage value before the positive and negative terminals of the output terminals can be connected in parallel to achieve the parallel function. This prevents the phenomenon of large circulating current caused by voltage difference between them, which can easily damage the components in the circuit.

[0097] Based on this, by controlling the on / off combinations of the four types of switches (serial contactor, interlocking contactor, serial circuit breaker and parallel circuit breaker) in the switch network matrix, the three-level power capacity function of the automatic switching circuit can be realized.

[0098] Parallel mode, third gear: ① First, control all switches to be in the open state; ② Then, control the two series circuit breakers to conduct sequentially (QF11 conducts + QF33 conducts) and the two parallel circuit breakers to conduct sequentially (QF12 conducts + QF23 conducts); ③ Finally, control the three branch switches to conduct sequentially (KM1 conducts + KM2 conducts + KM3 conducts); At this point, the third gear power-up circuit is complete. The specific equivalent circuit is as follows... Figure 8 As shown, the achieved power-up capacity is Its functional mechanism is as follows: These are the output currents of the branches containing the three DC / DC converters (in conjunction with the supercapacitor bank). These are the output power of the branches where the three DC / DC converters are located.

[0099] The total output power is the sum of the branch output power of the three DC / DC converters, and it is the highest power setting of the automatic switching circuit.

[0100] Parallel mode, second gear: ① First, control all switches to be in the open state; ② Then, control the two series circuit breakers to turn on sequentially (QF11 turns on + QF22 turns on), one parallel circuit breaker to turn on (QF12 turns on), one series contactor to turn on (KM23 turns on), and one interlocking contactor to turn on (KM33 turns on); ③ Finally, control the two branch switches to turn on (KM1 turns on + KM2 turns on); At this point, the second gear power-up circuit is complete. The specific equivalent circuit is as follows... Figure 9 As shown, the achieved power-up capacity is Its functional mechanism is as follows: These are the output currents of the branches containing the two DC / DC converters (in conjunction with the supercapacitor bank). These are the output power of the branches containing the two DC / DC converters, respectively.

[0101] ; The total output power is the sum of the branch output power of the two DC / DC converters (in conjunction with the supercapacitor bank), and is not limited to the combination of DC / DC1 converter and DC / DC2 converter. The automatic switching circuit can realize any combination of two DC / DC converters.

[0102] Parallel mode, gear 1: The control switch on / off steps are the same as in serial mode, gear 1, and will not be repeated here. The equivalent circuit is the same as... Figure 7 The circuit shown is the same, and the achieved power boost capacity is... Its functional mechanism is as follows: This is the output current of the branch containing the DC / DC1 converter (in conjunction with a supercapacitor bank). This refers to the output power of the branch containing the DC / DC1 converter. The total output power is equal to the output power of the branch containing one DC / DC converter (with a supercapacitor bank). It is not limited to the DC / DC1 converter. The automatic switching circuit can achieve the power output of any branch containing one DC / DC converter (with a supercapacitor bank). It is the lowest power setting of the automatic switching circuit.

[0103] 3. Hybrid mode

[0104] The functional mechanism of this mode requires the main electrical circuit architecture to be configured with at least n DC / DC converters and their corresponding branches, where n is an even number and greater than 2. Taking n as an example, the main circuit architecture of this hybrid mode is shown below. Figure 10 The mechanism of this mode is based on the electrical isolation characteristics of the input and output terminals of the four DC / DC converters and the function that the output voltage of each DC / DC converter can be independently adjusted. One possible hybrid connection method is to connect two DC / DC converters in parallel first and then two in series. The premise of the two parallel connection is that the output voltages of the two DC / DC converters to be connected in parallel are adjusted to equal voltage. Then, they are connected in parallel to form a series (forming a total of 2 series). The positive and negative terminals of the two series are connected in series and superimposed without electrical short circuits or large circulating currents in the series.

[0105] Based on this, by controlling the on / off combinations of the four types of switches (serial contactor, interlocking contactor, serial circuit breaker, and parallel circuit breaker) in the switch network matrix, a hybrid mode of automatic switching circuits can be achieved, realizing a dual-function boosting of both voltage and power. The switching steps in this mode are as follows: ① First, control all switches to be in the open state; ② Then, control the four serial circuit breakers to turn on sequentially (QF11 + QF22 + QF33 + QF44), the two parallel circuit breakers to turn on sequentially (QF12 + QF34), and the one serial contactor to turn on (KM23); ③ Finally, control the four branch circuit breakers to turn on sequentially (KM1 + KM2 + KM3 + KM4); At this point, the hybrid circuit is complete. The equivalent circuit is as follows: Figure 11 As shown, the achieved boost ratio is k Power capacity per liter is P O Its functional mechanism is as follows: = ; These are the output currents of the branches containing the four DC / DC converters (in conjunction with the supercapacitor bank). These represent the output power of the branches containing the four DC / DC converters.

[0106] Total output power.

[0107] Figure 10 The four configured DC / DC converters and their associated branches can only achieve single-level function in mixed-connection mode. By expanding the number of DC / DC modules and associated branches, multi-level function can also be achieved.

[0108] The reliability design of the switching circuit in this embodiment comes from both hardware and software levels, with an emphasis on hardware. Through the design of circuit interlock switches, self-locking switches, and synchronous switches, the reliability of the three corresponding modes—self-locking mode, interlocking mode, and synchronous mode—is achieved.

[0109] The switching circuit in this embodiment of the application has been designed with a focus on the stability of the output power quality. Its functional mechanism is as follows: 1. Power complementarity of supercapacitor banks The smallest power output unit of the switching circuit in this embodiment is shown below. Figure 12 It mainly consists of a single DC / DC converter and a matching supercapacitor bank connected in parallel. The two work together to provide external power output, with the DC / DC converter providing the primary output and the supercapacitor bank providing the secondary output. ; The above formula assumes that the supercapacitor bank, after being fully charged, coordinates with the DC / DC converter to output power. It is the total output current. , These are the output currents of the branches containing the DC / DC converter and the supercapacitor bank, respectively.

[0110] The benefit of the above circuit design is that it can solve the problem of unstable output power that occurs when relying solely on a DC / DC converter. The specific problem is as follows: When multiple minimum power output units work together, under the condition that the output voltage remains constant, the output current capability of all DC / DC converters will have consistent differences. The DC / DC converter with weaker capability will cause a power bottleneck in the overall circuit, and the DC / DC converters with these bottlenecks will change at different stages, which will cause the overall circuit output power to be unstable.

[0111] By adding a parallel supercapacitor bank design, the DC / DC converter with weaker current capability can receive real-time power replenishment from the supercapacitor bank, thus achieving a total output current balance. I 01 = I DC1 +I C1 。

[0112] 2. Real-time control of DC / DC converters

[0113] In this embodiment, the switching circuit must ensure both power stability and voltage stability in its power output. The latter is achieved primarily because the DC / DC converter selected in this application has the function of real-time controllable output voltage. When the overall circuit voltage fluctuates and the deviation exceeds the upper and lower limits, the control unit can monitor and adjust the output voltage of each DC / DC converter in real time to ensure that the overall voltage returns to the effective range.

[0114] A schematic diagram of the minimum power output unit of the switching circuit in this embodiment is shown below. Figure 12 As shown, the automatic switching circuit can boost the voltage to DC 2000V and above through conventional component selection and combination. Based on this, the safety design schematic diagram of the switching circuit in this application is shown below. Figure 13 and Figure 14 As shown, it has the following security design features: 1. Current and voltage decomposition design Compared to conventional boost converters that suffer from insufficient overcurrent and withstand voltage when using a single switching device, the switching network matrix design combined with a floating ground design in this application can effectively solve these problems, as detailed below: ① First, through structural insulation design, ensure that the switching circuit is electrically isolated from the external non-energized enclosure (regardless of the form of cabinet, box, etc.); ②Then, by designing multiple serial switches in the switch network matrix, it is possible to achieve, in series boost mode, that the total high voltage output is divided into n low voltage segments by the n-1 serial switches in the boost circuit, as shown in the following example. Figure 13As shown; ③ Then, by designing multiple parallel switches in the switch network matrix, it is possible to achieve, in parallel power boosting mode, that the total output large current is divided into n small current blocks by the n parallel switches in the power boosting circuit, as shown in the following example. Figure 14 As shown.

[0115] Based on ①, ② and ③ above, the overcurrent and withstand voltage performance of the control switch selected in the embodiments of this application only needs to meet the allocated overcurrent and withstand voltage capabilities.

[0116] 2. Input and output interfaces are fixed.

[0117] In any operating mode, the position of the input and output interfaces of the automatic switching circuit in this application remains unchanged. This avoids malfunctions caused by the input and output interfaces switching back and forth with the mode, and reduces the risk of accidents.

[0118] Compared with existing battery pack boost or voltage regulation solutions, the switching circuit provided in this application embodiment has the following advantages: 1) More functional The automatic switching circuit designed in this application embodiment has multiple working modes such as multi-level voltage boost, multi-level power adjustment, and parallel voltage and power adjustment. Compared with other existing solutions that only have single-level voltage boost or single-level power adjustment functions, the functions of this application embodiment are more powerful, and it solves the problems of inconsistent capacity (some battery packs will go offline) and inter-cluster circulating current (when clustered) that exist in conventional series and parallel voltage regulation of multiple battery packs.

[0119] 2) Higher reliability

[0120] The control switch designed in this application features self-locking, interlocking, and synchronization modes, which solve the low-probability accidents such as abnormal circuit breaks and abnormal short circuits that may occur in conventional automatic or manual shifting schemes from both hardware and software perspectives, resulting in higher reliability.

[0121] 3) Higher electrical energy stability

[0122] The parallel combination design of the DC / DC converter and the small-capacity supercapacitor bank adopted in this embodiment effectively solves the problem of unstable overall output power caused by the unstable output current of some DC / DC converters in conventional direct series boost schemes involving multiple DC / DC converters. Furthermore, by designing a branch switch in series between the DC / DC converter and the small-capacity supercapacitor bank, the independent discharge output function of the small-capacity supercapacitor bank can be achieved after the branch switch is opened (this function also has three modes: series, parallel, and mixed connection). Figure 15As shown, taking the third gear of series mode and the third gear of parallel mode as examples, this function is very suitable for high pulse discharge conditions, which can give full play to the high-rate discharge function of supercapacitors and avoid the power surge caused by this condition to the DC / DC converter and damage its performance.

[0123] 4) Easier component selection

[0124] This application embodiment utilizes a switch network matrix and floating ground design structure to break down the total output current and total voltage into smaller units, thereby reducing the selection criteria for components in each scattered branch. In particular, when the total voltage exceeds DC2000V and above, the DC / DC converter and various control switches inside the switching circuit can be selected from the component selection library of a conventional DC1000V working platform, thus eliminating the problem of difficult selection of high-voltage components.

[0125] 5) Possesses architectural scalability advantages

[0126] The switching circuit in this application uses 3 (or 4) DC / DC branches and a matching switch network matrix as an example to illustrate the functional mechanism of 3-level voltage regulation and 3-level power regulation. In fact, it is not limited to this number of levels. As long as the number of DC / DC converters is increased in a regular manner and the switch network matrix architecture is expanded, more switching levels can be achieved, but the overall output interface position remains unchanged to avoid misoperation caused by interface switching.

[0127] 6) Cost advantage

[0128] The switching circuit of this application requires a small number of battery packs (only one cluster), a small supercapacitor capacity (for auxiliary purposes), and conventional selection of DC / DC converters and various control switches (avoiding expensive customization). Compared with other existing solutions (either multiple battery packs, customized DC / DC converters, or customized circuit breakers, etc.), the cost advantage is significant.

[0129] The multi-voltage platform automatic switching circuit and control drive circuit provided in this application embodiment can be widely used in various power systems for DC voltage boosting, power adjustment, and other applications. It is not limited to battery packs as the input object. By replacing the DC / DC converter in the switching circuit with an AC / DC converter, it is also applicable to AC input objects, and its application range is very wide.

[0130] 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.

[0131] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A multi-voltage platform automatic switching circuit, characterized in that, The circuit includes: The power module is used to provide electrical energy; A multi-channel DC / DC converter module is used to convert the DC voltage of the power supply module into multiple DC outputs of different levels; The automatic switching and control module includes a switch network matrix connected to the multiple DC outputs. The switch network matrix automatically controls each DC output through different types of switches to switch the total output voltage between different voltage operating modes. The load module includes a power terminal powered by the total voltage.

2. The circuit according to claim 1, characterized in that, The circuit also includes: A charger, connected in parallel with the power terminal, is used to provide a reverse charging voltage for the power module.

3. The circuit according to claim 1, characterized in that, The multi-channel DC / DC converter module includes n parallel front-end branches, wherein: Each front-end branch includes a DC / DC converter. The input of each DC / DC converter is connected to the power module, and the output is connected in reverse parallel to a diode and in series with a branch switch.

4. The circuit according to claim 3, characterized in that, The multi-channel DC / DC converter module also includes: A capacitor bank is connected in parallel at the output of each DC / DC converter.

5. The circuit according to claim 1, characterized in that, The switch network matrix includes switches of the following types: n serial circuit breakers, n interlocking contactors, n-1 serial contactors, and n-1 parallel circuit breakers; wherein: The input terminals of n serial circuit breakers are connected in series with n DC outputs one-to-one; The main contacts of n interlocking contactors are connected in parallel one-to-one with the output terminals of n serial circuit breakers; The main contacts of any serial contactor are connected in series with the main contacts of two adjacent interlocking contactors, one end at a time. The positive and negative terminals of the input and output terminals of any parallel circuit breaker are connected in parallel one-to-one with the positive and negative terminals of the two adjacent DC outputs.

6. The circuit according to claim 5, characterized in that, In the multi-channel DC / DC converter module, each DC / DC converter output terminal is connected in series with a branch switch. The branch switch, interlock contactor, and serial contactor each include a corresponding normally open state feedback contact. When the branch switch, interlock contactor, and serial contactor are closed, the corresponding normally open state feedback contact is normally closed to form a self-locking mode.

7. The circuit according to claim 5, characterized in that, The interlocking contactor, serial contactor, serial circuit breaker, and parallel circuit breaker each include a corresponding normally closed contact for status feedback. When the serial circuit breaker is closed, the normally closed contact of the state feedback of the interlocking contactor that has an interlocking relationship with the serial circuit breaker is normally closed, forming an interlocking mode between the serial circuit breaker and the interlocking contactor. When the interlock contactor is closed, the normally closed contact of the status feedback of the series circuit breaker that has an interlock relationship with the interlock contactor is normally closed, forming an interlock mode between the interlock contactor and the series circuit breaker. When the serial contactor is closed, the normally closed contact of the state feedback of the parallel circuit breaker, which is interlocked with the serial contactor, is normally closed, forming an interlocking mode between the serial contactor and the parallel circuit breaker. When the parallel circuit breaker is closed, the normally closed contact of the state feedback of the serial contactor, which is interlocked with the parallel circuit breaker, is normally closed, forming an interlocking mode between the parallel circuit breaker and the serial contactor.

8. The circuit according to claim 5, characterized in that, The n serial circuit breakers each include a corresponding first shunt coil. By simultaneously energizing or de-energizing the first shunt coils, a synchronous mode is formed in which the n serial circuit breakers are simultaneously turned on or off. The n-1 parallel circuit breakers each include a corresponding second shunt coil. By simultaneously energizing or de-energizing the second shunt coils, a synchronous mode is formed in which the n-1 serial circuit breakers are simultaneously turned on or off.

9. The circuit according to claim 7, characterized in that, The serial circuit breaker and the interlocking contactor that are connected are interlocked. The serial contactor and the parallel circuit breaker that are connected to the adjacent front-end branch are interlocked.

10. A control drive circuit, characterized in that, include: The control unit is used to control the multiple DC / DC conversion modules to perform DC voltage conversion, and to control the switches in the switch network matrix through various control branches; Multiple control branches are provided, and any one type of control branch is connected to a switch of a certain type in the switch network matrix. Any one type of control branch is used to automatically control the DC outputs of the multi-channel DC / DC converter module by controlling the on / off state of the corresponding type of switch, so that the total output voltage switches between different voltage operating modes.

11. The circuit according to claim 10, characterized in that, The various types of control branches include: The first type of control branch is used to control the on / off state of n branch switches respectively; the second type of control branch is used to control the on / off state of n interlock contactors respectively; the third type of control branch is used to control the on / off state of n-1 serial contactors respectively; the fourth type of control branch is used to control the on / off state of n serial circuit breakers respectively; the fifth type of control branch is used to control the on / off state of n-1 parallel circuit breakers respectively; the sixth type of control branch is used to simultaneously control the de-energization of n serial circuit breakers; and the seventh type of control branch is used to simultaneously control the de-energization of n-1 parallel circuit breakers. The control interface of any switch is connected to the corresponding branch of one type of control branch, and the branch is connected upward to the control port of the control unit and downward to the ground terminal of the control unit.

12. The circuit according to claim 11, characterized in that, Each of the first type of control branch, the second type of control branch, and the third type of control branch includes a primary branch. Each primary branch is connected in series with the control interface of the corresponding switch and two secondary branches. One of the secondary branches is connected to the control port of the control unit, and the other secondary branch is connected in series with the normally open contact of the status feedback of the corresponding switch and then connected to the power supply terminal of the control unit.

13. The circuit according to claim 11, characterized in that, Each of the second, third, fourth, and fifth type of control branches includes a primary branch, and each primary branch is connected in series with the control interface of the corresponding switch and the normally closed contact of the state feedback switch that is interlocked with the switch.

14. The circuit according to claim 11, characterized in that, Both the sixth and seventh type control branches include two primary branches. One primary branch is connected in series with the control coil of an intermediate relay and then connected upwards to the control port of the control unit and downwards to the ground terminal of the control unit. The other primary branch is connected upwards to the power supply terminal of the control unit and downwards in series with the main contact of an intermediate relay and multiple secondary branches. One of the secondary branches is connected in series with the shunt coil of the corresponding switch and then downwards to the ground terminal of the control unit.

15. The circuit according to claim 10, characterized in that, The control unit is a programmable controller and is powered by an external power source or by drawing power from a battery pack via a switch. The power supply port of the control unit consists of a power supply terminal and a ground terminal.

16. The circuit according to claim 10, characterized in that, The different voltage operating modes may include any one or more of the following operating modes: A series output mode where at least one DC output is connected in series among multiple DC outputs; Parallel mode of output after at least one DC output is connected in parallel in a multi-channel DC output; A mixed-connection mode in which k DC outputs are connected in parallel and then connected in series, where k are positive integers greater than 1 and not greater than n, and n is the total number of DC outputs.

17. The circuit according to claim 10, characterized in that, The control unit first controls all switches to be in the off state, and after determining the target switch to be turned on under the current voltage operating mode, it turns on the target switch through the corresponding multiple control branches according to the following turn-on sequence for different types of switches: Serial circuit breaker, parallel circuit breaker, serial contactor, interlocking contactor, branch switch.

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