A dual-input high-voltage direct current circuit

Abstract

The application provides a double-input high-voltage direct-current circuit, comprising a first input branch, a second input branch and a common output branch, the positive line and the negative line of the first input branch are connected with a first thyristor and a first diode in series respectively, the positive line and the negative line of the second input branch are connected with a second thyristor and a second diode in series respectively, and the two input branches are connected with the common output branch through a joint node; a surge suppression and overcurrent protection unit is arranged between the joint node and the common output branch. The surge suppression unit and the overcurrent protection unit can be integrated in the same power conversion circuit, the power conversion circuit is controlled to limit the surge current during input connection or switching, and the power supply path is cut off when overcurrent or short circuit fault occurs. The application can realize automatic selection of double high-voltage direct-current input, reverse feedback prevention, surge suppression and overcurrent or short circuit protection.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, and in particular to a high-voltage DC dual-input circuit. Background Technology

[0002] With the development of data centers, high-power servers, telecommunications equipment, and other high-reliability electrical equipment, high-voltage direct current (HVDC) power supply systems are being used more and more widely. For example, in some data center power supply systems, 400VDC or 800VDC HVDC buses can be used to supply power to downstream power equipment. To improve power supply reliability, HVDC power supply systems typically have two independent input power sources. When one input power source experiences a power outage, abnormality, or other situation that prevents it from continuing to supply power, it is necessary to switch to the other input power source in a timely manner to maintain continuous power supply to downstream power supplies and loads.

[0003] In existing dual-input power supply systems, mechanical relays can be used to switch between the two input power sources. However, mechanical switching devices have a certain mechanical action time, typically around 10ms. Therefore, situations may arise where the first input has already lost power while the second input has not yet been connected, leading to insufficient energy storage to maintain the load's power supply, or even a complete power supply system shutdown. Furthermore, with increases in input voltage and system power, higher requirements are placed on the withstand voltage, insulation distance, and arc-extinguishing capability of mechanical relays, resulting in a corresponding increase in size and cost.

[0004] Furthermore, when a short circuit or severe overcurrent fault occurs inside the downstream power supply, the voltage of the current power input may drop due to the fault current. If the system determines that the current input is down based solely on the drop in input voltage and directly switches to the backup input, the backup input may continue to supply power to the same internal fault point, thereby causing the backup-side protection device to activate and affecting both inputs.

[0005] Therefore, it is necessary to provide a power supply switching circuit suitable for dual-input high-voltage DC power supply systems, taking into account input switching speed, surge current suppression, overcurrent or short-circuit fault isolation, as well as the number of components and space occupied. Summary of the Invention

[0006] According to one embodiment of this application, a dual-input high-voltage DC circuit is provided, comprising: a first input branch for connecting to a first high-voltage DC input, the first input branch including a first positive line and a first negative line; a second input branch for connecting to a second high-voltage DC input, the second input branch including a second positive line and a second negative line; a common output branch, the first input branch and the second input branch being connected to the common output branch via a combining node, the common output branch being used to supply power to a subsequent stage; the combining node including a positive combining node and a negative combining node; a first thyristor and a first diode, the first thyristor being connected in series with the first positive line and the first diode being connected in series with the first negative line; a second thyristor and a second diode, the second thyristor being connected in series with the first positive line and the first diode being connected in series with the first negative line. The second positive line has the second diode connected in series with the second negative line; a surge suppression unit and an overcurrent protection unit are disposed between the combining node and the common output branch; a controller is used to acquire the power supply status of the first high-voltage DC input and the second high-voltage DC input, as well as the current status of the common output branch, and to control the first thyristor and the second thyristor; wherein, when the currently powered high-voltage DC input loses power and the common output branch does not experience an overcurrent or short-circuit fault, the controller controls the thyristor corresponding to the other high-voltage DC input to conduct, so that the other high-voltage DC input supplies power to the common output branch; when the common output branch experiences an overcurrent or short-circuit fault, the overcurrent protection unit cuts off the power supply path between the combining node and the subsequent stage.

[0007] Furthermore, the surge suppression unit and the overcurrent protection unit are integrated into the same power conversion circuit.

[0008] Furthermore, the power conversion circuit includes a Buck converter, which includes a switching device configured to limit the inrush current flowing to the subsequent stage via PWM regulation during high-voltage DC input access or switching, and to turn off when an overcurrent or short-circuit fault is detected, thereby cutting off the power supply path between the combining node and the subsequent stage.

[0009] Furthermore, the surge suppression unit includes a first branch and a second branch connected in parallel. The first branch includes a current-limiting device and a first switch connected in series, and the second branch includes a bypass switch. The current-limiting device includes a PTC device and / or a power resistor, and the first switch and the bypass switch include a relay and / or a semiconductor switching device.

[0010] Furthermore, the overcurrent protection unit includes an electronic switch and / or a fuse.

[0011] According to another embodiment of this application, a dual-input high-voltage DC circuit is provided, comprising: a first input branch for connecting to a first high-voltage DC input, the first input branch including a first positive line and a first negative line; a second input branch for connecting to a second high-voltage DC input, the second input branch including a second positive line and a second negative line; a common output branch, the first input branch and the second input branch being connected to the common output branch via a combining node, the common output branch being used to supply power to a subsequent stage; the combining node including a positive combining node and a negative combining node; a first diode and a third diode, the first diode being connected in series with the first negative line, the third diode being connected in series with the first positive line; a second diode and a fourth diode, the second diode being connected in series with the second negative line, the fourth diode being connected in series with the second positive line. The circuit includes: a first surge suppression unit and a second surge suppression unit, respectively disposed in the first input branch and the second input branch; an overcurrent protection unit, disposed in the common output branch after the combining node, used to cut off the power supply path between the combining node and the subsequent stage in the event of an overcurrent or short-circuit fault; and a controller configured to acquire the power supply status of the first high-voltage DC input and the second high-voltage DC input, as well as the current status of the common output branch; when the currently powered high-voltage DC input fails and the common output branch does not experience an overcurrent or short-circuit fault, the controller controls the first surge suppression unit and the second surge suppression unit to supply power to the common output branch from another high-voltage DC input; and when the common output branch experiences an overcurrent or short-circuit fault, the overcurrent protection unit cuts off the power supply path between the combining node and the subsequent stage.

[0012] Furthermore, the first surge suppression unit and the second surge suppression unit include a Buck converter configured to limit surge current flowing to the subsequent stage by controlling the duty cycle of its switching devices.

[0013] Furthermore, the first surge suppression unit and the second surge suppression unit include a first branch and a second branch connected in parallel. The first branch includes a current limiting device and a first switch connected in series, and the second branch includes a bypass switch. The current limiting device includes a PTC device and / or a power resistor, and the first switch and the bypass switch include a relay and / or a semiconductor switching device.

[0014] Furthermore, the overcurrent protection unit includes an electronic switch and / or a fuse.

[0015] The features and technical advantages of this disclosure have been outlined quite extensively above to facilitate a better understanding of the detailed description that follows. Additional features and advantages of this disclosure, which form the subject matter of the claims, will be described below. Those skilled in the art will understand that the disclosed concepts and specific embodiments can be readily used as the basis for modifying or designing other structures or processes to achieve the same purpose as this disclosure. Those skilled in the art will also recognize that such equivalent structures do not depart from the spirit and scope of this disclosure as set forth in the appended claims. Attached Figure Description

[0016] To gain a more complete understanding of this disclosure and its advantages, the following description is given in conjunction with the accompanying drawings, wherein:

[0017] Figure 1 A schematic diagram of a dual-input high-voltage DC circuit according to an embodiment of this application is shown;

[0018] Figure 2 A schematic diagram of a dual-input high-voltage DC circuit according to another embodiment of this application is shown;

[0019] Figure 3(a) shows a circuit diagram of a surge suppression unit according to an embodiment of this application;

[0020] Figure 3(b) shows a circuit diagram of a surge suppression unit according to another embodiment of this application;

[0021] Figure 4 A circuit diagram of a surge suppression unit according to yet another embodiment of this application is shown;

[0022] Figure 5 A schematic diagram of a dual-input high-voltage DC circuit according to another embodiment of this application is shown;

[0023] Figure 6 A schematic diagram of a dual-input high-voltage DC circuit according to another embodiment of this application is shown;

[0024] Figure 7 A schematic diagram of a dual-input high-voltage DC circuit according to another embodiment of this application is shown;

[0025] Figure 8 A schematic diagram of a dual-input high-voltage DC circuit according to another embodiment of this application is shown;

[0026] Figure 9 A schematic diagram of a dual-input high-voltage DC circuit according to another embodiment of this application is shown.

[0027] in:

[0028] HV1+ and HV1- represent the positive and negative terminals of the first high-voltage DC input, respectively;

[0029] HV2+ and HV2- represent the positive and negative terminals of the second high-voltage DC input, respectively;

[0030] BULK+ and BULK- represent the positive and negative terminals of the common output branch, respectively.

[0031] B+ and B- represent positive and negative coincidence nodes, respectively;

[0032] D1 to D4 represent diodes;

[0033] SCR1 and SCR2 represent the first thyristor and the second thyristor, respectively.

[0034] DRV1 and DRV2 represent the first thyristor drive signal and the second thyristor drive signal, respectively.

[0035] Unless otherwise stated, corresponding numbers and symbols in the various figures generally refer to corresponding parts. These figures are drawn to clearly illustrate relevant aspects of the various embodiments and are not necessarily drawn to scale. Detailed Implementation

[0036] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. 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.

[0037] Please see Figure 1 The schematic diagram shown is of a dual-input high-voltage DC circuit according to an embodiment of this application. This embodiment provides a dual-input high-voltage DC circuit, including: a first input branch for connecting the positive terminal HV1+ and the negative terminal HV1- of a first high-voltage DC input HV1, having a first positive line and a first negative line; a second input branch for connecting the positive terminal HV2+ and the negative terminal HV2- of a second high-voltage DC input HV2, having a second positive line and a second negative line; and a common output branch, wherein the first input branch and the second input branch are connected to the common output branch via a combining node, and the common output branch is used to supply power to the subsequent BULK stage; the combining node includes a positive combining node B+ and a negative combining node B-.

[0038] Furthermore, a first diode D1 is connected in series on the first negative terminal of the first input branch, and a second diode D2 is connected in series on the second negative terminal of the second input branch. The negative terminal of the first diode is connected to the negative terminal HV1- of the first high-voltage DC input, and the negative terminal of the second diode D2 is connected to the negative terminal HV2- of the second high-voltage DC input. The first diode D1 and the second diode D2 are used to block the reverse current flowing from the output side to the input branch and can prevent reverse polarity of the input from affecting the subsequent circuitry.

[0039] Furthermore, the dual-input high-voltage DC circuit also includes a surge suppression unit and an overcurrent protection unit. The surge suppression unit is located before the combiner node or in the common output branch after the combiner node. The overcurrent protection unit, located in the common output branch after the combiner node, is used to disconnect the power supply path between the combiner node and the subsequent stage in the event of an overcurrent or short-circuit fault. A controller is used to acquire the power supply status of the first and second high-voltage DC inputs and the current status of the common output branch, and to control the surge suppression unit and / or the overcurrent protection unit.

[0040] Specifically, in such Figure 1 In the illustrated embodiment, the surge suppression unit includes a first surge suppression unit and a second surge suppression unit. The positive input terminal of the first surge suppression unit is connected to the positive terminal HV1+ of the first high-voltage DC input, and the negative input terminal is connected to the positive terminal of the first diode D1. The positive output terminal of the first surge suppression unit is connected to the positive closing node B+, and the negative output terminal is connected to the negative closing node B-. The positive input terminal of the second surge suppression unit is connected to the positive terminal HV2+ of the second high-voltage DC input, and the negative input terminal is connected to the positive terminal of the second diode D2. The positive output terminal of the second surge suppression unit is connected to the positive closing node B+, and the negative output terminal is connected to the negative closing node B-. An overcurrent protection unit, located in the common output branch after the closing node, is used to disconnect the power supply path between the closing node and the subsequent stage in the event of an overcurrent or short-circuit fault.

[0041] Upon initial power-on, the surge suppression circuit effectively suppresses inrush current. Furthermore, when, for example, the first high-voltage DC input HV1 experiences a power failure and there is no overcurrent or short-circuit fault in the circuit, the controller (not shown in the diagram) can disconnect the first surge suppression unit and activate the second surge suppression unit, allowing the second high-voltage DC input HV2 to take over the power supply to the subsequent stage. Thus, in addition to limiting inrush current, the first and second surge suppression units can also participate in power supply switching between the two inputs via their controllable switches.

[0042] Furthermore, when an overcurrent or short-circuit fault occurs in the common output branch or the downstream stage, the overcurrent protection unit disconnects to isolate the downstream fault from the two high-voltage DC inputs, thereby preventing the second high-voltage DC input from being connected to the same fault point after the first input drops due to an internal fault.

[0043] Please see Figure 2The diagram shows a dual-input high-voltage DC circuit according to another embodiment of this application. In this embodiment, both the surge suppression unit and the overcurrent protection unit are located in the common output branch after the closing node. As shown, the positive closing node B+ is connected to the positive terminal HV1+ of the first high-voltage DC input and the positive terminal HV2+ of the second high-voltage DC input. The negative closing node B- is connected to the positive terminal of the first diode D1 and the positive terminal of the second diode D2. The input terminals of the surge suppression unit are connected to the positive closing node B+ and the negative closing node B-, respectively. The output terminal of the surge suppression unit is connected to the input terminal of the overcurrent protection unit, and the output terminal of the overcurrent protection unit is connected to the subsequent power supply circuit. Figure 1 Compared to setting up complete surge suppression circuits for each of the two inputs, sharing a surge suppression unit can reduce the number of power devices and the corresponding control and drive devices, which is beneficial for reducing the circuit board area and system size.

[0044] It should be noted that this application does not limit the circuit structure and connection method of the surge suppression unit and the overcurrent protection unit. The surge suppression unit and the overcurrent protection unit can be set independently or integrated into the same power conversion circuit. When set independently, the surge suppression unit can also be set after the overcurrent protection unit.

[0045] Figures 3(a) and 3(b) are schematic diagrams of the surge suppression unit circuit structure of this application. Referring to Figures 3(a) and 3(b), the surge suppression unit may include a first branch and a second branch connected in parallel. The first branch includes a current-limiting device and a first switch connected in series, and the second branch includes a bypass switch. The current-limiting device may be a PTC device, a power resistor, or other current-limiting devices suitable for high-voltage DC power supply systems. The first switch and the bypass switch may be relays or semiconductor switching devices. When the high-voltage DC input is initially connected, the bypass switch remains open, and the first switch is open, allowing the input current to first pass through the current-limiting device to charge the subsequent capacitor with a small current. As the voltage of the subsequent capacitor increases and the charging current decreases, when the predetermined bypass condition is met, the first switch can be opened, and the bypass switch can be opened to bypass the current-limiting device, thereby reducing the power loss caused by the current-limiting device during continuous power supply. The bypass condition can be determined based on parameters such as the subsequent voltage, the input-output voltage difference, the charging time, or the charging current.

[0046] Figure 4 This is a schematic diagram of another embodiment of the surge suppression unit circuit of this application. See also... Figure 4The surge suppression unit can employ a Buck converter, which includes switching devices. The controller can perform PWM control on the switching devices in the Buck converter and control the current flowing from the high-voltage DC input to the subsequent stage by adjusting the duty cycle of the switching devices. When the high-voltage DC input is first connected or when switching between two inputs, a smaller duty cycle can be used, or the duty cycle can be gradually adjusted according to a preset change pattern, so that the current flowing to the subsequent stage is maintained within a predetermined range, thereby limiting the surge current generated by the charging of the subsequent stage capacitor. Compared with limiting surge current through a resistor with a fixed resistance value, using a Buck converter allows for more flexible adjustment of surge current and can reduce the heat loss caused by long-term series current limiting devices.

[0047] Please see Figure 5 The schematic diagram of a dual-input high-voltage DC circuit according to another embodiment of this application is shown in the figure. A third diode D3 is connected in series with the first positive terminal, and a fourth diode D4 is connected in series with the second positive terminal. The positive terminal of the third diode D3 is connected to the positive terminal HV1+ of the first high-voltage DC input, and the positive terminal of the fourth diode D4 is connected to the positive terminal HV2+ of the second high-voltage DC input. The surge suppression unit includes a first surge suppression unit and a second surge suppression unit. The positive input terminal of the first surge suppression unit is connected to the negative terminal of the third diode D3, and the negative input terminal is connected to the positive terminal of the first diode D1. The positive output terminal of the first surge suppression unit is connected to the positive-closed node B+, and the negative output terminal is connected to the negative-closed node B-. The positive input terminal of the second surge suppression unit is connected to the negative terminal of the fourth diode D4, and the negative input terminal is connected to the positive terminal of the second diode D2. The positive output terminal of the second surge suppression unit is connected to the positive-closed node B+, and the negative output terminal is connected to the negative-closed node B-. The outputs of the two surge suppression units form a common output branch at the positive and negative closing nodes, and supply power to the subsequent stage through the overcurrent protection unit set in the common output branch.

[0048] Please see Figure 6The schematic diagram of a dual-input high-voltage DC circuit according to another embodiment of this application shows that, in this embodiment, the anode of the third diode D3 is connected to the anode HV1+ of the first high-voltage DC input, and the cathode is connected to the positive closing node B+; the cathode of the first diode D1 is connected to the cathode HV1- of the first high-voltage DC input, and the anode is connected to the negative closing node B-; the anode of the fourth diode D4 is connected to the anode HV2+ of the second high-voltage DC input, and the cathode is connected to the positive closing node B+; the cathode of the second diode D2 is connected to the cathode HV2- of the second high-voltage DC input, and the anode is connected to the negative closing node B-. Both the surge suppression unit and the overcurrent protection unit are located in the common output branch after the closing node. The input terminals of the surge suppression unit are connected to the positive closing node B+ and the negative closing node B-, respectively, and the output terminal of the surge suppression unit is connected to the input terminal of the overcurrent protection unit. The output terminal of the overcurrent protection unit is connected to the subsequent power supply circuit. It should be noted that this application does not limit the circuit structure and connection method of the surge suppression unit and the overcurrent protection unit. Surge suppression units and overcurrent protection units can be set up independently or integrated into a single protection unit.

[0049] exist Figure 5 and Figure 6 In the embodiments, both the positive and negative power supply paths of the first high-voltage DC input and the second high-voltage DC input have diodes, which helps to further reduce the risk of reverse current or abnormal backflow between the two inputs.

[0050] Please see Figure 7 The schematic diagram of a dual-input high-voltage DC circuit according to another embodiment of this application is shown in the figure. A first thyristor SCR1 is connected in series on the first positive line, and a second thyristor SCR2 is connected in series on the second positive line. The positive terminal of the first thyristor SCR1 is connected to the positive terminal HV1+ of the first high-voltage DC input, and the positive terminal of the second thyristor SCR2 is connected to the positive terminal HV2+ of the second high-voltage DC input. The surge suppression unit includes a first surge suppression unit and a second surge suppression unit. The positive input terminal of the first surge suppression unit is connected to the negative terminal of the first thyristor SCR1, and the negative input terminal is connected to the positive terminal of the first diode D1. The positive output terminal of the first surge suppression unit is connected to the positive closing node B+, and the negative output terminal is connected to the negative closing node B-. The positive input terminal of the second surge suppression unit is connected to the negative terminal of the second thyristor SCR2, and the negative input terminal is connected to the positive terminal of the second diode D2. The positive output terminal of the second surge suppression unit is connected to the positive closing node B+, and the negative output terminal is connected to the negative closing node B-. The outputs of the two surge suppression units form a common output branch at the positive and negative closing nodes, and supply power to the subsequent stage through the overcurrent protection unit set in the common output branch.

[0051] The first thyristor SCR1 can be connected to the first drive signal DRV1, and the second thyristor SCR2 can be connected to the second drive signal DRV2. Under normal circumstances, for example, when the first high-voltage DC input HV1 is used as the current power supply input, SCR1 can be controlled to conduct, and SCR2 can be turned off, allowing HV1 to supply power to the subsequent stage via the first surge suppression unit and the common overcurrent protection unit. When HV1 loses power, the anode current flowing through SCR1 decreases. When the current of SCR1 falls below its holding current, SCR1 naturally turns off. The controller detects the power loss of HV1 and, after confirming that no overcurrent or short-circuit fault has occurred in the common output branch, can output the DRV2 drive signal to turn on SCR2, thereby allowing the second high-voltage DC input HV2 to take over the power supply to the subsequent stage. Because the power supply selection uses semiconductor solid-state devices such as thyristors, the mechanical delay and mechanical fatigue problems caused by mechanical contact operation can be avoided. Furthermore, by using an SCR in conjunction with a diode, the reverse current between the two high-voltage DC inputs can be limited, preventing one input from feeding back into the other, and reducing the risk of abnormal input polarity affecting subsequent stages.

[0052] It should be noted that, in this embodiment, the first surge suppression unit and the second surge suppression unit can be used to limit the surge current during the input access process. In some implementations, when the thyristor itself can already perform the required input selection function, the surge suppression units on both input sides can also be simplified or omitted according to system needs.

[0053] Please see Figure 8 The schematic diagram of a dual-input high-voltage DC circuit according to another embodiment of this application shows that, in this embodiment, the positive terminal of the first thyristor SCR1 is connected to the positive terminal HV1+ of the first high-voltage DC input, and the negative terminal is connected to the positive closing node B+; the negative terminal of the first diode D1 is connected to the negative terminal HV1- of the first high-voltage DC input, and the positive terminal is connected to the negative closing node B-; the positive terminal of the second thyristor SCR2 is connected to the positive terminal HV2+ of the second high-voltage DC input, and the negative terminal is connected to the positive closing node B+; the negative terminal of the second diode D2 is connected to the negative terminal HV2- of the second high-voltage DC input, and the positive terminal is connected to the negative closing node B-. Both the surge suppression unit and the overcurrent protection unit are located in the common output branch after the closing node. The input terminal of the surge suppression unit is connected to both the positive closing node B+ and the negative closing node B-, respectively; the output terminal of the surge suppression unit is connected to the input terminal of the overcurrent protection unit; and the output terminal of the overcurrent protection unit is connected to the subsequent power supply circuit.

[0054] It should be noted that this application does not limit the circuit structure and connection method of the surge suppression unit and the overcurrent protection unit. The surge suppression unit and the overcurrent protection unit can be set independently or integrated into the same power conversion circuit. When set independently, the surge suppression unit can also be set after the overcurrent protection unit.

[0055] Please see Figure 9 The diagram shows a dual-input high-voltage DC circuit according to another embodiment of this application. As shown, in this embodiment, the surge suppression unit can employ... Figure 4 The Buck converter shown employs a fuse FU for overcurrent protection. The controller limits the current flowing to the subsequent stage during input connection or switching by adjusting the duty cycle of the switching devices in the Buck converter, thus suppressing inrush current generated by the charging of the subsequent stage capacitors. In the event of an overcurrent or short-circuit fault, the fuse FU blows, disconnecting the power supply path between the closing node and the subsequent stage. Therefore, the switching devices in the Buck converter can perform inrush current regulation during normal connection or switching, and the fuse FU performs power supply disconnection in the event of an overcurrent or short-circuit fault, enabling the high-voltage DC circuit to possess both surge suppression and overcurrent protection functions.

[0056] When the first high-voltage DC input HV1 is powered, the first thyristor SCR1 is turned on, and the second thyristor SCR2 is turned off. When HV1 loses power, SCR1 naturally turns off because the anode current drops below the holding current. After confirming that HV1 is powered off and there is no overcurrent or short-circuit fault in the common output branch, the controller turns on the second thyristor SCR2, and the second high-voltage DC input HV2 continues to supply power to the common output branch. This application controls the access status of the first and second high-voltage DC inputs separately through two SCRs, which can switch to the other input when one input loses power or is abnormal, reducing the switching delay of mechanical relays and the limitation of mechanical life. Since this embodiment can be configured with only one surge suppression and overcurrent protection power circuit shared by the two inputs, it can reduce the power devices, driving devices, and space occupied by surge suppression and overcurrent protection.

[0057] Furthermore, this embodiment employs a Buck surge suppression scheme, limiting the surge current flowing to the downstream capacitor during input access or switching by controlling the duty cycle of the switching devices. Combined with current detection and switch shutdown, it achieves overcurrent or short-circuit protection, enabling the same power stage to possess soft-start, surge limiting, and fault protection functions. Moreover, the controller, by combining the current input power supply status and the current status of the common output branch, can distinguish between "genuine input-side power failure" and "downstream short-circuit or overcurrent fault." For normal power failure, the backup input is allowed to take over; for downstream overcurrent or short circuit, the common output protection module is preferentially disconnected to prevent the backup input from continuing to supply power to the fault point.

[0058] Although embodiments of the present disclosure and their advantages have been described in detail, it should be understood that various changes, substitutions and alterations may be made herein without departing from the spirit and scope of the present disclosure as defined by the appended claims.

[0059] Furthermore, the scope of this application is not intended to be limited to the specific embodiments of the processes, machines, manufactures, compositions of matter, apparatuses, methods, and steps described in the specification. As will be readily understood by those skilled in the art from the disclosure of this publication, processes, machines, manufactures, compositions of matter, means, methods, or steps that perform substantially the same function, currently exist or will be developed or implemented thereafter, will yield substantially the same results as the corresponding embodiments described herein that are available according to this disclosure. Therefore, the appended claims are intended to include such processes, machines, manufactures, compositions of matter, apparatuses, methods, or steps within their scope.

Claims

1. A dual-input high-voltage DC circuit, characterized in that, include: The first input branch is used to connect to the first high voltage DC input, and the first input branch includes a first positive line and a first negative line; The second input branch is used to connect to the second high-voltage DC input. The second input branch includes a second positive line and a second negative line. A common output branch is provided, wherein the first input branch and the second input branch are connected to the common output branch via a combining node, and the common output branch is used to supply power to the subsequent stage; the combining node includes a positive combining node and a negative combining node. A first thyristor and a first diode, wherein the first thyristor is connected in series in the first positive terminal line and the first diode is connected in series in the first negative terminal line; The second thyristor and the second diode are connected in series in the second positive terminal line and the second diode is connected in series in the second negative terminal line. A surge suppression unit and an overcurrent protection unit are disposed between the combining node and the common output branch; The controller is used to acquire the power supply status of the first high-voltage DC input and the second high-voltage DC input, as well as the current status of the common output branch, and to control the first thyristor and the second thyristor. When the current high-voltage DC input loses power and the common output branch does not experience an overcurrent or short-circuit fault, the controller controls the thyristor corresponding to the other high-voltage DC input to turn on, so that the other high-voltage DC input supplies power to the common output branch. When an overcurrent or short-circuit fault occurs in the common output branch, the overcurrent protection unit cuts off the power supply path between the combining node and the subsequent stage.

2. The dual-input high-voltage DC circuit according to claim 1, characterized in that, The surge suppression unit and overcurrent protection unit are integrated into the same power conversion circuit.

3. The dual-input high-voltage DC circuit according to claim 2, characterized in that, The power conversion circuit includes a Buck converter, which includes a switching device configured to limit the inrush current flowing to the subsequent stage via PWM regulation during high-voltage DC input access or switching, and to turn off when an overcurrent or short-circuit fault is detected, thereby cutting off the power supply path between the combining node and the subsequent stage.

4. The dual-input high-voltage DC circuit according to claim 1, characterized in that, The surge suppression unit includes a first branch and a second branch connected in parallel. The first branch includes a current limiting device and a first switch connected in series, and the second branch includes a bypass switch. The current limiting device includes a PTC device and / or a power resistor, and the first switch and the bypass switch include a relay and / or a semiconductor switching device.

5. The dual-input high-voltage DC circuit according to claim 4, characterized in that, The overcurrent protection unit includes an electronic switch and / or a fuse.

6. A dual-input high-voltage DC circuit, characterized in that, include: The first input branch is used to connect to the first high voltage DC input, and the first input branch includes a first positive line and a first negative line; The second input branch is used to connect to the second high-voltage DC input. The second input branch includes a second positive line and a second negative line. A common output branch is provided, wherein the first input branch and the second input branch are connected to the common output branch via a combining node, and the common output branch is used to supply power to the subsequent stage; the combining node includes a positive combining node and a negative combining node. A first diode and a third diode, wherein the first diode is connected in series with the first negative terminal line, and the third diode is connected in series with the first positive terminal line; A second diode and a fourth diode, wherein the second diode is connected in series with the second negative terminal line, and the fourth diode is connected in series with the second positive terminal line; The first surge suppression unit and the second surge suppression unit are respectively disposed in the first input branch and the second input branch; An overcurrent protection unit is installed on the common output branch after the combiner node, and is used to cut off the power supply path between the combiner node and the subsequent stage in the event of an overcurrent or short circuit fault. The controller is configured to acquire the power supply status of the first high-voltage DC input and the second high-voltage DC input, as well as the current status of the common output branch; when the currently powered high-voltage DC input loses power and the common output branch does not experience an overcurrent or short-circuit fault, the controller controls the first surge suppression unit and the second surge suppression unit to enable another high-voltage DC input to supply power to the common output branch; when the common output branch experiences an overcurrent or short-circuit fault, the overcurrent protection unit cuts off the power supply path between the combining node and the subsequent stage.

7. The dual-input high-voltage DC circuit according to claim 6, characterized in that, The first surge suppression unit and the second surge suppression unit include a Buck converter configured to limit surge current flowing to the subsequent stage by controlling the duty cycle of its switching devices.

8. The dual-input high-voltage DC circuit according to claim 6, characterized in that, The first surge suppression unit and the second surge suppression unit include a first branch and a second branch connected in parallel. The first branch includes a current limiting device and a first switch connected in series, and the second branch includes a bypass switch. The current limiting device includes a PTC device and / or a power resistor, and the first switch and the bypass switch include a relay and / or a semiconductor switching device.

9. The dual-input high-voltage DC circuit according to claim 6, characterized in that, The overcurrent protection unit includes an electronic switch and / or a fuse.

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