DCDC power supply automatic complementary and complementary device

Abstract

The invention provides an automatic redundancy complementary device for a DCDC power supply, which is applied to the field of power electronics. The main power supply module adopts a Buck circuit, the standby module adopts a Boost circuit, the input ends of the Buck circuit and the Boost circuit are connected in parallel to a direct-current power supply, and the output ends are connected to the switching control unit through an anti-parallel Schottky diode. According to the unit, the output voltage of a main power supply is detected in real time through a double-threshold comparison circuit, and when the output voltage exceeds preset upper and lower threshold values, a logic OR gate drives a low-on-resistance MOS tube to be switched to a standby power supply. The dynamic feedback compensation module collects load current changes through a current sampling resistor and synchronously adjusts the duty ratio or frequency of main and standby power supplies through an error amplifier. The output filter circuit restrains ripples through a common mode inductor and a low-equivalent series resistor-capacitor set, and the voltage detection module samples through a divider resistor and a filter capacitor and dynamically generates reference voltage in combination with a digital-to-analog converter. The magnetic beads are connected in series to an output path to block high-frequency noise, and the RS485 communication module is integrated to the switching unit to support remote parameter adjustment.

Description

Technical Field

[0001] This invention relates to the field of power electronics technology, and in particular to an automatic redundancy complementarity device for DC-DC power supplies. Background Technology

[0002] Traditional DC-DC redundant power supply systems typically employ a parallel architecture of primary and backup power supplies, switching to the backup power supply after a voltage detection module detects an anomaly in the primary power supply. However, such systems rely on a single threshold voltage comparison mechanism. When the primary power supply experiences a momentary drop or spike in output voltage due to input voltage fluctuations or sudden load changes, it is prone to frequent false switching due to voltage jitter, and even millisecond-level power outages due to response delays. Furthermore, the switching process between primary and backup power supplies lacks a dynamic coordination mechanism. When the load current changes drastically, the backup power supply cannot quickly match the real-time operating parameters of the primary power supply, leading to output voltage overshoot or drop, affecting the stability of downstream precision equipment.

[0003] Existing redundant power supplies often employ the same topology for their primary and backup modules, such as dual-Buck or dual-Boost circuits, which limits the range of input voltage adaptability. When the input voltage experiences a sudden rise or fall, both the primary and backup power supplies may exceed their normal operating range simultaneously, losing their redundancy protection function. For example, in industrial power supply scenarios, the input voltage may fluctuate drastically in a short period due to factors such as motor start-stop, lightning surges, etc. Traditional redundancy solutions struggle to cover a wide range of input voltage variations, significantly reducing system reliability.

[0004] On the other hand, noise generated by high-frequency switching power supplies can be reverse-coupled to the control loop through isolation diodes, interfering with the switching logic's judgment. Although some solutions attempt to suppress noise by adding filter capacitors or shielding measures, such designs often increase circuit size and cost, and cannot completely eliminate the impact of high-frequency interference on threshold detection accuracy. Existing technologies have not yet achieved an effective balance between fast switching, dynamic parameter adjustment, wide input compatibility, and anti-interference capabilities, which restricts the widespread adoption of redundant power supplies in high-reliability applications. Summary of the Invention

[0005] To address the technical problems in existing technologies, such as power outages caused by switching delays, poor adaptability to load changes leading to output voltage overshoot, limitations on the applicable range of input voltage due to the single main / standby power supply topology, and interference with switching control accuracy by high-frequency switching noise, this invention provides an automatic redundancy complementarity device for DC-DC power supplies.

[0006] The technical solution provided by this invention is as follows: The present invention provides an automatic redundancy complementation device for DC-DC power supplies, comprising: Main power supply module, backup power supply module, switching control unit, output filtering circuit, voltage detection module and dynamic feedback compensation module; The input terminals of the main power module and the backup power module are connected in parallel to the DC power supply VIN, and their output terminals are connected to the input terminal of the switching control unit through Schottky diodes D1 and D2 connected in reverse parallel, respectively. The switching control unit includes a dual threshold comparison circuit U1 and a low on-resistance MOSFET Q1. Its input terminal receives the output voltage of the main and backup power modules, and its output terminal is connected to the output filter circuit. The voltage detection module collects the output voltage of the main power module in real time and triggers the switching control unit to switch to the backup power module based on the dynamic reference voltage VREF. The dynamic feedback compensation module synchronously adjusts the output parameters of the main and backup power modules according to changes in load current, achieving seamless switching.

[0007] Furthermore, the main power supply module is a Buck step-down circuit, and the backup power supply module is a Boost step-up circuit. The overlap of their input voltage ranges is greater than 20% of the rated fluctuation range of the DC power supply VIN, in order to cover scenarios where the input voltage suddenly rises or falls.

[0008] Furthermore, the dual threshold comparison circuit (U1) includes: The first comparator U1A has its non-inverting input connected to the voltage divider signal of the voltage detection module, and its inverting input connected to the upper limit threshold voltage VH. The second comparator U1B has its inverting input connected to the voltage divider signal of the voltage detection module, and its non-inverting input connected to the lower limit threshold voltage VL. The outputs of the first and second comparators drive the MOSFET Q1 through the OR gate U2 to achieve fast switching between main and backup power supplies.

[0009] Furthermore, the dynamic feedback compensation module includes: The current sampling resistor R4 is connected in series between the output filter circuit and the load; Error amplifier U3 has its input terminal sampling the voltage drop across the current sampling resistor R4, and its output terminal connected to the feedback pins of the main and backup power modules respectively, adjusting their duty cycle or frequency in real time.

[0010] Furthermore, ferrite beads FB1 and FB2 are connected in series between the anodes of the Schottky diodes D1 and D2 and the corresponding power module output terminals to suppress the interference of high-frequency switching noise on the switching process.

[0011] Furthermore, the output filter circuit consists of a common-mode inductor L1 and two sets of electrolytic capacitors C2 and C3 with opposite polarities, and its equivalent series resistance ESR is less than 10mΩ to reduce output voltage ripple.

[0012] Furthermore, the switching control unit integrates an RS485 communication interface for receiving external control commands and dynamically modifying the threshold voltages VH and VL of the dual threshold comparison circuit U1, as well as the feedback compensation parameters.

[0013] Furthermore, the dynamic reference voltage VREF is generated by a digital-to-analog converter (DAC), and its input value is dynamically adjusted according to the load's operating mode using a lookup table method.

[0014] The beneficial effects of the technical solution provided by this invention include at least the following: (1) In this invention, the dual-threshold fast switching mechanism and dynamic feedback compensation design significantly shorten the main / backup power supply switching response time, avoiding the risks of malfunctions and power outages caused by traditional single-threshold detection. Simultaneously, the main / backup power supply adopts a Buck / Boost complementary topology, expanding the input voltage compatibility range and ensuring that at least one power module operates stably when the input voltage suddenly rises or falls, effectively addressing the complex power supply environment in industrial settings and improving the overall system reliability. (2) In this invention, a high-frequency noise suppression module and a low-ripple filter circuit are built-in. The transmission path of switching noise is blocked by ferrite bead isolation and common-mode inductor design, reducing the probability of interference to the control signal. The dynamic feedback compensation module adjusts the output parameters of the main and backup power supplies in real time to ensure that the output voltage fluctuation is minimal during load changes or switching, meeting the power supply requirements of precision electronic equipment. In addition, the integrated communication interface supports remote threshold configuration and status monitoring, enhancing the system's intelligence level and making it suitable for high-reliability application scenarios such as the Internet of Things. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the structure of an automatic redundancy complementation device for DC-DC power supplies provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the internal structure of the main and backup power modules of an automatic redundancy complementarity device for DC-DC power supplies, provided in an embodiment of the present invention.

[0017] In the diagram: 101, Main power supply module; 102, Backup power supply module; 200, Switching control unit; 300, Output filter circuit; 400, Load; 500, Voltage detection module; 600, Dynamic feedback compensation module; 700, RS485 communication module. Detailed Implementation

[0018] The technical solution of the present invention will now be described with reference to the accompanying drawings.

[0019] In embodiments of the present invention, words such as "exemplarily," "for example," etc., are used to indicate that something is an example, illustration, or description. Any embodiment or design described as "exemplary" in the present invention should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the word "exemplary" is intended to present the concept in a concrete manner. Furthermore, in embodiments of the present invention, the meaning expressed by "and / or" can be both, or either one.

[0020] To make the technical problems, technical solutions and advantages of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0021] Reference manual attached Figure 1 The diagram shows a schematic of an automatic redundancy complementation device for DC-DC power supplies provided in an embodiment of the present invention.

[0022] This invention provides an automatic redundancy complementation device for DC-DC power supplies, comprising: Main power module 101, backup power module 102, switching control unit 200, output filter circuit 300, voltage detection module 500 and dynamic feedback compensation module 600; The input terminals of the main power supply module 101 and the backup power supply module 102 are connected in parallel to the DC power supply VIN, and their output terminals are connected to the input terminal of the switching control unit 200 through Schottky diodes D1 and D2 connected in reverse parallel, respectively. The switching control unit 200 includes a dual threshold comparison circuit U1 and a low on-resistance MOSFET Q1. Its input terminal receives the output voltage of the main and backup power modules, and its output terminal is connected to the output filter circuit 300. The voltage detection module 500 collects the output voltage of the main power module in real time and triggers the switching control unit 200 to switch to the backup power module based on the dynamic reference voltage VREF. The dynamic feedback compensation module 600 synchronously adjusts the output parameters of the main and backup power modules according to changes in load current, achieving seamless switching.

[0023] Specifically, the main power module 101 is a Buck step-down circuit, and the backup power module 102 is a Boost step-up circuit. The overlapping area of ​​their input voltage ranges is greater than 20% of the rated fluctuation range of the DC power supply VIN, in order to cover scenarios where the input voltage rises or falls suddenly.

[0024] Specifically, the dual threshold comparison circuit U1 includes: The first comparator U1A has its non-inverting input connected to the voltage divider signal of the voltage detection module 500, and its inverting input connected to the upper limit threshold voltage VH. The second comparator U1B has its inverting input connected to the voltage divider signal of the voltage detection module 500, and its non-inverting input connected to the lower limit threshold voltage VL. The outputs of the first and second comparators drive the MOSFET Q1 through the OR gate U2, enabling rapid switching between main and backup power supplies.

[0025] Specifically, the dynamic feedback compensation module 600 includes: The current sampling resistor R4 is connected in series between the output filter circuit 300 and the load 400; Error amplifier U3 has its input terminal sampling the voltage drop across the current sampling resistor R4, and its output terminal connected to the feedback pins of the main and backup power modules respectively, adjusting their duty cycle or frequency in real time.

[0026] Specifically, ferrite beads FB1 and FB2 are connected in series between the anodes of Schottky diodes D1 and D2 and the corresponding power module output terminals to suppress the interference of high-frequency switching noise on the switching process.

[0027] Specifically, the output filter circuit 300 consists of a common-mode inductor L1 and two sets of electrolytic capacitors C2 and C3 with opposite polarities. Its equivalent series resistance ESR is less than 10mΩ to reduce output voltage ripple.

[0028] Specifically, the switching control unit 200 integrates an RS485 communication interface 700, which is used to receive external control commands and dynamically modify the threshold voltages VH and VL of the dual threshold comparison circuit U1 and the feedback compensation parameters.

[0029] Specifically, the dynamic reference voltage VREF is generated by a digital-to-analog converter (DAC), and its input value is dynamically adjusted according to the operating mode of the load 400 using a lookup table method.

[0030] like Figure 2As shown, the main power module 101 uses a Buck converter circuit. Its input line is labeled DC power supply VIN and is connected to the input terminal of the switching transistor Q2. The output terminal of the switching transistor Q2 is connected in series with the energy storage inductor L2. The other end of the energy storage inductor L2 is connected to the anode of the freewheeling diode D3. The cathode of the freewheeling diode D3 is grounded and connected in parallel with the output capacitor C4. The positive terminal of the output capacitor C4 is led out to the output terminal of the main power module 101. The backup power module 102 uses a Boost converter circuit. Its input line is also labeled DC power supply VIN and is connected to the input terminal of the boost inductor L3. The output terminal of the boost inductor L3 is connected in series with the drain of the switching transistor Q3. The source of the switching transistor Q3 is grounded. The boost inductor L3 and the switching transistor Q3 are connected to the anode of the output diode D4. The cathode of the output diode D4 is connected in parallel with the output capacitor C5. The positive terminal of the output capacitor C5 is led out to the output terminal of the backup power module 102.

[0031] In one possible implementation, the system includes a main power module 101, a backup power module 102, a switching control unit 200, an output filter circuit 300, a voltage detection module 500, and a dynamic feedback compensation module 600. The main power module 101 uses a Buck converter, with an input DC voltage of 24V, and outputs 12V / 5A through a switch Q2, a freewheeling diode D3, an energy storage inductor L2, and an output capacitor C4. The backup power module 102 uses a Boost converter, with an input voltage range of 10-30V, and also outputs 12V / 5A through a switch Q3, a boost inductor L3, an output diode D4, and a capacitor C5. The input voltage range of the main power module 101 is 18-30V, and that of the backup power module 102 is 10-25V, with the two overlapping within the 18-25V range.

[0032] The switching control unit 200 includes a dual threshold comparison circuit and a low on-resistance MOSFET Q1. The dual threshold comparison circuit consists of a first comparator U1A and a second comparator U1B: the non-inverting input of the first comparator U1A is connected to the voltage divider signal from the voltage detection module 500, and the inverting input is connected to the upper threshold voltage VH; the inverting input of the second comparator U1B is connected to the voltage divider signal, and the non-inverting input is connected to the lower threshold voltage VL. The outputs of the two comparators are connected to the gate of the MOSFET Q1 through a logic OR gate U2.

[0033] The output filter circuit 300 consists of an inductor L1 and low-ESR capacitors C2 and C3, with a current sampling resistor R4 connected in series at the output terminal to the load. The error amplifier U3 of the dynamic feedback compensation module 600 samples the voltage drop across R4, and the output signal adjusts the PWM duty cycle and switching frequency of the main power supply module 101 and the backup power supply module 102, respectively.

[0034] In one possible implementation, the output terminals of the main power supply module 101 and the backup power supply module 102 are connected in series with ferrite beads FB1 and FB2, respectively. The inductor L1 in the output filter circuit 300 is a differential-mode inductor, and the parallel capacitors C2 and C3 are a combination of ceramic and electrolytic capacitors. The voltage divider resistors R2 and R3 in the voltage detection module 500 are precision resistors, and a temperature compensation capacitor C1 is added to the voltage divider node. The dynamic reference voltage VREF is generated by the digital-to-analog converter (DAC), and its output value is adjusted according to a lookup table based on the load mode.

[0035] In one possible implementation, the switching control unit 200 integrates an RS485 communication module 700, whose data terminal is connected to the serial communication interface of the main control chip. When an external command is sent to modify the threshold voltages VH and VL, the main control chip adjusts the reference voltage through a DAC, and the error amplifier gain of the dynamic feedback compensation module 600 is updated synchronously.

[0036] The beneficial effects of the technical solutions provided in the embodiments of the present invention include at least the following: (1) In this invention, the dual-threshold fast switching mechanism and dynamic feedback compensation design significantly shorten the main / backup power supply switching response time, avoiding the risks of malfunctions and power outages caused by traditional single-threshold detection. Simultaneously, the main / backup power supply adopts a Buck / Boost complementary topology, expanding the input voltage compatibility range and ensuring that at least one power module operates stably when the input voltage suddenly rises or falls, effectively addressing the complex power supply environment in industrial settings and improving the overall system reliability. (2) In this invention, a high-frequency noise suppression module and a low-ripple filter circuit are built-in. The transmission path of switching noise is blocked by ferrite bead isolation and common-mode inductor design, reducing the probability of interference to the control signal. The dynamic feedback compensation module adjusts the output parameters of the main and backup power supplies in real time to ensure that the output voltage fluctuation is minimal during load changes or switching, meeting the power supply requirements of precision electronic equipment. In addition, the integrated communication interface supports remote threshold configuration and status monitoring, enhancing the system's intelligence level and making it suitable for high-reliability application scenarios such as the Internet of Things.

[0037] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

[0038] The following points need to be explained: (1) The accompanying drawings of the embodiments of the present invention only involve the structures involved in the embodiments of the present invention. Other structures can refer to the general design.

[0039] (2) For clarity, the thickness of layers or regions is enlarged or reduced in the drawings used to describe embodiments of the invention, i.e., these drawings are not drawn to scale. It is understood that when an element such as a layer, film, region or substrate is referred to as being “above” or “below” another element, the element may be “directly” located “above” or “below” the other element or there may be intermediate elements.

[0040] (3) Where there is no conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other to obtain new embodiments.

[0041] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. The scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An automatic redundancy complementation device for DC-DC power supplies, characterized in that, include: Main power module (101), backup power module (102), switching control unit (200), output filtering circuit (300), voltage detection module (500) and dynamic feedback compensation module (600). The input terminals of the main power supply module (101) and the backup power supply module (102) are connected in parallel to the DC power supply VIN, and their output terminals are connected to the input terminal of the switching control unit (200) through Schottky diodes D1 and D2 connected in reverse parallel, respectively. The switching control unit (200) includes a dual threshold comparison circuit U1 and a low on-resistance MOS transistor Q1. Its input terminal receives the output voltage of the main and backup power modules, and its output terminal is connected to the output filter circuit (300). The voltage detection module (500) collects the output voltage of the main power module in real time and triggers the switching control unit (200) to switch to the backup power module based on the dynamic reference voltage VREF. The dynamic feedback compensation module (600) adjusts the output parameters of the main and backup power modules synchronously according to the load current change, so as to achieve seamless switching.

2. The automatic redundancy complementation device for DC-DC power supply according to claim 1, characterized in that: The main power module (101) is a Buck step-down circuit, and the backup power module (102) is a Boost step-up circuit. The overlapping area of ​​their input voltage ranges is greater than 20% of the rated fluctuation range of the DC power supply VIN, in order to cover scenarios where the input voltage rises or falls suddenly.

3. The automatic redundancy complementation device for DC-DC power supply according to claim 1, characterized in that: The dual threshold comparison circuit (U1) includes: The first comparator U1A has its non-inverting input connected to the voltage divider signal of the voltage detection module (500), and its inverting input connected to the upper limit threshold voltage VH. The second comparator U1B has its inverting input connected to the voltage divider signal of the voltage detection module (500), and its non-inverting input connected to the lower limit threshold voltage VL. The outputs of the first and second comparators drive the MOSFET Q1 through the OR gate U2 to achieve fast switching between main and backup power supplies.

4. The automatic redundancy complementation device for DC-DC power supply according to claim 1, characterized in that: The dynamic feedback compensation module (600) includes: The current sampling resistor R4 is connected in series between the output filter circuit (300) and the load (400); Error amplifier U3 has its input terminal sampling the voltage drop across the current sampling resistor R4, and its output terminal connected to the feedback pins of the main and backup power modules respectively, adjusting their duty cycle or frequency in real time.

5. The automatic redundancy complementation device for DC-DC power supply according to claim 1, characterized in that: The anodes of the Schottky diodes D1 and D2 are connected in series with the corresponding power module output terminals, and ferrite beads FB1 and FB2 are used to suppress the interference of high-frequency switching noise on the switching process.

6. The automatic redundancy complementation device for DC-DC power supply according to claim 1, characterized in that: The output filter circuit (300) consists of a common-mode inductor L1 and two sets of electrolytic capacitors C2 and C3 with opposite polarities. Its equivalent series resistance ESR is less than 10mΩ to reduce output voltage ripple.

7. The automatic redundancy complementation device for DC-DC power supply according to claim 1, characterized in that: The switching control unit (200) integrates an RS485 communication interface (700) for receiving external control commands and dynamically modifying the threshold voltages VH and VL of the dual threshold comparison circuit U1 and the feedback compensation parameters.

8. The automatic redundancy complementation device for DC-DC power supply according to claim 1, characterized in that: The dynamic reference voltage VREF is generated by a digital-to-analog converter (DAC), and its input value is dynamically adjusted according to the operating mode of the load (400) by a lookup table method.

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