Two-stage surge current suppression device applied to high-power satellite power supply

Abstract

The utility model discloses a two -stage surge current suppression device for high -power satellite power supply, including battery bank, constant -current voltage -limiting power pre -charge circuit, MOS tube surge suppression circuit and bus capacitor, MOS tube surge suppression circuit is parallel in battery bank anode and bus capacitor anode between with constant -current voltage -limiting power pre -charge circuit, MOS tube surge suppression circuit is parallel in constant -current voltage -limiting power pre -charge circuit both ends, its input end connects the anode of battery bank, and the output end connects the anode of bus capacitor, constant -current voltage -limiting power pre -charge circuit includes constant -current voltage -limiting power, and the input end of constant -current voltage -limiting power connects the anode of battery bank, and the output end is connected to the anode of bus capacitor. Two -stage surge current suppression device that the application realizes through above -mentioned scheme has the advantages of charging time stability, avoids resistance overheat, effectively suppresses surge current, improves system security.

Description

Technical Field

[0001] This utility model relates to the field of satellite power system technology, and in particular to a two-stage surge current suppression device for high-power satellite power supply. Background Technology

[0002] In satellite power systems, when the battery bank is connected to the bus, the bus capacitor is not charged and the voltage is 0V. After connection, the battery bank discharges from high voltage to low voltage, generating a large inrush current. This large inrush current poses numerous safety risks to the system, such as causing grounding faults, equipment damage, and fuse blowouts. Furthermore, the high dV / dt associated with DC support capacitor charging can lead to ringing and component damage.

[0003] The basic method for limiting inrush current during satellite power-on operation is generally to use a pre-charge circuit in the battery pack discharge switch, which limits the inrush current through a current-limiting resistor. See, for example... Figure 1 Upon power-up, the pre-charging circuit operates first, closing switch S2 and limiting the inrush current through current-limiting resistor R1 to charge the bus capacitor. Once the bus voltage reaches the preset value, switch S1 closes and switch S2 opens, providing a large current supply to the bus.

[0004] While the existing solutions can limit surge current to some extent, they have many drawbacks. For example, the charging current is affected by the voltage difference between the battery pack and the bus, the charging time is unstable, and the pre-charging resistor may overheat due to repeated operation in a short period of time, which may expose the system to short circuit and failure risks, and may even damage the high-voltage circuit. Utility Model Content

[0005] A brief overview of embodiments of the present invention is provided below to provide a basic understanding of certain aspects of the invention. It should be understood that this overview is not an exhaustive summary of the invention. It is not intended to identify key or essential parts of the invention, nor is it intended to limit the scope of the invention. Its purpose is merely to present certain concepts in a simplified form as a prelude to the more detailed description that follows.

[0006] This invention aims to provide a two-stage surge current suppression device for high-power satellite power supplies, in order to solve the problems of unstable charging time and overheating of pre-charging resistors in traditional pre-charging circuits in the prior art, effectively suppressing surge current and ensuring the safe and stable operation of the satellite power supply system.

[0007] Specifically, this utility model provides a two-stage surge current suppression device for high-power satellite power supplies, comprising: Battery pack, constant current voltage limiting power supply pre-charge circuit, MOSFET surge suppression circuit and bus capacitor; The input terminal of the constant current voltage limiting power supply pre-charge circuit is connected to the positive terminal of the battery pack, the output terminal is connected to the positive terminal of the bus capacitor, and the negative terminal of the battery pack is connected to the negative terminal of the bus capacitor. The MOS transistor surge suppression circuit and the constant current voltage limiting power supply pre-charge circuit are connected in parallel between the positive terminal of the battery pack and the positive terminal of the bus capacitor. The constant current voltage limiting power supply pre-charge circuit includes a constant current voltage limiting power supply, the input terminal of which is connected to the positive terminal of the battery pack, and the output terminal is connected to the positive terminal of the bus capacitor. The MOS transistor surge suppression circuit includes a MOS transistor, the drain of which is connected to the positive terminal of the battery pack, and the source of which is connected to the positive terminal of the bus capacitor.

[0008] Furthermore, the constant current voltage limiting power supply pre-charge circuit also includes a diode, and the output terminal of the constant current voltage limiting power supply is connected in series with the diode and then connected to the bus capacitor.

[0009] Furthermore, the MOSFET surge suppression circuit includes a MOSFET and an on / off control unit. The gate of the MOSFET is connected to the on / off control unit, the drain of the MOSFET is connected to the positive terminal of the battery pack, and the source of the MOSFET is connected to the bus capacitor.

[0010] Furthermore, the input terminal of the on / off control unit is connected to a pre-charge control circuit, and the detection terminal of the pre-charge control circuit is connected to both ends of the bus capacitor to detect the bus voltage and output a control signal.

[0011] Compared with the prior art, the above-described solution has the following advantages: 1. Stable charging time: The constant current and voltage limiting power supply is used for pre-charging, and the charging current is constant. It is not affected by the voltage difference between the battery pack and the bus, so the charging time is more stable and reliable. It is not affected by temperature and load changes, which improves the stability of the satellite power system during power-on.

[0012] 2. Avoid resistor overheating: The traditional method of using current-limiting resistors in pre-charge circuits is abandoned, which avoids the pre-charge resistor being in a state of excessive current for a long time due to repeated pre-charge in a short period of time. This prevents the resistor from overheating, reduces the risk of system short circuits and failures, and extends the service life of high-voltage circuits.

[0013] 3. Effectively suppressing surge current: The soft-start mode of the MOSFET surge suppression circuit can effectively suppress the generation of surge current, avoiding electromagnetic interference and equipment damage caused by rapid current changes during main power supply switching, improving system stability and reliability, and ensuring the safe and stable operation of the satellite power system.

[0014] 4. Improved system safety: The voltage limiting function of the constant current voltage limiting power supply and the synergistic effect of the MOSFET surge suppression circuit ensure that the changes in bus voltage and current are always within a safe range, effectively avoiding safety risks such as grounding faults, equipment damage and fuse blowing, and improving the overall safety of the satellite power system. Attached Figure Description

[0015] This invention can be better understood by referring to the following description taken in conjunction with the accompanying drawings, in which the same or similar reference numerals are used throughout the drawings to denote the same or similar parts. These drawings, together with the following detailed description, are incorporated in and form part of this specification, and are used to further illustrate preferred embodiments of the invention and explain the principles and advantages of the invention. In the drawings: Figure 1 The circuit diagram of the pre-charging circuit in the prior art; Figure 2 This is a circuit diagram of the pre-charging circuit in an embodiment of this application. Detailed Implementation

[0016] Embodiments of the present invention will now be described with reference to the accompanying drawings. Elements and features described in one drawing or embodiment of the present invention may be combined with elements and features shown in one or more other drawings or embodiments. It should be noted that, for clarity, representations and descriptions of components and processes unrelated to the present invention and known to those skilled in the art have been omitted from the drawings and description.

[0017] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0018] The main drawbacks of existing pre-charging circuits are: (1) using high voltage for pre-charging, the charging current will vary due to the voltage difference between the battery pack and the bus. The smaller the voltage difference, the smaller the charging current and the longer the charging time. The charging time will vary greatly due to temperature and load changes. (2) repeated charging in a short period of time will cause the pre-charging resistor to be in a state of excessive current for a long time. This repeated power consumption will cause the resistor to overheat, putting the system at risk of short circuit and failure, and may also damage the high-voltage circuit. To this end, this application provides a two-stage surge current suppression device for high-power satellite power supplies, which improves the existing pre-charging circuit to solve the problems of unstable charging time and easy overheating of the pre-charging resistor in the existing technology, effectively suppressing surge current and ensuring the safe and stable operation of the satellite power system.

[0019] As a specific example, see Figure 2 This application provides a two-stage surge current suppression device for high-power satellite power supplies, which includes: a battery pack, a constant current voltage limiting power supply pre-charge circuit, a MOSFET surge suppression circuit, and a bus capacitor.

[0020] The negative terminal of the battery pack is directly connected to the negative terminal of the bus capacitor and grounded. The input terminal of the constant current limiting voltage power supply pre-charge circuit is connected to the positive terminal of the battery pack, and the output terminal is connected to the positive terminal of the bus capacitor, forming the first charging branch. The MOSFET surge suppression circuit is connected in parallel with the first charging branch, bridging the positive terminal of the battery pack and the positive terminal of the bus capacitor, forming the second power supply branch.

[0021] The constant current voltage limiting power supply pre-charge circuit includes a constant current voltage limiting power supply U1 and a diode D1. The input terminal of the constant current voltage limiting power supply U1 is connected to the positive terminal of the battery pack, and its positive output terminal is connected to the anode of the diode D1. The cathode of the diode D1 is connected to the positive terminal of the bus capacitor, thereby preventing reverse current flow.

[0022] The MOSFET surge suppression circuit includes an N-channel MOSFET Q1 and a switching control unit. The switching control unit can be implemented using a gate drive terminal. The drain of MOSFET Q1 is connected to the positive terminal of the battery pack, the source is connected to the positive terminal of the bus capacitor C1, and the gate is connected to the switching control unit through a gate resistor. The switching control unit receives external control levels to turn MOSFET Q1 on and off. Simultaneously, the MOSFET surge suppression circuit can use a soft-start process during conduction. Specifically, by controlling the rise rate of the MOSFET's gate voltage, the conduction process of the MOSFET is smoothly transitioned, effectively suppressing the generation of surge current. This soft-start method avoids electromagnetic interference and equipment damage caused by rapid current changes during switching, improving the stability and reliability of the system.

[0023] The detection terminal of the pre-charge control circuit is directly connected across the two ends of the bus capacitor to collect the bus voltage; its output terminal is connected to the on / off control unit, thereby sending the control level to the gate of MOSFET Q1.

[0024] Its working process is as follows: Upon initial power-up, MOSFET Q1 is off, and the battery pack charges the bus capacitor through the constant current limiting power supply U1 and diode D1. When the voltage across the bus capacitor reaches a set threshold, the output of the pre-charge control circuit flips, the on / off control unit receives a high level, MOSFET Q1 turns on, and the second power supply branch is activated, providing a high-current path for the downstream load. Since the turn-on of MOSFET Q1 is triggered by the hardware circuit node voltage, the entire switching process requires no software intervention, resulting in a simple structure and high reliability.

[0025] Through the hardware connection of the above two-stage parallel branches, the time-sharing operation of pre-charging and surge suppression is realized, meeting the surge current suppression requirements of high-power satellite power supplies.

[0026] In practical design, the pre-charge circuit described above can employ a switching power supply topology. Constant current output is achieved by controlling the duty cycle of the switching transistor, and voltage limiting is implemented using a feedback circuit. Its input is connected to the battery pack, and its output is connected to the bus capacitor and MOSFET surge suppression circuit. The constant charging current and voltage limit of the constant current-limiting power supply are determined based on the specific parameters of the satellite power system, such as battery pack voltage, bus capacitor capacity, and current requirements during normal system operation.

[0027] The surge suppression circuit uses a suitable MOSFET and designs a reasonable gate drive circuit based on the power requirements and current characteristics of the satellite power system to achieve a soft-start function. The gate drive circuit employs a ramp signal generator to produce a slowly rising gate voltage signal, controlling the conduction process of the MOSFET. The parameters of the gate drive circuit can be adjusted through experimental testing and simulation optimization, based on the characteristics of the MOSFET and the system's surge current suppression requirements, to determine the rise rate of the ramp signal generator.

[0028] The pre-charge control circuit is responsible for sending an enable signal to control the start and stop of the constant current voltage limiting power supply. Simultaneously, it monitors the bus voltage. When the bus voltage reaches a preset value, it controls the MOSFET surge suppression circuit to turn on and stops the operation of the constant current voltage limiting power supply. The preset bus voltage value should be set slightly lower than the bus voltage during normal system operation to ensure that the bus capacitor has sufficient stored energy for a smooth transition when switching to main power.

[0029] During operation, when the satellite power system is powered on, the pre-charging circuit uses a constant current voltage-limiting power supply for pre-charging. Upon power-up, the pre-charging circuit sends an enable signal to activate the constant current voltage-limiting power supply. This power supply charges the bus capacitor with a constant current, gradually increasing the bus voltage. Because the charging current remains constant and is unaffected by changes in the battery pack and bus voltage difference, the charging time is more stable and reliable, avoiding problems of excessive or insufficient charging current due to voltage difference variations. During pre-charging, the voltage-limiting function of the constant current voltage-limiting power supply ensures that the bus voltage does not exceed the preset safe voltage value, further guaranteeing system safety. During main power supply switching and surge suppression, when the bus voltage reaches the preset value, the MOSFET surge suppression circuit turns on, and the constant current voltage-limiting power supply stops operating. The MOSFET surge suppression circuit provides a large current supply to the bus, meeting the power requirements of the satellite power system during normal operation.

[0030] This application has the following improvements compared to the prior art: 1. In the prior art, the pre-charging circuit uses a current-limiting resistor R1 for pre-charging. This method causes the charging current to be affected by changes in the voltage difference between the battery pack and the bus, resulting in unstable charging time and the resistor being prone to overheating. In this application, the pre-charging circuit uses a constant current and voltage-limiting power supply for pre-charging, charging the bus capacitor with a constant current. The charging current is not affected by changes in the voltage difference between the battery pack and the bus, resulting in a more stable and reliable charging time, and avoiding the problem of resistor overheating.

[0031] 2. In the prior art, there are no special measures to suppress inrush current during main power supply switching, which may lead to electromagnetic interference and equipment damage. In this application, the MOSFET surge suppression circuit adopts a soft-start method during main power supply switching. By controlling the rise rate of the MOSFET gate voltage, the conduction process of the MOSFET is smoothly transitioned, effectively suppressing the generation of inrush current and improving the stability and reliability of the system.

[0032] 3. In existing technologies, current-limiting resistors are prone to overheating, increasing the risk of system short circuits and malfunctions. This application eliminates the use of current-limiting resistors in traditional pre-charge circuits, avoiding resistor overheating caused by repeated pre-charging within a short period, thus reducing the risk of system short circuits and malfunctions and improving system safety.

[0033] It should be emphasized that the term "including / comprises" as used herein refers to the presence of a feature, element, step, or component, but does not exclude the presence or addition of one or more other features, elements, steps, or components.

[0034] Although the present invention has been disclosed above through the description of specific embodiments, it should be understood that all the embodiments and examples described above are exemplary and not restrictive. Those skilled in the art can design various modifications, improvements, or equivalents to the present invention within the spirit and scope of the appended claims. These modifications, improvements, or equivalents should also be considered to be included within the protection scope of the present invention.

Claims

1. A two-stage surge current suppression device for high-power satellite power supplies, characterized in that: include: Battery pack, constant current voltage limiting power supply pre-charge circuit, MOSFET surge suppression circuit and bus capacitor; The input terminal of the constant current voltage limiting power supply pre-charge circuit is connected to the positive terminal of the battery pack, the output terminal is connected to the positive terminal of the bus capacitor, and the negative terminal of the battery pack is connected to the negative terminal of the bus capacitor. The MOS transistor surge suppression circuit and the constant current voltage limiting power supply pre-charge circuit are connected in parallel between the positive terminal of the battery pack and the positive terminal of the bus capacitor. The constant current voltage limiting power supply pre-charge circuit includes a constant current voltage limiting power supply, the input terminal of which is connected to the positive terminal of the battery pack, and the output terminal is connected to the positive terminal of the bus capacitor. The MOS transistor surge suppression circuit includes a MOS transistor, the drain of which is connected to the positive terminal of the battery pack, and the source of which is connected to the positive terminal of the bus capacitor.

2. The two-stage surge current suppression device for high-power satellite power supplies according to claim 1, characterized in that: The constant current voltage limiting power supply pre-charge circuit also includes a diode, and the output terminal of the constant current voltage limiting power supply is connected in series with the diode and then connected to the bus capacitor.

3. The two-stage surge current suppression device for high-power satellite power supplies according to claim 1, characterized in that: The MOSFET surge suppression circuit includes a MOSFET and an on / off control unit. The gate of the MOSFET is connected to the on / off control unit, the drain of the MOSFET is connected to the positive terminal of the battery pack, and the source of the MOSFET is connected to the bus capacitor.

4. The two-stage surge current suppression device for high-power satellite power supplies according to claim 3, characterized in that: The input terminal of the on / off control unit is connected to a pre-charge control circuit, and the detection terminal of the pre-charge control circuit is connected to both ends of the bus capacitor.

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