A secondary power conversion circuit, method and apparatus

Abstract

The application discloses a secondary power conversion circuit, which comprises a fuse protection module, a reverse connection prevention module, a surge suppression module, a filter module and a power conversion module which are electrically connected in sequence; the reverse connection prevention module is used for positive and negative direction conduction control of an input power supply; the fuse protection module is used for realizing fuse protection when the circuit overflows; the surge suppression module is used for suppressing power-on surge current and input surge voltage; the filter module is used for filtering electromagnetic interference in the circuit; and the power conversion module is used for converting primary power voltage into target secondary power voltage. The application can realize integrated protection of reverse connection prevention, overflow protection and surge suppression, and has high power supply stability.

Description

Technical Field

[0001] This invention relates to the field of circuit technology, and in particular to a secondary power conversion circuit, method, and apparatus. Background Technology

[0002] This section is intended to provide background or context for the embodiments of this application set forth in the claims. The description herein is not an admission that it is prior art simply because it is included in this section.

[0003] Secondary power conversion circuits are widely used in various circuit boards, and are designed to prevent reverse connection and are fusible. Summary of the Invention

[0004] One object of this application is to provide a secondary power conversion circuit. Another object of this application is to provide a secondary power conversion method. A further object of this application is to provide a secondary power conversion device.

[0005] To achieve the above objectives, this application discloses a secondary power conversion circuit, comprising a fuse protection module, a reverse connection protection module, a surge suppression module, a filter module, and a power conversion module connected in sequence. The reverse connection protection module is used to control the forward and reverse conduction of the input power supply; The fuse protection module is used to provide fuse protection when the circuit is overcurrent, and the surge suppression module is used to suppress power-on surge current and input surge voltage. The filtering module is used to filter out electromagnetic interference in the circuit. The power conversion module is used to convert the primary power supply voltage into the target secondary power supply voltage.

[0006] Optionally, the fuse protection module includes at least one fuse; When there are two or more fuses, the fuses are connected in parallel, and a current-limiting resistor is connected in series on one of the fuse branches; The resistance value of the current-limiting resistor is greater than a preset multiple of the DC resistance value of the fuse.

[0007] Optionally, the surge suppression module includes a surge current suppression unit and a surge voltage suppression unit; The surge current suppression unit includes a field-effect transistor and a delay network. The delay network is electrically connected to the gate of the field-effect transistor and is used to delay the turn-on of the field-effect transistor. The surge voltage suppression unit includes a surge suppression diode for suppressing surge voltage on the input side.

[0008] Optionally, a transient voltage suppression module is further provided between the surge suppression module and the filtering module; The transient voltage suppression module includes a transient voltage suppression diode for further filtering out transient voltage spikes in the circuit.

[0009] Another aspect of this application proposes a secondary power conversion method, applied to the circuit described above, including: An external primary power supply is input to the fuse protection module, which provides overcurrent protection for the circuit and outputs the primary power supply after overcurrent protection. The primary power supply after overcurrent protection is input to the reverse connection protection module, which controls the forward and reverse conduction of the input primary power supply and outputs the primary power supply after reverse connection protection. The primary power supply after reverse connection protection is input to the surge suppression module. The surge suppression module simultaneously suppresses the power-on surge current and input surge voltage, and outputs the surge-suppressed primary power supply. The surge-suppressed primary power supply is input to the filtering module, which filters out electromagnetic interference and electrical signal spikes in the circuit and outputs the filtered primary power supply. The filtered primary power supply is input to the power conversion module, which converts the primary power supply voltage into the target secondary power supply voltage, thus completing the secondary power conversion.

[0010] Optionally, the overcurrent protection of the circuit via the fuse protection module includes: When an external primary power supply is supplied to the fuse branch of the fuse protection module, the fuse continuously carries the operating current when the circuit is working normally. When an overcurrent or short-circuit fault occurs in the circuit, the fuse will quickly melt and cut off the circuit path according to the magnitude of the fault current, thus completing the overcurrent protection.

[0011] Optionally, it also includes: if the fuse protection module is a multi-fuse parallel structure, the external primary power supply is simultaneously supplied to each fuse branch, the working current is shunted through the parallel fuses, and the fuse branch with the series current-limiting resistor limits the branch current through the current-limiting resistor.

[0012] Optionally, the filtering of electromagnetic interference and electrical signal spikes in the circuit by the filtering module includes: The surge-suppressed primary power supply is input to a common-mode inductor, which filters out spike signals in the input voltage and current, and outputs the peak-suppressed primary power supply. The primary power supply after peak reduction is input to the filter, which filters out electromagnetic interference signals in the circuit and outputs the filtered primary power supply.

[0013] Optionally, before the surge-suppressed primary power input is sent to the filtering module, the following is also included: The surge-suppressed primary power supply is input to the transient voltage suppression module, where transient voltage spikes in the circuit are further filtered out by the transient voltage suppression diode. The primary power supply after filtering out the transient spikes is then input to the filtering module.

[0014] Another aspect of this application discloses a secondary power conversion device, comprising: Overcurrent protection unit: The external primary power supply is input to the fuse protection module, which performs overcurrent protection on the circuit and outputs the primary power supply after overcurrent protection; the primary power supply after overcurrent protection is input to the reverse connection protection module, which controls the forward and reverse conduction of the input primary power supply and outputs the primary power supply after reverse connection protection. Surge suppression unit: Inputs the primary power supply after reverse connection protection to the surge suppression module, which simultaneously suppresses the power-on surge current and input surge voltage, and outputs the surge-suppressed primary power supply. Filtering unit: Inputs the surge-suppressed primary power supply to the filtering module, which filters out electromagnetic interference and electrical signal spikes in the circuit and outputs the filtered primary power supply. Power conversion unit: The filtered primary power supply is input to the power conversion module, which converts the primary power supply voltage into the target secondary power supply voltage, thus completing the secondary power conversion.

[0015] The beneficial effects of this application are as follows: This application discloses a secondary power conversion circuit, comprising a fuse protection module, a reverse connection protection module, a surge suppression module, a filter module, and a power conversion module connected in sequence. The reverse connection protection module controls the forward and reverse conduction of the input power supply. The fuse protection module provides overcurrent protection. The surge suppression module suppresses power-on surge current and input surge voltage. The filter module filters out electromagnetic interference in the circuit. The power conversion module converts the primary power supply voltage to the target secondary power supply voltage. This circuit provides integrated protection against reverse connection, overcurrent, and surge, resulting in high power supply stability. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the 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. In the drawings: Figure 1 This paper shows a schematic diagram of a secondary power conversion circuit according to an embodiment of the present application; Figure 2This diagram shows a structural schematic of a delay network in a secondary power conversion circuit according to an embodiment of this application. Figure label: 100. Fuse protection module; 200. Reverse connection protection module; 300. Surge suppression module; 400. Filtering module; 500. Power conversion module. Detailed Implementation

[0017] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. The word "and / or" in the text is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Furthermore, in the description of the embodiments of this application, "multiple" refers to two or more than two.

[0018] It should be understood that the terms "first," "second," etc., in the specification, claims, and drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0019] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0020] In order to solve at least one of the problems existing in the prior art, according to one aspect of this application, such as Figure 1 As shown, this embodiment discloses a secondary power conversion circuit, including a fuse protection module 100, a reverse connection protection module 200, a surge suppression module 300, a filter module 400, and a power conversion module 500 connected in sequence. The reverse connection protection module 200 is used to control the forward and reverse conduction of the input power supply. The fuse protection module 100 is used to provide fuse protection when the circuit is overcurrent. The surge suppression module 300 is used to suppress the power-on surge current and the input surge voltage. The filter module 400 is used to filter out electromagnetic interference in the circuit. The power conversion module 500 is used to convert the primary power supply voltage into the target secondary power supply voltage.

[0021] Specifically, based on the different power supply voltage requirements of various electronic devices and circuit boards, the external primary power supply often cannot directly meet the working voltage requirements of the internal components of the device. Therefore, it is necessary to use a special circuit for conversion and protection, thus forming a secondary power conversion circuit.

[0022] In a specific example, the external primary power supply is first connected to the fuse protection module 100, which monitors the current in the circuit in real time. When the circuit is working normally, the current is within the preset normal range, and the fuse protection module 100 remains on, allowing the primary power supply to continue transmitting. When the circuit experiences overcurrent, short circuit, or other faults, the current exceeds the normal range, the fuse protection module 100 blows, directly cutting off the external power supply path. The primary power signal processed by the fuse protection module 100 is then input to the reverse connection protection module 200. The reverse connection protection module 200 identifies the positive and negative terminals of the input power supply: if the positive and negative terminals are connected correctly, the reverse connection protection module 200 conducts, allowing the power signal to pass; if the positive and negative terminals are reversed, the reverse connection protection module 200 cuts off, cutting off the power supply path. The power signal processed by the reverse connection protection module 200 is then input to the surge suppression module 300. The surge suppression module 300 simultaneously suppresses both power-on surge current and input surge voltage in the circuit: for power-on surge current, it slows down the charging speed of the downstream capacitive load by controlling the turn-on speed of relevant components, thereby suppressing the peak value of the surge current; for input surge voltage, it limits the surge voltage to a safe range through the clamping effect of dedicated components, preventing the surge voltage from impacting the circuit. The power signal processed by the surge suppression module 300 is then input to the filter module 400. The filter module 400, through the action of relevant components, filters out electromagnetic interference signals, electrical signal spikes, and other noise in the circuit, making the power signal stable and pure. The pure primary power signal processed by the filter module 400 is then input to the power conversion module 500. The power conversion module 500, through its internal conversion circuit, converts the primary power voltage to the target secondary power voltage. After conversion, the stable secondary power is delivered to the downstream equipment through the output terminal, providing power support for the downstream equipment.

[0023] In an optional implementation, the fuse protection module 100 includes at least one fuse; when there are two or more fuses, each fuse is connected in parallel, and a current-limiting resistor is connected in series on one of the fuse branches; the resistance value of the current-limiting resistor is greater than a preset multiple of the DC resistance value of the fuse.

[0024] Specifically, when an overcurrent or short-circuit fault occurs in a circuit, a fuse breaks the circuit by melting itself, thus protecting the circuit. A fuse has a certain rated current carrying capacity; when the current in the circuit exceeds its rated capacity, the fuse element melts, cutting off the circuit. A current-limiting resistor is used to limit the current in a branch of the circuit; its resistance value is usually set according to the circuit's operating requirements. Connecting a current-limiting resistor in series with a fuse branch limits the current in that branch, ensuring even current distribution across all branches. DC resistance is the resistance value presented when current flows through a DC circuit. Resistive components impede current flow during operation; this impediment in a DC circuit is called the DC resistance value. This value can be measured using specialized equipment. Measurement requires connecting the component to a DC circuit and calculating the resistance using Ohm's law by measuring current and voltage. The preset ratio refers to the ratio between the current-limiting resistor value and the fuse's DC resistance value. It is a pre-set value based on the circuit's protection requirements and operating characteristics; the specific ratio is determined according to the actual operating conditions and protection requirements of the circuit.

[0025] In a specific example, when there is only one fuse, it is connected in series in the circuit. The input terminal of the fuse is electrically connected to the external primary power supply, and the output terminal is electrically connected to the input terminal of the reverse connection protection module 200. All current in the circuit flows through this fuse. When the current is abnormal, the fuse blows, cutting off the entire circuit. When there are two or more fuses, they are connected in parallel. The input terminals of all fuses are connected together and electrically connected to the external primary power supply; the output terminals of all fuses are connected together and electrically connected to the input terminal of the reverse connection protection module 200. In the parallel structure of multiple fuses, a current-limiting resistor needs to be connected in series in one of the fuse branches. The resistance value of this current-limiting resistor must be greater than a preset multiple of the DC resistance value of the fuse. In practical use, the DC resistance values ​​of each fuse may have slight differences. If a current-limiting resistor is not set, the current distribution in each fuse branch will be uneven, and the current in some branches will be too high, which may cause the fuse in that branch to blow prematurely, affecting the normal operation of the fuse protection module 100. By connecting a current-limiting resistor in series, the current in that branch can be limited, making the current distribution in each fuse branch more uniform. This allows each fuse to work normally, and in the event of a circuit fault, the fuses can work together to achieve fuse protection.

[0026] In an optional embodiment, the surge suppression module 300 includes a surge current suppression unit and a surge voltage suppression unit; the surge current suppression unit includes a field-effect transistor and a delay network, the delay network being electrically connected to the gate of the field-effect transistor for delaying the turn-on of the field-effect transistor; the surge voltage suppression unit includes a surge suppression diode for suppressing surge voltage on the input side.

[0027] Specifically, at the moment of power-on, the downstream capacitive load generates a large charging current, forming a surge current. External power grid fluctuations, electromagnetic interference, lightning strikes, and other factors can cause instantaneous peak values ​​in the input voltage, forming surge voltage. The peak value of the surge signal is usually much higher than the normal operating current and voltage of the circuit, which can severely impact the components in the circuit, leading to accelerated aging, damage, and even circuit failure. A surge suppression module 300 is used to prevent surge signals from causing damage to the components in the circuit. Field-effect transistors (FETs) are divided into N-channel and P-channel types. FETs have characteristics such as high input impedance, high control precision, and fast switching speed. They can precisely control the conduction between the drain and source through the gate voltage, thereby controlling the current magnitude. Delay networks are used to delay the turn-on time of the FET, achieving delayed turn-on. To suppress inrush current, the charging speed of the downstream capacitive load needs to be slowed down. However, the turn-on speed of a field-effect transistor (FET) is relatively fast. Direct turn-on would cause the capacitive load to charge rapidly, generating a large inrush current. Therefore, a delay network is needed. This network uses the charging characteristics of a capacitor to delay the rise rate of the FET's gate voltage, thereby delaying the FET's turn-on time. The gate refers to the control electrode of the FET; by applying different voltages, the conduction state and current magnitude between the drain and source of the FET can be controlled. Surge suppression diodes are used to quickly conduct when a surge voltage occurs in the circuit, clamping the voltage within a preset safe range. The input surge voltage is the instantaneous peak voltage appearing in the external input power supply. For example... Figure 2 The diagram shows the circuit structure of the delay network and field-effect transistor (FET) of the surge current suppression unit in this embodiment. The circuit includes FET V2, delay resistor R15, delay capacitors C16 and C17, surge suppression diode V3, and voltage divider resistors R13, R14, R16, and R17. The source S of FET V2 is connected to the input +27VA, and the drain D is connected to the output +27VA_2. The gate G is connected to the delay network node formed by C16 and C17 in parallel through R15. The other end of the delay network is connected to the input power supply. When powered on, the power supply can charge C16 and C17 through R15 to control the gate voltage to rise slowly, thereby realizing the delayed turn-on of the FET. The voltage divider resistors R13 and R16, and R14 and R17 respectively form symmetrical voltage divider branches to provide a stable bias voltage for the gate. The surge suppression diode V3 is connected in parallel between the input +27VA and ground, serving as a surge voltage suppression unit to clamp the surge voltage on the input side within a safe range. This circuit uses a delay network to control the gradual increase of the gate-source voltage difference of the field-effect transistor, thereby achieving a gradual turn-on of the field-effect transistor and slowing down the charging speed of the capacitive load in the subsequent stage. This effectively suppresses the power-on surge current. At the same time, in conjunction with the surge suppression diode, it simultaneously clamps and protects against the input surge voltage, thus improving the overall power-on stability and shock resistance of the circuit.

[0028] In a specific example, upon power-on, after the power supply is connected, the capacitor is first charged through the resistor of the delay network. At this moment, the gate voltage of the MOSFET is low, and the gate-source voltage difference has not reached the turn-on voltage, so the MOSFET is in the off state, and the subsequent capacitive load cannot be charged, resulting in almost no current in the circuit. As the capacitor continues to charge, the gate voltage gradually rises, and the gate-source voltage difference gradually increases. When it reaches the turn-on voltage of the MOSFET, the MOSFET begins to conduct, the resistance between the drain and source gradually decreases, and the subsequent capacitive load begins to charge slowly, with the charging current gradually increasing. When the capacitor is fully charged, the gate voltage stabilizes at a certain value, the MOSFET is fully turned on, the resistance between the drain and source reaches its minimum value, the subsequent capacitive load charges normally, and the circuit enters a stable operating state. Throughout the entire process, the charging current remains within a controllable range, avoiding the generation of surge current. When a surge voltage occurs on the input side, the surge voltage amplitude rises rapidly. When it exceeds the breakdown voltage of the surge suppression diode, the internal resistance of the surge suppression diode decreases rapidly, and it enters the conducting state, clamping the input voltage near its breakdown voltage. At the same time, the surge energy is released to ground through the surge suppression diode, and the surge voltage amplitude is limited to a safe range. When the surge voltage disappears, the input voltage returns to the normal operating voltage, the internal resistance of the surge suppression diode increases again, and it enters the cutoff state, no longer affecting the normal operation of the circuit, thus achieving effective suppression of surge voltage.

[0029] In a specific example, a field-effect transistor (FET) V2 is placed at the positive terminal of the power supply. The FET is an RCS7422SAU1, an SMD-1 packaged CASTC-grade device with a maximum VDS of 100V. FET V2's gate voltage is pulled low by resistor R15, keeping it in an off state under normal conditions. When an input voltage is applied, the power supply first charges capacitors C16 and C17, gradually increasing the gate-source voltage difference of FET V2. The presence of C16 and C17 slows down the turn-on time of V2, effectively limiting the inrush current. This surge suppression circuit achieves delayed turn-on of the device by controlling the MOSFET's gate-source voltage, avoiding the large inrush current caused by directly charging the downstream capacitive load with a high voltage, thus fundamentally preventing the problem of fuses accidentally blowing due to inrush current.

[0030] In this embodiment, a surge suppression diode is configured in the surge suppression circuit. The SY5650A from Factory 873 is selected as the device. Its function is to specifically suppress the surge voltage on the input side. The diode has a maximum reverse working voltage of 43.6V and a breakdown voltage of 51V. It can clamp the surge voltage on the input side within a safe range and effectively avoid the impact damage of surge voltage to the components of the subsequent circuit.

[0031] In an optional embodiment, a transient voltage suppression module is further provided between the surge suppression module 300 and the filter module 400; the transient voltage suppression module includes a transient voltage suppression diode for further filtering out transient voltage spikes in the circuit.

[0032] A transient voltage suppression module is positioned between the surge suppression module 300 and the filter module 400 to filter transient voltage spikes that may still exist after surge suppression. This makes the power signal input to the filter module 400 more stable and prevents transient voltage spikes from affecting subsequent modules. Transient voltage suppression diodes are used to quickly respond to transient voltage spikes, clamping them within a safe range, thereby filtering out the transient voltage spikes. Transient voltage spikes are instantaneous voltage peaks that appear in the circuit. Their amplitude is usually lower than the surge voltage, and their duration is extremely short, but they may interfere with the operation of other components in the circuit, therefore, they need to be filtered out.

[0033] In a specific example, when the circuit is operating normally, the power signal input to the transient voltage suppression module is processed by the surge suppression module 300, which filters out surge voltages of a relatively large magnitude. At this time, the power supply voltage is within the normal range, the transient voltage suppression diode is in the off state, and it does not affect the normal transmission of the power signal. The power signal smoothly enters the filter module 400. When a transient voltage spike occurs in the circuit, whether it is a residual surge voltage that the surge suppression module 300 has not completely suppressed or a transient voltage spike generated inside the circuit, as long as the voltage amplitude exceeds the breakdown voltage of the transient voltage suppression diode, the transient voltage suppression diode will respond quickly and conduct in a very short time, presenting a low resistance state. This clamps the transient voltage spike near its breakdown voltage and releases the energy of the transient voltage spike to ground through itself, preventing the transient voltage spike from being transmitted to the filter module 400 and subsequent modules. When the transient voltage spike disappears, the power supply voltage returns to normal, the transient voltage suppression diode returns to the off state, and the circuit continues to operate normally, thereby achieving effective filtering of transient voltage spikes.

[0034] In a specific embodiment of this application, the surge suppression module 300 first suppresses large-amplitude surge voltages in the input power supply, limiting the voltage within a certain range. The power signal after surge suppression is input to the transient voltage suppression module, which further filters out any transient voltage spikes that may exist, ensuring that there are no obvious voltage anomalies in the power signal. The power signal after transient voltage suppression is input to the filtering module 400, which filters out electromagnetic interference and electrical signal noise in the circuit, making the power signal more stable. Finally, the clean power signal is input to the power conversion module 500 for voltage conversion, providing a stable secondary power supply for downstream equipment.

[0035] Another aspect of this application discloses a secondary power conversion method, applied to the circuit described above, comprising: S100: Input an external primary power supply to the fuse protection module 100, which performs overcurrent fuse protection on the circuit and outputs the primary power supply after overcurrent protection; input the primary power supply after overcurrent protection to the reverse connection protection module 200, which performs forward and reverse conduction control on the input primary power supply and outputs the primary power supply after reverse connection protection.

[0036] Specifically, an external primary power supply is connected to a fuse protection module 100. The fuse protection module 100 monitors the current in the circuit in real time. When the circuit is operating normally, the current is within the rated range, the fuse remains conductive, and the primary power supply smoothly passes through the fuse protection module 100, outputting the primary power supply after overcurrent protection. When an overcurrent or short-circuit fault occurs, the current exceeds the rated current of the fuse, causing the fuse to blow quickly, cutting off the circuit path and preventing the fault current from entering subsequent circuits. The primary power supply after overcurrent protection is input to a reverse connection protection module 200. The internal components of the reverse connection protection module 200 identify and control the polarity of the input power supply. If the positive and negative terminals are connected correctly, the components conduct in the forward direction, the power path is open, and the primary power supply smoothly passes through the reverse connection protection module 200, outputting the primary power supply after reverse connection protection. If the positive and negative terminals are reversed, the components cut off in the reverse direction, the power path is broken, and the primary power supply cannot enter subsequent circuits, thus preventing damage to subsequent modules and components such as surge suppression, filtering, and power conversion caused by reverse connection.

[0037] S200: Inputs the primary power supply after reverse connection protection to the surge suppression module 300. The surge suppression module 300 simultaneously suppresses the power-on surge current and input surge voltage, and outputs the surge-suppressed primary power supply.

[0038] Specifically, after the reverse connection protection primary power supply is input to the surge suppression module 300, the surge current suppression unit and surge voltage suppression unit in the surge suppression module 300 start working simultaneously. For the power-on surge current, the surge current suppression unit controls the field-effect transistor to turn on with a delay through a delay network, slowing down the charging speed of the subsequent capacitive load, thereby suppressing the peak value of the power-on surge current and avoiding the impact of the surge current on the circuit components. For the input surge voltage, the surge voltage suppression unit limits the surge voltage on the input side to a safe range through the clamping effect of the surge suppression diode, releasing surge energy and preventing the surge voltage from being transmitted to subsequent modules. Through the coordinated work of the two units, the power-on surge current and input surge voltage are suppressed synchronously, so that the output surge-suppressed primary power supply has no obvious surge signal.

[0039] S300: Inputs the surge-suppressed primary power supply to the filter module 400. The filter module 400 filters out electromagnetic interference and electrical signal spikes in the circuit and outputs the filtered primary power supply.

[0040] Specifically, after the surge-suppressed primary power supply is input to the filter module 400, the common-mode inductor and filter inside the filter module 400 start working sequentially, forming a multi-stage filtering protection. The common-mode inductor processes the power signal first, using the inductor's suppression characteristics for sudden signals to filter out spike signals in the input voltage and current caused by circuit operation or external interference, stabilizing the voltage and current amplitudes within the normal operating range, and outputting the peak-suppressed primary power supply. The peak-suppressed primary power supply then enters the filter, where the filter, through the coordinated action of its internal capacitors and inductors, attenuates and filters out common-mode and differential-mode electromagnetic interference in the power signal, effectively eliminating interference noise caused by the operation of internal components, external power grid fluctuations, and electromagnetic radiation, keeping the ripple and noise of the power signal within the threshold range. Through the dual effects of spike signal filtering and electromagnetic interference filtering, the filter module 400 outputs an interference-free and spike-free primary power supply.

[0041] S400: Input the filtered primary power supply to the power conversion module 500, which converts the primary power supply voltage into the target secondary power supply voltage, thus completing the secondary power conversion.

[0042] Specifically, the filtered, clean primary power supply is connected to the power conversion module 500. The primary power supply is first rectified and filtered to further optimize the stability of the power signal. Then, through the coordinated operation of internal components such as switching transistors, transformers, and voltage regulator circuits, the wide-range input primary power supply voltage is converted into a preset target secondary power supply voltage. During the conversion process, the power conversion module 500, based on its power derating design, samples and adjusts the output voltage in real time, controlling the output voltage accuracy within a preset error range. Simultaneously, it suppresses voltage fluctuations and ripple generated during the conversion process, ensuring the stability of the output secondary power supply. Finally, the power conversion module 500 outputs a stable, low-ripple, and interference-free target secondary power supply, directly powering downstream equipment.

[0043] In an optional implementation, the overcurrent protection of the circuit by the fuse protection module 100 includes: S110: When an external primary power supply is supplied to the fuse branch of the fuse protection module 100, the fuse continuously carries the operating current when the circuit is working normally.

[0044] S120: When an overcurrent or short-circuit fault occurs in the circuit, the fuse will quickly melt according to the magnitude of the fault current, cutting off the circuit path and completing the overcurrent protection.

[0045] In an optional implementation, if the fuse protection module 100 is a multi-fuse parallel structure, an external primary power supply is simultaneously supplied to each fuse branch, and the working current is shunted through the parallel fuses, and the fuse branch with the series current-limiting resistor limits the branch current through the current-limiting resistor.

[0046] In this specific example, the surface-mount thick-film fuse MF3216 series from Zhenhua Yunke was selected as the fuse protection device. According to the component derating criteria, when the current is less than or equal to 0.5A, the Class I derating factor should be at least 0.2 to 0.4. Considering the maximum expected operating current of 0.4A for the 27V bus, the fuse with a rated current greater than 2A and closest to 2A was selected. Finally, the fuse model MF3216-FF-125-2 was determined. This fuse has a rated voltage of 125V and a rated current of 2A. Its rated current value is the current that can be carried for a long time without melting at an operating temperature of 25℃, not the melting current value. The minimum melting current corresponding to the rated current of 2A of this fuse is 3.6A. When the fuse protection module 100 adopts a dual-fuse design, two MF3216-FF-125-2 fuses of the same specification are connected in parallel, and a current-limiting resistor is connected in series in one of the fuse branches. The resistance value of the current-limiting resistor is set to be more than 10 times the DC resistance value of the fuse. In this embodiment, the DC internal resistance of the fuse is less than 0.1Ω, so the RXG21 type wire-wound resistor RXG21-1W-V-1Ω-F from Factory 718 is selected as the current-limiting resistor. The series resistor type anti-fuse parallel design of this embodiment realizes the fuse protection function by connecting two fuses in parallel and connecting the above-mentioned current-limiting resistor in series in a single branch. When the circuit operating current is less than or equal to the rated current of the fuse, the two fuses maintain normal conduction. With the help of the current shunting effect of fuse F2, this parallel design can protect fuse F1 from current derating. When the circuit fails or a short-circuit current is generated, the two fuses burn out in sequence, quickly cutting off the fault path and realizing the fuse protection function. Verified in the product manual, when a short circuit occurs within the satellite receiver, the parallel fuse, operating at 25°C, can blow within 0.6-10ms, providing reliable overcurrent protection. Simultaneously, a surge suppression circuit is configured at the output of the reverse connection protection module 200 after the fuse protection module 100. This effectively prevents excessive surge current caused by the charging of the capacitive load at power-on, thus avoiding accidental fuse blown due to surge current.

[0047] In an optional implementation, the filtering of electromagnetic interference and electrical signal spikes in the circuit by the filtering module 400 includes: S310: Inputs the surge-suppressed primary power supply to the common-mode inductor, filters out spike signals in the input voltage and current through the common-mode inductor, and outputs the peak-suppressed primary power supply.

[0048] S320: Inputs the primary power supply after peak reduction to the filter, filters out electromagnetic interference signals in the circuit, and outputs the filtered primary power supply.

[0049] In an optional implementation, before the surge-suppressed primary power supply is input to the filter module 400, the following method is further included: S500: Inputs the primary power supply after surge suppression to the transient voltage suppression module, further filters out transient voltage spikes in the circuit through the transient voltage suppression diode, and inputs the primary power supply after filtering out transient spikes to the filter module 400.

[0050] Another aspect of this application discloses a secondary power conversion device, comprising: Overcurrent protection unit 11: Inputs external primary power supply to fuse protection module 100, performs overcurrent fuse protection on the circuit through fuse protection module 100, and outputs primary power supply after overcurrent protection; inputs primary power supply after overcurrent protection to reverse connection protection module 200, performs forward and reverse conduction control on the input primary power supply through reverse connection protection module 200, and outputs primary power supply after reverse connection protection.

[0051] Surge suppression unit 12: Inputs the primary power supply after reverse connection protection to surge suppression module 300, and the surge suppression module 300 simultaneously suppresses the power-on surge current and input surge voltage, and outputs the surge-suppressed primary power supply.

[0052] Filtering unit 13: Inputs the surge-suppressed primary power supply to the filtering module 400, which filters out electromagnetic interference and electrical signal spikes in the circuit and outputs the filtered primary power supply.

[0053] Power conversion unit 14: Inputs the filtered primary power supply to the power conversion module 500, and the power conversion module 500 converts the primary power supply voltage into the target secondary power supply voltage, thus completing the secondary power conversion.

[0054] Since the principle by which this device solves the problem is similar to the circuits and methods described above, the implementation of this device can be found in the implementation of the circuits and methods, and will not be repeated here.

[0055] The above description is merely an embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this application should be included within the scope of the claims of this application.

Claims

1. A secondary power conversion circuit, characterized in that, It includes a fuse protection module, a reverse connection protection module, a surge suppression module, a filtering module, and a power conversion module that are connected in sequence. The reverse connection protection module is used to control the forward and reverse conduction of the input power supply; The fuse protection module is used to provide fuse protection when the circuit is overcurrent, and the surge suppression module is used to suppress power-on surge current and input surge voltage. The filtering module is used to filter out electromagnetic interference in the circuit. The power conversion module is used to convert the primary power supply voltage into the target secondary power supply voltage.

2. The secondary power conversion circuit according to claim 1, characterized in that, The fuse protection module includes at least one fuse; When there are two or more fuses, the fuses are connected in parallel, and a current-limiting resistor is connected in series on one of the fuse branches; The resistance value of the current-limiting resistor is greater than a preset multiple of the DC resistance value of the fuse.

3. The secondary power conversion circuit according to claim 1, characterized in that, The surge suppression module includes a surge current suppression unit and a surge voltage suppression unit; The surge current suppression unit includes a field-effect transistor and a delay network. The delay network is electrically connected to the gate of the field-effect transistor and is used to delay the turn-on of the field-effect transistor. The surge voltage suppression unit includes a surge suppression diode for suppressing surge voltage on the input side.

4. The secondary power conversion circuit according to claim 1, characterized in that, A transient voltage suppression module is also provided between the surge suppression module and the filter module; The transient voltage suppression module includes a transient voltage suppression diode for further filtering out transient voltage spikes in the circuit.

5. A secondary power supply conversion method, applied to the circuit described in any one of claims 1-4, characterized in that, include: An external primary power supply is input to the fuse protection module, which performs overcurrent fuse protection on the circuit and outputs the primary power supply after overcurrent protection. The primary power supply after overcurrent protection is input to the reverse connection protection module. The reverse connection protection module controls the forward and reverse conduction of the input primary power supply and outputs the primary power supply after reverse connection protection. The primary power supply after reverse connection protection is input to the surge suppression module. The surge suppression module simultaneously suppresses the power-on surge current and input surge voltage, and outputs the surge-suppressed primary power supply. The surge-suppressed primary power supply is input to the filtering module, which filters out electromagnetic interference and electrical signal spikes in the circuit and outputs the filtered primary power supply. The filtered primary power supply is input to the power conversion module, which converts the primary power supply voltage into the target secondary power supply voltage, thus completing the secondary power conversion.

6. The secondary power conversion method according to claim 5, characterized in that, The overcurrent protection of the circuit via the fuse protection module includes: When an external primary power supply is supplied to the fuse branch of the fuse protection module, the fuse continuously carries the operating current when the circuit is working normally. When an overcurrent or short-circuit fault occurs in the circuit, the fuse will quickly melt and cut off the circuit path according to the magnitude of the fault current, thus completing the overcurrent protection.

7. The secondary power conversion method according to claim 6, characterized in that, Also includes: If the fuse protection module is a multi-fuse parallel structure, the external primary power supply is simultaneously supplied to each fuse branch. The working current is shunted through the parallel fuses, and the fuse branch with the series current-limiting resistor limits the branch current through the current-limiting resistor.

8. The secondary power conversion method according to claim 5, characterized in that, The process of filtering out electromagnetic interference and electrical signal spikes in the circuit via the filtering module includes: The surge-suppressed primary power supply is input to a common-mode inductor, which filters out spike signals in the input voltage and current, and outputs the peak-suppressed primary power supply. The primary power supply after peak reduction is input to the filter, which filters out electromagnetic interference signals in the circuit and outputs the filtered primary power supply.

9. The secondary power conversion method according to claim 5, characterized in that, Before the surge-suppressed primary power input is sent to the filtering module, the following is also included: The surge-suppressed primary power supply is input to the transient voltage suppression module, where transient voltage spikes in the circuit are further filtered out by the transient voltage suppression diode. The primary power supply after filtering out the transient spikes is then input to the filtering module.

10. A secondary power conversion device, characterized in that, include: Overcurrent protection unit: The external primary power supply is input to the fuse protection module, which performs overcurrent protection on the circuit and outputs the primary power supply after overcurrent protection; the primary power supply after overcurrent protection is input to the reverse connection protection module, which controls the forward and reverse conduction of the input primary power supply and outputs the primary power supply after reverse connection protection. Surge suppression unit: Inputs the primary power supply after reverse connection protection to the surge suppression module, which simultaneously suppresses the power-on surge current and input surge voltage, and outputs the surge-suppressed primary power supply. Filtering unit: Inputs the surge-suppressed primary power supply to the filtering module, which filters out electromagnetic interference and electrical signal spikes in the circuit and outputs the filtered primary power supply. Power conversion unit: The filtered primary power supply is input to the power conversion module, which converts the primary power supply voltage into the target secondary power supply voltage, thus completing the secondary power conversion.

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