A soft and hard combined overvoltage protection system and its working mode

Abstract

The present invention provides a hardware-software combined overvoltage protection system and its working method, including a power supply system and multiple sampling circuits, the sampling circuits including a system voltage sampling circuit V-Sample, a load sampling circuit I-Sample, and an internal voltage sampling circuit V-inner, the sampling circuits and the system overvoltage signal detection circuit HW-OV input to the MCU for collection and aggregation, and then input to the overvoltage protection hardware circuit; the power supply system includes multiple power supplies, the Vout+ and Vout- outputs of the power supplies are connected to the bus, and the power supplies are connected to each other via a serial port COM. The present invention utilizes a detection system that combines hardware and software to detect and judge faults, and based on its own algorithm, prevents misjudgment to ensure the safety and reliability of the countermeasures.

Description

Technical Field

[0001] The present invention relates to the technical field of power electronics and batteries, and in particular to a soft-hard combined overvoltage protection system and its working mode. Background Art

[0002] Overvoltage refers to any voltage whose peak value is greater than the corresponding peak value of the maximum steady-state voltage under normal operation. Overvoltages include transient overvoltages, which last for milliseconds or less and are the primary protection against lightning arresters. Transient overvoltages, or short-term overvoltages, last for a relatively long time, typically between 0.1 and 1 second. Overvoltage protection, also known as overvoltage protection, disconnects the power supply or reduces the voltage of the controlled equipment when the voltage on the protected circuit exceeds a predetermined maximum value.

[0003] At present, the main overvoltage protection schemes are: (1) For power frequency overvoltage, parallel reactors or reactive compensation devices can be installed on the line to limit power frequency overvoltage. The parallel reactor can be installed at the end, middle or head end of the line. (2) For single-phase grounding and intermittent grounding, the neutral point can adopt the arc suppression coil series resistor grounding method to reduce the amplitude of overvoltage to achieve overvoltage protection, etc. The main problems of the existing technology are: 1. The arc suppression coil series resistor grounding method can reduce the overvoltage amplitude to a certain extent, but the overvoltage hazards and hidden dangers still exist, and the reference source itself is single, and it is impossible to determine which fault causes the overvoltage; 2. The sampling circuit is single and cannot distinguish whether the voltage fault comes from the outside or the power supply; 3. After the overvoltage protection, the protection strategy adopted is single, generally a direct shutdown method. Summary of the Invention

[0004] To address the existing problems of being unable to distinguish the source of voltage faults and having a single protection strategy, the present invention provides a combined hardware and software overvoltage protection system and its operating method. This system utilizes a combined hardware and software detection system to detect and determine faults, and uses its own algorithm to prevent misjudgments, thereby ensuring the safety and reliability of the response measures. The specific technical solution is as follows:

[0005] A soft-hard combined overvoltage protection system includes a power supply system and multiple sampling circuits. The sampling circuits include a system voltage sampling V-Sample circuit, a load sampling I-Sample circuit, and an internal voltage sampling V-inner circuit. The sampling circuits and the system overvoltage signal detection HW-OV circuit are input into a microcontroller MCU for collection and aggregation, and then input into the overvoltage protection hardware circuit; the power supply system includes multiple power supplies, and the Vout+ and Vout- outputs of the power supplies are connected to the bus. The power supplies are connected to each other through a serial port COM.

[0006] Preferably, the system voltage sampling V-Sample circuit includes resistor R5, resistor R6, resistor R7, resistor R8, resistor R16, resistor R17, capacitor C2, capacitor C3, amplifier U2, voltage regulator diode ZD2, reference voltage Vref2, external output voltage Vout+, and sampling voltage V-Sample; the external output voltage Vout+ of the power supply is obtained by the voltage regulator circuit composed of resistor R5 and voltage regulator diode ZD2 to obtain the reference voltage Vref2; the reference voltage Vref2 is divided by the voltage divider circuit composed of resistor R16 and resistor R17, and the external output voltage Vout+ is divided by resistor R6 and resistor R7, which are respectively connected to the + / - amplifier pins of amplifier U2, and form a differential amplifier circuit with resistor R8 to obtain the sampling voltage V-Sample; wherein capacitor C2 and capacitor C3 are filter capacitors, the reference voltage Vref2 is the sampling reference voltage, and the power supply detects the output voltage of the power supply at the external output voltage Vout+ port.

[0007] Preferably, the load sampling I-Sample circuit includes a resistor R9, a resistor R10, a resistor R11, a resistor R12, a resistor R13, a resistor R14, a resistor Rsen, a capacitor C4, a capacitor C5, an amplifier U3, a reference voltage Vref2, and a current sampling voltage I-Sample; the reference voltage Vref2 is connected to the "+" input pin of the operational amplifier U3 through a voltage divider of the resistors R13 and R14 to form a reference 1; at the same time, the reference voltage Vref2 passes through the resistors R9, R11 and Rsen to obtain a basic sampling voltage at the left end of the resistor R10, and at the same time, the current Iout is After passing through resistor Rsen, a voltage of Iout*Rsen will be superimposed on resistor Rsen; this voltage will be superimposed on the basic sampling voltage to form the original current sampling voltage; this voltage is connected to the "-" input pin of amplifier U3 through resistor R10, and forms an inverting amplification circuit with resistor R12 to obtain the current sampling voltage I-Sample; the power supply detects the output current of the power supply at the external output voltage Vout- port, uses the reference voltage Vref2 as the sampling reference, and calculates the output power of the power supply with the current sampling voltage I-Sample and the sampling voltage V-Sample.

[0008] Preferably, the internal voltage sampling V-inner circuit includes a resistor R14, a resistor R15, a diode D1, a diode D2, a diode D3, a diode D4, a diode D5, a capacitor C6, a capacitor C7, a capacitor C8, a transistor Q1, a transistor Q2, an inductor L1, a transformer T1, an external output voltage Vout+, an internal power supply Vout-inn, and an internal sampling voltage V-inner; the left side of the transformer T1 is a power conversion circuit of a switching power supply, which is composed of a transistor Q1, a transistor Q2, a capacitor C6, and an inductor L1, which chop the DC into an AC waveform and transform it through the transformer T1; the diode D1 and the diode D 3 constitutes the rectifier of the main power circuit, and obtains the external output voltage Vout+ of the power supply on capacitor C7. The external output voltage Vout+ of the power supply is connected to the bus of the power supply system. Diodes D2 and D4 are connected to capacitor C8 to obtain the internal power supply Vout-inn of the power supply, which is isolated from the bus. The internal power supply Vout-inn is divided by the voltage divider circuit composed of resistors R14 and R15 to obtain the internal sampling voltage V-inner of the sampling power supply. The internal sampling voltage V-inner is input to the ADC pin of U4 of the microcontroller MCU for direct sampling, thereby obtaining the internal output voltage value of the power supply.

[0009] Preferably, the system overvoltage signal detection HW-OV circuit includes a resistor R1, a resistor R2, a resistor R3, a resistor R4, a capacitor C1, a comparator U1, a diode D6, a diode D7, a Zener diode ZD1, an external output voltage Vout+, and a reference voltage Vref1; the external output voltage Vout+ of the power supply is stabilized by the resistor R1 and the Zener diode ZD1 to obtain the reference voltage Vref1, which is input to the "-" input pin of the comparator U1; the external output voltage Vout+ is divided by the resistor R2 and the voltage R3, input to the "-" input pin of the comparator U1, and compared with the reference voltage Vref1; wherein the capacitor C1 is a filtering and smoothing capacitor, and the diode D6, the diode D7 and the resistor R4 form a hysteresis circuit to prevent the output HW-OV of the comparator U1 from oscillating and jumping at the overvoltage critical point; wherein the power supply detects whether the power supply has an overvoltage HW-OV at the external output voltage Vout+ port, the reference voltage Vref1 is a sampling reference, and HW-OV is output to the microcontroller MCU in the form of a digital signal.

[0010] Preferably, the overvoltage protection hardware circuit is a circuit for detecting the voltages of the system voltage sampling V-Sample circuit, the load sampling I-Sample circuit, the internal voltage sampling V-inner circuit, and the system overvoltage signal detection HW-OV circuit of the power supply, and inputting them into the microcontroller MCU for information collection and aggregation, and integration; the sampling voltage V-Sample, the current sampling voltage I-Sample, and the internal sampling voltage V-inner are input as analog signals into the ADC sampling port of U4 of the microcontroller MCU, so that the microcontroller MCU knows the external output voltage, output current, and internal output voltage of the power supply; HW-OV is the output of the comparator, which is input into the I / O port of U4 of the microcontroller MCU. When the HW-OV level jumps, the program of the microcontroller MCU is guided to enter the overvoltage interrupt processing subroutine.

[0011] A soft and hard combined overvoltage protection system working mode includes the following steps:

[0012] S1: First, the power supply detects the voltages of the four circuits: the system voltage sampling V-Sample circuit, the load sampling I-Sample circuit, the internal voltage sampling V-inner circuit, and the system overvoltage signal detection HW-OV circuit, and summarizes them to the microcontroller MCU;

[0013] S2: The voltage detected above is input to the microcontroller MCU for information collection and summary processing. The software inside the microcontroller MCU uses software logic analysis to provide "overvoltage information comprehensive analysis" and "overvoltage protection decision".

[0014] Preferably, the software logic analysis and processing flow is as follows: after the microcontroller MCU receives the HW-OV trigger, the internal protection count timer will be +1, and the protection count timer will be cleared to 0 regularly; at this time, the microcontroller MCU will detect whether the internal sampling voltage V-inner of the power supply is overvoltage. If the internal sampling voltage V-inner does not exceed the overvoltage threshold, it is determined whether the output power of the power supply exceeds 10% of the rated value. If it exceeds, a locked shutdown is still performed; if the internal sampling voltage V-inner exceeds the overvoltage threshold, but the count does not exceed 3 times, the SD1 automatic recovery shutdown is started to restart. If the counter is in the fixed If the value exceeds 3 times within a specified time, SD2 starts a locked shutdown; if the system has an internal sampling voltage V-inner overvoltage, the power supply output power will be calculated based on the sampling voltage V-Sample and the current sampling voltage I-sample; if the power does not exceed 10% of the rated value, then when the internal sampling voltage V-inner overvoltage time exceeds 0.2S, the power supply enters SD1 automatic recovery shutdown and restarts. If the internal sampling voltage V-inner is overvoltage and the output power of the power supply exceeds 10% of the rated value, the microcontroller MCU gives an SD2 locked shutdown signal, and the power supply enters SD2 locked shutdown.

[0015] Preferably, the signal of the system overvoltage signal detection HW-OV circuit adopts an interrupt mode, and when the level is flipped, the microcontroller MCU is triggered to enter the interrupt protection subroutine; the internal sampling voltage V-inner circuit adopts a cyclic query mode, and when the overvoltage condition is found to be met, the microcontroller MCU is triggered to enter the protection subroutine; these two methods use corresponding logic diagrams within the subroutine, and take corresponding protection processes according to the protection counter and output power.

[0016] Preferably, the Shut Down shutdown is divided into two shutdown commands: SD1 automatic recovery shutdown and SD2 locked shutdown, which act on different shutdown parts of the power supply respectively; SD1 automatic recovery shutdown is controlled by the output signal of the microcontroller MCU, and is released after 5 seconds, at which time the power supply can be restarted; SD2 locked shutdown can only be reset by receiving an external command from the microcontroller MCU and re-powering on.

[0017] Compared with the closest existing technology, the technical solution provided by the present invention has the following beneficial effects:

[0018] 1. Use a power supply system composed of multiple power supplies. In a system composed of multiple power modules, only the module with a fault needs to be exited from the system separately, without affecting the power supply of the entire system. The output of the power supply is connected to the bus. The power supply uses multiple sampling circuits to collect both the output port voltage and the internal voltage of the power supply. This can distinguish whether the overvoltage fault comes from the external or the power supply itself, preventing misjudgment. Utilize a detection system that combines software and hardware to detect and judge faults, and based on its own algorithms, prevent misjudgment to ensure the safety and reliability of the response measures.

[0019] 2. The overvoltage protection detection circuit of the power supply adopts multiple independent reference sources to prevent single faults of the reference source itself; multiple sampling circuits prevent external overvoltage from causing power interruption of the power supply, thereby causing system power interruption, and prevent the power supply itself from misprotecting under single fault conditions such as malfunction of a single detection circuit, effectively improving the reliability of protection, thereby more effectively providing uninterrupted power supply; uninterrupted power supply means that when multiple power supplies are connected, only the power supply with overvoltage fault is allowed to exit, and other power supplies with normal functions continue to supply power, thereby maximally ensuring uninterrupted power supply to the power supply system;

[0020] 3. The MCU software of this power supply calculates the power of the power supply based on the sampled output current through comprehensive analysis and processing of overvoltage information, which can be used to determine the speed of overvoltage protection action;

[0021] 4. The system overvoltage signal detection HW-OV signal adopts interrupt mode, and the internal voltage sampling V-inner adopts cyclic query mode. Two methods can be used to take corresponding protection processes according to the protection counter and output power. After overvoltage protection, two protection strategies can be adopted: automatic recovery shutdown and locked shutdown, for selective protection.

[0022] 5. Level-triggered interrupt protection uses a protection counter inside the MCU. The shutdown protection is locked only when the set number of times is reached within the set time. This can prevent transient overvoltage interference from occurring on the bus composed of multiple power supplies connected in parallel, which may cause the normally working power supply to shut down accidentally. However, when it is determined through multiple conditions that the power supply has an overvoltage, the power supply will be locked to prevent the overvoltage output of the power supply from affecting the entire power supply system. This protection method is more accurate and safer. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A diagram of a power supply system composed of multiple power supplies of the present invention;

[0024] Figure 2 This is a block diagram of the working principle of the overvoltage protection system of the present invention;

[0025] Figure 3 This is the voltage sampling V-Sample circuit diagram of the system of the present invention;

[0026] Figure 4 This is the load sampling I-Sample circuit diagram of the present invention;

[0027] Figure 5 This is the internal voltage sampling V-inner circuit diagram of the present invention;

[0028] Figure 6 This is the HW-OV circuit diagram for overvoltage signal detection of the system of the present invention;

[0029] Figure 7 This is the overvoltage protection hardware circuit diagram of the present invention;

[0030] Figure 8 The figure is a flowchart of the software logic analysis process of the MCU of the present invention. DETAILED DESCRIPTION

[0031] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0032] See also Figures 1 to 8 The present invention provides a technical solution: a soft and hard combined overvoltage protection system, comprising a power supply system and a plurality of sampling circuits, wherein the sampling circuit comprises a system voltage sampling V-Sample circuit, a load sampling I-Sample circuit, and an internal voltage sampling V-inner circuit, and the sampling circuit and the system overvoltage signal detection HW-OV circuit are input to the microcontroller MCU for collection and aggregation, and then input to the overvoltage protection hardware circuit; the power supply system comprises a plurality of power supplies, the Vout+ and Vout- output by the power supply are connected to the bus, and the power supplies are connected to each other via the serial port COM. In a power supply system composed of a plurality of power supplies, in a system composed of multiple power modules, only the module that has failed needs to exit the system separately, without affecting the power supply of the entire system. The output of the power supply is connected to the bus, and the power supply collects both the output port voltage and the internal voltage of the power supply through a plurality of sampling circuits, so that it can distinguish whether the overvoltage fault comes from the outside or the power supply, and prevent misjudgment.

[0033] See also Figure 3Furthermore, the system voltage sampling V-Sample circuit includes a resistor R5, a resistor R6, a resistor R7, a resistor R8, a resistor R16, a resistor R17, a capacitor C2, a capacitor C3, an amplifier U2, a voltage regulator diode ZD2, a reference voltage Vref2, an external output voltage Vout+, and a sampling voltage V-Sample; specifically: the external output voltage Vout+ of the power supply is obtained by a voltage regulator circuit composed of a resistor R5 and a voltage regulator diode ZD2 to obtain a reference voltage Vref2; the reference voltage Vref2 is divided by a voltage divider circuit composed of a resistor R16 and a resistor R17, and the external output voltage Vout+ is divided by a resistor R6 and a resistor R7, which are respectively connected to the + / - amplification pins of the amplifier U2, and form a differential amplification circuit with the resistor R8 to obtain a sampling voltage V-Sample; wherein the capacitor C2 and the capacitor C3 are filter capacitors, the reference voltage Vref2 is a sampling reference voltage, and the power supply detects the output voltage of the power supply at the external output voltage Vout+ port.

[0034] See also Figure 4 , further, the load sampling I-Sample circuit includes resistors R9, R10, R11, R12, R13, R14, Rsen, capacitor C4, C5, amplifier U3, reference voltage Vref2, and current sampling voltage I-Sample; specifically: the reference voltage Vref2 is connected to the "+" input pin of the operational amplifier U3 through the voltage division of resistors R13 and R14 to form a reference 1; at the same time, the reference voltage Vref2 passes through resistors R9, R11 and Rsen to obtain a basic sampling voltage at the left end of resistor R10, and at the same time Io When current ut flows through resistor Rsen, a voltage of Iout*Rsen will be superimposed on resistor Rsen; this voltage will be superimposed on the basic sampling voltage to form the original current sampling voltage; this voltage is connected to the "-" input pin of amplifier U3 through resistor R10, and forms an inverting amplification circuit with resistor R12 to obtain the current sampling voltage I-Sample; the power supply detects the output current of the power supply at the external output voltage Vout- port, uses the reference voltage Vref2 as the sampling reference, and calculates the output power of the power supply using the current sampling voltage I-Sample and the sampling voltage V-Sample.

[0035] See also Figure 5, further, the internal voltage sampling V-inner circuit includes resistor R14, resistor R15, diode D1, diode D2, diode D3, diode D4, diode D5, capacitor C6, capacitor C7, capacitor C8, transistor Q1, transistor Q2, inductor L1, transformer T1, external output voltage Vout+, internal power supply Vout-inn, and internal sampling voltage V-inner; specifically: the left side of transformer T1 is the power conversion circuit of the switching power supply, which is composed of transistor Q1, transistor Q2, capacitor C6, and inductor L1, which chop DC into AC waveform and transform it through transformer T1; diode D1 and diode Q2 are connected. Diode D3 forms a rectifier of the main power circuit, and the external output voltage Vout+ of the power supply is obtained on capacitor C7. The external output voltage Vout+ of the power supply is connected to the bus of the power supply system; diode D2 and diode D4 are connected to capacitor C8 to obtain the internal power supply Vout-inn of the power supply, which is isolated from the bus. The internal power supply Vout-inn is divided by a voltage divider circuit composed of resistors R14 and R15 to obtain the internal sampling voltage V-inner of the sampling power supply. The internal sampling voltage V-inner is input to the ADC pin of U4 of the microcontroller MCU for direct sampling, thereby obtaining the internal output voltage value of the power supply.

[0036] See also Figure 6 Furthermore, the system overvoltage signal detection HW-OV circuit includes a resistor R1, a resistor R2, a resistor R3, a resistor R4, a capacitor C1, a comparator U1, a diode D6, a diode D7, a Zener diode ZD1, an external output voltage Vout+, and a reference voltage Vref1; specifically: the external output voltage Vout+ of the power supply is stabilized by the resistor R1 and the Zener diode ZD1 to obtain the reference voltage Vref1, which is input to the "-" input pin of the comparator U1; the external output voltage Vout+ is divided by the resistor R2 and the voltage R3, input to the "+" input pin of the comparator U1, and compared with the reference voltage Vref1; wherein the capacitor C1 is a filtering and smoothing capacitor, and the diode D6, the diode D7 and the resistor R4 form a hysteresis circuit to prevent the output HW-OV of the comparator U1 from oscillating and jumping at the overvoltage critical point; wherein the power supply detects whether the power supply has an overvoltage HW-OV at the external output voltage Vout+ port, the reference voltage Vref1 is used as a sampling reference, and HW-OV is output to the microcontroller MCU in the form of a digital signal.

[0037] See also Figure 7Furthermore, the overvoltage protection hardware circuit detects the voltages of the system voltage sampling V-Sample circuit, the load sampling I-Sample circuit, the internal voltage sampling V-inner circuit, and the system overvoltage signal detection HW-OV circuit for the power supply, and inputs them into the microcontroller MCU for information collection and aggregation, and integration; the sampling voltage V-Sample, the current sampling voltage I-Sample, and the internal sampling voltage V-inner are input as analog signals into the ADC sampling port of U4 of the microcontroller MCU, so that the microcontroller MCU knows the external output voltage, output current, and internal output voltage of the power supply; HW-OV is the output of the comparator, which is input into the I / O port of U4 of the microcontroller MCU. When the HW-OV level jumps, the program of the microcontroller MCU is guided to enter the overvoltage interrupt processing subroutine.

[0038] See also Figure 2 , a soft and hard combined overvoltage protection system working mode, including the following steps:

[0039] S1: First, the power supply detects the voltages of the four circuits: the system voltage sampling V-Sample circuit, the load sampling I-Sample circuit, the internal voltage sampling V-inner circuit, and the system overvoltage signal detection HW-OV circuit, and summarizes them to the microcontroller MCU;

[0040] S2: The detected voltages are input to the microcontroller (MCU) for information collection and processing. Software within the MCU uses software logic analysis to generate a comprehensive overvoltage analysis and overvoltage protection decision. This integrated hardware and software detection system detects and determines faults, and uses its own algorithms to prevent misjudgments and ensure safe and reliable response measures.

[0041] See also Figure 8Furthermore, the software logic analysis includes comprehensive analysis of overvoltage information and overvoltage protection decision-making; the specific processing flow of the comprehensive analysis of overvoltage information is as follows: after the microcontroller MCU receives the HW-OV trigger, the internal protection count timer will be +1, and this protection count timer will be cleared to 0 regularly; at this time, the microcontroller MCU will detect whether the internal sampling voltage V-inner of the power supply is overvoltage. The specific overvoltage protection decision-making process is as follows: If the internal sampling voltage V-inner does not exceed the overvoltage threshold, the power supply is determined to see whether its output power exceeds 10% of the rated value. If so, a locked shutdown is still performed. If the internal sampling voltage V-inner exceeds the overvoltage threshold but the count does not exceed three times, SD1 automatic recovery shutdown is initiated for restart. If the counter value exceeds three times within a fixed time, SD2 locked shutdown is initiated. If the system experiences an internal sampling voltage V-inner overvoltage, the power supply output power is calculated based on the sampling voltage V-Sample and the current sampling voltage I-sample. If the power does not exceed 10% of the rated value, if the internal sampling voltage V-inner overvoltage lasts for more than 0.2 seconds, the power supply enters SD1 automatic recovery shutdown for restart. If the internal sampling voltage V-inner overvoltage and the power supply output power exceeds 10% of the rated value, the microcontroller MCU generates an SD2 locked shutdown signal, and the power supply enters SD2 locked shutdown. The MCU software overvoltage information comprehensive analysis and processing flow of this power supply calculates the power of the power supply based on the sampled output current, which can be used to judge the speed of overvoltage protection action.

[0042] See also Figure 8 Furthermore, the system overvoltage signal detection HW-OV circuit uses an interrupt method. When the level flips, it triggers the microcontroller MCU to enter the interrupt protection subroutine. The internal sampling voltage V-inner circuit uses a cyclic query method. When the query finds that the overvoltage condition is met, it triggers the microcontroller MCU to enter the protection subroutine. These two methods use corresponding logic diagrams within the subroutine, and adopt corresponding protection processes based on the protection counter and output power. The level-triggered interrupt protection uses a protection counter within the MCU. It locks the shutdown protection only after reaching a set number of times within a set time. This can prevent transient overvoltage interference on the bus composed of multiple parallel power supplies, which could cause normally operating power supplies to shut down accidentally. However, when multiple conditions determine that the power supply has an overvoltage, it locks the power supply to prevent its overvoltage output from affecting the entire power supply system. This protection method is more accurate and safe.

[0043] See also Figure 8Furthermore, the Shut Down command is divided into two types: SD1 automatic recovery shutdown and SD2 locked shutdown, each acting on a different shutdown point on the power supply. SD1 automatic recovery shutdown is controlled by an output signal from the microcontroller (MCU) and is released after 5 seconds, allowing the power supply to restart. SD2 locked shutdown can only be reset by receiving an external command from the MCU and then powering on again. Two protection methods can be used, depending on the protection counter and output power. After overvoltage protection, both automatic recovery shutdown and locked shutdown strategies can be used for selective protection.

[0044] System working principle: A soft and hard combined overvoltage protection system, which uses overvoltage detection circuit, output voltage sampling circuit and load detection circuit to detect the circuit status and, combined with the power output, detect whether the output voltage is internal overvoltage or external overvoltage, so as to isolate and exit the faulty module, prevent the external transient overvoltage from causing all the power supplies on the bus to shut down, and implement protection measures according to the protection status, thereby achieving overvoltage protection for the faulty power supply in the system while protecting the system safely and uninterrupted power supply to the greatest extent.

[0045] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the same. Although the present invention has been described in detail with reference to the above embodiments, a person skilled in the art may still modify or make equivalent substitutions to the specific implementations of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention are within the scope of protection of the claims of the present invention to be approved.

Claims

1. A method for operating a soft-hard combined overvoltage protection system, characterized in that: The overvoltage protection system includes a power supply system and multiple sampling circuits, wherein the sampling circuits include a system voltage sampling V-Sample circuit, a load sampling I-Sample circuit, and an internal voltage sampling V-inner circuit. The sampling circuits and the system overvoltage signal detection HW-OV circuit input the signals into the microcontroller MCU for collection and aggregation, and then input the signals into the overvoltage protection hardware circuit. The power supply system includes multiple power supplies, and the Vout+ and Vout- outputs of the power supplies are connected to the bus. The power supplies are connected to each other via a serial port COM. The working method of the overvoltage protection system includes the following steps: S1: First, the power supply detects the voltages of the four circuits: the system voltage sampling V-Sample circuit, the load sampling I-Sample circuit, the internal voltage sampling V-inner circuit, and the system overvoltage signal detection HW-OV circuit, and summarizes them to the microcontroller MCU; S2: The detected voltage is input to the microcontroller MCU for information collection and summary processing. The software inside the microcontroller MCU uses software logic analysis to provide a comprehensive analysis of the overvoltage information and overvoltage protection decision; Among them, the software logic analysis and processing flow is as follows: after the microcontroller MCU receives the HW-OV trigger, the internal protection count timer will be +1, and this protection count timer will be cleared to 0 regularly; at this time, the microcontroller MCU will detect whether the internal sampling voltage V-inner of the power supply is overvoltage. If the internal sampling voltage V-inner does not exceed the overvoltage threshold, it will determine whether the output power of the power supply exceeds 10% of the rated value. If it exceeds, it will still perform a locked shutdown; if the internal sampling voltage V-inner exceeds the overvoltage threshold, but the count does not exceed 3 times, the SD1 automatic recovery shutdown will be started to restart. If the counter value exceeds 3 times within a fixed time, SD2 will start a locked shutdown; if the system has an internal sampling voltage V-inner overvoltage, it will be based on the sampling voltage V-Sample The power supply output power is calculated with the current sampling voltage I-sample; if the power does not exceed 10% of the rated value, then when the internal sampling voltage V-inner is overvoltage for more than 0.2s, the power supply enters SD1 automatic recovery shutdown and restarts. If the internal sampling voltage V-inner is overvoltage and the power supply output power exceeds 10% of the rated value, the microcontroller MCU gives an SD2 locked shutdown signal, and the power supply enters SD2 locked shutdown.

2. The method for operating a soft-hard combined overvoltage protection system according to claim 1, characterized in that: The system voltage sampling V-Sample circuit includes resistor R5, resistor R6, resistor R7, resistor R8, resistor R16, resistor R17, capacitor C2, capacitor C3, amplifier U2, voltage stabilizing diode ZD2, reference voltage Vref2, external output voltage Vout+, and sampling voltage V-Sample; the external output voltage Vout+ of the power supply is obtained by the voltage stabilizing circuit composed of resistor R5 and voltage stabilizing diode ZD2 to obtain the reference voltage Vref2; the reference voltage Vref2 is divided by the voltage divider circuit composed of resistor R16 and resistor R17, and the external output voltage Vout+ is divided by resistor R6 and resistor R7, which are respectively connected to the + / - amplification pins of amplifier U2, and form a differential amplification circuit with resistor R8 to obtain the sampling voltage V-Sample; wherein capacitor C2 and capacitor C3 are filter capacitors, the reference voltage Vref2 is the sampling reference voltage, and the power supply detects the output voltage of the power supply at the external output voltage Vout+ port.

3. The method for operating a soft-hard combined overvoltage protection system according to claim 1, characterized in that: The load sampling I-Sample circuit includes resistors R9, R10, R11, R12, R13, R14, Rsen, capacitors C4, C5, amplifier U3, reference voltage Vref2, and current sampling voltage I-Sample; the reference voltage Vref2 is connected to the "+" input pin of the operational amplifier U3 through a voltage divider of resistors R13 and R14 to form a reference 1; at the same time, the reference voltage Vref2 passes through resistors R9, R11, and Rsen to obtain a basic sampling voltage at the left end of the resistor R10. At the same time, when Iout flows through the resistor Rsen, a voltage of Iout*Rsen will be superimposed on the resistor Rsen; this voltage will be superimposed on the basic sampling voltage to form the original current sampling voltage; this voltage is connected to the "-" input pin of the amplifier U3 through the resistor R10, and forms an inverting amplification circuit with the resistor R12, thereby obtaining the current sampling voltage I-Sample; The power supply detects the output current of the power supply at the external output voltage Vout- port, uses the reference voltage Vref2 as a sampling reference, and calculates the output power of the power supply using the current sampling voltage I-Sample and the sampling voltage V-Sample.

4. The method for operating a soft-hard combined overvoltage protection system according to claim 1, characterized in that: The internal voltage sampling V-inner circuit includes a resistor R14, a resistor R15, a diode D1, a diode D2, a diode D3, a diode D4, a diode D5, a capacitor C6, a capacitor C7, a capacitor C8, a transistor Q1, a transistor Q2, an inductor L1, a transformer T1, an external output voltage Vout+, an internal power supply Vout-inn, and an internal sampling voltage V-inner; the left side of the transformer T1 is a power conversion circuit of a switching power supply, which is composed of a transistor Q1, a transistor Q2, a capacitor C6, and an inductor L1, which chop DC into an AC waveform and transform it through the transformer T1; the diode D1 and the diode D 3 constitutes the rectifier of the main power circuit, and obtains the external output voltage Vout+ of the power supply on capacitor C7. The external output voltage Vout+ of the power supply is connected to the bus of the power supply system. Diodes D2 and D4 are connected to capacitor C8 to obtain the internal power supply Vout-inn of the power supply, which is isolated from the bus. The internal power supply Vout-inn is divided by the voltage divider circuit composed of resistors R14 and R15 to obtain the internal sampling voltage V-inner of the sampling power supply. The internal sampling voltage V-inner is input to the ADC pin of U4 of the microcontroller MCU for direct sampling, thereby obtaining the internal output voltage value of the power supply.

5. The method for operating a soft-hard combined overvoltage protection system according to claim 1, characterized in that: The system overvoltage signal detection HW-OV circuit includes a resistor R1, a resistor R2, a resistor R3, a resistor R4, a capacitor C1, a comparator U1, a diode D6, a diode D7, a Zener diode ZD1, an external output voltage Vout+, and a reference voltage Vref1; the external output voltage Vout+ of the power supply is stabilized by the resistor R1 and the Zener diode ZD1 to obtain the reference voltage Vref1, which is input to the "-" input pin of the comparator U1; the external output voltage Vout+ is divided by the resistor R2 and the voltage regulator R3, input to the "+" input pin of the comparator U1, and compared with the reference voltage Vref1; wherein the capacitor C1 is a filter smoothing capacitor, and the diodes D6, D7 and the resistor R4 form a hysteresis circuit to prevent the output HW-OV of the comparator U1 from oscillating and jumping at the overvoltage critical point; The power supply detects whether there is an overvoltage HW-OV at the external output voltage Vout+ port of the power supply, and the reference voltage Vref1 is used as a sampling reference. HW-OV is output to the microcontroller MCU in the form of a digital signal.

6. The method for operating a soft-hard combined overvoltage protection system according to claim 1, characterized in that: The overvoltage protection hardware circuit is a circuit in which the power supply detects the voltages of the system voltage sampling V-Sample circuit, the load sampling I-Sample circuit, the internal voltage sampling V-inner circuit, and the system overvoltage signal detection HW-OV circuit, and inputs them into the microcontroller MCU for information collection and aggregation, and integration. The sampling voltage V-Sample, the current sampling voltage I-Sample, and the internal sampling voltage V-inner are input as analog signals into the ADC sampling port of U4 of the microcontroller MCU, so that the microcontroller MCU knows the external output voltage, output current, and internal output voltage of the power supply. HW-OV is the output of the comparator and is input into the I / O port of U4 of the microcontroller MCU. When the HW-OV level jumps, the program of the microcontroller MCU is guided to enter the overvoltage interrupt processing subroutine.

7. The method for operating a soft-hard combined overvoltage protection system according to claim 1, characterized in that: The signal of the system overvoltage signal detection HW-OV circuit adopts an interrupt mode. When the level is reversed, the microcontroller MCU is triggered to enter the interrupt protection subroutine; the internal sampling voltage V-inner circuit adopts a cyclic query mode. When the overvoltage condition is found to be met, the microcontroller MCU is triggered to enter the protection subroutine. These two modes use corresponding logic diagrams within the subroutine and adopt corresponding protection processes according to the protection counter and output power.

8. The method for operating a soft-hard combined overvoltage protection system according to claim 1, characterized in that: The ShutDown shutdown is divided into two shutdown commands: SD1 automatic recovery shutdown and SD2 locked shutdown, which act on different shutdown parts of the power supply respectively; SD1 automatic recovery shutdown is controlled by the output signal of the microcontroller MCU and is released after 5 seconds, at which time the power supply can be restarted; SD2 locked shutdown can only be reset by receiving an external command from the microcontroller MCU and re-powering on.

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