A surge voltage suppression system and control method thereof

Abstract

Based on the above problems, the present invention proposes a surge voltage suppression system and its control method. By obtaining a pre-configured target output voltage U e and a pressure difference threshold ΔU th , the target output voltage is the rated voltage of the load device connected to the surge voltage suppression system. The input voltage U in of the surge voltage suppression system is detected in real time, and the first voltage difference ΔU1 = U in between the input voltage U e and the target output voltage U in -U e is calculated. It is judged whether the first voltage difference ΔU1 is greater than the pressure difference threshold ΔU th . When ΔU1 ≤ ΔU th , at least one parallel-connected MOS transistor is controlled to enter the first conduction state. When ΔU1 > ΔU th , at least one parallel-connected MOS transistor is controlled to enter the second conduction state. The gate voltage U GS of the MOS transistors in the second conduction state is adjusted according to the number of MOS transistors in the second conduction state to perform current balancing between the conducting MOS transistors, which can effectively balance the energy absorption of the surge suppression device and has higher reliability.

Description

Technical Field

[0001] The present invention relates to the technical field of power supply control, and in particular to a surge voltage suppression system and a control method thereof. Background Art

[0002] When a circuit is struck by lightning or when a large load is connected or disconnected, a very high surge voltage will be generated. Surge voltage is a very serious power interference. If there is no effective means to suppress surge voltage in the circuit, it may cause serious damage to the electrical equipment in the circuit. In the prior art, the more common surge voltage suppression scheme is the two-stage cascade suppression technology, which uses a two-stage surge suppressor in cascade to step down the surge voltage in sections to achieve surge voltage suppression, effectively improving the problems of limited voltage drop, low control accuracy and low reliability of a single surge suppressor. However, the two-stage cascade suppression cannot flexibly adjust the voltage drop amplitude of the two-stage surge suppressor for surge voltages of different sizes. Therefore, the energy absorption of the two-stage surge suppressor is unbalanced, which is easy to burn out the subsequent suppression circuit. Summary of the invention

[0003] Based on the above problems, the present invention proposes a surge voltage suppression system and a control method thereof, which can effectively balance the energy absorption of the surge suppression device and have higher reliability.

[0004] In view of this, a first aspect of the present invention proposes a surge voltage suppression system, comprising an input voltage monitoring module for monitoring an input voltage, a voltage suppression module for stabilizing and shunting the input voltage, an output voltage feedback module for collecting and feeding back an output voltage, and a voltage control module for controlling the voltage suppression module according to the input voltage sampled by the input voltage monitoring module and the output voltage sampled by the output voltage feedback module, wherein the voltage suppression module comprises a plurality of MOS tubes connected in parallel, the input voltage monitoring module comprises a first sampling resistor and a voltage detection circuit whose input end is connected to the first sampling resistor, the output voltage feedback module comprises a second sampling resistor and a voltage feedback circuit whose input end is connected to the second sampling resistor, the voltage control circuit comprises a controller, the controller is connected to the output end of the voltage monitoring circuit, the output end of the voltage sampling feedback circuit, and the gate of the metal oxide semiconductor field effect transistor, and the controller is configured as follows:

[0005] Get the pre-configured target output voltage U e And the pressure difference threshold ΔU th , the target output voltage is the rated voltage of the load device connected to the surge voltage suppression system;

[0006] Real-time detection of the input voltage U of the surge voltage suppression systemin ;

[0007] Calculate the input voltage U in With the target output voltage U e The first voltage difference between:

[0008] ΔU1=U in -U e ;

[0009] Determine whether the first voltage difference ΔU1 is greater than the voltage difference threshold ΔU th ;

[0010] When ΔU1≤ΔU th When the at least one MOS tube connected in parallel is controlled to enter a first conducting state;

[0011] When ΔU1>ΔU th When the at least one MOS tube connected in parallel is controlled to enter the second conduction state;

[0012] The gate voltage U of the MOS tube in the second conduction state is adjusted according to the number of the MOS tubes in the second conduction state. GS To perform current balancing among the conducting MOS tubes.

[0013] A second aspect of the present invention provides a control method for a surge voltage suppression system, comprising:

[0014] Get the pre-configured target output voltage U e And the pressure difference threshold ΔU th , the target output voltage is the rated voltage of the load device connected to the surge voltage suppression system;

[0015] Real-time detection of the input voltage U of the surge voltage suppression system in ;

[0016] Calculate the input voltage U in With the target output voltage U e The first voltage difference between:

[0017] ΔU1=U in -U e ;

[0018] Determine whether the first voltage difference ΔU1 is greater than the voltage difference threshold ΔUt h ;

[0019] When ΔU1≤ΔU th When the at least one MOS tube connected in parallel is controlled to enter a first conducting state;

[0020] When ΔU1>ΔU thWhen the at least one MOS tube connected in parallel is controlled to enter the second conduction state;

[0021] The gate voltage U of the MOS tube in the second conduction state is adjusted according to the number of the MOS tubes in the second conduction state. GS To perform current balancing among the conducting MOS tubes.

[0022] Furthermore, the step of controlling at least one parallel MOS tube to enter a first conduction state specifically includes:

[0023] Obtaining the output current range corresponding to the number of pre-configured shunt MOS tubes;

[0024] Detect the output current I of the surge voltage suppression system out ;

[0025] Determine the output current I out The number of first shunt MOS tubes corresponding to the output current interval n1 cond , where 1≤n1 cond ≤n mos , n mos is the number of MOS tubes connected in parallel in the voltage suppression module of the surge voltage suppression system;

[0026] Control n1 cond The MOS tube enters the first conduction state.

[0027] Furthermore, the step of controlling at least one parallel MOS tube to enter the second conduction state specifically includes:

[0028] Detect the output current I of the surge voltage suppression system out ;

[0029] According to the output current I out And the first voltage difference ΔU1 determines the number n2 of the second shunt MOS tubes cond , where 1≤n2 cond ≤n mos ;

[0030] Control n2 cond The MOS tube enters the second conduction state.

[0031] Further, according to the output current I out And the first voltage difference ΔU1 determines the number n2 of the second shunt MOS tubes cond The steps specifically include:

[0032] According to the output current I out And the maximum drain-source current I of the MOS tube DSMCalculate the number n1 of the first candidate shunt MOS tubes of the surge voltage suppression system alt ;

[0033] According to the output current I out , the first voltage difference ΔU1 and the maximum drain-source resistance R of the MOS tube DSM Calculate the number n2 of the second candidate shunt MOS tubes of the surge voltage suppression system alt ;

[0034] Compare the first candidate shunt MOS tube quantity n1 alt The number of the second candidate shunt MOS tubes n2 alt size;

[0035] When n1 alt <n2 alt When n2 cond In (n1 alt , n2 alt ) interval.

[0036] Further, according to the output current I out And the maximum drain-source current I of the MOS tube DSM Calculate the number n1 of the first candidate shunt MOS tubes of the surge voltage suppression system alt The steps specifically include:

[0037] Get the maximum drain-source current I of the MOS tube DSM ;

[0038] Compare the maximum drain-source current I DSM With the output current I out size;

[0039] When I out >I DSM When the number of the first candidate shunt MOS tubes is

[0040] Further, according to the output current I out , the first voltage difference ΔU1 and the maximum drain-source resistance R of the MOS tube DSM Calculate the number n2 of the second candidate shunt MOS tubes of the surge voltage suppression system alt The steps specifically include:

[0041] Get the maximum drain-source resistance R of the MOS tube DSM ;

[0042] Comparing the output current I out With the maximum drain-source resistance R DSM The product Iout ·R DSM The magnitude of the voltage difference ΔU1 with the first voltage;

[0043] When(I out ·R DSM )>ΔU1, the number of the second candidate shunt MOS tubes is

[0044] Furthermore, the gate voltage U of the MOS transistor in the second conduction state is adjusted according to the number of the MOS transistors in the second conduction state. GS The steps of performing current balancing between the conducting MOS tubes specifically include:

[0045] Determine the MOS transistor in the second conduction state as the target MOS transistor;

[0046] Obtain the instantaneous temperature rise ΔT of the target MOS tube i (t) and the average instantaneous temperature rise where i∈[1,n2 cond ], where ΔT i (t) is the instantaneous temperature rise of the i-th target MOS tube at time t, is n2 cond The average instantaneous temperature rise of the target MOS tube at time t;

[0047] For any target MOS tube that satisfies When the preset step length ΔU GS Reduce satisfaction The gate voltage U of the target MOS tube GS .

[0048] Furthermore, the instantaneous temperature rise ΔT of the target MOS tube is detected in real time. i (t) and the average instantaneous temperature rise The steps specifically include:

[0049] Real-time acquisition of the temperature T of the target MOS tube i (t), T i (t) is the temperature of the i-th target MOS tube at time t;

[0050] Calculate the instantaneous temperature rise of the target MOS tube:

[0051]

[0052] Where Δt is the temperature sampling time interval of the temperature sensor;

[0053] Calculate the average instantaneous temperature rise of the target MOS tube:

[0054]

[0055] Further, the gate voltage U of the MOS transistor in the second conduction state is adjusted according to the number of the MOS transistors in the second conduction state. GS After performing the step of current balancing between the conducting MOS tubes, the method further includes:

[0056] Real-time detection of the output voltage U of the surge voltage suppression system out and output current I out ;

[0057] Calculate the output voltage U out With the target output voltage U e The second voltage difference between:

[0058] ΔU2=U out -U e ;

[0059] According to the second voltage difference ΔU2 and the output current I out Dynamically adjust the on-resistance of the MOS tube in the first on-state or the second on-state to adjust the output voltage U out Stable at the target output voltage U e nearby.

[0060] Based on the above problems, the present invention proposes a surge voltage suppression system and a control method thereof, by obtaining a pre-configured target output voltage U e And the pressure difference threshold ΔU th The target output voltage is the rated voltage of the load device connected to the surge voltage suppression system, and the input voltage U of the surge voltage suppression system is detected in real time. in , calculate the input voltage U in With the target output voltage U e The first voltage difference between ΔU1 and U in -U e , determine whether the first voltage difference ΔU1 is greater than the voltage difference threshold ΔU th , when ΔU1≤ΔU th When ΔU1>ΔU th When the at least one MOS tube connected in parallel is controlled to enter the second conduction state, the gate voltage U of the MOS tube in the second conduction state is adjusted according to the number of the MOS tubes in the second conduction state. GS By performing current balancing between the conducting MOS tubes, the energy absorption of the surge suppression device can be effectively balanced, and the reliability is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 is a schematic diagram of a surge voltage suppression system provided by an embodiment of the present invention;

[0062] Figure 2 The present invention is a flowchart of a method for controlling a surge voltage suppression system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0063] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0064] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0065] In the description of the present invention, the term "multiple" refers to two or more. Unless otherwise clearly defined, the orientation or positional relationship indicated by the terms "upper", "lower", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation of the present invention. The terms "connection", "installation", "fixation", etc. should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second", etc. can explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, the meaning of "multiple" is two or more.

[0066] In the description of this specification, the description of the terms "one embodiment", "some implementations", "specific embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0067] A surge voltage suppression system and a control method thereof provided according to some embodiments of the present invention will be described below with reference to the accompanying drawings.

[0068] like Figure 1 As shown, the first aspect of the present invention proposes a surge voltage suppression system, including an input voltage monitoring module for monitoring input voltage, a voltage suppression module for stabilizing and shunting the input voltage, an output voltage feedback module for collecting and feeding back output voltage, and a voltage control module for controlling the voltage suppression module according to the input voltage sampled by the input voltage monitoring module and the output voltage sampled by the output voltage feedback module. The voltage suppression module includes a plurality of MOS tubes connected in parallel with each other, the input voltage monitoring module includes a first sampling resistor and a voltage detection circuit whose input end is connected to the first sampling resistor, the output voltage feedback module includes a second sampling resistor and a voltage feedback circuit whose input end is connected to the second sampling resistor, and the voltage control circuit includes a controller, and the controller is connected to the output end of the voltage monitoring circuit, the output end of the voltage sampling feedback circuit, and the gate of the metal oxide semiconductor field effect transistor.

[0069] Specifically, the voltage suppression module of the surge voltage suppression system includes multiple parallel branches, each of which includes a MOS tube (Metal-Oxide-Semiconductor Field-Effect Transistor). Preferably, the MOS tubes in the voltage suppression module are all MOS tubes of the same model.

[0070] like Figure 2 As shown, the controller is configured as follows:

[0071] Get the pre-configured target output voltage U e And the pressure difference threshold ΔU th , the target output voltage is the rated voltage of the load device connected to the surge voltage suppression system;

[0072] Real-time detection of the input voltage U of the surge voltage suppression system in ;

[0073] Calculate the input voltage U in With the target output voltage U e The first voltage difference between:

[0074] ΔU1=U in -U e ;

[0075] Determine whether the first voltage difference ΔU1 is greater than the voltage difference threshold ΔU th;

[0076] When ΔU1≤ΔU th When the at least one MOS tube connected in parallel is controlled to enter a first conducting state;

[0077] When ΔU1>ΔU th When the at least one MOS tube connected in parallel is controlled to enter the second conduction state;

[0078] The gate voltage U of the MOS tube in the second conduction state is adjusted according to the number of the MOS tubes in the second conduction state. GS To perform current balancing among the conducting MOS tubes.

[0079] Specifically, the surge voltage suppression system can be set at the power input end of an independent electrical device, or at the power input end of a local electrical network composed of a series of electrical devices. When the surge voltage suppression system is set at the power input end of an independent electrical device, the load device is the independent electrical device. Similarly, when the surge voltage suppression system is set at the power input end of a local electrical network composed of a series of electrical devices, the load device is a collection of electrical devices in the local electrical network. In this embodiment, the electrical devices in the local electrical network have the same rated voltage, for example, the rated voltages of these electrical devices can all be 220 volts or all be 380 volts.

[0080] In the technical solution of the above embodiment, the first conduction state is a low resistance conduction state. In the first conduction state, the MOS tube supplies power to the load device at a very low voltage and low power loss. The second conduction state is a variable resistance state. In the second conduction state, the controller adjusts the gate voltage U of the MOS tube. GS To control the on-resistance and voltage drop of the MOS tube.

[0081] The pressure difference threshold ΔU th The output voltage U of the pre-configured surge voltage suppression system out and the rated voltage of the load device, i.e., the target output voltage U e The maximum tolerable fluctuation amplitude difference between the transient input voltage U in With the target output voltage U e The first voltage difference ΔU1 between the th When the input voltage U in Approximately the same output voltage U outWhen the instantaneous input voltage U in With the target output voltage U e The first voltage difference ΔU1 between the th When the instantaneous input voltage U in The voltage drop of the surge voltage suppression system is adjusted by controlling at least one parallel MOS tube to enter the second conduction state, so that the output voltage U out Stable at the target output voltage U e nearby to avoid surge voltage from damaging the load equipment.

[0082] In the technical solution of the above-mentioned implementation mode, since the first conduction state is a low resistance conduction state, in the step of controlling at least one parallel MOS tube to enter the first conduction state, each MOS tube in the first conduction state is configured to be in a low conduction resistance state, so each MOS tube in the first conduction state has the characteristics of conduction resistance and low voltage drop, and the current size of each MOS tube is related to the input voltage U of the surge voltage suppression system. in And it is related to the load size of the load device. The MOS tube in the first conduction state will adaptively balance the current according to its working state during operation. Specifically, in the technical solution of the present invention, the MOS tubes are all connected in parallel to the circuit, so the MOS tubes in the first conduction state have the same voltage drop. Due to individual differences, even if the same type of MOS tubes are used, their individual properties including their packages and voltages will still have slight differences. The MOS tube with a small saturation voltage will pass a larger current in the initial state, so the temperature rise of its channel region will be faster than that of other MOS tubes, resulting in an increase in its on-resistance. The surge voltage suppression system performs voltage stabilization control on the surge voltage suppression system through an output voltage feedback module and a voltage control module. Therefore, in the external circuit parameter, that is, the input voltage U of the surge voltage suppression system in , output voltage U out And when the load size of the load device remains unchanged, the change of the on-resistance of each MOS tube will cause the current in each parallel branch to be redistributed, thereby realizing adaptive current sharing.

[0083] Further, in the step of controlling at least one parallel MOS tube to enter the first conducting state, the controller is configured to:

[0084] Obtaining the output current range corresponding to the number of pre-configured shunt MOS tubes;

[0085] Detect the output current I of the surge voltage suppression system out ;

[0086] Determine the output current I out The number of first shunt MOS tubes corresponding to the output current interval n1 cond , where 1≤n1 cond ≤n mos , n mos is the number of MOS tubes connected in parallel in the voltage suppression module of the surge voltage suppression system;

[0087] Control n1 cond The MOS tube enters the first conduction state.

[0088] In the technical solutions of some embodiments of the present invention, after obtaining the pre-configured target output voltage U e And the pressure difference threshold ΔU th Before the step of, it also includes configuring a correspondence between a plurality of output current intervals and the number of shunt MOS tubes, wherein the larger the current in the output current interval is, the larger the number of the corresponding shunt MOS tubes is.

[0089] Specifically, due to the maximum drain-source current I of the MOS tube DSM It is related to the type of MOS tube, process parameters and the real-time temperature during operation. The maximum drain-source current I DSM Refers to the maximum on-state current allowed to pass between the drain and source of the MOS tube. Generally speaking, the operating current of the MOS tube is between 6A and 9A, and the maximum should not exceed 20A, otherwise the MOS tube will be damaged. For applications with high-power load equipment, even in the absence of surge voltage, using only one MOS tube is not enough to withstand the operating current of the load equipment.

[0090] In the technical solution of the above-mentioned implementation mode, by configuring the number of first shunt MOS tubes corresponding to different output current intervals, when the load device operates within different current intervals, the surge voltage suppression system configures a corresponding number of MOS tubes for shunt, thereby avoiding damage to the MOS tube due to being unable to withstand excessive conduction current.

[0091] In the technical solution of the above embodiment, when controlling nl cond The step of entering the first conduction state of the MOS tubes also includes making the remaining n mos -nl cond Keep the remaining n MOS tubes in the cut-off state. mos -nl cond The MOS tubes are kept in the cut-off state. Specifically, the controller adjusts the remaining n mos -n1 cond The gate voltage of the MOS tubes is set to make the remaining n mos -n1cond Each MOS tube works in the cut-off region.

[0092] Further, in the step of controlling at least one parallel MOS tube to enter the second conduction state, the controller is configured to:

[0093] Detect the output current I of the surge voltage suppression system out ;

[0094] According to the output current I out And the first voltage difference ΔU1 determines the number n2 of the second shunt MOS tubes cond , where 1≤n2 cond ≤n mos ;

[0095] Control n2 cond The MOS tube enters the second conduction state.

[0096] When the first voltage difference ΔU1 is larger, it means that the surge voltage is larger, and the voltage drop required to be achieved by the surge voltage suppression system is larger. At this time, the more MOS tubes are connected in parallel, the smaller the total on-resistance will be. It is necessary to comprehensively consider the real-time output current I ou x and the size of the first voltage difference ΔU1 determine the number n2 of the second shunt MOS tubes that need to be turned on cond , to avoid the second shunt MOS tube number n2 cond Too large to achieve the corresponding voltage drop effect, or because the number of the second shunt MOS tubes n2 cond If the current is too small, the MOS tube will be damaged.

[0097] In the technical solution of the above embodiment, when controlling n2 cond The step of entering the second conduction state of the MOS tubes also includes making the remaining n mos -n2 cond Keep the remaining n MOS tubes in the cut-off state. mos -n2 cond The MOS tubes are kept in the cut-off state. Specifically, the controller adjusts the remaining n mos -n2 cond The gate voltage of the MOS tubes is set to make the remaining n mos -n2 cond Each MOS tube works in the cut-off region.

[0098] Further, according to the output current I out And the first voltage difference ΔU1 determines the number n2 of the second shunt MOS tubes cond In the steps, the controller is configured to:

[0099] According to the output current I out And the maximum drain-source current I of the MOS tube DSM Calculate the number n1 of the first candidate shunt MOS tubes of the surge voltage suppression system alt ;

[0100] According to the output current I out , the first voltage difference ΔU1 and the maximum drain-source resistance R of the MOS tube DSM Calculate the number n2 of the second candidate shunt MOS tubes of the surge voltage suppression system alt ;

[0101] Compare the first candidate shunt MOS tube quantity n1 alt The number of the second candidate shunt MOS tubes n2 alt size;

[0102] When n1 alt <n2 alt When n2 cond In (n1 alt , n2 alt ) interval.

[0103] In the technical solutions of some embodiments of the present invention, the voltage suppression module of the surge voltage suppression system further includes a voltage-dividing resistor connected in series with the MOS tube and a switch connected to the controller. In the initial state, the voltage-dividing resistor is in a disconnected state, and the MOS tube is directly connected to the input end of the surge voltage suppression system. When comparing the number n1 of the first candidate shunt MOS tubes alt The number of the second candidate shunt MOS tubes n2 alt After the size step, also include:

[0104] When n1 alt ≥n2 alt When the switching switch is controlled to disconnect the MOS tube from the input end of the surge voltage suppression system, the voltage dividing resistor is connected to connect the MOS tube to the input end of the surge voltage suppression system through the voltage dividing resistor.

[0105] Further, according to the output current I out And the maximum drain-source current I of the MOS tube DSM Calculate the number n1 of the first candidate shunt MOS tubes of the surge voltage suppression system alt In the steps, the controller is configured to:

[0106] Get the maximum drain-source current I of the MOS tube DSM ;

[0107] Compare the maximum drain-source current I DSM With the output current I out size;

[0108] When I out >I DSM When the number of the first candidate shunt MOS tubes is

[0109] In the technical solutions of some embodiments of the present invention, when comparing the maximum drain-source current I DSM With the output current I out After the size step, also include:

[0110] When I out ≤I DSM When n1 alt =1.

[0111] Further, according to the output current I out , the first voltage difference ΔU1 and the maximum drain-source resistance R of the MOS tube DSM Calculate the number n2 of the second candidate shunt MOS tubes of the surge voltage suppression system alt The steps specifically include:

[0112] Get the maximum drain-source resistance R of the MOS tube DSM ;

[0113] Comparing the output current I out With the maximum drain-source resistance R DSM The product I out ·R DSM The magnitude of the voltage difference ΔU1 with the first voltage;

[0114] When(I out ·R DSM )>ΔU1, the number of the second candidate shunt MOS tubes is

[0115] In the technical solutions of some embodiments of the present invention, when comparing the output current I out With the maximum drain-source resistance R DSM The product I out ·R DSM After the step of determining the magnitude of the first voltage difference ΔU1, the method further comprises:

[0116] When(I out ·R DSM )≤ΔU1, let n2 alt =1;

[0117] The switching switch is controlled to disconnect the MOS tube from the input end of the surge voltage suppression system, and the voltage-dividing resistor is connected to connect the MOS tube to the input end of the surge voltage suppression system through the voltage-dividing resistor.

[0118] In the technical solution of the above implementation, since the number of the first candidate shunt MOS tubes n1 alt The number of the second candidate shunt MOS tubes n2 alt are extreme values, that is, when n2 cond =n1 alt When the MOS tube is in the on state, the operating current is its maximum drain-source current I DSM ; Similarly, when n2 cond =n2 alt When the MOS tube is in the on state, the on resistance is its maximum drain-source resistance R DSM Therefore, we need to change n2 cond Configured as (n1 alt ,1n2 alt ) is the intermediate value in the interval that is relatively far from the endpoints of the two intervals. For example, its mean can be taken as:

[0119]

[0120] Further, the gate voltage U of the MOS transistor in the second conduction state is adjusted according to the number of the MOS transistors in the second conduction state. GS In the step of performing current balancing between the conducting MOS tubes, the controller is configured as follows:

[0121] Determine the MOS transistor in the second conduction state as the target MOS transistor;

[0122] Obtain the instantaneous temperature rise ΔT of the target MOS tube i (t) and the average instantaneous temperature rise where i∈[1, n2 cond ], where ΔT i (t) is the instantaneous temperature rise of the i-th target MOS tube at time t, is n2 cond The average instantaneous temperature rise of the target MOS tube at time t;

[0123] For any target MOS tube that satisfies When the preset step length ΔU GS Reduce satisfaction The gate voltage U of the target MOS tube GS .

[0124] At a preset step size ΔU GS Reduce satisfaction The gate voltage U of the target MOS tube GS After the steps, it also includes:

[0125] Continuously monitor the input voltage U of the surge voltage suppression system in ;

[0126] Calculate the input voltage U in With the target output voltage U e The first voltage difference between:

[0127] ΔU1=U in -U e ;

[0128] Determine whether the first voltage difference ΔU1 is greater than the voltage difference threshold ΔU th ;

[0129] When ΔU1≤ΔU th When the at least one MOS tube connected in parallel is controlled to enter the first conducting state.

[0130] After the step of controlling at least one parallel MOS tube to enter the first conduction state, the step of adjusting the gate voltage U of the MOS tube in the second conduction state according to the number of the MOS tubes in the second conduction state is no longer performed. GS The step of current balancing between the conducting MOS tubes is performed.

[0131] Typically, the input voltage U in The fluctuation will not last too long and will fall back to the target output voltage U in a very short time. e Therefore, after the surge voltage is generated, the first voltage difference ΔU1 will be a continuously changing value.

[0132] Furthermore, the instantaneous temperature rise ΔT of the target MOS tube is detected in real time. i (t) and the average instantaneous temperature rise In the steps, the controller is configured to:

[0133] Real-time acquisition of the temperature T of the target MOS tube i (t), T i (t) is the temperature of the i-th target MOS tube at time t;

[0134] Calculate the instantaneous temperature rise of the target MOS tube:

[0135]

[0136] Where Δt is the temperature sampling time interval of the temperature sensor;

[0137] Calculate the average instantaneous temperature rise of the target MOS tube:

[0138]

[0139] Specifically, each parallel branch of the voltage suppression module of the surge voltage suppression system further includes a temperature sensor for monitoring the temperature of the MOS tube in the corresponding parallel branch, and the temperature sensor is connected to the controller to monitor the temperature value T of the MOS tube. i (t) provided to the controller.

[0140] Further, the gate voltage U of the MOS transistor in the second conduction state is adjusted according to the number of the MOS transistors in the second conduction state. GS After executing the step of current balancing between the conducting MOS tubes, the controller is configured as follows:

[0141] Real-time detection of the output voltage U of the surge voltage suppression system out and output current I out ;

[0142] Calculate the output voltage U out With the target output voltage U e The second voltage difference between:

[0143] ΔU2=U out —U e ;

[0144] According to the second voltage difference ΔU2 and the output current I out Dynamically adjust the on-resistance of the MOS tube in the first on-state or the second on-state to adjust the output voltage U out Stable at the target output voltage U e nearby.

[0145] In order to maintain the output voltage U out and the output current I out The gate voltage U of the MOS tube in the second conduction state is adjusted according to the number of the MOS tubes in the second conduction state. GS After performing the step of current balancing between the conducting MOS tubes, it is necessary to continuously monitor the output voltage U out and the output current I out , and according to the output voltage U out and the output current I out The size of the on-resistance of the MOS tube is dynamically adjusted.

[0146] Specifically, the controller monitors the output voltage U of the surge voltage suppression system through the output voltage feedback module.out and output current I out The size of the second voltage difference ΔU2 and the output current I out The size of the on-resistance of the MOS tube in the first on-state or the second on-state is dynamically adjusted to increase the output voltage U out Stable at the target output voltage U e Preferably, the number of the first shunt MOS tubes n1 cond And the number of the second shunt MOS tubes n2 cond Much smaller than the number of the second candidate shunt MOS tubes n2 alt , so that the on-resistance of the MOS tube in the first on-state or the second on-state has enough redundancy to implement voltage regulation.

[0147] like Figure 2 As shown, the second aspect of the present invention provides a control method for a surge voltage suppression system, comprising:

[0148] Get the pre-configured target output voltage U e And the pressure difference threshold ΔU th , the target output voltage is the rated voltage of the load device connected to the surge voltage suppression system;

[0149] Real-time detection of the input voltage U of the surge voltage suppression system in ;

[0150] Calculate the input voltage U in With the target output voltage U e The first voltage difference between:

[0151] ΔU1=U in -U e ;

[0152] Determine whether the first voltage difference ΔU1 is greater than the voltage difference threshold ΔU th ;

[0153] When ΔU1≤ΔU th When the at least one MOS tube connected in parallel is controlled to enter a first conducting state;

[0154] When ΔU1>ΔU th When the at least one MOS tube connected in parallel is controlled to enter the second conduction state;

[0155] The gate voltage U of the MOS tube in the second conduction state is adjusted according to the number of the MOS tubes in the second conduction state. GS To perform current balancing among the conducting MOS tubes.

[0156] Specifically, the surge voltage suppression system can be set at the power input end of an independent electrical device, or at the power input end of a local electrical network composed of a series of electrical devices. When the surge voltage suppression system is set at the power input end of an independent electrical device, the load device is the independent electrical device. Similarly, when the surge voltage suppression system is set at the power input end of a local electrical network composed of a series of electrical devices, the load device is a collection of electrical devices in the local electrical network. In this embodiment, the electrical devices in the local electrical network have the same rated voltage, for example, the rated voltages of these electrical devices can all be 220 volts or all be 380 volts.

[0157] In the technical solution of the above embodiment, the first conduction state is a low resistance conduction state. In the first conduction state, the MOS tube supplies power to the load device at a very low voltage and low power loss. The second conduction state is a variable resistance state. In the second conduction state, the controller adjusts the gate voltage U of the MOS tube. GS To control the on-resistance and voltage drop of the MOS tube.

[0158] The pressure difference threshold ΔU th The output voltage U of the pre-configured surge voltage suppression system out and the rated voltage of the load device, that is, the target output voltage U e The maximum tolerable fluctuation amplitude difference between the transient input voltage U in With the target output voltage U e The first voltage difference ΔU1 between the th When the input voltage U in Approximately the same output voltage U out When the instantaneous input voltage U in With the target output voltage U e The first voltage difference ΔU1 between the th When the instantaneous input voltage U in The voltage drop of the surge voltage suppression system is adjusted by controlling at least one parallel MOS tube to enter the second conduction state, so that the output voltage U out Stable at the target output voltage U e nearby to avoid surge voltage from damaging the load equipment.

[0159] In the technical solution of the above-mentioned implementation mode, since the first conduction state is a low resistance conduction state, in the step of controlling at least one parallel MOS tube to enter the first conduction state, each MOS tube in the first conduction state is configured to be in a low conduction resistance state, so each MOS tube in the first conduction state has the characteristics of conduction resistance and low voltage drop, and the current size of each MOS tube is related to the input voltage U of the surge voltage suppression system. in And it is related to the load size of the load device. The MOS tube in the first conduction state will adaptively balance the current according to its working state during operation. Specifically, in the technical solution of the present invention, the MOS tubes are all connected in parallel to the circuit, so the MOS tubes in the first conduction state have the same voltage drop. Due to individual differences, even if the same type of MOS tubes are used, their individual properties including their packages and voltages will still have slight differences. The MOS tube with a small saturation voltage will pass a larger current in the initial state, so the temperature rise of its channel region will be faster than that of other MOS tubes, resulting in an increase in its on-resistance. The surge voltage suppression system performs voltage stabilization control on the surge voltage suppression system through an output voltage feedback module and a voltage control module. Therefore, in the external circuit parameter, that is, the input voltage U of the surge voltage suppression system in , output voltage U out And when the load size of the load device remains unchanged, the change of the on-resistance of each MOS tube will cause the current in each parallel branch to be redistributed, thereby realizing adaptive current sharing.

[0160] Furthermore, the step of controlling at least one parallel MOS tube to enter a first conduction state specifically includes:

[0161] Obtaining the output current range corresponding to the number of pre-configured shunt MOS tubes;

[0162] Detect the output current I of the surge voltage suppression system out ;

[0163] Determine the output current I out The number of first shunt MOS tubes corresponding to the output current interval n1 cond , where 1≤n1 cond ≤n mos , n mos is the number of MOS tubes connected in parallel in the voltage suppression module of the surge voltage suppression system;

[0164] Control n1 cond The MOS tube enters the first conduction state.

[0165] In the technical solutions of some embodiments of the present invention, after obtaining the pre-configured target output voltage U e And the pressure difference threshold ΔU th Before the step of, it also includes configuring a correspondence between a plurality of output current intervals and the number of shunt MOS tubes, wherein the larger the current in the output current interval is, the larger the number of the corresponding shunt MOS tubes is.

[0166] Specifically, due to the maximum drain-source current I of the MOS tube DSM It is related to the type of MOS tube, process parameters and the real-time temperature during operation. The maximum drain-source current I DSM Refers to the maximum on-state current allowed to pass between the drain and source of the MOS tube. Generally speaking, the operating current of the MOS tube is between 6A and 9A, and the maximum should not exceed 20A, otherwise the MOS tube will be damaged. For applications with high-power load equipment, even in the absence of surge voltage, using only one MOS tube is not enough to withstand the operating current of the load equipment.

[0167] In the technical solution of the above-mentioned implementation mode, by configuring the number of first shunt MOS tubes corresponding to different output current intervals, when the load device operates within different current intervals, the surge voltage suppression system configures a corresponding number of MOS tubes for shunt, thereby avoiding damage to the MOS tube due to being unable to withstand excessive conduction current.

[0168] In the technical solution of the above embodiment, when controlling n1 cond The step of entering the first conduction state of the MOS tubes also includes making the remaining n mos -n1 cond Keep the remaining n MOS tubes in the cut-off state. mos -n1 cond The MOS tubes are kept in the cut-off state. Specifically, the controller adjusts the remaining n mos -n1 cond The gate voltage of the MOS tubes is set to make the remaining n mos -n1 cond Each MOS tube works in the cut-off region.

[0169] Furthermore, the step of controlling at least one parallel MOS tube to enter the second conduction state specifically includes:

[0170] Detect the output current I of the surge voltage suppression system out ;

[0171] According to the output current I out And the first voltage difference ΔU1 determines the number n2 of the second shunt MOS tubes cond , where 1≤n2 cond≤n mos ;

[0172] Control n2 cond The MOS tube enters the second conduction state.

[0173] When the first voltage difference ΔU1 is larger, it means that the surge voltage is larger, and the voltage drop required to be achieved by the surge voltage suppression system is larger. At this time, the more MOS tubes are connected in parallel, the smaller the total on-resistance will be. It is necessary to comprehensively consider the real-time output current I out The first voltage difference ΔU1 is used to determine the number n2 of the second shunt MOS tubes that need to be turned on. cond , to avoid the second shunt MOS tube number n2 cond Too large to achieve the corresponding voltage drop effect, or because the number of the second shunt MOS tubes n2 cond If the current is too small, the MOS tube will be damaged.

[0174] In the technical solution of the above embodiment, when controlling n2 cond The step of entering the second conduction state of the MOS tubes also includes making the remaining n mos -n2 cond Keep the remaining n MOS tubes in the cut-off state. mos -n2 cond The MOS tubes are kept in the cut-off state. Specifically, the controller adjusts the remaining n mos -n2 cond The gate voltage of the MOS tubes is set to make the remaining n mos -n2 cond Each MOS tube works in the cut-off region.

[0175] Further, according to the output current I out And the first voltage difference ΔU1 determines the number n2 of the second shunt MOS tubes cond The steps specifically include:

[0176] According to the output current I out And the maximum drain-source current I of the MOS tube DSM Calculate the number n1 of the first candidate shunt MOS tubes of the surge voltage suppression system alt ;

[0177] According to the output current I out , the first voltage difference ΔU1 and the maximum drain-source resistance R of the MOS tube DSM Calculate the number n2 of the second candidate shunt MOS tubes of the surge voltage suppression system alt ;

[0178] Compare the first candidate shunt MOS tube quantity n1 alt The number of the second candidate shunt MOS tubes n2 alt size;

[0179] When n1 alt <n2 alt When n2 cond In (n1 alt , n2 alt ) interval.

[0180] In the technical solutions of some embodiments of the present invention, the voltage suppression module of the surge voltage suppression system further includes a voltage-dividing resistor connected in series with the MOS tube and a switch connected to the controller. In the initial state, the voltage-dividing resistor is in a disconnected state, and the MOS tube is directly connected to the input end of the surge voltage suppression system. When comparing the number n1 of the first candidate shunt MOS tubes alt The number of the second candidate shunt MOS tubes n2 alt After the size step, also include:

[0181] When n1 alt ≥n2 alt When the switching switch is controlled to disconnect the MOS tube from the input end of the surge voltage suppression system, the voltage dividing resistor is connected to connect the MOS tube to the input end of the surge voltage suppression system through the voltage dividing resistor.

[0182] Further, according to the output current I out And the maximum drain-source current I of the MOS tube dSM Calculate the number n1 of the first candidate shunt MOS tubes of the surge voltage suppression system alt The steps specifically include:

[0183] Get the maximum drain-source current I of the MOS tube DSM ;

[0184] Compare the maximum drain-source current I DSM With the output current I out size;

[0185] When I out >I DSM When the number of the first candidate shunt MOS tubes is

[0186] In the technical solutions of some embodiments of the present invention, when comparing the maximum drain-source current I DSM With the output current I out After the size step, also include:

[0187] When I out ≤I DSM When n1 alt =1.

[0188] Further, according to the output current I out , the first voltage difference ΔU1 and the maximum drain-source resistance R of the MOS tube DSM Calculate the number n2 of the second candidate shunt MOS tubes of the surge voltage suppression system alt The steps specifically include:

[0189] Get the maximum drain-source resistance R of the MOS tube DSM ;

[0190] Comparing the output current I out With the maximum drain-source resistance R DSM The product I out ·R DSM The magnitude of the voltage difference ΔU1 with the first voltage;

[0191] When(I out ·R DSM )>ΔU1, the number of the second candidate shunt MOS tubes is

[0192] In the technical solutions of some embodiments of the present invention, when comparing the output current I out With the maximum drain-source resistance R DSM The product I out ·R DSM After the step of determining the magnitude of the first voltage difference ΔU1, the method further comprises:

[0193] When(I out ·R DSM )≤ΔU1, let n2 alt =1;

[0194] The switching switch is controlled to disconnect the MOS tube from the input end of the surge voltage suppression system, and the voltage-dividing resistor is connected to connect the MOS tube to the input end of the surge voltage suppression system through the voltage-dividing resistor.

[0195] In the technical solution of the above implementation, since the number of the first candidate shunt MOS tubes nl alt The number of the second candidate shunt MOS tubes n2 alt are extreme values, that is, when n2 cond =n1 alt When the MOS tube is in the on state, the operating current is its maximum drain-source current I DSM ; Similarly, when n2cond =n2 alt When the MOS tube is in the on state, the on resistance is its maximum drain-source resistance R DSM Therefore, we need to change n2 cond Configured as (n1 alt , n2 alt ) is the intermediate value in the interval that is relatively far from the endpoints of the two intervals. For example, its mean can be taken as:

[0196]

[0197] Furthermore, the gate voltage U of the MOS transistor in the second conduction state is adjusted according to the number of the MOS transistors in the second conduction state. GS The steps of performing current balancing between the conducting MOS tubes specifically include:

[0198] Determine the MOS transistor in the second conduction state as the target MOS transistor;

[0199] Obtain the instantaneous temperature rise ΔT of the target MOS tube i (t) and the average instantaneous temperature rise where i∈[1, n2 cond ], where ΔT i (t) is the instantaneous temperature rise of the i-th target MOS tube at time t, is n2 cond The average instantaneous temperature rise of the target MOS tube at time t;

[0200] For any target MOS tube that satisfies When the preset step length ΔU GS Reduce satisfaction The gate voltage U of the target MOS tube GS .

[0201] At a preset step size ΔU GS Reduce satisfaction The gate voltage U of the target MOS tube GS After the steps, it also includes:

[0202] Continuously monitor the input voltage U of the surge voltage suppression system in ;

[0203] Calculate the input voltage U in With the target output voltage U e The first voltage difference between:

[0204] ΔU1=U in -U e ;

[0205] Determine whether the first voltage difference ΔU1 is greater than the voltage difference threshold ΔU th ;

[0206] When ΔU1≤ΔU th When the at least one MOS tube connected in parallel is controlled to enter the first conducting state.

[0207] After the step of controlling at least one parallel MOS tube to enter the first conduction state, the step of adjusting the gate voltage U of the MOS tube in the second conduction state according to the number of the MOS tubes in the second conduction state is no longer performed. GS The step of current balancing between the conducting MOS tubes is performed.

[0208] Typically, the input voltage U in The fluctuation will not last too long and will fall back to the target output voltage U in a very short time. e Therefore, after the surge voltage is generated, the first voltage difference ΔU1 will be a continuously changing value.

[0209] Furthermore, the instantaneous temperature rise ΔT of the target MOS tube is detected in real time. i (t) and the average instantaneous temperature rise The steps specifically include:

[0210] Real-time acquisition of the temperature T of the target MOS tube i (t), T i (t) is the temperature of the i-th target MOS tube at time t;

[0211] Calculate the instantaneous temperature rise of the target MOS tube:

[0212]

[0213] Where Δt is the temperature sampling time interval of the temperature sensor;

[0214] Calculate the average instantaneous temperature rise of the target MOS tube:

[0215]

[0216] Specifically, each parallel branch of the voltage suppression module of the surge voltage suppression system further includes a temperature sensor for monitoring the temperature of the MOS tube in the corresponding parallel branch, and the temperature sensor is connected to the controller to monitor the temperature value T of the MOS tube. i (t) provided to the controller.

[0217] Further, the gate voltage U of the MOS transistor in the second conduction state is adjusted according to the number of the MOS transistors in the second conduction state.GS After performing the step of current balancing between the conducting MOS tubes, the method further includes:

[0218] Real-time detection of the output voltage U of the surge voltage suppression system out and output current I out ;

[0219] Calculate the output voltage U out With the target output voltage U e The second voltage difference between:

[0220] ΔU2=U out -U e ;

[0221] According to the second voltage difference ΔU2 and the output current I out Dynamically adjust the on-resistance of the MOS tube in the first on-state or the second on-state to adjust the output voltage U out Stable at the target output voltage U e nearby.

[0222] In order to maintain the output voltage U out and the output current I out The gate voltage U of the MOS tube in the second conduction state is adjusted according to the number of the MOS tubes in the second conduction state. GS After performing the step of current balancing between the conducting MOS tubes, it is necessary to continuously monitor the output voltage U out and the output current I out , and according to the output voltage U out and the output current I out The size of the on-resistance of the MOS tube is dynamically adjusted.

[0223] Specifically, the controller monitors the output voltage U of the surge voltage suppression system through the output voltage feedback module. out and output current I out The size of the second voltage difference ΔU2 and the output current I out The size of the on-resistance of the MOS tube in the first on-state or the second on-state is dynamically adjusted to increase the output voltage U out Stable at the target output voltage U e Preferably, the number of the first shunt MOS tubes n1 cond And the number of the second shunt MOS tubes n2 cond Much smaller than the number n2 of the second candidate shunt MOS tubes alt, so that the on-resistance of the MOS tube in the first on-state or the second on-state has enough redundancy to implement voltage regulation.

[0224] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0225] According to the embodiments of the present invention as described above, these embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments described. Obviously, many modifications and changes can be made based on the above description. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can make good use of the present invention and the modified use based on the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A surge voltage suppression system, characterized in that: The invention comprises an input voltage monitoring module for monitoring input voltage, a voltage suppression module for stabilizing and shunting input voltage, an output voltage feedback module for collecting and feeding back output voltage, and a voltage control module for controlling the voltage suppression module according to the input voltage sampled by the input voltage monitoring module and the output voltage sampled by the output voltage feedback module. The voltage suppression module comprises a plurality of MOS tubes connected in parallel with each other. The input voltage monitoring module comprises a first sampling resistor and a voltage detection circuit whose input end is connected to the first sampling resistor. The output voltage feedback module comprises a second sampling resistor and a voltage feedback circuit whose input end is connected to the second sampling resistor. The voltage control circuit comprises a controller. The controller is connected to the output end of the voltage detection circuit, the output end of the voltage feedback circuit, and the gate of the MOS tube. The controller is configured as follows: Get a pre-configured target output voltage And the pressure difference threshold , the target output voltage is the rated voltage of the load device connected to the surge voltage suppression system; Real-time detection of the input voltage of the surge voltage suppression system ; Calculate the input voltage with the target output voltage The first voltage difference between: ； Determine the first voltage difference Is it greater than the pressure difference threshold? ; when When the at least one MOS tube connected in parallel is controlled to enter a first conducting state; when When the at least one MOS tube connected in parallel is controlled to enter the second conduction state; Adjusting the gate voltage of the MOS tube in the second conduction state according to the number of the MOS tubes in the second conduction state To perform current balancing between the conducting MOS tubes; According to the number of MOS tubes in the second conduction state, the gate voltage of the MOS tube in the second conduction state is adjusted. In the step of performing current balancing between the conducting MOS tubes, the controller is configured as follows: Determine the MOS transistor in the second conduction state as the target MOS transistor; Obtain the instantaneous temperature rise of the target MOS tube and the average instantaneous temperature rise ,in ,in For the The target MOS tube is The instantaneous temperature rise at a certain moment, for The target MOS tube is The instantaneous mean temperature rise at time; For any target MOS tube that satisfies When the preset step length Reduce satisfaction The gate voltage of the target MOS tube .

2. A control method for a surge voltage suppression system, applied to the surge voltage suppression system as claimed in claim 1, characterized in that: include: Get a pre-configured target output voltage And the pressure difference threshold , the target output voltage is the rated voltage of the load device connected to the surge voltage suppression system; Real-time detection of the input voltage of the surge voltage suppression system ; Calculate the input voltage with the target output voltage The first voltage difference between: ； Determine the first voltage difference Is it greater than the pressure difference threshold? ; when When the at least one MOS tube connected in parallel is controlled to enter a first conducting state; when When the at least one MOS tube connected in parallel is controlled to enter the second conduction state; Adjusting the gate voltage of the MOS tube in the second conduction state according to the number of the MOS tubes in the second conduction state To perform current balancing between the conducting MOS tubes; Adjusting the gate voltage of the MOS tube in the second conduction state according to the number of the MOS tubes in the second conduction state The steps of performing current balancing between the conducting MOS tubes specifically include: Determine the MOS transistor in the second conduction state as the target MOS transistor; Obtain the instantaneous temperature rise of the target MOS tube and the average instantaneous temperature rise ,in ,in For the The target MOS tube is The instantaneous temperature rise at a certain moment, for The target MOS tube is The instantaneous mean temperature rise at time; For any target MOS tube that satisfies When the preset step length Reduce satisfaction The gate voltage of the target MOS tube .

3. The control method of the surge voltage suppression system according to claim 2, characterized in that: The step of controlling at least one parallel MOS tube to enter a first conduction state specifically includes: Obtaining the output current range corresponding to the number of pre-configured shunt MOS tubes; Detecting the output current of the surge voltage suppression system ; Determine the output current The number of first shunt MOS tubes corresponding to the output current interval ,in , is the number of MOS tubes connected in parallel in the voltage suppression module of the surge voltage suppression system; control The MOS tube enters the first conduction state.

4. The control method of the surge voltage suppression system according to claim 3, characterized in that: The step of controlling at least one parallel MOS tube to enter the second conduction state specifically includes: Detecting the output current of the surge voltage suppression system ; According to the output current And the first voltage difference Determine the number of second shunt MOS tubes ,in ; control The MOS tube enters the second conduction state.

5. The control method of the surge voltage suppression system according to claim 4, characterized in that: According to the output current And the first voltage difference Determine the number of second shunt MOS tubes The steps specifically include: According to the output current And the maximum drain-source current of the MOS tube Calculate the number of first candidate shunt MOS tubes for the surge voltage suppression system ; According to the output current , the first voltage difference And the maximum drain-source resistance of the MOS tube Calculate the number of second candidate shunt MOS tubes for the surge voltage suppression system ; Compare the number of the first candidate shunt MOS tubes The number of the second candidate shunt MOS tube size; when hour, exist Take a value in the interval.

6. The control method of the surge voltage suppression system according to claim 5, characterized in that: According to the output current And the maximum drain-source current of the MOS tube Calculate the number of first candidate shunt MOS tubes for the surge voltage suppression system The steps specifically include: Get the maximum drain-source current of the MOS tube ; Compare the maximum drain-source current With the output current size; when When the number of the first candidate shunt MOS tubes is .

7. The control method of the surge voltage suppression system according to claim 5, characterized in that: According to the output current , the first voltage difference And the maximum drain-source resistance of the MOS tube Calculate the number of second candidate shunt MOS tubes for the surge voltage suppression system The steps specifically include: Get the maximum drain-source resistance of the MOS tube ; Comparing the output current With the maximum drain-source resistance The product between The difference between the first voltage size; when When the number of the second candidate shunt MOS tubes is .

8. The control method of the surge voltage suppression system according to claim 2, characterized in that: Real-time detection of the instantaneous temperature rise of the target MOS tube and the average instantaneous temperature rise The steps specifically include: Real-time acquisition of the temperature of the target MOS tube , For the The target MOS tube is in time Temperature; Calculate the instantaneous temperature rise of the target MOS tube: ， in It is the temperature sampling time interval of the temperature sensor; Calculate the average instantaneous temperature rise of the target MOS tube: 。 9. The control method of the surge voltage suppression system according to claim 2, characterized in that: According to the number of MOS tubes in the second conduction state, the gate voltage of the MOS tube in the second conduction state is adjusted. After performing the step of current balancing between the conducting MOS tubes, the method further includes: Real-time detection of the output voltage of the surge voltage suppression system and output current ; Calculate the output voltage with the target output voltage The second voltage difference between: ； According to the second voltage difference and the output current Dynamically adjust the on-resistance of the MOS tube in the first on-state or the second on-state to adjust the output voltage stabilized at the target output voltage nearby.

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