Charging system with high-voltage protection

Abstract

The invention provides a charging system with high-voltage protection, which relates to the technical field of elevator emergency power supply and comprises a transformer, a voltage stabilizing circuit, a sampling circuit, an on-off circuit, a surge protection circuit, a constant current and voltage stabilizing circuit and a control circuit. The transformer reduces commercial power high voltage to low voltage; the voltage stabilizing circuit provides a stable direct-current power supply for the sampling and control circuit; the sampling circuit is used for conditioning the AC voltage and outputting a feedback signal; and the control circuit performs mode analysis by utilizing a pre-judgment algorithm according to the feedback signal so as to control the on-off circuit to cut off the mains supply input or switch the output mode of the constant current and voltage stabilizing circuit. Through an intelligent protection mechanism comprising sampling, control and on-off circuits, the device can be suitable for single-phase electric equipment, and quick and accurate response to abnormal high voltage is realized. And the transformer is adopted for voltage conversion and isolation, and the surge protection circuit and the on-off circuit are combined, so that the protection performance is ensured, and the overall cost and size of the system are effectively controlled.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of elevator emergency power supply, in particular to a charging system with high-voltage protection. BACKGROUND

[0002] An elevator device will experience various power supply modes in its life cycle, including temporary power supply during building infrastructure stage, normal power supply after building completion, and emergency power supply during power failure. In particular, in temporary power supply and emergency power supply modes, the grid voltage is prone to be unstable or even abnormally high, and high voltage may also enter due to circuit wiring errors. These abnormally high voltages can cause permanent damage to the power supply equipment of the elevator, especially the charging module.

[0003] Currently, there are two common protection schemes in the elevator field for high voltage problems: One is to use a phase sequence protector. When detecting abnormal voltage rise, the phase sequence protector disconnects the contact of its internal relay, thereby cutting off the power input contactor, and protecting the downstream equipment. However, this scheme relies on three-phase voltage detection, which is not applicable to single-phase power supply devices and is extremely inconvenient to install.

[0004] The second is to use a method of increasing the voltage withstand value of the circuit components on the power input side. By selecting components that can withstand higher voltage to resist high voltage impact. However, in temporary power supply scenarios, abnormal voltage may be as high as 380V and last for a long time, which not only poses a high requirement on component selection, but also significantly increases the cost and design difficulty of the system, which is not conducive to the popularization and application of products.

[0005] Therefore, the existing technology has the problems of inapplicability of the protection scheme to single-phase devices and high cost and difficulty of implementation of the high-voltage scheme, and there is an urgent need for a more universal, economical and reliable solution. SUMMARY

[0006] The present application aims to overcome the shortcomings of the prior art and provide a charging system with high-voltage protection to solve the problem of inapplicability of existing protection schemes to single-phase devices and high cost of high-voltage schemes.

[0007] To achieve the above-mentioned purpose, the present application provides the following technical solutions: The application discloses a charging system with high-voltage protection, which comprises a transformer, a primary connection of commercial power, a secondary connection of a sampling circuit and a voltage stabilizing circuit, which is used for reducing a wide range of high voltage of the commercial power into a low voltage in a required range; the voltage stabilizing circuit has an input end connected with one of the windings of the secondary of the transformer and an output end connected with a control circuit, which is used for converting alternating voltage outputted by the transformer into stable direct current voltage to provide a stable working power source for the sampling circuit and the control circuit; the sampling circuit has an input end connected with another winding of the secondary of the transformer and an output end connected with the control circuit, which is used for signal conditioning of the alternating voltage outputted by the transformer and outputting a direct current feedback voltage signal to the control circuit; a switch circuit has an input end connected with the commercial power, an output end connected with an input end of a surge protection circuit and a control end connected with the control circuit, which is used for on-off control of the commercial power input according to the control instruction of the control circuit; the surge protection circuit has an input end connected with the output end of the switch circuit and is used for absorbing surges to protect the constant current and voltage stabilizing circuit in the rear stage from being damaged; the constant current and voltage stabilizing circuit has an input end connected with the output end of the surge protection circuit and a control end connected with the control circuit, which is used for outputting direct current working voltage in a constant current mode or a constant voltage mode as the output of the charging system according to the control instruction of the control circuit to charge the backup battery; the control circuit receives and processes the direct current feedback voltage signal sent by the sampling circuit, performs mode analysis based on a pre-judgment algorithm, sends on-off control signals to the switch circuit and / or sends constant current / constant voltage mode switching control signals to the constant current and voltage stabilizing circuit according to the mode analysis result.

[0008] The application provides a preferred scheme, wherein the modes in the control circuit specifically include a mutation mode, a stable mode and an off mode; the mode analysis based on the pre-judgment algorithm and the sending of the on-off control signals to the switch circuit according to the mode analysis result specifically include: the mutation mode is triggered when the system needs to be charged, initial power-on or when it is monitored or predicted that the voltage has a sharp mutation or a sharp fluctuation from the stable mode or the off mode; the mutation mode is exited and switched to the stable mode when it is monitored that the commercial power voltage has no large fluctuation within a preset stable period; the stable mode is switched to the mutation mode and the off control signal is sent to the switch circuit to make the switch circuit cut off the commercial power input when it is predicted or monitored in real time that the voltage exceeds a preset safety threshold; or the stable mode is switched to the mutation mode and the off control signal is sent to the switch circuit to make the switch circuit cut off the commercial power input when it is monitored that the voltage does not exceed the preset safety threshold but the change rate before and after the voltage exceeds a preset change rate; or the stable mode is switched to the off mode when the signal that the backup battery is fully charged is acquired; the off mode sends the off control signal to the switch circuit to make the switch circuit completely cut off the commercial power input, and the system needs to be charged again, the state of the commercial power is re-evaluated and the mode analysis is performed.

[0009] The present invention provides a preferred solution in which the input AC mains voltage ranges from AC80V to AC600V, is reduced to AC5V to AC38V by a transformer, and after rectification by a voltage regulator circuit, is regulated to a working voltage of 3.3V by a DC-DC voltage regulator chip.

[0010] The present invention provides a preferred embodiment in which another set of windings of the transformer secondary provides AC voltage from the mains to the sampling circuit. After rectification and filtering, the sampling circuit provides a DC feedback voltage of 0~3V to the control circuit according to the design voltage value of up to 600V.

[0011] This invention provides a preferred embodiment where the prediction algorithm is a voltage maximum value prediction algorithm. Specifically, the sampling circuit converts the signal into a 0~3V DC feedback voltage after rectification. When a 0V voltage is sampled, it represents the 0 potential of the AC current. The time difference between two 0 potential positions is Δt. The frequency f of the AC current is calculated using the formula f=1 / (2Δt). Then, based on the sampling frequency f... s The formula θ=(360f) / f s Calculate the angle θ for each sampled signal, and then, starting from 0 potential, calculate the highest voltage value U of the AC current one by one using the sampled value y, and this highest voltage value U is the predicted highest voltage value.

[0012] The present invention provides a preferred embodiment in which the on / off circuit uses a bidirectional thyristor to control the mains power input.

[0013] The present invention provides a preferred embodiment in which the on / off circuit uses a relay to control the mains power input.

[0014] The present invention provides a preferred solution in which the control circuit does not immediately turn on the bidirectional thyristor when the voltage crosses the zero potential, but turns on the bidirectional thyristor after sampling at multiple sampling points and determining that the current voltage does not exceed a preset safety threshold.

[0015] The present invention provides a preferred embodiment in which the preset stabilization period is 30 seconds.

[0016] The present invention provides a preferred embodiment in which the preset safety threshold is 253V and the preset change rate is 20%.

[0017] Compared with the prior art, the present invention has the following advantages: The application can be effectively applied to single-phase electrical equipment by designing an intelligent protection mechanism including sampling, control and on-off circuits, realizing rapid and accurate response to abnormal high voltage, and directly cutting off the power input, thereby reliably protecting the subsequent circuit. By introducing a multi-mode analysis to switch the mode of the control logic, timely protection action can be taken when the voltage is suddenly changed or the steady state is exceeded, significantly improving the response speed and protection reliability of the system.

[0018] The application optimizes the system architecture, uses a transformer for voltage conversion and isolation, and combines a surge protection circuit and an on-off circuit to effectively control the overall cost and volume of the system while ensuring protection performance, thereby improving the cost performance and market competitiveness of the product.

[0019] Based on the pre-judgment algorithm of the highest voltage, the application can predict the peak value change trend of the alternating voltage in advance, avoid misjudgment caused by instantaneous overvoltage, and realize more accurate protection control. The sampling circuit combines rectification and DC feedback mechanism, so that the control circuit can accurately capture the voltage zero-crossing time and amplitude change, and provide reliable data support for the pre-judgment algorithm. Combined with the preset safety threshold and change rate constraint, normal fluctuation and dangerous high voltage can be effectively distinguished, and the probability of misoperation is reduced. At the same time, the design of delaying the conduction of silicon controlled rectifier near the zero-crossing point reduces the damage of switching impact current to the device and prolongs the service life of the system. The overall scheme takes into account safety, stability and practicability, and is suitable for electrical equipment protection in complex power grid environment. In addition, the application sets a stable period to ensure that the system can fully judge the power grid state after power-on or voltage fluctuation, and avoid frequent false triggering of protection action. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor on the basis of the provided drawings.

[0021] Figure 1 A circuit module of a charging system with high voltage protection according to one specific embodiment of the present application is shown in the figure. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0023] Please refer to Figure 1 In an alternative embodiment, a charging system with high voltage protection is provided, which includes seven parts: a transformer, a voltage stabilizing circuit, a sampling circuit, a control circuit, a on-off circuit, a surge protection circuit, and a constant current and voltage stabilizing circuit. The transformer has a primary winding connected to the mains and a secondary winding connected to the sampling circuit and the voltage stabilizing circuit, and is used to reduce the wide range of high voltage of the mains to the required range of low voltage; the voltage stabilizing circuit has an input end connected to one of the secondary windings of the transformer and an output end connected to the control circuit, and is used to convert the alternating voltage output by the transformer into a stable direct current voltage to provide a stable working power supply for the sampling circuit and the control circuit; the sampling circuit has an input end connected to another of the secondary windings of the transformer and an output end connected to the control circuit, and is used to perform signal conditioning on the alternating voltage output by the transformer and output a direct current feedback voltage signal to the control circuit; the on-off circuit has an input end connected to the mains, an output end connected to the input end of the surge protection circuit, and a control end connected to the control circuit, and is used to control the input of the mains according to the control instruction of the control circuit; the surge protection circuit has an input end connected to the output end of the on-off circuit, and is used to absorb surges and protect the constant current and voltage stabilizing circuit from being damaged; the constant current and voltage stabilizing circuit has an input end connected to the output end of the surge protection circuit and a control end connected to the control circuit, and is used to output a direct current working voltage in a constant current mode or a constant voltage mode according to the control instruction of the control circuit, as the output of the charging system, to charge the backup battery; the control circuit receives and processes the direct current feedback voltage signal sent by the sampling circuit, performs mode analysis based on a pre-judgment algorithm, sends a on-off control signal to the on-off circuit and / or a constant current / constant voltage mode switching control signal to the constant current and voltage stabilizing circuit according to the mode analysis result.

[0024] The control circuit judges whether the input voltage exceeds the preset safety threshold by monitoring the feedback voltage signal in real time, and once detects high voltage abnormalities, immediately drives the on-off circuit to cut off the mains input, and at the same time starts a protection delay mechanism to ensure that the system resumes operation in a safe state. When the sampling circuit detects that the output voltage abnormally rises, the control circuit immediately triggers the protection mechanism, cuts off the mains input through the on-off circuit, and at the same time starts the voltage limiting function of the constant current and voltage stabilizing circuit to ensure that the output voltage is stable within a safe range.

[0025] In actual implementation, the input AC voltage range is AC 80V~AC 600V, which is reduced to AC 5V~AC 38V through a transformer, rectified by a voltage stabilizing circuit, and then stabilized to 3.3V working voltage by a DC-DC voltage stabilizing chip. The working voltage provides stable power supply for the control circuit and the sensor module, ensuring the continuous operation of the monitoring and prediction functions. Under wide range of input AC voltage, the system can still maintain sampling accuracy and response speed, adapting to different regional power grid fluctuation requirements. Another set of windings in the secondary of the transformer provides AC voltage for the sampling circuit. After rectification and filtering, the sampling circuit provides a 0~3V DC feedback voltage to the control circuit according to the design voltage value of 600V. After analog-to-digital conversion, the feedback voltage is analyzed by the control circuit in real time as the instantaneous value of the AC power supply, combined with the preset threshold and change rate criteria, to dynamically adjust the working mode. The sampling circuit has an overvoltage protection unit to prevent high voltage from damaging subsequent components. Through the independent power supply design of the double-winding, the main power supply and the sampling signal are electrically isolated, enhancing the system's anti-interference ability and safety.

[0026] In consideration of the fact that most of the abnormal mains is accompanied by a sudden change in voltage, the sudden change in voltage includes a sudden increase or decrease in voltage, therefore, by controlling the condition of the sudden change in voltage, the problem of voltage abnormality can be basically solved. In the state of voltage mutation, it often lasts for a period of time, therefore, in the mutation mode, through the voltage stability judgment of the predetermined stabilization period (such as 30 seconds), effective effect can also be achieved. In addition, the charging time of the battery is relatively small compared with the use time, therefore, the circuit is in the off state for a long time, which is also very good to solve the impact caused by the mains abnormality. Therefore, in a preferred embodiment, the control circuit includes: mutation mode, stable mode and off mode; based on the mode analysis result, the on-off circuit sends the on-off control signal, which specifically includes: mutation mode: when the system needs to be charged, the initial power-on triggers, or, when the voltage is monitored or predicted to have a sudden mutation or a sudden fluctuation, the mutation mode is triggered; when it is monitored that the mains voltage has no large fluctuation within the preset stabilization period, the mutation mode is exited and switched to the stable mode; stable mode: from the mutation mode after the stabilization period is determined; when the voltage exceeds the preset safety threshold based on the prediction algorithm, the stable mode is exited and switched to the mutation mode, the off control signal is sent to the on-off circuit to make the on-off circuit cut off the mains input; or, even if the voltage does not exceed the preset safety threshold, but the change rate before and after exceeds the preset change rate, the stable mode is exited and switched to the mutation mode, the off control signal is sent to the on-off circuit to make the on-off circuit cut off the mains input; or, when the signal that the backup battery is fully charged is obtained, the stable mode is exited and switched to the off mode; off mode: the off control signal is sent to the on-off circuit to make the on-off circuit completely cut off the mains input, when the system needs to be charged again, the mains state is re-evaluated and the mode is analyzed. In an optional embodiment, the preset safety threshold is 253V and the preset change rate is 20%.

[0027] Further, in the mutation mode, the control circuit starts the high-frequency sampling mechanism, and combines the dynamic threshold adjustment algorithm to track and predict the voltage change trend in real time, so as to ensure that the response is made at the initial stage of voltage fluctuation. At the same time, the system introduces a delay conduction mechanism to avoid misjudgment caused by instantaneous interference. When entering the stable mode, the control circuit reduces the sampling frequency to reduce power consumption, and continuously monitors the voltage amplitude and change rate to maintain the output stable. In the off mode, the system maintains a low-power listening state, regularly detects whether the mains power is available for charging, and restarts the charging process after confirming safety, thereby ensuring the long-term operation reliability of the equipment. Under the cooperative control of the three modes, the system can accurately identify the state change of the mains power, realize the balance between millisecond-level response and low-power operation, effectively isolate voltage impact in the mutation mode, prevent abnormal input from damaging the charging circuit, ensure efficient and continuous charging process in the stable mode, and minimize standby power consumption in the off mode. By combining the prediction algorithm with multi-dimensional voltage parameters, the system not only ensures safe battery charging, but also significantly improves the anti-interference ability and energy efficiency of the whole machine, and is suitable for long-term stable operation in complex power grid environment.

[0028] The charging system of the application adopts a transformer, and since the working current of the control circuit is very small, the working voltage of the control circuit is provided after voltage stabilization by the transformer, which not only has a small size, but also solves the voltage sampling problem by increasing a set of windings. Since the transformer is used, the power supply is effectively isolated, and the reliability of the circuit is also increased. In addition, the introduction of the transformer forms effective electrical isolation between the high-voltage side and the low-voltage side of the system, greatly improving personal safety and equipment surge resistance. The control circuit obtains the sampling voltage through the auxiliary winding without additional voltage dividing resistor network, simplifying the structure and improving the precision.

[0029] The charging system of the application utilizes the protection of the surge protection circuit, and since a bidirectional thyristor is used as the off device, a certain delay will be caused during off due to the 0-voltage off characteristic. At this time, the sudden high voltage will enter the rear-end circuit through the bidirectional thyristor, and the surge protection circuit can effectively prevent the short-time high voltage access, thereby reducing the circuit and improving the reliability.

[0030] In a more preferred embodiment, the on-off circuit uses a bidirectional thyristor to control the mains input. The control circuit does not immediately turn on the bidirectional thyristor when the voltage exceeds the 0 potential, but after sampling at multiple sampling points, it determines that the current voltage does not exceed the preset safety threshold, and then turns on the bidirectional thyristor. The bidirectional thyristor only needs a low voltage to be effectively turned on, so it can be controlled by an optical coupling device. In addition, the thyristor can realize infinite repeated switching, so it can realize the switching control of each wave pattern. Further improve the reliability of the device. Through optical coupling isolation control signal, the bidirectional thyristor realizes accurate conduction and shutdown in every half power frequency cycle, effectively suppresses the inrush current. Combined with the zero-crossing detection circuit, the system triggers the thyristor at the voltage zero-crossing point, reduces electromagnetic interference, and improves switching safety. The control circuit dynamically adjusts the conduction angle according to the sampling feedback, adapts to different load requirements, and optimizes power output. At the same time, the fast response characteristics of the thyristor support millisecond-level cutting in mutation mode, enhancing the system's ability to protect against grid anomalies. When triggered in mutation mode, the control circuit immediately blocks the thyristor drive signal, cutting off the main circuit power supply, preventing high voltage or inrush from damaging the downstream circuit. The system monitors the rate of change of the feedback voltage in real time, identifies transient anomalies such as lightning strikes, sudden rises or drops, and activates the protection mechanism the moment it detects a safety threshold. During the recovery process, the control circuit gradually reconnects to the mains to avoid another impact. The entire protection and recovery process does not require human intervention, ensuring the long-term reliable operation of the device in complex power environments.

[0031] Considering that the mains will also have a probability of voltage mutation in a stable state, if the voltage value is determined to exceed the standard range when it exceeds the rated range, the shutdown will not be timely due to the delay of the thyristor. However, by using voltage prediction to predict the maximum voltage in advance, the timeliness of the power shutdown can be greatly reduced. Therefore, in a more preferred embodiment, the prediction algorithm is a voltage maximum prediction algorithm, which specifically includes: the sampling circuit converts the signal to a 0-3V DC feedback voltage after rectification, at which time the 0V voltage sampled is the 0 potential of the alternating current. The time difference between the positions of the two 0 potentials is Δt, and the frequency f of the alternating current is calculated by the formula f = 1 / (2Δt). Then, according to the sampling frequency f s , the formula θ = (360f) / f sThe angle θ of each sampling signal is calculated, and the highest voltage value U of the alternating current is calculated by the formula U=y / sinθ using the sampling value y as the starting point of the 0 potential, and the highest voltage value U is the highest voltage value of the pre-judgment. When the pre-judged highest voltage value U exceeds the set safety threshold, the control circuit immediately starts the protection mechanism, and adjusts the silicon-controlled silicon conduction angle or triggers the shutdown instruction in advance to avoid damage to the equipment caused by voltage peak. The pre-judgment algorithm combines high-frequency sampling and real-time operation to complete trend judgment before the power supply suddenly changes, significantly improves the response speed and system reliability, and effectively makes up for the shortcomings of traditional lag detection. By real-time monitoring of the frequency change of the alternating current and the voltage phase relationship, the system can accurately predict the peak value at the initial stage of the rising voltage waveform, achieving millisecond-level response.

[0032] In an alternative embodiment, the on-off circuit uses a relay to control the input of the power supply. The use of a relay will adjust the control method. Due to the limited service life of the relay, frequent on-off control will not be used, and only the on or off state will be maintained. Only when the condition changes will the switch state be changed. When the system detects power grid abnormalities and triggers protection, the relay will only perform a closing operation once under the condition of confirming safety recovery, avoiding repeated on-off causing contact wear. The control circuit combines the voltage trend information output by the pre-judgment algorithm, and only issues a relay closing instruction when the power supply returns to normal and the voltage fluctuation is less than the threshold for more than one cycle. At the same time, the relay coil is driven by an optical coupling isolation, improving the anti-interference ability of the control signal. This design takes into account the response speed and device durability, prolonging the service life of the on-off element and ensuring long-term operation stability.

[0033] The charging system based on the above specific embodiments can achieve the following beneficial technical effects: The application realizes real-time estimation of the highest voltage of alternating current by dynamically identifying the voltage fluctuation characteristics of commercial power and combining with a prediction algorithm, effectively avoiding the misoperation caused by instantaneous sharp peaks in traditional overvoltage protection, ensuring power safety while improving power continuity; a multi-mode switching mechanism is adopted to balance the response requirements under different working conditions, enhancing the system adaptability; the on-off circuit is controllably turned on near the zero-crossing point, reducing the impact current and prolonging the service life of the equipment; the overall scheme has simple structure and accurate response, and has good practical value and promotion prospect. By setting a 30-second preset stabilization period, the system can continuously monitor the voltage fluctuation trend at the initial power-on stage, and judge the power grid stability combined with a 20% change rate threshold, automatically put into load after the fluctuation tends to be stable and does not exceed the safety range, further improving the reliability and intelligent level of the protection mechanism. On this basis, the system realizes intelligent switching of the on-off mode through the cooperative control of bidirectional thyristors and relays, adopts accurate zero-crossing triggering of thyristors in high-frequency regulation scenes to reduce electromagnetic interference and energy loss; the relay hard isolation is enabled during long-term stable operation to improve insulation reliability. The whole protection mechanism pays equal attention to real-time and foresight, not only responds quickly, but also has the ability to predict voltage trends, thereby avoiding potential risks at the source and ensuring that the power supply environment of the electrical equipment is always safe and stable.

[0034] The technical features of the above-described embodiments can be combined arbitrarily, and to make the description concise, not all possible combinations of the technical features in the above-described embodiments are described, however, as long as the combinations of the technical features do not exist contradictory, they should be considered as the scope of the present application. The above-described embodiments only express several embodiments of the present application, which are described in detail and in detail, but should not be interpreted as a limitation on the scope of the present application. For those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application.

Claims

1. A charging system with high-voltage protection, characterized in that, include: A transformer, with its primary winding connected to the mains power and its secondary winding connected to a sampling circuit and a voltage regulator circuit, is used to reduce the high voltage of the mains power over a wide range to the low voltage of the desired range. The voltage regulator circuit has its input terminal connected to one of the windings of the transformer's secondary winding and its output terminal connected to the control circuit. It is used to convert the AC voltage output by the transformer into a stable DC voltage, providing a stable operating power supply for the sampling circuit and the control circuit. The sampling circuit has its input end connected to another winding of the transformer's secondary winding and its output end connected to the control circuit. It is used to condition the AC voltage output by the transformer and output a DC feedback voltage signal to the control circuit. The on / off circuit has an input terminal connected to the mains power, an output terminal connected to the input terminal of the surge protection circuit, and a control terminal connected to the control circuit. It is used to control the on / off state of the mains power input according to the control instructions of the control circuit. The surge protection circuit has its input terminal connected to the output terminal of the switching circuit. It is used to absorb surges and protect the subsequent constant current and voltage regulation circuits from damage. The constant current and voltage regulation circuit has its input terminal connected to the output terminal of the surge protection circuit and its control terminal connected to the control circuit. It is used to output a DC working voltage in constant current or constant voltage mode according to the control command of the control circuit, as the output of the charging system to charge the backup battery. The control circuit receives and processes the DC feedback voltage signal from the sampling circuit, performs mode analysis based on the prediction algorithm, sends on / off control signals to the on / off circuit according to the mode analysis results, and / or sends constant current / constant voltage mode switching control signals to the constant current and voltage regulation circuit.

2. The charging system with high-voltage protection according to claim 1, characterized in that, In the control circuit, the modes specifically include: mutation mode, stable mode, and shutdown mode; Based on the prediction algorithm, pattern analysis is performed, and on / off control signals are sent to the on / off circuit according to the pattern analysis results. Specifically, this includes: Sudden change mode: Triggered when the system needs to be charged, either during initial power-on or when a sudden change or fluctuation in voltage is detected or predicted from stable mode or shutdown mode; when the mains voltage is detected to have no significant fluctuation within the preset stabilization period, the sudden change mode is exited and the system switches to stable mode. Stable Mode: Entered after a stable period determination from Abrupt Change Mode; if the voltage exceeds the preset safety threshold based on the prediction algorithm or real-time monitoring, the stable mode is exited and switched to Abrupt Change Mode, and a power-off control signal is sent to the switching circuit to cut off the mains power input; or, even if the voltage does not exceed the preset safety threshold based on the prediction or real-time monitoring, but the rate of change exceeds the preset rate of change, the stable mode is exited and switched to Abrupt Change Mode, and a power-off control signal is sent to the switching circuit to cut off the mains power input; or, when a signal indicating that the backup battery is fully charged is obtained, the stable mode is exited and switched to shutdown mode. Shutdown mode: Send a shutdown control signal to the on / off circuit to completely shut off the mains power input. When the system needs to be recharged, reassess the mains power status and perform mode analysis.

3. The charging system with high-voltage protection according to claim 1, characterized in that, The input AC mains voltage ranges from AC80V to AC600V. It is reduced to AC5V to AC38V by a transformer, and after rectification by the voltage regulator circuit, it is regulated to a working voltage of 3.3V by a DC-DC voltage regulator chip.

4. The charging system with high-voltage protection according to claim 2, characterized in that, The other set of windings on the secondary side of the transformer provides the AC voltage from the mains to the sampling circuit. After rectification and filtering, the sampling circuit provides a DC feedback voltage of 0~3V to the control circuit according to the design voltage value of up to 600V.

5. The charging system with high-voltage protection according to claim 4, characterized in that, The aforementioned prediction algorithm is a voltage maximum value prediction algorithm, specifically as follows: After rectification, the sampling circuit converts the signal into a 0~3V DC feedback voltage. When a 0V voltage is sampled, it represents the 0 potential of the AC current. The time difference between the two 0 potential positions is Δt. The frequency f of the AC current is calculated using the formula f=1 / (2Δt). Then, based on the sampling frequency f... s The formula θ=(360f) / f s Calculate the angle θ for each sampled signal, and then, starting from 0 potential, calculate the highest voltage value U of the AC current one by one using the sampled value y, and this highest voltage value U is the predicted highest voltage value.

6. The charging system with high-voltage protection according to claim 2, characterized in that, The on / off circuit uses a bidirectional thyristor to control the mains power input.

7. The charging system with high-voltage protection according to claim 2, characterized in that, The on / off circuit uses a relay to control the mains power input.

8. The charging system with high-voltage protection according to claim 7, characterized in that, The control circuit does not immediately turn on the bidirectional thyristor when the voltage crosses the zero potential. Instead, it turns on the bidirectional thyristor after sampling at multiple sampling points and confirming that the current voltage does not exceed the preset safety threshold.

9. The charging system with high-voltage protection according to claim 2, characterized in that, The preset stabilization period is 30 seconds.

10. The charging system with high-voltage protection according to claim 2, characterized in that, The preset safety threshold is 253V; the preset change rate is 20%.

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