Lightning protection circuit for elevator power supply

Abstract

The utility model discloses an elevator power supply lightning protection circuit which comprises a power supply input end and a power supply output end, the power supply input end is connected with an external power supply, and the power supply output end is connected with an elevator control system. The system comprises an extensive discharge protection level, a medium-voltage limit protection level and a fine protection level, the medium-voltage limiting protection stage comprises a coordination impedance element and a piezoresistor array and is used for carrying out secondary clamping on residual surge voltage; and the fine protection level comprises a diode array and a precision filter network, and is used for accurately clamping and filtering low-energy high-frequency interference which is finally broken through, so that the quality of a power supply output to an elevator control system is ensured. Various surges and interferences generated by direct lightning and inductive lightning are effectively resisted, and safe and stable operation of an elevator control system is ensured.

Description

TECHNICAL FIELD

[0001] The utility model relates to building electrical lightning protection technology especially, a kind of elevator power lightning protection circuit, applied to lightning protection field of industrial and civil building elevator system. BACKGROUND

[0002] Elevator, as important vertical traffic equipment in building, its safe operation is closely related to personnel life and property safety.Elevator system usually works in 220V / 380V industrial voltage environment, contains complex electrical control system, such as frequency converter, PLC controller, sensor network and other precision electronic equipment.These devices are highly sensitive to power quality, and extremely sensitive to surge, transient and electromagnetic interference caused by lightning.

[0003] Since elevator shaft usually penetrates the whole height of building, combined with the metal guide rail and steel cable in elevator shaft forming a natural lightning introduction channel, elevator system is extremely vulnerable to lightning and induced lightning.Statistical data shows that in lightning-prone areas, elevator system downtime events caused by lightning failure account for more than 20% of all failures, causing significant economic losses and safety hazards.

[0004] Traditional elevator lightning protection mainly relies on building lightning protection grounding system or simple surge protector (SPD), and these schemes have the following problems: first, traditional protection devices can only provide protection against single type of lightning, and are difficult to cope with diversified lightning characteristics;Second, the response speed is slow, and it is often impossible to respond to microsecond-level transient generated by lightning;Third, the protection capacity is limited, and it is easy to fail under continuous lightning or high-energy lightning environment;Finally, traditional lightning protection system is mostly single-stage protection, lacks multi-stage linkage protection capability, resulting in power surge breaking through single-stage protection directly affecting equipment safety.

[0005] In elevator control system, any electronic component damage or malfunction caused by lightning may lead to elevator failure, emergency stop and even trapped event, not only affecting the normal operation of building, but also may cause personal safety accidents and social influence.Especially for high-speed elevator in high-rise building, once it fails due to lightning, it takes a long time to repair and has a wide impact.

[0006] Therefore, it is of great significance to develop a lightning protection circuit system specially designed for elevator system characteristics, which can provide comprehensive, reliable and fast response lightning protection.The system needs to provide hierarchical protection for lightning of different energy levels, to ensure the safe and stable operation of elevator control system in various lightning environments. UTILITY MODEL CONTENT

[0007] The utility model discloses a lightning protection circuit for elevator power supply, which can comprehensively protect the power supply system of an elevator, effectively resist various surges and interference caused by direct lightning and induced lightning, and ensure the safe and stable operation of the elevator control system.

[0008] The above technical purpose of the utility model is realized by the following technical scheme:

[0009] A lightning protection circuit for elevator power supply includes a power input end and a power output end, the power input end is connected with an external power supply, and the power output end is connected with an elevator control system; the system includes a coarse protection level, a medium voltage limiting protection level and a fine protection level; the coarse protection level includes a three-electrode gas discharge tube and a high-energy voltage-dependent resistor, is used for bearing and leading away main lightning current; the medium voltage limiting protection level includes a coordinated impedance element and a voltage-dependent resistor array, is used for twice clamping of residual surge voltage; the fine protection level includes a TVS diode array and a precision filter network, is used for accurate clamping and filtering of final breakthrough low-energy high-frequency interference, and ensures the power quality output to the elevator control system.

[0010] The utility model further sets up: the three-electrode gas discharge tube of coarse protection level is SPD1 series gas discharge tube, and its discharge voltage is 600V, and discharge current is 20kA.

[0011] The utility model further sets up: the high-energy voltage-dependent resistor of coarse protection level is MOV1 series voltage-dependent resistor, and its rated voltage is 275V / 420V, and the maximum through-flow capacity is 40kA.

[0012] The utility model further sets up: the coordinated impedance element of medium voltage limiting protection level includes RC1 series resistance capacitor component, is used for controlling the distribution of discharge current and delaying the rise time.

[0013] The utility model further sets up: the voltage-dependent resistor array of medium voltage limiting protection level is MOV2 series voltage-dependent resistor, and its rated voltage is 275V / 420V, and the maximum through-flow capacity is 20kA.

[0014] The utility model further sets up: the TVS diode array of fine protection level is TVS series transient suppression diode, and response time is less than 1ns, and residual voltage is 400V.

[0015] The utility model further sets up: the precision filter network of fine protection level includes LC1 series common mode inductance and CX / CY capacitor, is used for filtering high-frequency interference.

[0016] The utility model further sets up: the system is provided with a plurality of parallel module, each module contains complete three -level protection structure, is used for protecting different line.

[0017] The utility model further sets up: each protection level of the system passes through reasonable layout and coordination work, makes the extensive electric protection level first response big energy impact, the medium voltage limit protection level handles medium energy impact, the fine protection level handles low energy high frequency interference, forms the echelon protection mechanism.

[0018] The utility model further sets up: the system adopts modular design, all protection elements are connected to same PE grounding system, ensures that the surge current is effectively imported to the earth.

[0019] Summarized above, the utility model has following beneficial effect:

[0020] 1. Three -level echelon protection: the system adopts extensive electric protection level, medium voltage limit protection level and fine protection level three -level protection structure, forms complete protection link, can provide comprehensive protection to different characteristics lightning impact, the first level mainly responds high energy impact current, the second level further clamps residual surge voltage, the third level accurately handles residual low energy high frequency interference, ensures that the elevator control system works in clean power supply environment. This multistage protection structure significantly improves the protection ability and reliability of system, prevents the damage of equipment caused by single protection breakthrough.

[0021] 2. Fast response speed: the protection link of the system that adopts gas discharge tube, voltage-dependent resistor and TVS diode constitutes response time echelon decreases, from the microsecond level of extensive electric protection level to the nanosecond level of fine protection level, the response time of final TVS diode is less than 1ns, ensures that protection channel is rapidly established before lightning transient reaches equipment. This response characteristic solves the protection delay problem of traditional lightning protection system and provides timely and effective protection for elevator control system.

[0022] 3. High energy tolerance: the extensive electric protection level in the system adopts large capacity element, and the gas discharge tube can withstand 20kA impact current, and the high energy voltage-dependent resistor can withstand 40kA through-flow capacity, and the system as a whole can continuously withstand multiple standard waveform impacts without performance attenuation. This high energy tolerance characteristic makes the system can cope with continuous lightning in strong thunderstorm weather and provide continuous and reliable protection.

[0023] 4. Modular design facilitates maintenance: the system adopts modular design, and divides the protection circuit into multiple functional modules, and each module contains complete three -level protection structure. This design facilitates installation, repair and replacement, reduces maintenance difficulty and cost. When a single module fails, only the corresponding module needs to be replaced, without replacing the whole system, which greatly improves the maintenance efficiency and economy of the system.

[0024] 5. No MCU control, high reliability: the system adopts traditional electronic components optimized combination, does not depend on micro control unit, realizes lightning protection function through pure hardware mode. This design avoids potential problems such as software failure and program crash, and the system has high reliability, and is particularly suitable for long-term stable operation in industrial environment.

[0025] 6. Comprehensive suppression of electromagnetic interference: the system can not only handle energy type surge, but also effectively suppress electromagnetic interference generated by lightning through precise filter network, thereby guaranteeing electromagnetic compatibility of the elevator control system. This has important significance for preventing misoperation of the elevator signal system, ensuring stable operation and safe control of the elevator. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 It is a circuit principle diagram of the lightning protection circuit for the elevator power supply of the utility model;

[0027] Figure 2 It is a circuit principle diagram of L2 phase. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the utility model more clear, the utility model will be described in further detail below in combination with the drawings.

[0029] In the description of the utility model, it should be understood that the directions or position relations indicated by the terms up, down, front, back, left, right, top, bottom, inner and outer are based on the directions or position relations shown in the drawings, and are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the utility model.

[0030] As shown in Figure 1 , Figure 2 The utility model provides a lightning protection circuit for elevator power supply, which is installed in an elevator power distribution system, a power input end is connected with an external 220V / 380V power supply, and a power output end is connected with an elevator control system. The system mainly consists of three protection levels: a rough lightning protection level, a medium voltage limiting protection level and a fine protection level, and the three protection levels form a complete lightning protection link.

[0031] The system adopts modular design, as can be seen from the drawing, the system contains four parallel protection modules for protecting three-phase power lines and zero lines (or three-phase four-wire system), and each module contains a complete three-level protection structure. This design makes the system have good expansibility and maintainability, and the number of protection modules can be increased or decreased according to the specific requirements of the elevator system.

[0032] The coarse discharge protection stage is the first line of defense in the system, directly facing the threat of external lightning strikes. In each protection module, the coarse discharge protection stage includes an SPD1 series triode gas discharge tube and a MOV1 series high-energy varistor. The SPD1 gas discharge tube has a discharge voltage of 600V and a discharge current of up to 20kA. When a lightning overvoltage occurs on the line, the gas discharge tube can quickly break down and conduct within microseconds, providing a low-impedance path for the lightning current and directly diverting most of the lightning energy to the PE grounding system.

[0033] Connected in parallel with the gas discharge tube is the MOV1 series high-energy varistor, with a rated voltage of 275V (single-phase) or 420V (three-phase) and a maximum current capacity of 40kA. Working in conjunction with the gas discharge tube, the varistor absorbs some of the lightning strike energy while the gas discharge tube is activated, and clamps the residual voltage after the discharge tube's arc is extinguished, preventing excessive residual voltage leakage to the next level of protection circuitry. This combination of gas discharge tube and varistor design leverages both the high current capacity of the gas discharge tube and the fast response of the varistor, creating a synergistic protection effect.

[0034] In the first protection module, the coarse discharge protection stage also includes an overcurrent indicator, which is used to visually display whether the system has been struck by lightning, making it easier for maintenance personnel to judge the system status.

[0035] The medium-voltage limiting protection stage is the system's second line of defense, used to handle residual surges that have breached the first-level protection. This stage mainly consists of RC1 series coordinating impedance elements and MOV2 series varistor arrays. The RC1 coordinating impedance elements include resistor and capacitor components, which delay voltage rise time and control discharge current distribution, ensuring that each protection stage operates in a predetermined sequence and avoiding reduced protection efficiency caused by simultaneous operation of multiple protection stages.

[0036] The MOV2 series varistor array consists of multiple varistors connected in parallel, with a rated voltage of 275V / 420V and a maximum current capacity of 20kA. After the coarse discharge protection stage operates, the residual surge voltage is clamped again by the varistor array of the medium voltage limiting protection stage, further reducing the voltage amplitude and protecting subsequent circuits from damage.

[0037] The fine protection level is the last line of defense in the system, directly protecting the elevator control system. This level mainly consists of a TVS series transient voltage suppressor diode array and an LC1 series precision filter network. The TVS diodes have a response time of less than 1ns and a residual voltage of 400V, which can precisely clamp low-energy high-frequency interference that ultimately breaks through the first two levels of protection, ensuring that no voltage exceeds the tolerance capacity of the elevator control equipment.

[0038] The precision filter network includes common mode inductance and CX / CY safety capacitor, forms a multi-stage LC filter, can effectively filter out high-frequency interference and electromagnetic pulse generated by lightning, and ensures the power quality output to the elevator control system. Since the PLC, frequency converter, sensor and other devices in the elevator control system have high requirements for power purity, the setting of the precision filter network greatly improves the stability and reliability of the elevator system in the lightning environment.

[0039] All protection levels and modules of the system are connected to the same PE grounding system, which is a key link of lightning protection. A good grounding system ensures that the lightning current can be quickly and safely introduced into the ground to prevent back strike and rebound phenomenon. The grounding end of the system adopts a thick wire specification to reduce the grounding impedance and improve the discharge efficiency.

[0040] The working process of the system is as follows: when the lightning current is conducted through the elevator power supply line, the gas discharge tube in the coarse discharge protection level is first broken down and conducted quickly, and the high-energy varistor absorbs most of the lightning energy. Then, the impedance element controls the current distribution, so that the varistor array in the medium voltage limiting protection level starts immediately after the coarse discharge protection level acts, and clamps the residual voltage again. Finally, the TVS diode array in the fine protection level accurately clamps the low-energy high-frequency interference that finally breaks through, and the precision filter network filters out the last high-frequency component to ensure the power quality output to the elevator control system. The whole process is coordinated and completed instantly.

[0041] The advantage of the system is that it can effectively protect various types of lightning impact. For high-energy direct lightning, the coarse discharge protection level can quickly conduct most of the energy; for the medium energy surge generated by induced lightning, the medium voltage limiting protection level can effectively clamp; for the electromagnetic interference and high-frequency noise generated by lightning, the fine protection level can accurately suppress. This comprehensive protection capability enables the elevator system to operate safely and stably in various lightning environments.

[0042] The system is easy to install and can be directly integrated into the elevator distribution cabinet or control cabinet through standard guide rails or bolts. The wiring terminals are clearly marked as input and output to ensure correct installation. The system operates without manual intervention or routine maintenance, can automatically start the protection function when lightning occurs, and automatically returns to normal state after the lightning ends, greatly reducing the maintenance difficulty and cost. When individual protection elements reach the service life or are damaged, the system function can be quickly restored by replacing the corresponding module, avoiding long-term downtime maintenance.

[0043] The utility model discloses a three-level protection structure and optimized traditional component combination, effectively solve the lightning protection problem faced by the elevator system, improve the safety and reliability of the elevator operation, and have important application prospect.

[0044] The above merely describes preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A surge protection circuit for elevator power supply, characterized in that, include: The system includes a power input terminal and a power output terminal. The power input terminal is connected to an external power supply, and the power output terminal is connected to the elevator control system. The system includes: a coarse discharge protection stage, a medium voltage limiting protection stage, and a fine protection stage. The coarse discharge protection stage includes a triode gas discharge tube and a high-energy varistor to withstand and conduct the main lightning current. The medium voltage limiting protection stage includes a harmonic impedance element and a varistor array to perform secondary clamping on residual surge voltage. The fine protection stage includes a TVS diode array and a precision filter network to accurately clamp and filter out low-energy, high-frequency interference that ultimately breaks through, ensuring the power quality output to the elevator control system.

2. The elevator power supply lightning protection circuit according to claim 1, characterized in that: The three-electrode gas discharge tube of the coarse discharge protection stage is an SPD1 series gas discharge tube with a discharge voltage of 600V and a discharge current of 20kA.

3. The elevator power supply lightning protection circuit according to claim 1, characterized in that: The high-energy varistor of the coarse discharge protection stage is a MOV1 series varistor with a rated voltage of 275V / 420V and a maximum current capacity of 40kA.

4. The elevator power supply lightning protection circuit according to claim 1, characterized in that: The coordinating impedance element of the medium-voltage limiting protection stage includes an RC1 series resistor-capacitor assembly, which is used to control the distribution of discharge current and delay rise time.

5. The elevator power supply lightning protection circuit according to claim 1, characterized in that: The varistor array of the medium-voltage limiting protection stage is a MOV2 series varistor with a rated voltage of 275V / 420V and a maximum current capacity of 20kA.

6. The elevator power supply lightning protection circuit according to claim 1, characterized in that: The TVS diode array of the fine protection level is a TVS series transient suppression diode with a response time of less than 1ns and a residual voltage of 400V.

7. The elevator power supply lightning protection circuit according to claim 1, characterized in that: The precision filter network of the fine protection level includes LC1 series common-mode inductors and CX / CY capacitors, used to filter out high-frequency interference.

8. The elevator power supply lightning protection circuit according to claim 1, characterized in that: The system is equipped with multiple parallel modules, each containing a complete three-level protection structure for protecting different lines.

9. The elevator power supply lightning protection circuit according to claim 1, characterized in that: Through reasonable layout and coordinated operation, the various protection levels of the system enable the coarse discharge protection level to respond first to large energy impacts, the medium voltage limiting protection level to handle medium energy impacts, and the fine protection level to handle low energy high frequency interferences, thus forming a tiered protection mechanism.

10. The elevator power supply lightning protection circuit according to claim 1, characterized in that: The system adopts a modular design, with all protection components connected to the same PE grounding system to ensure that surge current is effectively conducted to the ground.

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