Arc suppressing device for power lock, power supply system and electric vehicle

Abstract

The application provides an arc suppression device of a power lock, a power supply system and an electric vehicle, and relates to the electrical protection field.The device comprises a lock switch of the power lock and an RC absorption circuit.The RC absorption circuit comprises a resistor and a capacitor.The lock switch comprises a moving contact, a first stationary contact and a second stationary contact.One end of the resistor is electrically connected with the first stationary contact, and the other end of the resistor is electrically connected with one end of the capacitor.The other end of the capacitor is electrically connected with the second stationary contact, and the moving contact is drivingly connected with a lock core of the power lock.The arc suppression device can completely eliminate the arc spark generated when the power lock is turned on and turned off through the RC absorption circuit, can effectively resist the high-frequency vibration of the electric motorcycle and the corrosion of the hot and humid environment, ensures long-term stable operation, and realizes the multiple improvement of performance, reliability and economy through the modular design, which not only simplifies the installation process, but also seamlessly adapts to the existing power lock structure, significantly reduces the production cost and the transformation cost, and realizes the multiple improvement of performance, reliability and economy.

Description

Technical Field

[0001] This application relates to the field of electrical protection, and more specifically, to an arc suppression device for a power lock, a power supply system, and an electric vehicle. Background Technology

[0002] As the core control hub of the entire vehicle's circuitry, the performance of the electric vehicle's power lock directly impacts riding safety and user experience. In actual operation, electric vehicles equipped with 48V, 60V, or even 72V high-voltage platforms often operate at currents exceeding 5A. When the power lock contacts perform on / off operations, the back electromotive force generated by inductive loads such as the controller and motor induces a strong arc discharge between the contacts. The high-temperature energy released instantaneously by these arcs continuously erodes the contact surface, causing metal melting, oxidation, and scaling, resulting in a sharp increase in contact resistance. As the usage period extends, contact erosion gradually develops from fine pitting into large-area depressions, leading not only to poor contact and intermittent circuitry but also potentially causing localized overheating due to excessive resistance, posing a safety hazard. Frequent malfunctions force owners to repeatedly replace the power lock, increasing maintenance costs and reducing travel convenience, becoming a key pain point restricting the reliability of electric vehicles. Utility Model Content

[0003] The purpose of this application is to provide an arc suppression device for a power lock, a power system, and an electric vehicle, so as to solve the above-mentioned problems existing in the prior art and solve the problem of arcing generated by the power lock contacts due to switching high voltage and high current.

[0004] In a first aspect, this application provides an arc suppression device for a power lock, the device comprising: a lock switch for the power lock and an RC absorption circuit; The RC absorption circuit includes a resistor and a capacitor; the lock switch includes a moving contact, a first stationary contact, and a second stationary contact; One end of the resistor is electrically connected to the first stationary contact, and the other end of the resistor is electrically connected to one end of the capacitor; the other end of the capacitor is electrically connected to the second stationary contact, and the moving contact is driven to the lock cylinder of the power lock.

[0005] In one possible implementation, the RC snubber circuit is housed within an insulating housing.

[0006] In one possible implementation, an aerogel insulation layer is provided on the inner side of the insulating shell.

[0007] In one possible implementation, the insulating shell is made of epoxy resin or flame-retardant engineering plastic.

[0008] In one possible implementation, one end of the resistor is connected to the first stationary contact via a wire or solder joint; the other end of the capacitor is connected to the second stationary contact via a wire or solder joint.

[0009] In one possible implementation, the resistor is a metal film resistor or a cement resistor.

[0010] In one possible implementation, the capacitor is a CBB capacitor or a ceramic capacitor.

[0011] In one possible implementation, the capacitor has a withstand voltage higher than twice the operating voltage of the power lock.

[0012] Secondly, this application provides a power supply system that includes an arc suppression device for the power lock described in any of the first aspects.

[0013] Thirdly, this application provides an electric vehicle that includes the power system described in any of the second aspects.

[0014] This application provides an arc suppression device for a power lock, comprising a lock switch and an RC absorption circuit. The RC absorption circuit includes a resistor and a capacitor. The lock switch includes a moving contact, a first stationary contact, and a second stationary contact. One end of the resistor is electrically connected to the first stationary contact, and the other end of the resistor is electrically connected to one end of the capacitor. The other end of the capacitor is electrically connected to the second stationary contact. The moving contact is driven by the lock cylinder of the power lock. This arc suppression device, through optimized component parameters and parallel contact design in the RC absorption circuit, can completely eliminate the arc sparks generated when the power lock is switched on and off. The epoxy resin encapsulation combined with a snap-fit ​​bracket structure effectively resists high-frequency vibrations and humid heat from electric motorcycles, ensuring long-term stable operation. The modular design not only simplifies the installation process but also seamlessly adapts to existing power lock structures, significantly reducing production and modification costs, and achieving multiple improvements in performance, reliability, and economy. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the structure of an arc suppression device for a power lock provided in an embodiment of this application; Figure 2 This is a structural diagram of the epoxy resin encapsulated RC absorption circuit provided in an embodiment of this application; Figure 3 Arc energy spectrum of a power lock without RC absorption circuit provided in an embodiment of this application; Figure 4Arc energy spectrum of a power lock with RC absorption circuit configuration provided in an embodiment of this application. Detailed Implementation

[0017] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0018] The performance of the power lock, located within the power system of an electric vehicle, directly affects riding safety and user experience. For electric vehicles operating on 48V, 60V, or even 72V high-voltage platforms, their operating current typically exceeds 5A. When the power lock switches on and off, the presence of inductive loads such as the controller and motor generates a back electromotive force, causing a strong electric arc in the contact gap. This arc, which instantly releases high-temperature energy, continuously erodes the contact surface, leading to melting of the metal material, accumulation of oxide layers, and a rapid increase in contact resistance. Over time, this corrosion, which gradually deteriorates from tiny pits into large-area corrosion, not only causes poor contact and unstable circuit connections but may also lead to localized temperature increases due to excessive resistance, posing safety hazards. This situation necessitates frequent replacement of the power lock, increasing maintenance costs and reducing ease of use, becoming one of the main issues affecting the reliability of electric vehicles.

[0019] Therefore, this application provides an arc suppression device for a power lock, which is located inside the power system to solve the above-mentioned problems existing in the prior art and can solve the problem of arcing generated by the power lock contacts due to switching high voltage and high current.

[0020] The preferred embodiments of this application are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit this application. Furthermore, the embodiments and features in the embodiments of this application can be combined with each other without conflict.

[0021] like Figure 1 As shown, this application provides an arc suppression device for a power lock, which may include: a lock switch for the power lock and an RC absorption circuit; The RC snubber circuit includes resistor 3 and capacitor 4; specifically, the RC snubber circuit can be composed of resistor 3 and capacitor 4 connected in series.

[0022] The lock switch includes a moving contact 1, a first stationary contact 21, and a second stationary contact 22; wherein, the lock switch can be a mechanical switch for the main power supply of an electric vehicle; the first stationary contact 21 can be the output terminal of the lock switch, and the second stationary contact 22 is the input and output terminal of the lock switch.

[0023] One end of resistor 3 can be electrically connected to the first stationary contact 21, and the other end of resistor 3 can be electrically connected to one end of capacitor 4; the other end of capacitor 4 can be electrically connected to the second stationary contact 22, and moving contact 1 is connected to the lock cylinder of the power lock.

[0024] Furthermore, one end of resistor 3 can be connected to the first stationary contact 21 via a wire or solder joint; the other end of capacitor 4 can be connected to the second stationary contact 22 via a wire or solder joint.

[0025] The conductors must be high-temperature resistant silicone wires with a cross-sectional area ≥ 0.5 square millimeters to ensure low-impedance connection. The resistance of resistor 3 should range from 250Ω to 670Ω (the resistor R and capacitor C work together to form a time constant τ = RC); the power rating can be from 1W to 5W; the capacitance should range from 0.01μF to 1μF.

[0026] In summary, the RC absorption circuit is connected in parallel with the lock switch. It can be understood that the other end of the first stationary contact 21 is connected to the power output side (load or load-related branch); the other end of the second stationary contact 22 is connected to the power side (power supply or power supply-related branch).

[0027] The resistors mentioned above can be high-temperature resistant, impact-resistant metal film resistors or cement resistors; the capacitors can be CBB capacitors or ceramic capacitors with optimized high-frequency characteristics. The capacitors have a voltage rating higher than twice the operating voltage of the power supply lock.

[0028] Furthermore, in combination Figure 2 As shown, the RC absorption circuit is housed in a high-temperature resistant and shockproof insulating shell 5. The insulating shell 5 is made of epoxy resin or flame-retardant engineering plastic (UL94 V0 flame retardant rating), and can dissipate heat through epoxy resin encapsulation. The cross-sectional area of ​​the internal conductors of this insulating shell is ≥0.5 square millimeters. An aerogel insulation layer may also be provided on the inner side of the insulating shell.

[0029] In some embodiments, the RC snubber circuit and the lock switch are integrated in the same module, enabling quick installation via plug-in terminals.

[0030] The arc suppression device of this application can be adapted to the main power switch scenarios of electric bicycles, electric motorcycles, and electric vehicles, and can also be extended to the arc suppression scenarios of DC contactors, charging pile relays, and other equipment.

[0031] The configuration process of the arc suppression device in this application may include: Test the maximum load current of the power supply lock (I)max The capacitor C and voltage (V) are used to calculate the RC parameters according to the formula. The value of the capacitor C must satisfy C≥(I×t) / V (t is the duration of the arc), and the resistor R is calculated according to R=V / I (I is the allowable peak current).

[0032] After completing the above parameter calculations, the RC absorption circuit is encapsulated with epoxy resin to form a square module with dimensions of 8mm × 6mm × 14mm. The output terminals of this module can be directly soldered or fixed near the switch contacts via terminals.

[0033] The principle of the arc suppression device for a power lock provided in this application is as follows: When the power lock switch is in the open position, the back electromotive force generated by inductive loads such as the motor controller will be discharged through the RC absorption circuit. The capacitor quickly absorbs the transient energy brought by the back electromotive force, preventing the energy from being released in a concentrated manner, while the resistor effectively slows down the rise rate of the voltage between the contacts by limiting the discharge current, preventing excessive voltage difference from generating an electric arc.

[0034] When the power lock switch is closed, the RC snubber circuit buffers the surge current generated by the power supply. By suppressing the surge current, the impact of the large current on the contacts is reduced, thereby avoiding contact erosion caused by excessive instantaneous current and effectively protecting the switch contacts.

[0035] The lock switches without RC snubber circuits and those with RC snubber circuits were tested. The test methods and results are shown in Tables 1 and 2. Table 1 - Test methods and results for lock switches without RC snubber circuits

[0036] Table 2 - Test methods and results for latching switches configured with RC snubber circuits

[0037] In summary, combining Tables 1 and 2 above, and Figure 3 and Figure 4 The arc energy indicates that the lock switch without an RC absorption circuit exhibits a significant cluster of high-frequency, high-amplitude pulses, representing a large number of transient arc discharges. These dense pulses correspond to the release of arc energy triggered by the back electromotive force of the inductive load when the switch is turned on and off. The arc is continuously generated and the energy is dispersed but relatively high overall. The lock switch with an RC absorption circuit has a smooth curve with no significant pulses, indicating that the arc is effectively suppressed.

[0038] In some embodiments, a multi-stage RC absorption circuit (two stages in series or parallel) is provided, which can achieve a wider surge frequency absorption range (a single-stage RC absorption circuit is only for a specific frequency, while a multi-stage absorption circuit can cover high to low frequencies); it also has a stronger surge energy dissipation capability (multi-stage series resistors can limit current in stages, and multi-stage parallel capacitors can store more energy).

[0039] Furthermore, a multi-stage RC snubber circuit can consist of two RC snubber stages connected in parallel between the input and output terminals. Alternatively, the first-stage capacitor C1 can be connected in parallel at the input terminal; the second-stage capacitor C2 can be connected in parallel at the output terminal; and a resistor R can be connected in series between the two capacitor stages.

[0040] In this method, when the power lock switch is in the open state, capacitor C1 quickly absorbs the reverse electromotive force generated by the inductive load (as the first buffer pool); the remaining energy is discharged to C2 through resistor R (as the second buffer pool), reducing the voltage between contacts in stages. In this method, when the power lock switch is closed, capacitor C1 suppresses the power surge current (equivalent to a large capacitor for energy storage buffer), and capacitor C2 filters out the voltage fluctuations generated when the resistor R limits the current, reducing spark discharge between contacts.

[0041] Furthermore, multilayer ceramic capacitors (MLCCs) can be used to replace electrolytic capacitors (which can reduce the size by 70%), and chip resistors (such as 0603 packages) can be used to replace through-hole resistors. Multi-stage RC snubber circuits can integrate components onto a ceramic substrate and fix them with silicone potting to prevent solder joints from breaking due to vibration.

[0042] The multi-stage RC absorption circuit in this method can improve the arc suppression effect while balancing the requirements of circuit size and reliability.

[0043] This application provides an arc suppression device for a power lock, comprising a lock switch and an RC absorption circuit. The RC absorption circuit includes a resistor and a capacitor. The lock switch includes a moving contact, a first stationary contact, and a second stationary contact. One end of the resistor is electrically connected to the first stationary contact, and the other end of the resistor is electrically connected to one end of the capacitor. The other end of the capacitor is electrically connected to the second stationary contact. The moving contact is driven by the lock cylinder of the power lock. This arc suppression device, through optimized component parameters and parallel contact design in the RC absorption circuit, can completely eliminate the arc sparks generated when the power lock is switched on and off. The epoxy resin encapsulation combined with a snap-fit ​​bracket structure effectively resists high-frequency vibrations and humid heat from electric motorcycles, ensuring long-term stable operation. The modular design not only simplifies the installation process but also seamlessly adapts to existing power lock structures, significantly reducing production and modification costs, and achieving multiple improvements in performance, reliability, and economy.

[0044] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0045] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the utility model is in use. They are used only for the convenience of describing this utility model and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," and "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0046] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0047] Although preferred embodiments have been described in this application, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the embodiments of this application.

[0048] Obviously, those skilled in the art can make various modifications and variations to the embodiments of this application without departing from the spirit and scope of the embodiments of this application. Therefore, if these modifications and variations to the embodiments of this application fall within the scope of the claims in this application and their equivalents, then this application also intends to include these modifications and variations.

Claims

1. An arc suppression device for a power lock, characterized in that, The device includes: a power lock switch and an RC snubber circuit; The RC absorption circuit includes a resistor and a capacitor; the lock switch includes a moving contact, a first stationary contact, and a second stationary contact; One end of the resistor is electrically connected to the first stationary contact, and the other end of the resistor is electrically connected to one end of the capacitor; the other end of the capacitor is electrically connected to the second stationary contact, and the moving contact is driven to the lock cylinder of the power lock.

2. The apparatus as claimed in claim 1, characterized in that, The RC absorption circuit is housed within an insulating casing.

3. The apparatus as described in claim 2, characterized in that, An aerogel insulation layer is provided on the inner side of the insulating shell.

4. The apparatus as described in claim 3, characterized in that, The insulating shell is made of epoxy resin or flame-retardant engineering plastic.

5. The apparatus as claimed in claim 1, characterized in that, One end of the resistor is connected to the first stationary contact via a wire or solder joint; the other end of the capacitor is connected to the second stationary contact via a wire or solder joint.

6. The apparatus as claimed in claim 1, characterized in that, The resistor is a metal film resistor or a cement resistor.

7. The apparatus as claimed in claim 1, characterized in that, The capacitor is a CBB capacitor or a ceramic capacitor.

8. The apparatus as claimed in claim 7, characterized in that, The capacitor has a withstand voltage that is more than twice the operating voltage of the power lock.

9. A power supply system, characterized in that, The system includes the arc suppression device of the power lock according to any one of claims 1-7.

10. An electric vehicle, characterized in that, The electric vehicle includes the power system as described in claim 9.

Images