Protection device for abnormal discharge of electric motorcycle

Abstract

The utility model relates to the technical field of safety of electric motorcycles, and discloses a protection device for abnormal discharge of an electric motorcycle, which comprises a power loop and a control loop which are connected in parallel. The power loop comprises a plurality of power MOS (Metal Oxide Semiconductor) tubes, and the control loop controls the on-off of the MOS tubes by controlling the voltage of the grid electrode. The beneficial effects of the utility model are that the protection device is composed of the MOS tubes, thereby solving the problem of abnormal discharge when the electrode of the charger is short-circuited, and being more reliable and effective compared with a mode of reducing the probability of abnormal occurrence by means of structural protection; and the device can be matched with electric motorcycles with different charging voltages and different charging currents by adjusting the models or the number of the MOS tubes.

Description

Technical Field

[0001] The utility model relates to the technical field of electric motorcycle safety, in particular to a protection device for abnormal discharge of an electric motorcycle. Background Art

[0002] The charging circuit of a traditional electric motorcycle generally consists of a charger, a charging port and a storage battery, as Figure 3 , where the charging port is often exposed outside the vehicle body and there is no effective protection measure. When the charger is disconnected, if a foreign object is placed in the charging port or other abnormal conditions cause a short circuit between the positive and negative electrodes of the charging port, it is easy to form a discharge circuit between the charging port electrode and the storage battery. This abnormal discharge process is extremely harmful to the human body and other items. Most of the existing protection measures are to add a protective cover at the charging port to reduce the probability of short circuit of the charging port electrode.

[0003] In addition, according to GB 24155-2020 "Safety Requirements for Electric Motorcycles and Electric Mopeds", since January 1, 2021, newly produced electric motorcycle products shall meet the requirements of this standard. Among them, item 4.2.4.2 requires that the charging interface fixedly installed on the electric motorcycle shall meet at least one of the following requirements when disconnected: 1. The circuit connected to the power grid shall be powered off within 1 s, and the powered-off circuit shall meet the requirements of 4.2.2.12; 2. Meet the requirements of IPXXB in GB / T 4208-2017 and be powered off within the time specified by the manufacturer; for the B-level voltage circuit with a fault in 4.2.2.12, power-off protection can be adopted, and the circuit for cutting off the power supply shall meet one of the following requirements within the time specified by the vehicle manufacturer: 1. The alternating current circuit shall drop below 30 V a.c. (RMS), and the direct current circuit shall drop below 60 V d.c.; 2. The total energy stored in the circuit is less than 0.2 J.

[0004] The existing charging protection device adds a protective cover at the charging port, which can reduce the probability of short circuit of the charging port electrode. However, when the protective cover is opened and there is a short circuit of the electrode, a circuit will still be formed to cause abnormal discharge. There is an urgent need for a device to prevent the short circuit of the charging port electrode from forming a discharge circuit, so as to achieve the protection purpose. Summary of the Invention

[0005] The purpose of this part is to outline some aspects of the embodiments of the utility model and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this part, as well as in the abstract of the specification and the title of the utility model of this application, to avoid obscuring the purpose of this part, the abstract of the specification and the title of the utility model. However, such simplifications or omissions shall not be used to limit the scope of the utility model.

[0006] In view of the above problems in the prior art, the utility model is proposed.

[0007] The purpose of the present utility model is to provide a protection device for abnormal discharge of an electric motorcycle, aiming to solve the problems of difficult quality assurance, long processing time, high technical requirements for workers, and high labor intensity of workers during the processing of special-shaped surfaces, resulting in high production costs.

[0008] To solve the above technical problems, the present utility model provides the following technical solutions: A protection device for abnormal discharge of an electric motorcycle, which includes a power circuit and a control circuit, and the power circuit is connected in parallel with the control circuit; the power circuit includes a plurality of power MOS transistors, and the control circuit controls the on and off of the MOS transistors by controlling the voltage of the gate.

[0009] As a preferred scheme of the protection device for abnormal discharge of the electric motorcycle of the present utility model, wherein: the power circuit includes a capacitor C1 connected to the negative pole of the charging port, a resistor R4 connected to the negative pole of the battery, and MOS transistors Q1 and Q2 connected to the capacitor C1 and the resistor R4.

[0010] As a preferred scheme of the protection device for abnormal discharge of the electric motorcycle of the present utility model, wherein: the MOS transistors Q1 and Q2 are connected in parallel, and the resistor R4 and the capacitor C1 form a spike absorption circuit to absorb the high voltage generated by the inductor at the moment of MOS transistor switching.

[0011] As a preferred scheme of the protection device for abnormal discharge of the electric motorcycle of the present utility model, wherein: the control circuit includes a resistor R2 connected to the MOS transistor Q1, a Schottky diode D1 connected to the resistor R2, and a resistor R1 connected to the Schottky diode D1, and the other end of the resistor R1 is connected to the control terminal.

[0012] As a preferred scheme of the protection device for abnormal discharge of the electric motorcycle of the present utility model, wherein: a TVS tube TVS1 and a resistor R5 are connected in parallel at one end of the resistor R1 close to the control terminal.

[0013] As a preferred scheme of the protection device for abnormal discharge of the electric motorcycle of the present utility model, wherein: a triode Q3 is connected in parallel to the Schottky diode D1, and both ends of the triode Q3 are connected to the resistor R1 and the resistor R2 respectively.

[0014] As a preferred scheme of the protection device for abnormal discharge of the electric motorcycle of the present utility model, wherein: a clamping diode DZ1 and a resistor R3 are connected in parallel at one end of the resistor R2 close to the MOS transistor Q1, and the other end of the resistor R3 is connected to the MOS transistor Q2.

[0015] The beneficial effects of the protection device for abnormal discharge of the electric motorcycle of the present utility model are as follows: By using MOS transistors to form the protection device, the present utility model solves the problem of abnormal discharge when the charger electrode is short-circuited. Compared with the method of relying on structural protection to reduce the probability of abnormal occurrence, it is more reliable and effective. Moreover, the device can match electric motorcycles with different charging voltages and different charging currents by adjusting the type or quantity of MOS transistors. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the following will briefly introduce the drawings required for use in the description of the embodiments. Obviously, the following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings. Among them:

[0017] Figure 1 is the circuit diagram of the protection device for abnormal discharge of the electric motorcycle in the present utility model.

[0018] Figure 2 is the structural schematic diagram of the protection mechanism for abnormal discharge of the electric motorcycle in the present utility model.

[0019] Figure 3 is the schematic diagram of the traditional electric motorcycle charging circuit of the protection device for abnormal discharge of the electric motorcycle in the present utility model.

[0020] Figure 4 is the schematic diagram of the electric motorcycle charging circuit of the protection device for abnormal discharge of the electric motorcycle in the present utility model.

[0021] Figure 5 is the schematic diagram of the discharge simulation of the protection device for abnormal discharge of the electric motorcycle in the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] In order to make the above-mentioned objects, features, and advantages of the present utility model more obvious and understandable, the following will make a detailed description of the specific embodiments of the present utility model in conjunction with the drawings in the specification.

[0023] Many specific details are set forth in the following description in order to fully understand the present utility model. However, the present utility model can also be implemented in other ways different from those described herein. Those skilled in the art can make similar generalizations without departing from the connotation of the present utility model. Therefore, the present utility model is not limited by the specific embodiments disclosed below.

[0024] Second, the "one embodiment" or "embodiment" referred to herein means a specific feature, structure, or characteristic that may be included in at least one implementation manner of the present utility model. The "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that excludes other embodiments.

[0025] The present utility model will be described in detail with reference to the schematic diagrams. When detailing the embodiments of the present utility model, for the convenience of explanation, the cross-sectional views showing the device structure will be enlarged locally in a non-general proportion, and the schematic diagrams are only examples and should not limit the scope of protection of the present utility model herein. In addition, in actual production, three-dimensional spatial dimensions including length, width, and depth should be included.

[0026] At the same time, in the description of the present utility model, it should be noted that the orientation or positional relationship indicated by terms such as "upper, lower, inner, and outer" is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present utility model. In addition, the terms "first, second, or third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0027] Unless otherwise clearly defined and limited in the present utility model, the terms "installed, connected, and coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can also be a mechanical connection, an electrical connection, or a direct connection, and can also be indirectly connected through an intermediate medium, or can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0028] Embodiment 1:

[0029] Referring to Figures 1 - 2 , this is the first embodiment of the present utility model. This embodiment provides a protection device for abnormal discharge of an electric motorcycle. As Figure 1 , it includes a power circuit and a control circuit. The power circuit and the control circuit are connected in parallel. Among them, it mainly focuses on 2 power MOS tubes. Preferably, the power circuit includes several power MOS tubes. Among them, the number of MOS tubes depends on the current of forward charging. In this embodiment, the power circuit includes 2 power MOS tubes. The control circuit controls the on and off of the MOS tube by controlling the voltage of the gate.

[0030] Exemplarily, the power circuit includes a capacitor C1 connected to the negative terminal of the charging port, a resistor R4 connected to the negative terminal of the battery, and MOS transistors Q1 and Q2 connected to the capacitor C1 and the resistor R4. Preferably, the MOS transistors Q1 and Q2 are connected in parallel. The resistor R4 and the capacitor C1 form a spike absorption circuit to absorb the high voltage generated by the inductor at the moment when the MOS transistor switches.

[0031] Specifically, the MOS transistors Q1 and Q2 are used to pass the charging current. Using two MOS transistors in parallel can reduce the heat generation of the MOS transistors, thereby improving the over-current capacity of the product during charging.

[0032] Preferably, the control circuit includes a resistor R2 connected to the MOS transistor Q1, a Schottky diode D1 connected to the resistor R2, and a resistor R1 connected to the Schottky diode D1. The other end of the resistor R1 is connected to the control terminal. A TVS diode TVS1 and a resistor R5 are connected in parallel at the end of the resistor R1 close to the control terminal. A triode Q3 is connected in parallel to the Schottky diode D1. The two ends of the triode Q3 are respectively connected to the resistor R1 and the resistor R2. A clamping diode DZ1 and a resistor R3 are connected in parallel at the end of the resistor R2 close to the MOS transistor Q1. The other end of the resistor R3 is connected to the MOS transistor Q2.

[0033] It should be noted that the function of the TVS diode TVS1 is to absorb voltage spikes and maintain the voltage stability of the control signal. The function of the clamping diode DZ1 is to control the G / S voltage of the MOS transistor within a suitable range, meet the requirements of the G / S voltage range of the MOS transistor, and reduce the risk of G / S breakdown of the MOS transistor.

[0034] The main functions of the Schottky diode D1, the triode Q3, and the resistors R1 and R2 are to improve the switching speed and switching stability of the MOS transistor.

[0035] Specifically, when the MOS transistor is turned on, the resistors R1 and R2 limit the current to prevent the instantaneous charging current from being too large, charge the capacitance of the MOS transistor, and then turn on the MOS transistor. When it is turned off, the be current of the triode controls and amplifies the ec current to quickly discharge the charge of the gate of the MOS transistor, thereby achieving the effect of accelerating the turn-off, and reducing the requirement for the turn-off ability of the control signal be. The function of the resistor R5 is to discharge the voltage at the input end when the control signal is pulled low. The resistor R3 is both a "bias voltage" and can also discharge the voltage when turning off the MOS transistor.

[0036] Working principle: During the turn-on process of the MOS transistor, a 12V (9 - 16V) control signal is given to the control terminal. The control signal passes through the resistor R1 → the Schottky diode D1 → the resistor R2 and reaches the gate of the MOS transistor, and the MOS transistor is turned on, completing the connection of the circuit from the negative terminal of the battery to the negative terminal of the charging port.

[0037] During the MOS transistor turn-off process, a 0V control signal is applied to the control terminal. At this time, the voltage at the positive electrode of diode D1 is lower than that at the negative electrode, that is, the voltage at the emitter of transistor Q3 is greater than that at the base. Transistor Q3 turns on, and the gate voltage of the MOS transistor is quickly discharged through resistor R2 → transistor Q3 → the negative terminal of the battery. The MOS transistor is quickly turned off, and the connection of the circuit from the negative terminal of the battery to the negative terminal of the charging port is disconnected.

[0038] The above is a schematic solution of a protection device for abnormal discharge of an electric motorcycle in this embodiment. It should be noted that the technical solution of the protection mechanism for abnormal discharge of this electric motorcycle belongs to the same concept as the technical solution of the protection device for abnormal discharge of the above electric motorcycle. For the details not described in detail in the technical solution of the protection mechanism for abnormal discharge of the electric motorcycle in this embodiment, reference can be made to the description of the technical solution of the protection device for abnormal discharge of the above electric motorcycle.

[0039] Refer to Figure 2 , the protection mechanism for abnormal discharge of the electric motorcycle in this embodiment includes: a protection device 101 for abnormal discharge of the electric motorcycle, a housing 102, a connector 103, and a wiring harness 104. The protection device 101 for abnormal discharge of the electric motorcycle and the housing 102 are filled with polyurethane glue, which can meet the IP67 and flame-retardant UL94_V0 standards, and is connected between the battery and the charging port of the electric motorcycle through the connector 103.

[0040] Embodiment 2:

[0041] Refer to Figures 3 - 5 , which is the second embodiment of the present invention, provides a protection device for abnormal discharge of an electric motorcycle. In order to verify its beneficial effects, the comparison results of two schemes are provided.

[0042] The protection device for abnormal discharge of the electric motorcycle in the present invention is one of the components of the electric vehicle charging circuit, located between the negative terminal of the battery and the negative terminal of the charging port. The protection device, charger, charging port, battery, etc. form a complete charging circuit, as Figure 4 shown.

[0043] When the charger is connected, the protection device acts like a wire, and the charger can charge the battery. The current direction is charger positive electrode → battery → protection device → charger negative electrode; when the charger is disconnected, the protection device acts like an open switch.

[0044] Taking Figure 3 the traditional charger circuit as an example, when the charger is disconnected and the charging port electrode is short-circuited, a complete current circuit will be formed between the battery and the charging port, and the current direction is battery positive → charging port electrode → battery negative, forming abnormal discharge. However, for the protection device of the present invention, as Figure 4In the connection mode, the current is blocked at the protection device and no loop can be formed.

[0045] In actual work, simulate a Figure 5 discharge loop as shown. When the power output and the load output are turned on and no control signal is provided or the control signal is low, the circuit cannot form a loop and no current is generated in the circuit, which can solve the abnormal discharge when the charger electrode is short-circuited. Compared with the method of reducing the probability of abnormality by relying on structural protection, it is more reliable and effective.

[0046] Importantly, it should be noted that the construction and arrangement of the present application shown in multiple different exemplary embodiments are merely illustrative. Although only a few embodiments are described in detail in this disclosure, those who refer to this disclosure should easily understand that many modifications are possible (for example, the dimensions, scales, structures, shapes and proportions of various components, and parameter values (such as temperature, pressure, etc.), installation arrangements, use of materials, color, orientation changes, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in this application. For example, an element shown as integrally formed may be composed of multiple parts or elements, the position of the element may be inverted or otherwise changed, and the nature, number or position of discrete elements may be changed or altered. Therefore, all such modifications are intended to be included within the scope of the present utility model. The order or sequence of any process or method steps may be changed or reordered according to alternative embodiments. In the claims, any "means-plus-function" clause is intended to cover the structure that performs the recited function herein, and not only structural equivalents but also equivalent structures. Other substitutions, modifications, changes and omissions may be made in the design, operating conditions and arrangement of the exemplary embodiments without departing from the scope of the present utility model. Therefore, the present utility model is not limited to a specific embodiment, but extends to various modifications that still fall within the scope of the appended claims.

[0047] In addition, in order to provide a concise description of the exemplary embodiments, not all features of the actual embodiments may be described (i.e., those features that are not relevant to the currently considered best mode of implementing the present utility model or those features that are not relevant to the implementation of the present utility model).

[0048] It should be understood that in the development of any actual implementation, as in any engineering or design project, a large number of specific implementation decisions may be made. Such development efforts may be complex and time-consuming, but for those of ordinary skill in the art who benefit from this disclosure, without excessive experimentation, such development efforts will be a routine task of design, manufacturing and production.

[0049] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A protection device for abnormal discharge of an electric motorcycle, characterized in that: Including, A power circuit and a control circuit, the power circuit being in parallel with the control circuit; The power circuit includes a plurality of power MOS transistors, and the control circuit controls the on / off of the MOS transistors by controlling the voltage of the gate.

2. The protection device for abnormal discharge of an electric motorcycle according to claim 1, characterized in that: The power circuit includes a capacitor C1 connected to the negative pole of the charging port, a resistor R4 connected to the negative pole of the battery, and MOS transistors Q1 and Q2 connected to the capacitor C1 and the resistor R4.

3. The protection device for abnormal discharge of an electric motorcycle according to claim 2, wherein: The MOS transistor Q1 and the MOS transistor Q2 are in parallel, and the resistor R4 and the capacitor C1 form a spike absorption circuit to absorb the high voltage generated by the inductor at the moment of MOS transistor switching.

4. The protection device for abnormal discharge of an electric motorcycle according to claim 1 or 2, characterized in that: The control circuit includes a resistor R2 connected to the MOS transistor Q1, a Schottky diode D1 connected to the resistor R2, and a resistor R1 connected to the Schottky diode D1, and the other end of the resistor R1 is connected to the control terminal.

5. The protection device for abnormal discharge of an electric motorcycle according to claim 4, characterized in that: A TVS diode TVS1 and a resistor R5 are connected in parallel to the end of the resistor R1 close to the control terminal.

6. The protection device for abnormal discharge of an electric motorcycle according to claim 5, characterized in that: A triode Q3 is connected in parallel to the Schottky diode D1, and both ends of the triode Q3 are connected to the resistor R1 and the resistor R2 respectively.

7. The protection device for abnormal discharge of an electric motorcycle according to claim 6, characterized in that: A clamping diode DZ1 and a resistor R3 are connected in parallel to the end of the resistor R2 close to the MOS transistor Q1, and the other end of the resistor R3 is connected to the MOS transistor Q2.

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