Power supply device and electric vehicle
By designing a power supply device that includes overvoltage clamp protection circuit and buck circuit, the problems of over-discharge risk of electric vehicle batteries and high-priced buck circuit chips are solved, and the battery life is extended and the production cost is reduced.
Patent Information
- Application Number
- CN202510043160.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-10
- Publication Date
- 2025-04-08
AI Technical Summary
The risks of over-discharge of batteries and the problems of high-priced step-down circuit chips in existing electric vehicles lead to short battery life and high production costs.
A power supply device including an overvoltage clamp protection circuit and a buck circuit is designed. Through an overvoltage clamp protection circuit composed of a voltage stabilizer diode, a first transistor and a second transistor, the battery voltage is restricted below the set value to prevent over-discharge; at the same time, an undervoltage protection circuit composed of an LDO module and a comparator is used to determine that the battery voltage is lower than the threshold and the connection between the battery and the system is disconnected.
Effectively protect the risk of over-discharge of batteries, extend the battery life, while reducing production costs and reducing dependence on high-priced step-down circuit chips.
Smart Images
Figure CN119787571A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a power supply device and an electric vehicle. Background Art
[0002] With the development of electric bicycles, electric two-wheelers are required to have long-term power supply, GPS and networking functions, and real-time vehicle status. However, the overall circuit will be more complicated, requiring the vehicle's power management system to be safer and more reliable.
[0003] In the current electric two-wheeled vehicle market, safety accidents frequently occur, and the main reason is that the design of electrical and electronic systems is imperfect or the cost is too high. Several electronic components of electric two-wheeled vehicles must be powered by batteries, but because the battery voltage of electric two-wheeled vehicles ranges from 48-72V, the operating voltage is high, and the voltage is extremely unstable, it is easy to have surges and reverse electromotive force when going downhill, and the voltage may be as high as hundreds of volts; and the traditional power supply design will use TVS (transient voltage suppressor) high-voltage power supply chip solutions to achieve overvoltage protection, and because the high voltage of electric two-wheeled vehicles lasts for a long time, the selected voltage of TVS cannot be too low, otherwise TVS will not play a protective role and it will be easily damaged. If the voltage of TVS is selected to be high, the power chip at the back end must be higher than the clamping voltage of TVS so that it will not be easily damaged. The voltage of such chips must exceed 100 volts, and such chips are currently expensive; the power supply cost of such designs is high and the reliability is poor.
[0004] Another solution in the early days was to have an OVP (overvoltage protection) circuit in the front, but the disadvantage of the OVP (overvoltage protection) circuit is that as long as there is a surge or high voltage during riding, it will cut off the power supply of the subsequent system, causing the system to lose power or malfunction during riding, requiring the vehicle to be restarted.
[0005] In addition, cars need to have positioning and real-time communication reporting functions, which requires some accessories to have long-term power, that is, they will consume battery power for a long time. However, based on traditional designs, vehicles basically do not have low-voltage protection functions, or use MCU to provide low-voltage protection solutions, but the MCU itself is also a power-consuming chip. This leads to the battery being over-discharged if the vehicle itself is out of power and not ridden for a long time, thereby accelerating battery aging and causing safety problems when recharging. Summary of the invention
[0006] The technical problem to be solved by the present invention is to overcome the defects of the prior art that electric vehicles have the risk of battery over-discharge and the step-down circuit chip is expensive, and to provide a power supply device and electric vehicle that can effectively protect the risk of battery over-discharge, extend the battery life, and have low production cost.
[0007] The present invention solves the above technical problems through the following technical solutions:
[0008] A power supply device for an electric vehicle, characterized in that the power supply device comprises an overvoltage clamping protection circuit and a voltage step-down circuit.
[0009] The input end of the overvoltage clamping protection circuit is connected to the battery of the electric vehicle. The overvoltage clamping protection circuit includes a voltage-stabilizing diode, a first transistor and a second transistor. The emitter voltage of the first transistor is lower than the stable voltage value of the voltage-stabilizing diode, the emitter voltage of the second transistor is lower than the emitter of the first transistor, the emitter of the second transistor is connected to the input end of the step-down circuit, and the output end of the step-down circuit is connected to the system power supply pin of the electric vehicle.
[0010] Preferably, the overvoltage clamping protection circuit also includes a first resistor, one end of the first resistor is connected to the input end of the overvoltage clamping protection circuit, the collector of the first transistor, and the collector of the second transistor, the other end of the first resistor is connected between the voltage regulator diode and the base of the first transistor, and the emitter of the first transistor is connected to the base of the second transistor.
[0011] Preferably, the power supply device further comprises an undervoltage protection circuit, and the undervoltage protection circuit is used to determine whether the voltage of the battery is lower than a threshold voltage, and if so, the connection between the battery and the system power supply pin is cut off by the step-down circuit.
[0012] Preferably, the undervoltage protection circuit includes an LDO module and a comparator, the input end of the LDO module is connected to the battery, the output end of the LDO module is connected to the power supply pin of the comparator, the input end of the comparator is connected to the battery through a voltage-dividing resistor, the output end of the comparator is connected to the base of a third transistor, the comparator is used to output a high level when the battery voltage is lower than the threshold voltage of the comparator, the collector of the third transistor is connected to the enable pin of the step-down circuit and the emitter is grounded, and the output end of the step-down circuit is disconnected from the system power supply pin of the electric vehicle when the enable pin is at a low level.
[0013] Preferably, the positive electrode of the battery is grounded through a second resistor and a third resistor connected in series, the positive electrode of the battery and the second resistor are connected to the input end of the LDO module through a fourth resistor, the fourth resistor and the input end of the LDO module are grounded through a fifth resistor, the output end of the LDO module and the power supply pin of the comparator are grounded through a first capacitor, and the output end of the comparator is connected to the base of the third transistor through a sixth resistor.
[0014] Preferably, the comparator also includes a hysteresis circuit, which includes a seventh resistor and an eighth resistor, the second resistor and the third resistor are connected to the negative input terminal of the comparator, the two ends of the seventh resistor are respectively connected to the positive input terminal and the reference pin of the comparator, the two ends of the eighth resistor are respectively connected to the output terminal and the positive input terminal of the comparator, the seventh resistor and the eighth resistor are both grounded through the second capacitor, the sixth resistor and the base of the third transistor are grounded through the third capacitor, and the second resistor and the third resistor are grounded through the fourth capacitor.
[0015] Preferably, the power supply device also includes a power anti-shake circuit, which is connected to the battery through an ignition switch of the electric vehicle, and is used to shield the connection between the undervoltage protection circuit and the system power enable pin after the ignition switch is closed.
[0016] Preferably, the power supply anti-jitter circuit includes a ninth resistor, a tenth resistor, a fourth transistor and a fifth capacitor, the battery is connected to the base of the fourth transistor through an ignition switch and a ninth resistor connected in series, the ninth resistor and the fourth transistor are grounded through a tenth resistor and a fifth capacitor connected in parallel, the emitter of the fourth transistor is grounded and the collector is connected to the base of the third transistor.
[0017] Preferably, the electric vehicle also includes an IMU module and a processing chip, the IMU module is used to collect the driving posture of the electric vehicle and transmit it to the processing chip, the processing chip is used to obtain the potential data of the enable pin, and use the driving posture and the point data corresponding to the driving posture to calculate the value of the voltage regulator diode and the battery management plan of the battery.
[0018] The present invention also provides an electric vehicle, characterized in that the electric vehicle comprises the power supply device as described above.
[0019] On the basis of being in accordance with the common sense in the art, the above-mentioned preferred conditions can be arbitrarily combined to obtain the preferred embodiments of the present invention.
[0020] The positive and progressive effects of the present invention are:
[0021] The present invention can effectively protect the battery from over-discharge risks, extend the battery life, and has a low production cost, which can effectively solve the dependence on high-priced step-down circuit chips.
[0022] While providing low voltage protection, this application also takes into account power supply anti-shake to prevent the sudden power failure during normal use, which will cause the vehicle to be unable to ride. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 This is a schematic diagram of the structure of the power supply device of Example 1 of the present invention. DETAILED DESCRIPTION
[0024] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples.
[0025] Example 1
[0026] See also Figure 1 , this embodiment provides an electric vehicle, which is an electric vehicle or an electric vehicle.
[0027] The electric vehicle described in this embodiment is an electric two-wheeled vehicle.
[0028] The electric two-wheeled vehicle comprises a power supply device.
[0029] The power supply device includes an overvoltage clamping protection circuit 21 and a voltage step-down circuit 31.
[0030] The input end of the overvoltage clamping protection circuit is connected to the battery of the electric vehicle.
[0031] The overvoltage clamping protection circuit 21 includes a voltage stabilizing diode 211 , a first transistor 212 , and a second transistor 213 .
[0032] The emitter voltage of the first transistor is lower than the stable voltage value of the voltage-stabilizing diode, and the emitter voltage of the second transistor is lower than the emitter voltage of the first transistor.
[0033] The emitter of the second transistor is connected to the input end of the step-down circuit, and the output end of the step-down circuit is connected to the system power supply pin 61 of the electric vehicle.
[0034] The overvoltage clamping protection circuit further includes a first resistor 214 .
[0035] One end of the first resistor 214 is connected to the input end of the overvoltage clamp protection circuit, the collector of the first transistor, and the collector of the second transistor.
[0036] The other end of the first resistor 214 is connected between the voltage stabilizing diode and the base of the first transistor, and the emitter of the first transistor is connected to the base of the second transistor.
[0037] The overvoltage clamping protection circuit can set the required overvoltage protection voltage through the Zener diode 211; the emitter voltage of the first transistor is always lower than the stable voltage value of the Zener diode, and similarly, the emitter voltage of the second transistor is always lower than the emitter of the first transistor, that is, the battery voltage output by the second transistor can always be guaranteed to be lower than the voltage set by the Zener diode, thereby achieving overvoltage clamping.
[0038] The overvoltage clamping protection circuit limits the base voltage of the first transistor to below the stabilization voltage Vzt of the zener diode through the current limiting of the first resistor and the low current stabilization function of the zener diode, thereby ensuring that the emitter voltage of the first transistor is also limited to below Vzt-0.6V. The emitter of the first transistor is connected to the base of the second transistor, so the emitter voltage of the second transistor (i.e., the output voltage) will be limited to below Vzt-0.6-0.6V, so that even if a surge occurs at the input end, it will be limited to below the set voltage by the overvoltage clamping circuit, protecting the back-end circuit from damage, and can operate normally under surge conditions.
[0039] The power supply device also includes an undervoltage protection circuit 41, which is used to determine whether the voltage of the battery is lower than the threshold voltage. If so, the connection between the battery and the system power supply pin is cut off through the buck circuit. The enable terminal of the buck circuit BUCK buck chip is pulled down by the transistor, and the power supply is cut off to achieve the undervoltage protection function.
[0040] Furthermore, the undervoltage protection circuit 41 includes an LDO module 411 and a comparator 412 .
[0041] The input end of the LDO module 411 is connected to the battery, and the output end of the LDO module is connected to the power supply pin of the comparator.
[0042] The input terminal of the comparator is connected to the positive electrode of the battery through a voltage-dividing resistor, and the output terminal 4121 of the comparator is connected to the base of a third transistor 413 .
[0043] The comparator is used to output a high level when the battery voltage is lower than the threshold voltage of the comparator. The collector of the third transistor is connected to the enable pin 311 of the step-down circuit 31 and the emitter is grounded.
[0044] When the enable pin 311 is at a low level, the output end of the buck circuit is disconnected from the system power supply pin of the electric vehicle.
[0045] The positive electrode of the battery is grounded through a second resistor 414 and a third resistor 415 connected in series, the positive electrode of the battery and the second resistor 414 are connected to the input end of the LDO module through a fourth resistor 416, the fourth resistor 416 and the input end of the LDO module are grounded through a fifth resistor 417, the output end of the LDO module and the power supply pin of the comparator are grounded through a first capacitor 418, and the output end of the comparator is connected to the base of the third transistor through a sixth resistor 419.
[0046] The comparator also includes a hysteresis circuit, which includes a seventh resistor 420 and an eighth resistor 421, the second resistor 414 and the third resistor 415 are connected to the negative input terminal of the comparator, the two ends of the seventh resistor 420 are respectively connected to the positive input terminal and the reference pin of the comparator, the two ends of the eighth resistor 421 are respectively connected to the output terminal and the positive input terminal of the comparator, the seventh resistor 420 and the eighth resistor 421 are both grounded through the second capacitor 422, the sixth resistor and the base of the third transistor are grounded through the third capacitor, and the second resistor and the third resistor are grounded through the fourth capacitor 423. After the undervoltage protection circuit is turned on, the comparison voltage (+) of the comparator will change and can be adjusted by the seventh resistor and the eighth resistor. Thereby, the hysteresis effect is achieved, and it will not jump back and forth at the undervoltage protection point.
[0047] The fourth resistor 416 and the fifth resistor 417 are connected to the battery input terminal through the voltage divider resistor, providing a small current to the LDO module, thereby outputting a voltage to power the comparator. The voltage is divided by the second resistor and the third resistor and connected to the comparator. The divided voltage is compared with the reference voltage of the comparator. If the input voltage is lower than the reference voltage of the comparator, the comparator turns on the output high level, which is given to the third NPN transistor through the sixth resistor. The third transistor is turned on, and the enable pin of the buck chip is pulled down to achieve judgment.
[0048] The power supply device also includes a power anti-shake circuit 51, which is connected to the battery through the ignition switch of the electric vehicle. The power anti-shake circuit is used to shield the connection between the undervoltage protection circuit and the system power enable pin after the ignition switch is closed, and to conduct the connection between the battery and the system power pin through the undervoltage protection circuit.
[0049] The power supply anti-jitter circuit includes a ninth resistor 511, a tenth resistor 512, a fourth transistor 513 and a fifth capacitor 514. The battery is connected to the base of the fourth transistor 513 through an ignition switch 71 and the ninth resistor 511 connected in series. The ninth resistor 511 and the fourth transistor are grounded through a tenth resistor and a fifth capacitor connected in parallel. The emitter of the fourth transistor is grounded and the collector is connected to the base of the third transistor.
[0050] The power supply anti-shake circuit is connected to the ACC ignition switch. When the ACC ignition switch is turned on, the fourth transistor is turned on, that is, the third transistor is turned off, so that when the power supply shakes instantaneously, the undervoltage protection circuit will not be triggered by mistake, thereby realizing the power supply anti-shake function. When the ignition switch is turned on, the base voltage of the fourth transistor is high, the fourth transistor is turned on, and the collector of the fourth transistor is grounded, so that the third transistor is cut off, and the enable of the subsequent step-down chip is high, so that the power supply circuit is always kept in the open state. It is realized that some abnormal power supply jitters that cause power failure are shielded in the ignition state.
[0051] The electric vehicle also includes an IMU module and a processing chip. The IMU module is used to collect the driving posture of the electric vehicle and transmit it to the processing chip. The processing chip is used to obtain the potential data of the enable pin, and use the driving posture and the point data corresponding to the driving posture to calculate the value of the voltage regulator diode and the battery management plan of the battery.
[0052] Although the specific embodiments of the present invention are described above, those skilled in the art should understand that these are only examples, and the protection scope of the present invention is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but these changes and modifications all fall within the protection scope of the present invention.
Claims
1. A power supply device for an electric vehicle, characterized in that: The power supply device includes an overvoltage clamping protection circuit and a voltage step-down circuit. The input end of the overvoltage clamping protection circuit is connected to the battery of the electric vehicle. The overvoltage clamping protection circuit includes a voltage-stabilizing diode, a first transistor and a second transistor. The emitter voltage of the first transistor is lower than the stable voltage value of the voltage-stabilizing diode, the emitter voltage of the second transistor is lower than the emitter of the first transistor, the emitter of the second transistor is connected to the input end of the step-down circuit, and the output end of the step-down circuit is connected to the system power supply pin of the electric vehicle.
2. The power supply device according to claim 1, characterized in that: The overvoltage clamping protection circuit also includes a first resistor, one end of which is connected to the input end of the overvoltage clamping protection circuit, the collector of the first transistor, and the collector of the second transistor, the other end of the first resistor is connected between the voltage regulator diode and the base of the first transistor, and the emitter of the first transistor is connected to the base of the second transistor.
3. The power supply device according to claim 1, characterized in that: The power supply device further comprises an undervoltage protection circuit, which is used to determine whether the voltage of the battery is lower than a threshold voltage, and if so, the connection between the battery and the system power supply pin is cut off by the step-down circuit.
4. The power supply device according to claim 3, characterized in that: The undervoltage protection circuit includes an LDO module and a comparator, the input end of the LDO module is connected to the battery, the output end of the LDO module is connected to the power supply pin of the comparator, the input end of the comparator is connected to the battery through a voltage-dividing resistor, the output end of the comparator is connected to the base of a third transistor, the comparator is used to output a high level when the battery voltage is lower than the threshold voltage of the comparator, the collector of the third transistor is connected to the enable pin of the step-down circuit and the emitter is grounded, and the output end of the step-down circuit is disconnected from the system power supply pin of the electric vehicle when the enable pin is at a low level.
5. The power supply device according to claim 4, characterized in that: The positive electrode of the battery is grounded through a second resistor and a third resistor connected in series, the positive electrode of the battery and the second resistor are connected to the input end of the LDO module through a fourth resistor, the fourth resistor and the input end of the LDO module are grounded through a fifth resistor, the output end of the LDO module and the power supply pin of the comparator are grounded through a first capacitor, and the output end of the comparator is connected to the base of the third transistor through a sixth resistor.
6. The power supply device according to claim 5, characterized in that: The comparator also includes a hysteresis circuit, which includes a seventh resistor and an eighth resistor. The second resistor and the third resistor are connected to the negative input terminal of the comparator, the two ends of the seventh resistor are respectively connected to the positive input terminal and the reference pin of the comparator, the two ends of the eighth resistor are respectively connected to the output terminal and the positive input terminal of the comparator, the seventh resistor and the eighth resistor are both grounded through the second capacitor, the sixth resistor and the base of the third transistor are grounded through the third capacitor, and the second resistor and the third resistor are grounded through the fourth capacitor.
7. The power supply device according to claim 4, characterized in that: The power supply device further includes a power supply anti-shake circuit, which is connected to the battery through the ignition switch of the electric vehicle, and is used to shield the connection between the undervoltage protection circuit and the system power supply enable pin after the ignition switch is closed.
8. The power supply device according to claim 7, characterized in that: The power supply anti-jitter circuit includes a ninth resistor, a tenth resistor, a fourth transistor and a fifth capacitor. The battery is connected to the base of the fourth transistor through an ignition switch and a ninth resistor connected in series. The ninth resistor and the fourth transistor are grounded through a tenth resistor and a fifth capacitor connected in parallel. The emitter of the fourth transistor is grounded and the collector is connected to the base of the third transistor.
9. The power supply device according to claim 4, characterized in that: The electric vehicle also includes an IMU module and a processing chip. The IMU module is used to collect the driving posture of the electric vehicle and transmit it to the processing chip. The processing chip is used to obtain the potential data of the enable pin, and use the driving posture and the point data corresponding to the driving posture to calculate the value of the voltage regulator diode and the battery management plan of the battery.
10. An electric vehicle, characterized in that: The electric vehicle comprises the power supply device according to any one of claims 1 to 9.