High-voltage bleeder circuit, motor controller, power converter and electric two-wheeled vehicle
Through the coordinated design of the control unit, the first transistor, and the holding unit, safe and rapid discharge of the high voltage input is achieved, solving the problems of continuous power consumption and lack of intelligent control in traditional solutions, and providing fault detection function.
Patent Information
- Application Number
- CN202511454244.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-13
- Publication Date
- 2026-02-10
AI Technical Summary
In high-voltage power electronic systems, if the high voltage remaining at the high-voltage input terminal after a power outage is not discharged in time, it may cause electric shock risk and equipment damage. Traditional discharge schemes have problems such as continuous power consumption and lack of intelligent control.
The system employs a coordinated design of a control unit, a first transistor, a holding unit, and a discharge resistor. The control unit monitors the high-voltage input voltage. When the voltage is lower than a preset threshold, the control unit outputs a signal to turn on the first transistor, triggering the holding unit to conduct internally, forming a positive feedback loop to ensure that the discharge process continues until the voltage is lower than the transistor's turn-on voltage.
It achieves safe and rapid discharge of high voltage input, preventing electric shock risk and equipment damage, while avoiding continuous power consumption and having fault detection function.
Smart Images
Figure CN121508299A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of integrated circuits, and more particularly to high-voltage discharge circuits, motor controllers, power converters, and electric two-wheeled vehicles. Background Technology
[0002] In high-voltage power electronic systems (such as motor controllers, power converters, or industrial drive equipment in electric two-wheelers), high voltage (typically above 100V) often remains at the high-voltage input terminals (such as bus capacitors or battery ports) after a power outage. If these residual voltages are not discharged in time, they may cause electric shock risks, equipment damage, or safety hazards, especially in maintenance or fault scenarios.
[0003] For example, in the field of electric two-wheelers: when the vehicle loses power or malfunctions, the residual voltage of the high-voltage battery (such as a 48V / 60V system) may remain through the controller or converter, threatening the user's safety.
[0004] Traditional fixed bleeder resistor solutions achieve bleedering by connecting a fixed resistor in parallel between the high-voltage input and ground. While simple in structure, this approach has serious drawbacks. First, continuous power consumption: the resistor continuously consumes energy during system operation, reducing overall efficiency. Second, lack of intelligent control: it cannot dynamically start and stop based on voltage conditions, potentially leading to premature bleedering (e.g., malfunction during normal system operation) or incomplete bleedering (continued power consumption even after the voltage drops below a threshold). Summary of the Invention
[0005] This invention provides a high-voltage discharge circuit, a motor controller, a power converter, and an electric two-wheeler, which safely and quickly release residual charge at the high-voltage input terminal, preventing continuous consumption, electric shock risk, or equipment damage.
[0006] To achieve the above objectives, a first aspect of the present application provides a high-voltage discharge circuit, including: a control unit, a first transistor and a holding unit, and a discharge resistor; The detection terminal of the control unit is connected to the high-voltage input terminal, and the I / O terminal of the control unit is connected to the base of the first transistor. The emitter of the first transistor is connected to ground, and the collector of the first transistor is connected to the controlled terminal of the holding unit. The input terminal of the holding unit is connected to the high-voltage input terminal, the ground terminal of the holding unit is grounded, and the discharge terminal of the holding unit is connected to one end of the discharge resistor. The other end of the discharge resistor is grounded. When the voltage at the detection terminal of the control unit is lower than a preset voltage threshold, a control signal is output at the IO terminal of the control unit to turn on the first transistor. The input terminal of the holding unit is internally connected to the discharge terminal of the holding unit until the voltage at the high voltage input terminal is lower than or equal to the turn-on voltage of the first transistor.
[0007] In one possible implementation of the first aspect, the holding unit includes a second transistor, a third transistor, a first resistor, a second resistor, a third resistor, and a fourth resistor; The base of the second transistor is connected to one end of the first resistor and one end of the second resistor, and the emitter of the second transistor is connected to the other end of the second resistor; the other end of the first resistor is connected to the collector of the third transistor; the base of the third transistor is connected to one end of the third resistor and one end of the fourth resistor, and the emitter of the third transistor is connected to the other end of the fourth resistor; the other end of the third resistor is connected to the collector of the second transistor.
[0008] In one possible implementation of the first aspect, the collector of the second transistor and the other end of the third resistor are connected to the collector of the first transistor; the emitter of the second transistor and the other end of the second resistor are grounded; the emitter of the third transistor and the other end of the fourth resistor are connected to the high-voltage input terminal; and the other end of the first resistor and the collector of the third transistor are connected to one end of the bleeder resistor.
[0009] In one possible implementation of the first aspect, after the input terminal of the holding unit is internally connected to the discharge terminal of the holding unit, it further includes: The conduction of the third transistor is controlled by the second transistor.
[0010] In one possible implementation of the first aspect, the preset voltage threshold value ranges from 40V to 60V.
[0011] In one possible implementation of the first aspect, the first transistor is an NPN transistor, the second transistor is an NPN transistor, and the third transistor is a PNP transistor.
[0012] In one possible implementation of the first aspect, the control unit includes a fault detection module for triggering a fault alarm if the voltage at the detection terminal of the control unit fails to drop to a safety threshold within a preset time during the discharge process.
[0013] A second aspect of this application provides a motor controller, including a high-voltage discharge circuit as described above.
[0014] A third aspect of this application provides a power converter, including a high-voltage discharge circuit as described above.
[0015] A fourth aspect of this application provides an electric two-wheeled vehicle, including a motor controller as described above, or a power converter as described above.
[0016] Compared to existing technologies, this invention provides a high-voltage discharge circuit, a motor controller, a power converter, and an electric two-wheeler. The control unit continuously monitors the high-voltage input voltage. When the voltage drops below a preset threshold, the control unit's I / O terminal outputs a high-level signal (assuming NPN transistor control), turning on the first transistor. After the first transistor turns on, its collector pulls down the voltage, triggering the holding unit to conduct internally (short-circuiting the input and discharge terminals). The charge at the high-voltage input terminal flows to ground through the discharge resistor, and the voltage begins to drop. Once the holding unit is on, the discharge process continues even if the control unit's I / O signal disappears (the control unit may stop outputting after the voltage drops). This is because the second and third transistors in the holding unit form a positive feedback loop, ensuring that the conduction state of the third transistor is maintained by the second transistor until the voltage is extremely low (below the conduction voltage of the first transistor, typically 0.7V), thereby safely discharging the residual charge at the high-voltage input terminal and preventing the risk of electric shock or equipment damage. Attached Figure Description
[0017] Figure 1 This is a schematic diagram of a high-voltage discharge circuit provided in an embodiment of the present invention. Detailed Implementation
[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0019] To resolve the above issues, please refer to [link / reference]. Figure 1 One embodiment of the present invention provides a high-voltage discharge circuit, comprising a control unit 10, a first transistor 20, a holding unit 30, and a discharge resistor 40.
[0020] The detection terminal of the control unit 10 is connected to the high-voltage input terminal, and the IO terminal of the control unit 10 is connected to the base of the first transistor 20. The emitter of the first transistor 20 is connected to ground, and the collector of the first transistor 20 is connected to the controlled terminal of the holding unit 30. The input terminal of the holding unit 30 is connected to the high-voltage input terminal, the ground terminal of the holding unit 30 is grounded, and the discharge terminal of the holding unit 30 is connected to one end of the discharge resistor 40. The other end of the discharge resistor 40 is grounded.
[0021] When the detection terminal voltage of the control unit 10 is lower than the preset voltage threshold, the control unit 10 outputs a control signal at the IO terminal to turn on the first transistor 20. The input terminal of the holding unit 30 is internally connected to the discharge terminal of the holding unit 30 until the voltage at the high voltage input terminal is lower than or equal to the turn-on voltage of the first transistor 20.
[0022] During normal operation (high voltage state), if the high voltage input voltage exceeds a preset threshold (e.g., 60V), the control unit 10 detects a high voltage and outputs a low level at the I / O terminal. The first transistor 20 is cut off (no current flows to the base), and the collector is in a high-impedance state. The holding unit 30 is internally disconnected, no current flows through the bleeder resistor 40, and there is no standby power consumption.
[0023] When the system loses power or malfunctions, the voltage at the high-voltage input terminal drops below a preset threshold (e.g., 50V). The control unit 10 detects the voltage change and outputs a high-level control signal at the IO terminal. The first transistor 20 turns on, and its collector voltage is pulled low to near ground potential (0V). The low-level signal is input to the controlled terminal of the holding unit 30, triggering the holding unit to conduct internally.
[0024] During the discharge phase (when the self-holding mechanism is activated), the input terminal of the holding unit 30 and the discharge terminal are internally connected. The high-voltage input terminal forms a discharge circuit through the discharge resistor 40 (high-voltage input terminal → holding unit 30 → discharge resistor 40 → ground). Positive feedback is formed within the holding unit 30, maintaining the conducting state. Even if the I / O signal of the control unit 10 disappears (the control unit stops outputting after a voltage drop), the discharge continues. Example: If the high-voltage input terminal voltage briefly rises above the threshold due to load fluctuations, the discharge will not be interrupted (traditional solutions are prone to accidental termination).
[0025] When the voltage at the high-voltage input terminal drops below the turn-on voltage of the first transistor 20 (≤0.7V), the voltage at the detection terminal of the control unit 10 is too low to maintain the output at the IO terminal. The first transistor 20 is turned off, the controlled terminal of the holding unit 30 returns to a high level, and the internal circuit is disconnected. The current in the bleeder resistor 40 returns to zero, and the circuit returns to its initial state.
[0026] This embodiment achieves precise triggering (40–60V threshold), thorough discharge (lasting up to 0.7V), and no redundant power consumption (operating only after power failure) through the coordinated design of intelligent triggering control unit 10, first transistor switch 20, self-holding holding unit 30, and discharge resistor 40.
[0027] For example, the holding unit 30 includes a second transistor TR1, a third transistor TR2, a first resistor R1, a second resistor R2, a third resistor R3, and a fourth resistor R4.
[0028] The base of the second transistor TR1 is connected to one end of the first resistor R1 and one end of the second resistor R2, and the emitter of the second transistor TR1 is connected to the other end of the second resistor R2; the other end of the first resistor R1 is connected to the collector of the third transistor TR2; the base of the third transistor TR2 is connected to one end of the third resistor R3 and one end of the fourth resistor R4, and the emitter of the third transistor TR2 is connected to the other end of the fourth resistor R4; the other end of the third resistor R3 is connected to the collector of the second transistor TR1.
[0029] For example, the collector of the second transistor TR1 and the other end of the third resistor R3 are connected to the collector of the first transistor 20; the emitter of the second transistor TR1 and the other end of the second resistor R2 are grounded; the emitter of the third transistor TR2 and the other end of the fourth resistor R4 are connected to the high-voltage input terminal; the other end of the first resistor R1 and the collector of the third transistor TR2 are connected to one end of the bleeder resistor 40.
[0030] For example, after the input terminal of the holding unit 30 is internally connected to the discharge terminal of the holding unit 30, it further includes: The conduction of the third transistor TR2 is controlled by the second transistor TR1.
[0031] Under high-voltage operating conditions (before discharge, e.g., voltage > 70V), TR1 is cut off. High voltage at the high-voltage input → high emitter potential of TR2 → voltage divider R4 brings the base voltage of TR2 close to the emitter → TR2 is cut off. The collector of TR2 is in a high-impedance state → R1 cannot pull the base of TR1 low → TR1 is cut off. Discharge path: disconnected. Because TR2 is cut off → there is no connection between the high-voltage input and the discharge resistor 40 → no standby power consumption. Control unit 10 behavior: low-level output at the IO terminal → first transistor 20 is cut off → its collector is at a high potential (does not trigger the holding unit).
[0032] Assuming a preset voltage threshold of 50V, if control unit 10 detects a high-voltage input voltage < 50V, the IO terminal outputs a high level. The first transistor 20 turns on, pulling its collector voltage down to approximately 0.2V (saturation voltage drop). The collector voltage of TR1 and the other end of R3 are simultaneously pulled down to approximately 0.2V. R3 pulls down the collector of TR1, forming a bias current at the base of TR1 through R2 / R1, turning TR1 on. The emitter current of TR1 flows to ground through R2, resulting in a base-emitter voltage > 0.7V, maintaining conduction. With TR1 on, R1 pulls down the collector of TR2, causing the base voltage of TR2 to < emitter voltage, thus turning TR2 on.
[0033] by Figure 1 For example: After the I / O port is pulled high, the first transistor 20, as shown in the figure, conducts, and pins 5 and 6 of the holding circuit are pulled low. After pin 6 is pulled low, TR2 conducts, pins 4 and 3 conduct, and the high voltage passes through the bleeder resistor 40. Pins 3 and 2 are connected, the gate of TR1 is pulled high, and TR1 conducts. After TR1 conducts, pins 6 and 1 of the holding circuit are grounded. Since pins 6 and 5 are connected, the subsequent conduction of TR2 is controlled by TR1, that is, the self-holding unit 30 completes the closed loop. The subsequent auxiliary defense circuit does not require control unit 10.
[0034] During the discharge phase (self-holding mechanism activated, voltage dropping), TR2 conducts → charge at the high-voltage input terminal flows through the collector of TR2 → R1 → the base of TR1, forcing TR1 to remain on (even if the first transistor 20 is off). TR1 continues to conduct → R3 maintains a low potential at the base of TR2 → TR2 remains on. This forms a positive feedback loop of "TR1 on ⇄ TR2 on", and the discharge process cannot be interrupted. The discharge path at this time is: TR2 on → high-voltage input terminal → TR2 emitter → R4 → TR2 base (bypass) → TR2 collector → R1 → discharge resistor 40 → ground. The main discharge path is: high-voltage input terminal → TR2 emitter → TR2 collector → discharge resistor 40 → ground (R4 / R1 only provide bias and do not dominate the current).
[0035] During the termination phase (voltage returns to zero, ≤0.7V), the high-voltage input voltage ≤ the emitter-base turn-on voltage of TR2 (silicon transistor ≈0.7V) → the base voltage of TR2 cannot fall below the emitter voltage → TR2 is cut off. With TR2 cut off, R1 cannot pull the base of TR1 low → the base current of TR1 disappears → TR1 is cut off. The collector voltage of TR1 rises again → the collector of the first transistor 20 returns to a high potential.
[0036] This embodiment achieves precise triggering through the complementary positive feedback design of TR1 and TR2: it starts when the high voltage input voltage is ≤50V; it ensures complete discharge: the self-holding mechanism ensures that the voltage continues to drop to ≤0.7V (claim 1); and it is fault-safe: it supports real-time monitoring and alarm.
[0037] For example, the preset voltage threshold value ranges from 40V to 60V.
[0038] The preset voltage threshold range of 40V–60V is the core safety boundary of the high-voltage discharge circuit. 60V maximum: Mandatory by law to ensure compliance with standards such as IEC 60950-1 and avoid the risk of electric shock.
[0039] Lower limit 40V: a safety margin for human physiological safety, covering extreme scenarios such as humid environments.
[0040] For example, the first transistor 20 is an NPN transistor, the second transistor TR1 is an NPN transistor, and the third transistor TR2 is a PNP transistor.
[0041] For example, the control unit 10 includes a fault detection module, which is used to trigger a fault alarm if the voltage at the detection terminal of the control unit 10 fails to drop to a safety threshold within a preset time during the discharge process.
[0042] The fault detection module does not operate independently but is deeply integrated with the self-holding mechanism of the holding unit 30 to ensure that: it only monitors the effective discharge process; the fault detection module only starts timing after the holding unit 30 is internally connected (i.e., the discharge path is truly established), avoiding false alarms (such as during the natural voltage drop phase). The fault alarm only outputs a signal and does not disconnect the main discharge circuit (the holding unit 30 continues to discharge) until the voltage naturally returns to zero. If the latching structure of the holding unit 30 fails (e.g., TR2 is open), the voltage stops, and the fault detection module triggers an alarm within a preset time.
[0043] Compared to existing technologies, this invention provides a high-voltage discharge circuit, a motor controller, a power converter, and an electric two-wheeler. The control unit 10 continuously monitors the high-voltage input voltage. When the voltage falls below a preset threshold, the control unit 10 outputs a high-level signal (assuming NPN transistor control) at its I / O terminal, turning on the first transistor 20. After the first transistor 20 turns on, its collector pulls down the voltage, triggering the internal conduction of the holding unit 30 (short-circuiting the input and discharge terminals). The charge at the high-voltage input terminal flows to ground through the discharge resistor 40, and the voltage begins to drop. Once the holding unit 30 is turned on, the discharge process continues even if the I / O signal of the control unit 10 disappears (the control unit 10 may stop outputting after the voltage drops). This is because the second transistor TR1 and the third transistor TR2 in the holding unit 30 form a positive feedback loop, ensuring that the conduction state of the third transistor TR2 is maintained by the second transistor TR1 until the voltage is extremely low (below the conduction voltage of the first transistor 20, typically 0.7V), thereby safely discharging the residual charge at the high voltage input terminal and preventing the risk of electric shock or equipment damage.
[0044] One embodiment of this application provides a motor controller, including a high-voltage discharge circuit as described above.
[0045] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working process of the motor controller described above can be referred to the corresponding process in the aforementioned circuit embodiments, and will not be repeated here.
[0046] Compared to existing technologies, the motor controller provided in this embodiment of the invention has a control unit 10 that continuously monitors the voltage at the high-voltage input terminal. When the voltage is lower than a preset threshold, the I / O terminal of the control unit 10 outputs a high-level signal (assuming NPN transistor control), turning on the first transistor 20. After the first transistor 20 is turned on, its collector pulls down the voltage, triggering the internal conduction of the holding unit 30 (short-circuiting the input terminal and the discharge terminal). The charge at the high-voltage input terminal flows to ground through the discharge resistor 40, and the voltage begins to drop. Once the holding unit 30 is turned on, the discharge process continues even if the I / O signal of the control unit 10 disappears (the control unit 10 may stop outputting after the voltage drops). This is because the second transistor TR1 and the third transistor TR2 in the holding unit 30 form a positive feedback loop, ensuring that the conduction state of the third transistor TR2 is maintained by the second transistor TR1 until the voltage is extremely low (below the conduction voltage of the first transistor 20, typically 0.7V), thereby safely discharging the residual charge at the high-voltage input terminal and preventing the risk of electric shock or equipment damage.
[0047] One embodiment of this application provides a power converter, including a high-voltage discharge circuit as described above.
[0048] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working process of the power converter described above can be referred to the corresponding process in the aforementioned circuit embodiments, and will not be repeated here.
[0049] Compared to existing technologies, this invention provides a power converter in which the control unit 10 continuously monitors the high-voltage input voltage. When the voltage falls below a preset threshold, the control unit 10 outputs a high-level signal (assuming NPN transistor control) at its I / O terminal, turning on the first transistor 20. After the first transistor 20 turns on, its collector pulls down the voltage, triggering the internal conduction of the holding unit 30 (short-circuiting the input and discharge terminals). The charge at the high-voltage input terminal flows to ground through the discharge resistor 40, and the voltage begins to drop. Once the holding unit 30 is turned on, the discharge process continues even if the I / O signal of the control unit 10 disappears (the control unit 10 may stop outputting after the voltage drops). This is because the second transistor TR1 and the third transistor TR2 in the holding unit 30 form a positive feedback loop, ensuring that the conduction state of the third transistor TR2 is maintained by the second transistor TR1 until the voltage is extremely low (below the conduction voltage of the first transistor 20, typically 0.7V), thereby safely discharging the residual charge at the high-voltage input terminal and preventing the risk of electric shock or equipment damage.
[0050] One embodiment of this application provides an electric two-wheeled vehicle, including a motor controller as described above, or a power converter as described above.
[0051] Since this electric two-wheeler adopts the technical solutions of all the above embodiments, it has at least the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.
[0052] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.
Claims
1. A high-voltage discharge circuit, characterized in that, include: Control unit, first transistor, holding unit, and bleed resistor; The detection terminal of the control unit is connected to the high-voltage input terminal, and the I / O terminal of the control unit is connected to the base of the first transistor. The emitter of the first transistor is connected to ground, and the collector of the first transistor is connected to the controlled terminal of the holding unit. The input terminal of the holding unit is connected to the high-voltage input terminal, the ground terminal of the holding unit is grounded, and the discharge terminal of the holding unit is connected to one end of the discharge resistor. The other end of the discharge resistor is grounded. When the voltage at the detection terminal of the control unit is lower than a preset voltage threshold, a control signal is output at the IO terminal of the control unit to turn on the first transistor. The input terminal of the holding unit is internally connected to the discharge terminal of the holding unit until the voltage at the high voltage input terminal is lower than or equal to the turn-on voltage of the first transistor. The preset voltage threshold is greater than the turn-on voltage of the first transistor.
2. The high-voltage discharge circuit as described in claim 1, characterized in that, The holding unit includes a second transistor, a third transistor, a first resistor, a second resistor, a third resistor, and a fourth resistor; The base of the second transistor is connected to one end of the first resistor and one end of the second resistor, and the emitter of the second transistor is connected to the other end of the second resistor; the other end of the first resistor is connected to the collector of the third transistor; the base of the third transistor is connected to one end of the third resistor and one end of the fourth resistor, and the emitter of the third transistor is connected to the other end of the fourth resistor; the other end of the third resistor is connected to the collector of the second transistor.
3. The high-voltage discharge circuit as described in claim 2, characterized in that, The collector of the second transistor and the other end of the third resistor are connected to the collector of the first transistor; the emitter of the second transistor and the other end of the second resistor are grounded; the emitter of the third transistor and the other end of the fourth resistor are connected to the high-voltage input terminal; the other end of the first resistor and the collector of the third transistor are connected to one end of the bleeder resistor.
4. The high-voltage discharge circuit as described in claim 2, characterized in that, After the input terminal of the holding unit is internally connected to the discharge terminal of the holding unit, it also includes: The conduction of the third transistor is controlled by the second transistor.
5. A high-voltage discharge circuit as described in claim 1, characterized in that, The preset voltage threshold value range is 40V to 60V.
6. The high-voltage discharge circuit as described in claim 1, characterized in that, The first transistor is an NPN transistor, the second transistor is an NPN transistor, and the third transistor is a PNP transistor.
7. The high-voltage discharge circuit as described in claim 1, characterized in that, The control unit includes a fault detection module, which is used to trigger a fault alarm if the voltage at the detection terminal of the control unit fails to drop to a safe threshold within a preset time during the discharge process.
8. A motor controller, characterized in that, Includes a high-voltage discharge circuit as described in any one of claims 1-7.
9. A power converter, characterized in that, Includes a high-voltage discharge circuit as described in any one of claims 1-7.
10. An electric two-wheeled vehicle, characterized in that, It includes a motor controller as described in claim 8, or a power converter as described in claim 9.