A high-voltage suppression and protection circuit for a lithium-ion battery forklift controller and the forklift thereof

Abstract

This utility model provides a high-voltage suppression protection circuit for a lithium-ion battery forklift controller and the forklift thereof, comprising: an operating switch; a vehicle controller; and a high-voltage suppression module disposed between the operating switch and the vehicle controller, which includes an input filtering unit, a voltage detection and comparison unit, and an output voltage regulator unit connected in sequence. The voltage detection and comparison unit is connected to the input filtering unit and is used to compare the filtered power supply voltage with a reference voltage, and selectively direct the power signal to a transient voltage suppression branch or a direct conduction branch based on the comparison result to absorb surge energy. The output voltage regulator unit is connected to the output terminal of the voltage detection and comparison unit to regulate and filter the processed power signal again, and output a stable rated voltage to the vehicle controller. This provides comprehensive protection for the controller's logic power ports and switching ports, improving the reliability and safety of the entire vehicle.

Description

Technical Field

[0001] This utility model relates to the field of forklift technology, specifically to a high-voltage suppression and protection circuit for a lithium-ion forklift controller and the forklift thereof. Background Technology

[0002] Lithium-ion battery-powered forklifts have been widely used in warehousing, logistics, and manufacturing due to their advantages such as environmental friendliness, high efficiency, and low maintenance costs. Lithium-ion batteries, as their power source, are characterized by high energy density and long cycle life. However, in actual use, changes in the operating state of the lithium-ion battery system can easily lead to voltage fluctuations, which can adversely affect the vehicle's electronic control system.

[0003] Specifically, voltage surge problems are likely to occur under the following operating conditions: First, when a lithium battery has just finished charging, its terminal voltage is at a high level. If the operator turns on the key switch at this time, the instantaneous voltage spike will be superimposed on the battery voltage, which may exceed the maximum withstand voltage of the controller's power input terminal (such as the KSI terminal).

[0004] Secondly, during vehicle operation, such as when suddenly braking or releasing the accelerator, the energy feedback current will flow into the battery pack, causing the battery voltage to rise further. The superimposed voltage may also exceed the controller's tolerance limit.

[0005] Furthermore, the transient voltage generated when the lifting switch or other function switches are operated immediately after charging may also impact the switching ports of the controller.

[0006] In summary, existing technologies typically lack effective transient voltage suppression and filtering measures at the controller front end. Long-term and repeated voltage surges can easily reduce the lifespan of the controller's power input or signal ports, or even cause permanent damage, affecting the reliability and safety of the entire vehicle.

[0007] Therefore, it is necessary to provide a solution that can effectively suppress high-voltage surges and protect the controller interface circuit. Utility Model Content

[0008] In a first aspect, to solve the above-mentioned technical problems, this utility model provides a high-voltage suppression and protection circuit for a lithium-ion forklift controller, comprising: Operate the switch; Vehicle controller; and The high-voltage suppression module, located between the operating switch and the vehicle controller, includes an input filtering unit, a voltage detection and comparison unit, and an output voltage regulation unit connected in sequence, wherein: The voltage detection and comparison unit is connected to the input filtering unit and is used to compare the filtered power supply voltage with the reference voltage, and selectively guide the power supply signal to the transient voltage suppression branch or directly conduct the branch according to the comparison result to absorb surge energy. The output voltage regulator unit is connected to the output terminal of the voltage detection and comparison unit to regulate and filter the processed power signal, and output a stable rated voltage to the vehicle controller.

[0009] Furthermore, the voltage detection and comparison unit includes a comparator, a TVS diode, and a diode, wherein: The input terminals of the comparator are respectively connected to the reference voltage and the power supply voltage processed by the input filtering unit; The cathode of the TVS tube is connected to the output terminal of the input filter unit, and the anode is grounded, so as to absorb surges when the input voltage exceeds its clamping voltage. The anode of the diode is connected to the output terminal of the comparator, and the cathode is connected to the input terminal of the output voltage regulator unit, so that when the input voltage is higher than the reference voltage, the comparator controls the branch containing the TVS diode to work first.

[0010] Furthermore, the output voltage regulator unit includes an MCU, the input terminal of which is connected to the cathode of the diode for receiving a selected power signal, and the output terminal of the MCU is connected to the input terminal of the vehicle controller to output the vehicle's rated voltage.

[0011] Optionally, the MCU chip model is STM32F103C8T6.

[0012] Furthermore, the input filtering unit includes at least one filter capacitor and a current-limiting resistor.

[0013] Furthermore, the operating switch includes at least one of a key switch, a lifting switch, a tilting switch, a side-shifting switch, and an attachment switch.

[0014] Furthermore, the high-voltage suppression module is independently configured for each of the operating switches.

[0015] A second aspect of this utility model provides a forklift, including a vehicle controller, wherein the vehicle controller is provided with the high-voltage suppression protection circuit for the lithium battery forklift controller described above.

[0016] Compared with the prior art, the present invention has the following beneficial effects: This invention effectively suppresses overvoltage caused by various factors such as key switch transients, energy feedback, and load operation by setting a high-voltage suppression module, comprehensively protecting the logic power port and switching port of the controller, and improving the reliability and safety of the entire vehicle. Attached Figure Description

[0017] Figure 1 This is a circuit schematic diagram disclosed in an embodiment of the present utility model.

[0018] In the picture: 10. Operate the switch; 20. Vehicle controller; 30. High voltage suppression module; 31. Input filtering unit; 32. Voltage detection and comparison unit; 33. Output voltage regulation unit. Detailed Implementation

[0019] To make the technical solutions and effects of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments. Obviously, the described embodiments are some embodiments of this utility model, but not all embodiments.

[0020] The present invention aims to provide a high-voltage suppression and protection circuit for lithium-ion battery forklift controllers, solving the technical problems of easy damage and poor reliability of controller logic ports caused by instantaneous high voltage and feedback current in existing lithium-ion battery forklifts.

[0021] Please see Figure 1 The circuit mainly includes the operating switch 10 of the lithium battery forklift, the vehicle controller 20, and the high voltage suppression module 30 located between the operating switch 10 and the vehicle controller 20.

[0022] In this design, the operating switches 10 include key switches, lifting switches, tilt switches, side shift switches, and attachment switches. High-voltage suppression modules 30 are independently configured for each operating switch 10.

[0023] In a further embodiment, the high-voltage suppression module 30 includes an input filtering unit 31, a voltage detection and comparison unit 32, and an output voltage regulation unit 33 connected in sequence. The following is a brief description of these components.

[0024] First, the input filtering unit 31 will be described in detail.

[0025] The input filtering unit 31 includes at least one filter capacitor and one current-limiting resistor. The filter capacitor is connected in parallel between the input port and ground to absorb voltage spikes; the current-limiting resistor is connected in series in the main input circuit. The current-limiting resistor limits the instantaneous inrush current of the subsequent circuit; the filter capacitor absorbs voltage spikes from the operating switch and performs preliminary filtering, forming the first line of passive protection.

[0026] Next, the voltage detection and comparison unit 32 will be described in detail.

[0027] The input terminal of the voltage detection and comparison unit 32 is connected to the output terminal of the input filtering unit 31. It is used to compare the filtered power supply voltage with the reference voltage and selectively guide the power supply signal to the transient voltage suppression branch or the direct conduction branch according to the comparison result to absorb surge energy.

[0028] In this scheme, the voltage detection and comparison unit 32 includes a comparator, a TVS diode, and a diode, wherein: The input terminals of the comparator are connected to the reference voltage and the power supply voltage processed by the input filter unit 31, respectively.

[0029] The cathode of the TVS diode is connected to the output of the input filter unit 31, and the anode is grounded to absorb surges when the input voltage exceeds its clamping voltage. Specifically, when a transient high voltage is detected, i.e., the input voltage is greater than the reference voltage, the TVS diode will break down rapidly, absorbing the surge energy at nanosecond speeds and guiding it to the ground wire, clamping the voltage to a safe level.

[0030] The anode of the diode is connected to the output of the comparator, and the cathode is connected to the input of the output voltage regulator unit 33. This ensures that when the input voltage is higher than the reference voltage, the comparator controls the branch containing the TVS diode to operate preferentially. In other words, the diode acts as a path selection switch in the voltage detection and comparison unit 32. When the input voltage is normal, i.e., the input voltage is less than or equal to the reference voltage, the comparator control signal turns on the diode, and the voltage signal bypasses the TVS absorption circuit and is directly transmitted to the next stage, thereby eliminating unnecessary losses and ripple voltage effects.

[0031] Finally, the output voltage regulator unit 33 will be described in detail.

[0032] The output voltage regulator unit 33 is connected to the output terminal of the voltage detection and comparison unit 32 to regulate and filter the processed power signal, and output a stable rated voltage to the vehicle controller 20, regardless of the fluctuation of the front-end input voltage.

[0033] In this solution, the output voltage regulator unit 33 includes an MCU. The input terminal of the MCU is connected to the cathode of a diode to receive a selected power supply signal. The output terminal of the MCU is connected to the input terminal of the vehicle controller 20 to output the vehicle's rated voltage. Optionally, the MCU chip model is STM32F103C8T6.

[0034] This solution addresses instantaneous high voltage by employing a two-stage energy absorption path: the first stage uses the capacitor in the input filter unit 31 to absorb high-frequency spikes; the second stage uses a TVS diode to absorb large-amplitude surge energy. This hierarchical approach efficiently dissipates surge energy, preventing concentrated energy from impacting a single device. Simultaneously, a comparator monitors the voltage in real time to determine whether the current condition is normal or a high-voltage surge. Under normal conditions, the signal follows a low-loss direct path to ensure efficiency; under high-voltage surge conditions, the signal is forced through the TVS absorption path to ensure safety. This dynamic switching mechanism balances low power consumption and high reliability. Finally, an intelligent voltage regulator unit composed of an MCU actively adjusts the output voltage to a constant and precise value for the vehicle controller 20, regardless of voltage fluctuations, thus fundamentally preventing controller damage caused by excessive or unstable voltage.

[0035] It should be noted that this utility model also protects a lithium-ion forklift, which includes a vehicle controller and is equipped with the aforementioned high-voltage suppression protection circuit.

[0036] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high voltage suppression protection circuit for a lithium electric fork truck controller, comprising: include: Operation switch (10); Vehicle controller (20); as well as The high-voltage suppression module (30) located between the operating switch (10) and the vehicle controller (20) includes an input filtering unit (31), a voltage detection and comparison unit (32), and an output voltage regulator unit (33) connected in sequence, wherein: The voltage detection and comparison unit (32) is connected to the input filtering unit (31) and is used to compare the filtered power supply voltage with the reference voltage, and selectively guide the power supply signal to the transient voltage suppression branch or directly conduct the branch according to the comparison result to absorb surge energy. The output voltage regulator unit (33) is connected to the output terminal of the voltage detection and comparison unit (32) to regulate and filter the processed power signal and output a stable rated voltage to the vehicle controller (20).

2. The high-voltage suppression and protection circuit for a lithium-ion forklift controller according to claim 1, characterized in that, The voltage detection and comparison unit (32) includes a comparator, a TVS diode, and a diode, wherein: The input terminals of the comparator are respectively connected to the reference voltage and the power supply voltage processed by the input filtering unit (31); The cathode of the TVS tube is connected to the output terminal of the input filter unit (31), and the anode is grounded, so as to absorb surges when the input voltage exceeds its clamping voltage. The anode of the diode is connected to the output terminal of the comparator, and the cathode is connected to the input terminal of the output voltage regulator unit (33), so that when the input voltage is higher than the reference voltage, the comparator controls the branch where the TVS tube is located to work first.

3. The high-voltage suppression and protection circuit for a lithium-ion forklift controller according to claim 2, characterized in that, The output voltage regulator unit (33) includes an MCU, the input terminal of which is connected to the cathode of the diode for receiving a selected power signal, and the output terminal of which is connected to the input terminal of the vehicle controller (20) for outputting the vehicle's rated voltage.

4. The high-voltage suppression and protection circuit for a lithium-ion forklift controller according to claim 3, characterized in that, The MCU chip model is STM32F103C8T6.

5. The high-voltage suppression and protection circuit for a lithium-ion forklift controller according to claim 1, characterized in that, The input filtering unit (31) includes at least one filter capacitor and a current-limiting resistor.

6. The high-voltage suppression and protection circuit for a lithium-ion forklift controller according to claim 1, characterized in that, The operating switch (10) includes at least one of a key switch, a lifting switch, a tilting switch, a side-shifting switch, and an attachment switch.

7. The high-voltage suppression protection circuit for a lithium-ion battery forklift controller according to claim 1 or 6, characterized in that, The high voltage suppression module (30) is set independently for each of the operating switches (10).

8. A forklift, comprising a vehicle controller, characterized in that, The vehicle controller is equipped with a high-voltage suppression protection circuit for a lithium-ion forklift controller as described in any one of claims 1-7.

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