Single motor governor based on non-inductive FOC

Abstract

The utility model discloses a single electric governor based on non -inductive FOC, including circuit board and set up on its power input interface, voltage reducing module, main control chip, three -phase gate drive chip, three -phase inverter circuit and motor power output interface. Power input interface connects voltage reducing module, and voltage reducing module respectively supplies power for three -phase gate drive chip and main control chip, and the PWM output pin of main control chip is connected three -phase gate drive chip, and three -phase gate drive chip is connected by three -phase inverter circuit that six NMOS tubes are formed, and the output of three -phase inverter circuit is connected motor power output interface. Circuit board adopts four -layer board, and the copper skin of widened copper skin is laid to the heavy current wiring of three -phase inverter circuit, and sets up current sampling circuit and exports sampling signal to the ADC sampling pin of main control chip. The utility model discloses compact structure is favorable to improve current sampling accuracy, drive stability and current carrying capacity.

Description

Technical Field

[0001] This utility model relates to the field of motor drive and control technology, specifically a single-unit ESC based on sensorless FOC. Background Technology

[0002] Currently, multi-rotor drones and other model aircraft widely adopt brushless ESCs based on the six-step commutation method. This technology has become the mainstream solution due to its simple control algorithm and low implementation cost. However, square wave drive controls the motor through discrete commutation points, resulting in inherent technical defects: significant torque ripple during operation, causing fuselage vibration and considerable noise; non-sinusoidal current waveform leads to low energy efficiency and shortened flight time; and poor control linearity in the low-speed domain affects flight stability and control response speed.

[0003] To improve performance, field-oriented control (FOC) technology was introduced. FOC achieves precise decoupling control of motor torque and magnetic field through vector transformation, generating a smooth sinusoidal magnetic field, theoretically offering advantages such as high efficiency, low vibration, and stable operation. Sensorless FOC technology goes a step further, eliminating the need for physical position sensors and estimating rotor angles through algorithms, making it more suitable for size and cost-sensitive UAV applications. However, sensorless FOC algorithms place higher demands on the real-time processing capabilities, current sampling accuracy, and drive stability of the hardware circuitry.

[0004] In existing solutions, insufficient computing power of the hardware platform, inadequate sampling circuit precision, or low driving efficiency all limit the full potential of sensorless FOC performance, making it difficult to achieve the comprehensive advantages of square wave driving at the same cost. Therefore, there is an urgent need for a dedicated hardware circuit structure that is deeply optimized for sensorless FOC algorithms to address the challenges it faces in practical applications.

[0005] A search revealed a Chinese patent document disclosing a multi-rotor heavy-duty drone [Application No.: 202223474152.4, Publication No.: CN218986975U], which includes: the multi-rotor heavy-duty drone drive device comprising a drone, a control module, a drive module, a power module, a sensor module, and an image transmission module. Although this patent achieves the basic function of seamless FOC control for drones, the drive circuit of this invention has fewer peripheral components and a simpler layout, improving integration and reliability within a limited space. This is a specific hardware optimization structure not covered by the comparative patent. Utility Model Content

[0006] In view of the problems existing in the prior art, the purpose of this utility model is to provide a single-unit ESC based on sensorless FOC.

[0007] A single-unit ESC based on sensorless FOC, characterized in that it includes: a circuit board and a power input interface, a step-down module, a main control chip, a three-phase gate drive chip, a three-phase inverter circuit and a motor power output interface disposed thereon; The power input interface is connected to the input terminal of the step-down module; The first output terminal of the buck module is connected to the power supply pin of the three-phase gate driver chip, and the second output terminal of the buck module is connected to the power supply pin of the main control chip. The PWM output pin of the main control chip is connected to the input pin of the three-phase gate drive chip; The output pins of the three-phase gate drive chip are connected to the control electrodes of each power switch in the three-phase inverter circuit; The power supply terminal of the three-phase inverter circuit is connected to the power input interface, and its output terminal is connected to the motor power output interface. The three-phase inverter circuit described above consists of six NMOS transistors. Preferably, the circuit board is a four-layer board, and the high-current traces of the three-phase inverter circuit are covered with widened copper foil.

[0008] Through the above technical solutions, the circuit board's load-bearing capacity and current transmission reliability can be significantly improved. The adoption of a four-layer board structure not only effectively improves the circuit integration and optimizes electromagnetic compatibility performance, but also enables a compact arrangement of functional modules within a limited space. Furthermore, the use of widened copper foil for the high-current traces in the three-phase inverter circuit can significantly reduce trace impedance, improve current carrying capacity, and reduce heat generation and energy loss caused by high current, thereby enhancing the stability and safety of the drive motor.

[0009] Specifically, by using a wider copper foil design in the high-current trace areas of the three-phase inverter circuit, not only can current be effectively dispersed to prevent localized overheating and component damage, but it also helps reduce the overall circuit board temperature rise, improving system reliability and lifespan. Furthermore, the four-layer board structure optimizes the layout of the power and ground layers, providing ample return paths for high-speed and high-current signals, further enhancing the stability and anti-interference capabilities of control signals.

[0010] Preferably, the individual ESC also includes a current sampling circuit; the sampling circuit is connected in series between the three-phase half-bridge output and the three-phase lines of the brushless motor, and its output terminal is connected to the ADC sampling pin of the main control chip.

[0011] The above technical solution enables real-time and accurate detection of the motor's operating status. The current sampling circuit, connected in series between the three-phase inverter circuit and ground, accurately monitors the current flowing through the circuit during motor operation and directly transmits the collected signal to the ADC sampling pin of the main control chip. This provides current feedback information to the main control chip, facilitating closed-loop control and effectively improving the system's control over the motor's dynamic performance and safety.

[0012] Specifically, by connecting a current sampling circuit in series between the three-phase inverter circuit and ground, the current changes of each phase can be accurately collected. The sampled signal is amplified by a current sampling amplifier chip and then input to the ADC sampling pin of the main control chip, facilitating real-time recording and analysis of the motor's operating status by the intelligent control system. This design not only improves the sensitivity of the entire drive system but also provides fundamental data support for algorithms such as the sliding diaphragm observer + PLL rotor position detection and three-loop PID feedback control, achieving high-precision and fast-response sensorless FOC control.

[0013] Preferably, the current sampling circuit includes a sampling resistor connected in series and a current sampling amplifier chip; the input terminal of the current sampling amplifier chip is connected across the two ends of the sampling resistor.

[0014] The above technical solution enables high-precision detection and amplification of current signals. By connecting a sampling resistor in series in the current sampling circuit, the current in the motor circuit can be directly sampled. The input terminal of the current sampling amplification chip is connected across the sampling resistor, which amplifies the weak sampled voltage signal before output, significantly improving the signal resolution and reliability, and providing a high-quality data foundation for the subsequent acquisition and processing of the main control chip.

[0015] Specifically, the sampling resistor converts the passing current into a proportional voltage signal, and the current sampling amplifier chip amplifies this minute voltage signal with high precision before outputting it to the ADC sampling port of the main control chip. This design reduces the influence of external interference, improves the signal amplification accuracy and response speed, and ensures real-time and accurate monitoring of the motor drive current, thus providing reliable data for functional modules such as the sensorless FOC algorithm, current loop, and rotor position control.

[0016] Preferably, the individual ESC also includes a communication interface, whose signal pins are connected to the communication pins of the main control chip.

[0017] The above technical solution enables efficient and reliable communication between the individual ESC and external control equipment. By setting up an independent communication interface and connecting its signal pins to the communication pins of the main control chip, not only is the real-time performance and stability of data transmission guaranteed, but the system is also compatible with common devices such as flight controllers and receivers, thereby expanding the product's application range and intelligence level.

[0018] Specifically, the communication interface allows the main control chip to flexibly receive various control commands from external devices, while simultaneously transmitting the ESC's current operating status or feedback information to the host computer or remote control system in a timely manner. This design supports commonly used UAV control protocols such as Dshot600, facilitating easy integration with different types of flight control boards or receiving devices to achieve integrated intelligent control. The standardized communication interface and multi-protocol compatibility significantly improve the product's adaptability and portability.

[0019] Preferably, the step-down module includes a DC-DC step-down chip and an LDO chip connected in sequence; the output terminal of the DC-DC step-down chip is the first output terminal, the output terminal of the LDO chip is the second output terminal, and the output terminal of the LDO chip is also connected to a BEC output interface.

[0020] The above technical solution enables efficient and stable power supply to devices with different voltage requirements. By using a DC-DC step-down chip and an LDO chip connected sequentially in the step-down module, the high input voltage can be effectively converted into the required lower voltage. Furthermore, the LDO chip provides a high-precision, low-noise power output, meeting the power supply requirements of the main control chip, sensors, and other sensitive components. Simultaneously, the output terminal of the DC-DC step-down chip serves as the first output terminal, providing high-current, high-efficiency power to the load; while the output terminal of the LDO chip serves as the second output terminal, providing a stable, low-noise voltage to the parts of the system with high power quality requirements.

[0021] Specifically, the DC-DC step-down chip reduces the external input voltage to a lower operating voltage suitable for the system circuitry, ensuring efficient operation of the entire circuit board. The LDO chip further stabilizes the voltage and reduces noise, enhancing the stability and purity of the DC-DC output voltage, making it particularly suitable for powering components with stringent power quality requirements, such as the main controller and communication modules. Simultaneously, the LDO chip's output connects to a BEC output interface, enabling power supply to external devices like flight controllers and remote controllers without the need for additional batteries, thus improving system integration and ease of use.

[0022] Preferably, in the three-phase inverter circuit, every two NMOS transistors are connected in series to form a bridge arm, and the three bridge arms are connected in parallel to form a three-phase full-bridge circuit. The midpoint of the connection between the two NMOS transistors in each bridge arm serves as a phase output terminal of the three-phase inverter circuit.

[0023] The above technical solution enables efficient three-phase drive control of the motor. The design of using two NMOS transistors connected in series to form a bridge arm, and then connecting the three bridge arms in parallel to form a three-phase full-bridge structure, improves current carrying capacity and switching efficiency. Connecting the midpoint of the two NMOS transistors in each bridge arm serves as the output terminal for the corresponding phase, allowing precise control of the three-phase current switching and meeting the high requirements of motor operation for the drive waveform.

[0024] Specifically, the three-phase full-bridge circuit structure, through a reasonable bridge arm layout, allows the main control chip to perform PWM control on each NMOS transistor independently, achieving independent drive of the three-phase windings of the motor. This design effectively reduces drive losses, improves inverter efficiency, and is compatible with advanced control algorithms such as FOC, enabling low-noise, low-power, and high-response operation of the motor. As switching devices, NMOS transistors have advantages such as low on-resistance and fast switching speed, better able to withstand high current surges in applications such as drones and high-speed electric equipment, ensuring system stability and reliability.

[0025] Compared with the prior art, the present invention has the following advantages: 1. This utility model, through its specific hardware structure, helps improve the smoothness and reliability of the UAV's power system. Specifically, by employing a sensorless FOC control algorithm combined with a high-performance microcontroller and a precise current sampling circuit, it can achieve smooth control of the motor torque, thereby reducing torque ripple caused by traditional square wave drive methods. This smooth drive characteristic helps reduce fuselage vibration, which may not only improve flight stability and the quality of aerial footage, but also create a gentler working environment for the motor itself, thus having a positive impact on extending the motor's service life.

[0026] 2. The power module of this utility model adopts a structure of synchronous rectification buck chip and low dropout linear regulator cascaded together, which aims to reduce internal power consumption. At the same time, the four-layer circuit board design and the widened copper layout on the key power path enhance heat dissipation and overcurrent capacity. This integrated and robust physical design enables the ESC to maintain a small size while helping to improve overall energy efficiency. This is a valuable feature for drone applications that are sensitive to endurance, and it also makes it easy to integrate into other devices that require compact drive solutions. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the DC-DC step-down circuit in this utility model; Figure 2 This is a schematic diagram of the driving bridge circuit and gate driving chip circuit in this utility model; Figure 3 This is a schematic diagram of the current sampling circuit in this utility model; Figure 4This is a schematic diagram of the 3D simulation of the structure of this utility model. Detailed Implementation

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0029] Please see Figures 1 to 4 This utility model provides a technical solution: A single-unit ESC based on sensorless FOC, characterized in that it includes: a circuit board and a power input interface, a step-down module, a main control chip, a three-phase gate drive chip, a three-phase inverter circuit and a motor power output interface disposed thereon; The power input interface is connected to the input terminal of the step-down module; The first output terminal of the buck module is connected to the power supply pin of the three-phase gate driver chip, and the second output terminal of the buck module is connected to the power supply pin of the main control chip. The PWM output pin of the main control chip is connected to the input pin of the three-phase gate drive chip; The output pins of the three-phase gate drive chip are connected to the control electrodes of each power switch in the three-phase inverter circuit; The power supply terminal of the three-phase inverter circuit is connected to the power input interface, and its output terminal is connected to the motor power output interface. The three-phase inverter circuit described above consists of six NMOS transistors. Specifically, the circuit board is a four-layer board, and the high-current traces of the three-phase inverter circuit are covered with widened copper foil, which significantly improves the circuit board's load-bearing capacity and the reliability of current transmission. The four-layer board structure not only effectively improves circuit integration and optimizes electromagnetic compatibility performance, but also allows for a compact arrangement of functional modules within a limited space. Furthermore, the widened copper foil used for the high-current traces of the three-phase inverter circuit significantly reduces trace impedance, increases current carrying capacity, and reduces heat generation and energy loss caused by high current, thereby enhancing the stability and safety of the drive motor.

[0030] Specifically, by using a wider copper foil design in the high-current trace areas of the three-phase inverter circuit, not only can current be effectively dispersed to prevent localized overheating and component damage, but it also helps reduce the overall circuit board temperature rise, improving system reliability and lifespan. Furthermore, the four-layer board structure optimizes the layout of the power and ground layers, providing ample return paths for high-speed and high-current signals, further enhancing the stability and anti-interference capabilities of control signals.

[0031] In practical applications, this structure and process design better meet the demands of drones and other applications for miniaturized, highly reliable, and high-current-carrying ESC modules. It ensures stable current transmission and good thermal management during motor drive, providing strong support for equipment operation under long-term, complex conditions. This design is of great significance for improving the performance of drone ESCs and related application products.

[0032] Specifically, the individual ESC also includes a current sampling circuit. This sampling circuit is connected in series between the three-phase half-bridge output and the three-phase lines of the brushless motor. Its output is connected to the ADC sampling pin of the main control chip, enabling real-time and accurate detection of the motor's operating status. The current sampling circuit is also connected in series between the three-phase inverter circuit and ground, allowing for precise monitoring of the current flowing through the circuit during motor operation and directly transmitting the collected signal to the ADC sampling pin of the main control chip. This provides current feedback information to the main control chip, enabling closed-loop control and effectively improving the system's control over the motor's dynamic performance and safety.

[0033] Specifically, by connecting a current sampling circuit in series between the three-phase inverter circuit and ground, the current changes of each phase can be accurately collected. The sampled signal is amplified by a current sampling amplifier chip and then input to the ADC sampling pin of the main control chip, facilitating real-time recording and analysis of the motor's operating status by the intelligent control system. This design not only improves the sensitivity of the entire drive system but also provides fundamental data support for algorithms such as the sliding diaphragm observer + PLL rotor position detection and three-loop PID feedback control, achieving high-precision and fast-response sensorless FOC control.

[0034] In practical applications, using the STM32G431 as the main control chip, combined with a current sampling circuit and the INA240A1PWR current amplifier chip, can better adapt to high-speed motor drive applications such as drones. The system can accurately sense current changes and achieve closed-loop control of motor operation, which not only improves the control accuracy and response speed of the ESC but also enhances operational safety and intelligent performance, effectively ensuring the stable operation of drones and other equipment under long-term, complex operating conditions. This current sampling design is of great significance for improving the performance and reliability of drone drive systems.

[0035] Specifically, the current sampling circuit includes a series sampling resistor and a current sampling amplifier chip. The input terminal of the current sampling amplifier chip uses a Kelvin connection, which greatly improves accuracy. Connected across the sampling resistor, it enables high-precision detection and amplification of the current signal. By connecting the sampling resistor in series in the current sampling circuit, the current in the motor circuit can be directly sampled. The input terminal of the current sampling amplifier chip, connected across the sampling resistor, amplifies the weak sampled voltage signal before output, significantly improving signal resolution and reliability, and providing a high-quality data foundation for subsequent acquisition and processing by the main control chip.

[0036] Specifically, the sampling resistor converts the passing current into a proportional voltage signal, and the current sampling amplifier chip amplifies this minute voltage signal with high precision before outputting it to the ADC sampling port of the main control chip. This design reduces the influence of external interference, improves the signal amplification accuracy and response speed, and ensures real-time and accurate monitoring of the motor drive current, thus providing reliable data for functional modules such as the sensorless FOC algorithm, current loop, and rotor position control.

[0037] In practical applications, this current sensing scheme, combining a sampling resistor with a high-performance amplifier chip, can meet the requirements of high sensitivity and high stability in high-speed applications such as drones, effectively improving the feedback control accuracy and overall operating efficiency of the ESC system. This current sampling circuit design is of significant engineering importance for ensuring the long-term, efficient, and reliable operation of drones and other application devices.

[0038] Specifically, the individual ESC also includes a communication interface, whose signal pins are connected to the communication pins of the main control chip, enabling efficient and reliable communication between the individual ESC and external control devices. By setting up an independent communication interface and connecting its signal pins to the communication pins of the main control chip, not only is the real-time performance and stability of data transmission guaranteed, but the system is also compatible with common devices such as flight controllers and receivers, thereby expanding the product's application range and intelligence level.

[0039] Specifically, the communication interface allows the main control chip to flexibly receive various control commands from external devices, while simultaneously transmitting the ESC's current operating status or feedback information to the host computer or remote control system in a timely manner. This design supports commonly used UAV control protocols such as Dshot600, facilitating easy integration with different types of flight control boards or receiving devices to achieve integrated intelligent control. The standardized communication interface and multi-protocol compatibility significantly improve the product's adaptability and portability.

[0040] In practical applications, by setting up an independent communication interface and effectively connecting it to the main control chip, the high-speed, low-latency communication requirements of multi-rotor drones, electric model aircraft, and other scenarios can be met, ensuring precise and efficient motor control of the aircraft under various complex operating conditions. Furthermore, this solution can be extended to fixed-wing aircraft, model boats, and fans requiring intelligent electronic speed control, further enhancing the system integration and market application value of the product. This communication interface design is of great significance for improving the data interaction capabilities and intelligence level of devices such as drones.

[0041] Specifically, the step-down module includes DC-DC step-down chips connected in sequence. The output terminal of the DC-DC step-down chip is the first output terminal, and the BEC interface is located at the first output terminal of the DC-DC step-down chip, enabling efficient and stable power supply to devices with different voltage requirements. Through the DC-DC step-down chips connected in sequence in the step-down module, the input high voltage can be effectively converted into the required lower voltage, further meeting the power supply requirements of the main control chip, sensors, and other sensitive components. Simultaneously, the output terminal of the DC-DC step-down chip, as the first output terminal, can provide high-current, high-efficiency electrical energy to the load. Specifically, the DC-DC step-down chip is responsible for reducing the external input voltage to a lower operating voltage suitable for the system circuitry, ensuring efficient operation of the entire circuit board. It also boosts the DC-DC output voltage to higher stability and purity, making it particularly suitable for powering components with stringent power quality requirements, such as the main control processor and communication modules. Simultaneously, the DC-DC chip's output also connects to a BEC output interface, enabling power supply to external devices such as flight controllers and receivers without the need for additional batteries, thus improving system integration and ease of use.

[0042] In practical applications, this buck module design meets the multi-channel power supply requirements of highly integrated electronic devices such as drones, achieving separate supply of high-efficiency, high-current and high-precision, low-noise power supplies, ensuring the stability and safety of the entire ESC system. Whether powering the STM32G431 main control chip on the ESC (specifically, the amplification chip of the sampling circuit in the sensor; the ESC itself does not have a communication module), or powering the flight control board and external expansion devices, it ensures power quality and reliable system operation. This buck module design is of great significance for improving the overall performance and market application value of ESC products.

[0043] Specifically, in the three-phase inverter circuit, every two NMOS transistors are connected in series to form a bridge arm, and the three bridge arms are connected in parallel to form a three-phase half-bridge circuit. The midpoint of the connection between the two NMOS transistors in each bridge arm serves as one phase output terminal of the three-phase inverter circuit, enabling efficient three-phase drive control of the motor. The design of using every two NMOS transistors in series to form a bridge arm and connecting the three bridge arms in parallel to form a three-phase half-bridge structure is beneficial for improving current carrying capacity and switching efficiency. The midpoint of the connection between the two NMOS transistors in each bridge arm serves as the output terminal of the corresponding phase, enabling precise control of the three-phase current switching and meeting the high requirements of motor operation for the drive waveform.

[0044] Specifically, the three-phase full-bridge circuit structure, through a reasonable bridge arm layout, allows the main control chip to drive the three half-bridge circuits separately via the control gate driver chip. This design effectively reduces drive losses, improves inverter efficiency, and is compatible with advanced control algorithms such as FOC, enabling low-noise, low-power, and high-response motor operation. NMOS transistors, as switching devices, have advantages such as low on-resistance and fast switching speed, better able to withstand high current surges in applications such as drones and high-speed electric equipment, ensuring system stability and reliability.

[0045] In practical applications, the three-phase half-bridge circuit enables precise three-phase inverter drive of brushless motors and is widely used in high-speed control fields such as drones, electric model aircraft, and intelligent fans. This structure not only helps improve the overall efficiency and stability of the ESC system but also facilitates the application of high-speed main control chips and matching driver chips to achieve real-time feedback and intelligent adjustment of complex motion characteristics. Optimized design of the three-phase inverter circuit is of great significance for improving the reliability and response speed of the motor drive system under long-term, high-speed, and complex operating conditions.

[0046] In practical applications, the symmetrical layout of the two power drive units is particularly crucial for the synchronous control of dual brushless motors in scenarios such as drones, robots, and gimbals. This facilitates the balance of left-right or front-back motor movements, improving the system's control accuracy and reliability. This technical solution is of great significance for enhancing the integration, performance stability, and industrial applicability of multi-purpose dual brushless motor drive boards.

[0047] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0048] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0049] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A single-cell electronic speed controller based on sensorless FOC, characterized in that, include: The circuit board and the power input interface, step-down module, main control chip, three-phase gate drive chip, three-phase inverter circuit and motor power output interface mounted on it; The power input interface is connected to the input terminal of the step-down module; The first output terminal of the buck module is connected to the power supply pin of the three-phase gate driver chip, and the second output terminal of the buck module is connected to the power supply pin of the main control chip. The PWM output pin of the main control chip is connected to the input pin of the three-phase gate drive chip; The output pins of the three-phase gate drive chip are connected to the control electrodes of each power switch in the three-phase inverter circuit; The power supply terminal of the three-phase inverter circuit is connected to the power input interface, and its output terminal is connected to the motor power output interface. The three-phase inverter circuit consists of six NMOS transistors.

2. The single-unit ESC according to claim 1, characterized in that, The circuit board is a four-layer board, and the high-current traces of the three-phase inverter circuit are covered with widened copper foil.

3. The single-unit ESC according to claim 1, characterized in that, The individual ESC also includes a current sampling circuit; the sampling circuit is connected in series between the three-phase half-bridge output and the three-phase lines of the brushless motor, and its output is connected to the ADC sampling pin of the main control chip.

4. The single-unit ESC according to claim 3, characterized in that, The current sampling circuit includes a sampling resistor connected in series and a current sampling amplifier chip; the input terminal of the current sampling amplifier chip is connected across the two ends of the sampling resistor.

5. The single-unit ESC according to claim 1, characterized in that, The individual ESC also includes a communication interface, whose signal pins are connected to the communication pins of the main control chip.

6. The single-unit ESC according to claim 1, characterized in that, The step-down module includes a DC-DC step-down chip and an LDO chip connected in sequence; the output terminal of the DC-DC step-down chip is the first output terminal, the output terminal of the LDO chip is the second output terminal, and the output terminal of the LDO chip is also connected to a BEC output interface.

7. The single-unit ESC according to claim 1, characterized in that, In the aforementioned three-phase inverter circuit, each pair of NMOS transistors connected in series forms a bridge arm, and the three bridge arms are connected in parallel to form a three-phase full-bridge circuit. The midpoint of the connection between the two NMOS transistors in each bridge arm serves as a phase output terminal of the three-phase inverter circuit.

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