A fuel pump motor speed control system

Abstract

This invention discloses a fuel pump motor speed control system, including a fuel pump motor and a drive module. The fuel pump motor controller acquires the target speed of the fuel pump motor body and outputs a drive pulse signal to the drive module based on the target speed. The drive module converts the drive pulse signal into a drive voltage signal when the drive pulse signal is high-level and sends the drive voltage signal to the fuel pump motor body to enable its operation. The fuel pump motor controller also receives the speed of the fuel pump motor body while it is operating, and adjusts the duty cycle of the drive pulse signal sent to the drive module when the speed is outside a preset motor speed range of the target speed, based on the speed and the target speed, to ensure that the speed of the fuel pump motor body is within the preset motor speed range of the target speed. Using this system, accurate control of the fuel pump motor body speed is achieved.

Description

Technical Field

[0001] This invention relates to the technical field of aircraft engines, and more particularly to a fuel pump motor speed control system. Background Technology

[0002] In recent years, multi-electric / hybrid aero-engine technology has sparked a research boom internationally, with researchers conducting studies on its key components to varying degrees. The aero-engine fuel pump motor control system, with the electric fuel pump motor as its core architecture, is one of the key components in the development of multi-electric / hybrid engines and is considered by the industry as a major revolution in aero-engine fuel pump motor control systems. The aero-engine fuel pump motor controller is an important component of an aero-engine; it is responsible for controlling the operating state of the fuel pump to ensure the engine receives the appropriate amount of fuel. The fuel pump motor is typically installed inside the fuel tank and is responsible for delivering fuel from the tank to the engine; the control of the fuel quantity needs to be determined based on the rotational speed of the fuel pump motor.

[0003] Existing methods for controlling the speed of fuel pump motors typically utilize software control. This involves acquiring relevant parameters of the fuel pump, and the controller processes these parameters to control the motor speed. However, this approach requires extensive code design and timely updates to achieve speed control, resulting in complex logic, high manpower costs, slow operation, and poor reliability. Summary of the Invention

[0004] This invention provides a fuel pump motor speed control system that utilizes a pure hardware structure to achieve precise control of the fuel pump motor speed. It requires no software code, is simple to design, has a simple control method, and is highly reliable.

[0005] This invention provides a fuel pump motor speed control system, including a fuel pump motor and a drive module;

[0006] The fuel pump motor includes a fuel pump motor controller and a fuel pump motor body; the fuel pump motor controller is electrically connected to both the fuel pump motor body and the drive module, and the drive module is electrically connected to the fuel pump motor body.

[0007] The fuel pump motor controller is used to obtain the target speed of the fuel pump motor body and output drive pulse signals to the drive module according to the target speed;

[0008] The drive module is used to convert the drive pulse signal into a drive voltage signal when the drive pulse signal is high, and send the drive voltage signal to the fuel pump motor body to make the fuel pump motor body work.

[0009] The fuel pump motor controller is also used to receive the rotational speed of the fuel pump motor body when the fuel pump motor body is working, and adjust the duty cycle of the drive pulse signal sent to the drive module according to the rotational speed and the target rotational speed, when the rotational speed is outside the preset motor speed range of the target rotational speed, so that the rotational speed of the fuel pump motor body is within the preset motor speed range of the target rotational speed.

[0010] Optionally, the system may also include a power module;

[0011] The power module is electrically connected to the fuel pump motor controller, the fuel pump motor body, and the drive module, respectively.

[0012] The power module is used to convert the unstable input DC control voltage into a stable DC output voltage to power the fuel pump motor controller and drive module.

[0013] Optionally, the driving voltage signal is a DC driving voltage signal, and the system also includes a three-phase inverter circuit;

[0014] The three-phase inverter circuit is electrically connected between the drive module and the fuel pump motor body;

[0015] The three-phase inverter circuit is used to convert the DC drive voltage signal into an AC drive voltage signal so that the fuel pump motor body can work.

[0016] Optionally, the system may also include a current sampling circuit;

[0017] The current sampling circuit is electrically connected between the three-phase inverter circuit and the fuel pump motor controller; the current sampling circuit is used to collect the output current of the three-phase inverter circuit and amplify the output current before inputting it to the fuel pump motor controller.

[0018] The fuel pump motor controller is also used to receive the output current and, based on the output current and a preset current threshold, control the drive pulse signal to output a low level when the output current is greater than or equal to the preset current threshold.

[0019] Optionally, the current sampling circuit includes a first resistor, a differential amplifier, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a first capacitor, and a second capacitor;

[0020] The first resistor is electrically connected between the current output terminal and the ground terminal of the three-phase inverter circuit, and is connected in series between the second and third resistors; the other end of the second resistor is electrically connected to the positive input terminal of the differential amplifier, and the other end of the third resistor is electrically connected to the negative input terminal of the differential amplifier; the first capacitor is connected in parallel between the positive and negative input terminals of the differential amplifier; the output terminal of the differential amplifier is electrically connected to one end of the sixth resistor, and the other end of the sixth resistor is electrically connected to the fourth and seventh resistors respectively; one end of the fifth resistor is electrically connected to the other end of the seventh resistor, and the other end of the seventh resistor is grounded; the other ends of the fourth and fifth resistors are both electrically connected to the fuel pump motor controller, and the second capacitor is connected in parallel between the other ends of the fifth resistor.

[0021] Optionally, the system also includes a target speed protection module;

[0022] The target speed protection module is electrically connected to the fuel pump motor controller;

[0023] The target speed protection module is used to control the target speed protection module to output a high-level soft start signal and input it to the fuel pump motor controller when the target speed is greater than the preset target speed, based on the target speed and in combination with the preset target speed.

[0024] The fuel pump motor controller is also used to output a high-level drive pulse signal after receiving a high-level soft-start signal.

[0025] Optionally, the system may also include a target speed input circuit;

[0026] The target speed input circuit is electrically connected to the fuel pump motor controller;

[0027] The fuel pump motor controller obtains the target speed of the fuel pump motor body through the target speed input circuit.

[0028] Optionally, the fuel pump motor controller includes a brushless DC motor control chip.

[0029] Optionally, the system may also include a signal processing module and a speed control circuit;

[0030] The signal processing module is electrically connected between the fuel pump motor body and the fuel pump motor controller; the speed control circuit is electrically connected to the fuel pump motor controller.

[0031] The signal processing module is used to acquire the three-phase Hall signal of the fuel pump motor body when the fuel pump motor body is working, and to perform a second level flip of the three-phase Hall signal to convert it into a three-phase pulse signal and send it to the fuel pump motor controller.

[0032] The fuel pump motor controller is also used to output the speed frequency signal of the fuel pump motor body based on the three-phase pulse signal;

[0033] The speed control circuit is used to convert the speed frequency signal into a speed signal and send it to the fuel pump motor controller so that the fuel pump motor controller can receive the speed of the fuel pump motor body.

[0034] Optionally, the speed control circuit includes an eighth resistor, a ninth resistor, a tenth resistor, an operational amplifier, a third capacitor, and a fourth capacitor;

[0035] The eighth resistor and the third capacitor are connected in series between the speed output terminal and the ground terminal of the brushless DC motor control chip; the series connection point of the eighth resistor and the third capacitor is connected between the speed input terminal of the brushless DC motor control chip and the positive input terminal of the operational amplifier, respectively; the negative input terminal and the output terminal of the operational amplifier are electrically connected; the ninth resistor is electrically connected between the output terminal of the operational amplifier and the reverse speed input terminal of the brushless DC motor control chip; the tenth resistor and the fourth capacitor are connected in series between the reverse speed input terminal and the error output terminal of the brushless DC motor control chip.

[0036] The technical solution of this invention involves electrically connecting a fuel pump motor controller to both the fuel pump motor body and a drive module, with the drive module also electrically connected to the fuel pump motor body. This allows the fuel pump motor controller to acquire the target rotational speed of the fuel pump motor body and output a drive pulse signal to the drive module based on the target speed. When the drive pulse signal is high, the drive module converts it into a drive voltage signal and sends it to the fuel pump motor body to activate it. While the fuel pump motor body is operating, the fuel pump motor controller receives the rotational speed of the fuel pump motor body and, if the speed is outside the preset range of the target speed, adjusts the duty cycle of the drive pulse signal sent to the drive module to bring the rotational speed of the fuel pump motor body within the preset range of the target speed. Using this system, precise control of the fuel pump motor speed is achieved through a purely hardware structure, thereby realizing precise control of the aero-engine speed. This eliminates the need for software coding, resulting in a simple design, straightforward control method, and high reliability.

[0037] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 This is a schematic diagram of a fuel pump motor speed control system provided in an embodiment of the present invention;

[0040] Figure 2 A circuit diagram of a power module provided for an embodiment of the present invention;

[0041] Figure 3 This is a schematic diagram of the structure of a second fuel pump motor speed control system provided in an embodiment of the present invention;

[0042] Figure 4 A circuit diagram of a brushless DC motor control chip and some peripheral circuits provided for an embodiment of the present invention;

[0043] Figure 5 A circuit diagram of a driving module provided in an embodiment of the present invention;

[0044] Figure 6 A circuit diagram of a three-phase inverter circuit provided for an embodiment of the present invention;

[0045] Figure 7 A circuit diagram of a current sampling circuit provided in an embodiment of the present invention;

[0046] Figure 8 A circuit diagram of a target speed protection module provided in an embodiment of the present invention;

[0047] Figure 9 This is a circuit diagram of a signal processing module provided in an embodiment of the present invention. Detailed Implementation

[0048] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. 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 should fall within the scope of protection of the present invention.

[0049] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0050] In one embodiment, Figure 1 This is a schematic diagram of a fuel pump motor speed control system provided in an embodiment of the present invention. This embodiment is applicable to situations where the speed of the fuel pump body in an aero-engine system is accurately controlled within a preset speed range of the target speed using hardware structures, such as... Figure 1 As shown, the system includes: a fuel pump motor 1 and a drive module 2; the fuel pump motor 1 includes a fuel pump motor controller 11 and a fuel pump motor body 12; the fuel pump motor controller 11 is electrically connected to the fuel pump motor body 12 and the drive module 2 respectively, and the drive module 2 is electrically connected to the fuel pump motor body 12; the fuel pump motor controller 11 is used to obtain the target speed of the fuel pump motor body 12, and output a drive pulse signal to the drive module 2 according to the target speed; the drive module 2 is used to convert the drive pulse signal into a drive voltage signal when the drive pulse signal is high level, and send the drive voltage signal to the fuel pump motor body 12 to make the fuel pump motor body 12 work; the fuel pump motor controller 11 is also used to receive the speed of the fuel pump motor body 12 when the fuel pump motor body 12 is working, and adjust the duty cycle of the drive pulse signal sent to the drive module 2 according to the speed and the target speed, when the speed is outside the preset motor speed range of the target speed, so that the speed of the fuel pump motor body 12 is within the preset motor speed range of the target speed.

[0051] The fuel pump motor controller 11 is the core control system of the fuel pump motor. It is used to acquire the target speed and actual speed of the fuel pump motor body 12, and adjust the duty cycle of the output drive pulse signal according to the target speed and actual speed to ensure that the speed of the fuel pump motor body 12 is within the preset motor speed range of the target speed. In this embodiment, the fuel pump motor controller 11 is a brushless DC motor control chip, model DCD7501. The fuel pump motor body 12 is a structure that delivers fuel from the fuel tank to the combustion chamber to provide power to the aircraft engine. The drive module 2 is used to output a drive voltage signal to drive the fuel pump motor body 12 to work and generate a certain speed.

[0052] Specifically, when controlling the speed of the fuel pump motor body 12, the fuel pump motor controller 11 is electrically connected to both the fuel pump motor body 12 and the drive module 2. The drive module 2 is also electrically connected to the fuel pump motor body 12. This allows the fuel pump motor controller 11 to obtain the target speed of the fuel pump motor body 12. The target speed of the fuel pump motor body 12 can be determined by the engine controller based on relevant engine parameters; essentially, it is a target speed voltage value. After obtaining the target speed, the fuel pump motor controller 11 outputs a drive pulse signal to the drive module 2. Upon receiving the drive pulse signal, the drive module 2 checks whether the output drive pulse signal is a high-level or low-level signal. When the drive pulse signal is low, the drive module 2 stops working and cannot output a drive voltage signal to the fuel pump motor body 12 to drive it. At this time, the fuel pump motor body 12 does not work and there is no speed output. Only when the drive pulse signal is high-level will the drive module 2 convert the high-level drive pulse signal into a drive voltage signal and send it to the fuel pump motor body 12. After receiving the drive voltage signal, the fuel pump motor body 12 starts to work and generates a certain speed. The fuel pump motor controller 11 will obtain the speed generated by the fuel pump motor body 12 during operation and compare the speed with the target speed. When the speed is within the preset motor speed range of the target speed, it indicates that the speed control of the fuel pump motor body 12 has been achieved and the preset speed requirement has been met. In this case, the fuel pump motor body 12 will continue to work under the drive pulse signal. When the speed is not within the preset motor speed range of the target speed, such as when the speed is higher or lower than the preset motor speed range of the target speed, it indicates that the speed of the fuel pump motor body 12 is too high or too low. Continuing to work with this drive pulse signal may result in too much or too little fuel being delivered to the aircraft engine, causing the aircraft engine speed to be too fast or too slow, which will have a certain impact on the performance of the aircraft engine. At this time, the fuel pump motor controller 11 adjusts the duty cycle of the drive pulse signal output to the drive module 2 and obtains the adjusted rotational speed of the fuel pump motor body 12. It determines whether the rotational speed of the fuel pump motor body 12 is adjusted to within the preset motor speed range of the target speed. If the adjusted speed is within the preset motor speed range of the target speed, the adjustment is complete, and the adjusted drive pulse signal is sent to the drive module 2. If the adjusted speed is still not within the preset motor speed range of the target speed, the duty cycle of the drive pulse signal is adjusted again until the speed is within the preset motor speed range of the target speed. Then the adjustment is complete, and the finally adjusted drive pulse signal is sent to the drive module 2. In this embodiment, the preset motor speed range can be 1%, achieving precise control of the rotational speed of the fuel pump motor body 12.

[0053] Furthermore, after the speed adjustment of the fuel pump motor body 12 is completed, the fuel quantity can be controlled by the speed of the fuel pump motor body 12. This allows for control of the aircraft engine speed based on the fuel quantity, ensuring the aircraft engine speed remains within a preset range. In this embodiment, the preset engine speed range can be 0.5%, achieving precise control of the aircraft engine speed.

[0054] The technical solution of this invention involves electrically connecting a fuel pump motor controller to both the fuel pump motor body and a drive module, with the drive module also electrically connected to the fuel pump motor body. This allows the fuel pump motor controller to acquire the target rotational speed of the fuel pump motor body and output a drive pulse signal to the drive module based on the target speed. When the drive pulse signal is high, the drive module converts it into a drive voltage signal and sends it to the fuel pump motor body to activate it. While the fuel pump motor body is operating, the fuel pump motor controller receives the rotational speed of the fuel pump motor body and, if the speed is outside the preset range of the target speed, adjusts the duty cycle of the drive pulse signal sent to the drive module to bring the rotational speed of the fuel pump motor body within the preset range of the target speed. Using this system, precise control of the fuel pump motor speed is achieved through a purely hardware structure, thereby realizing precise control of the aero-engine speed. This eliminates the need for software code, resulting in a simple design, straightforward control method, and high reliability.

[0055] In another alternative embodiment, Figure 2 This is a circuit diagram of a power module provided in an embodiment of the present invention. Figure 3 This is a schematic diagram of the structure of the second fuel pump motor speed control system provided in an embodiment of the present invention, with reference to... Figure 2 and Figure 3 As shown, optionally, the system also includes a power supply module 3; the power supply module 3 is electrically connected to the fuel pump motor controller 11, the fuel pump motor body 12 and the drive module 2 respectively; the power supply module 3 is used to convert the input unstable DC control voltage into a stable DC output voltage to power the fuel pump motor controller 11 and the drive module 2.

[0056] The power module 3 supplies power to the fuel pump motor controller 11 and the drive module 2, enabling the fuel pump motor controller 11, the fuel pump motor body 12, and the drive module 2 to operate. (Reference) Figure 2 Inductors L1 and L2 are both filter inductors, capacitors C1-C8 and C10-C12 are both filter capacitors, resistors R1-R7 are both voltage divider resistors, U1 is a step-down chip with model number XC8821FCC, and U2 is a three-terminal regulator with model number LM7805.

[0057] For details, please refer to Figure 2 The input is an unstable 28V DC voltage. After passing through the filter inductor L1, the DC voltage enters the step-down chip U1 for step-down processing and outputs the stepped-down DC voltage. The output stepped-down DC voltage is filtered by the filter inductor L2, filter capacitor C10, and filter capacitor C11 to become a stable 12V DC voltage and is then output. A portion of the stable 12V DC voltage is converted into a 5V DC voltage by the three-terminal regulator U2. The 12V DC voltage and 5V DC voltage generated after step-down are used to provide auxiliary power to the fuel pump motor controller 11 and drive module 2 to enable the fuel pump motor controller 11 and drive module 2 to work normally.

[0058] Optionally, the fuel pump motor controller 11 includes a brushless DC motor control chip U5. Figure 4 This is a circuit diagram of a brushless DC motor control chip and some of its peripheral circuits provided in an embodiment of the present invention. Figure 5 This is a circuit diagram of a driving module provided in an embodiment of the present invention, with reference to... Figure 4 and Figure 5 As shown, the three-phase drive chips U3, U6, and U7 are all IR2110. Capacitors C14, C26, and C35 are bootstrap capacitors. Diodes D3, D6, and D10 are bootstrap diodes. Capacitors C17, C13, C22, C28, C33, and C40 are filter capacitors. The remaining resistors are voltage divider resistors. The input terminal of drive chip U3 is the drive pulse signal output from the fuel pump motor controller 11, namely PUA, PUB, PUC, PDA, PDB, and PDC. The drive pulse signals PUA, PUB, and PUC of the lower half-bridge are input to the low-end drive pulse signal input terminal LIN of drive module 2, and the drive pulse signals PDA, PDB, and PDC of the upper half-bridge are input to the high-end drive pulse signal input terminal HIN of drive module 2. After processing by the drive chip, a floating three-phase drive voltage signal is output to send the three-phase drive voltage signal to the fuel pump motor body 12, so that the fuel pump motor body 12 works.

[0059] Optional, Figure 6 This is a circuit diagram of a three-phase inverter circuit provided in an embodiment of the present invention, with reference to... Figure 3 and Figure 6 As shown, the drive voltage signal is a DC drive voltage signal, and the system also includes a three-phase inverter circuit 4; the three-phase inverter circuit 4 is electrically connected between the drive module 2 and the fuel pump motor body 12; the three-phase inverter circuit 4 is used to convert the DC drive voltage signal into an AC drive voltage signal so that the fuel pump motor body 12 can work.

[0060] Among them, reference Figure 6 The on-resistance of MOSFETs Q8 and Q9 connected in parallel is 1.2mΩ. Similarly, the on-resistance of MOSFETs Q10-Q19 is also 1.2mΩ. Resistors R49-R51, R54-R56, and R60-R65 are all voltage divider resistors.

[0061] Specifically, the three-phase inverter circuit 4 is used to convert the DC drive voltage signal output by the drive module 2 into an AC drive voltage signal, and send the AC drive voltage signal to the fuel pump motor body 12 so that the fuel pump motor body 12 can work.

[0062] Optional, Figure 7 This is a circuit diagram of a current sampling circuit provided in an embodiment of the present invention, with reference to... Figure 3 and Figure 7 As shown, the system also includes a current sampling circuit 5; the current sampling circuit 5 is electrically connected between the three-phase inverter circuit 4 and the fuel pump motor controller 11; the current sampling circuit 5 is used to collect the output current of the three-phase inverter circuit 4, and amplify the output current before inputting it to the fuel pump motor controller 11; the fuel pump motor controller 11 is also used to receive the output current, and according to the output current, combined with a preset current threshold, when the output current is greater than or equal to the preset current threshold, control the drive pulse signal to output a low level.

[0063] Optional, continue to refer to Figure 7 The current sampling circuit includes a first resistor R223, a differential amplifier U30, a second resistor R222, a third resistor R224, a fourth resistor R333, a fifth resistor R33, a sixth resistor R31, a seventh resistor R301, a first capacitor C330, and a second capacitor C30. The first resistor R223 is electrically connected between the current output terminal and the ground terminal GND of the three-phase inverter circuit 4, and is connected in series between the second resistor R222 and the third resistor R224. The other end of the second resistor R222 is electrically connected to the positive input terminal of the differential amplifier U30, and the other end of the third resistor R224 is electrically connected to the negative input terminal of the differential amplifier U30. The first capacitor C330 is connected in parallel between the positive and negative input terminals of the differential amplifier U30; the output terminal of the differential amplifier U30 is electrically connected to one end of the sixth resistor R31, and the other end of the sixth resistor R31 is electrically connected to the fourth resistor R333 and the seventh resistor R301 respectively; one end of the fifth resistor R33 is electrically connected to the other end of the seventh resistor R301, and the other end of the seventh resistor R301 is grounded; the other ends of the fourth resistor R333 and the other ends of the fifth resistor R33 are both electrically connected to the fuel pump motor controller 11, and the second capacitor C30 is connected in parallel between the other ends of the fifth resistor R33 and the other ends of the fifth resistor R33.

[0064] Among them, reference Figure 7The first resistor R223 is a sampling resistor, the second resistor R222, the third resistor R224, the fourth resistor R333, the fifth resistor R33, the sixth resistor R31 and the seventh resistor R301 are all voltage divider resistors, and the first capacitor C330 and the second capacitor C30 are both filter capacitors.

[0065] Specifically, the AC output current from the three-phase inverter circuit 4 is sampled after passing through the first resistor R223. The sampled AC output current is amplified by the differential amplifier U30 and then fed back to the fuel pump motor controller 11. Upon receiving the feedback AC output current signal, the fuel pump motor controller 11 compares the received AC output current with a preset current threshold. The preset current threshold can be 120A, but can be set according to actual conditions without limitation. When the fuel pump motor controller 11 determines that the AC output current is less than the preset current threshold, it indicates that the output current is within the normal range, and it outputs a high-level drive pulse signal to the drive module 2. When the fuel pump motor controller 11 determines that the AC output current is greater than or equal to the preset current threshold, it indicates that the output current is too high and exceeds the preset current threshold, and it outputs a low-level drive pulse signal to the drive module 2 to stop the drive module 2 from outputting the drive voltage signal.

[0066] Optional, continue to refer to Figure 3 , Figure 4 and Figure 7 The system also includes a target speed input circuit 7; the target speed input circuit 7 is electrically connected to the fuel pump motor controller 11; the fuel pump motor controller 11 obtains the target speed of the fuel pump motor body 12 through the target speed input circuit 7.

[0067] Among them, reference Figure 7 The target speed input circuit 7 includes a differential amplifier U30 (model AD620), resistors R310, R15, R12, and R17, capacitors C15 and C210, and operational amplifier U4B. Resistors R310, R15, and R17 are voltage divider resistors, resistor R12 and capacitor C15 form an RC filter circuit, and operational amplifier U4B amplifies the input target speed signal.

[0068] Specifically, the positive and negative input terminals of the differential amplifier U30 are the target speed signal input terminals. The input is a 0-5V voltage signal, which is processed by the differential amplifier U30 and output to the operational amplifier U4 for signal following, so that the target speed signal is input to pin 1 of the brushless DC motor control chip U5, i.e., the positive input terminal E / AIN(+).

[0069] Optional, Figure 8This is a circuit diagram of a target speed protection module provided in an embodiment of the present invention, with reference to... Figure 3 , Figure 4 and Figure 8 As shown, the system also includes a target speed protection module 6; the target speed protection module 6 is electrically connected to the fuel pump motor controller 11; the target speed protection module 6 is used to control the target speed protection module to output a high-level soft start signal and input it to the fuel pump motor controller 11 when the target speed is greater than the preset target speed, based on the target speed and in combination with the preset target speed; the fuel pump motor controller 11 is also used to output a high-level drive pulse signal after receiving the high-level soft start signal.

[0070] Among them, resistors R77, R79, R80, R82, R84, R86-R89, and R93 are all voltage divider resistors; resistor R94 and capacitor C80 form an RC filter circuit; capacitors C73, C76, and C78 are all filter capacitors; U11B and U11C are both comparators; and diodes D1, D15, and D16 are all Zener diodes.

[0071] Specifically, after receiving the target speed input to the fuel pump motor controller 11, the target speed protection module 6 compares the target speed with a preset target speed. It should be noted that the input target speed is essentially a voltage value; therefore, the comparison involves comparing the target voltage value corresponding to the target speed with a preset voltage threshold. That is, the target speed signal input at the positive input terminal E / AIN(+), i.e., the target voltage signal, is input to the negative input terminal of comparator U11B and compared with the voltage division value of the voltage divider resistors R80 and R82 connected to the positive input terminal of comparator U11B. This voltage division value is the preset voltage threshold. When the target voltage is lower than the preset voltage threshold, the output terminal of comparator U11B will output a high level. This high-level signal is sent to the peripheral circuit of the soft-start signal input terminal SSTART of the fuel pump motor controller 11, causing the MOSFET D9 to... When the capacitor C29 is turned on, it begins to discharge, causing the voltage at the soft-start signal input terminal SSTART of the brushless DC motor control chip U5 to be low. When the soft-start signal input terminal SSTART is low, the corresponding outputs PUA, PUB, PUC, PDA, PDB, and PDC from pins 18, 17, 16, 14, 13, and 12 of the brushless DC motor control chip U5 are all low. The drive module 2 stops working, all MOSFETs in the three-phase inverter circuit 4 are turned off, and the fuel pump motor controller 11 has no output. This method avoids interference signals from interfering with the target speed signal input to the positive input terminal E / AIN(+) of the brushless DC motor control chip U5, which could lead to erroneous starting and output of the fuel pump motor controller 11.

[0072] Optional, Figure 9 This is a circuit diagram of a signal processing module provided in an embodiment of the present invention, with reference to... Figure 3 , Figure 4 and Figure 9 As shown, the system also includes a signal processing module 8 and a speed control circuit 9; the signal processing module 8 is electrically connected between the fuel pump motor body 12 and the fuel pump motor controller 11; the speed control circuit 9 is electrically connected to the fuel pump motor controller 11; the signal processing module 8 is used to acquire the three-phase Hall signal of the fuel pump motor body 12 when the fuel pump motor body 12 is working, and to perform a second level flip on the three-phase Hall signal to convert it into a three-phase pulse signal and send it to the fuel pump motor controller 11; the fuel pump motor controller 11 is also used to output the speed frequency signal of the fuel pump motor body 12 according to the three-phase pulse signal; the speed control circuit 9 is used to convert the speed frequency signal into a speed signal and send it to the fuel pump motor controller 11 so that the fuel pump motor controller 11 receives the speed of the fuel pump motor body 12.

[0073] Optionally, the speed control circuit 9 includes an eighth resistor R36, a ninth resistor R35, a tenth resistor R25, an operational amplifier U4A, a third capacitor C34, and a fourth capacitor C25; the eighth resistor R36 and the third capacitor C34 are connected in series between the speed output terminal TACH-OUT of the brushless DC motor control chip U5 and the ground terminal GND; the series connection point of the eighth resistor R36 and the third capacitor C34 is respectively between the speed input terminal SPEED-IN of the brushless DC motor control chip U5 and the positive input terminal of the operational amplifier U4; the negative input terminal and the output terminal of the operational amplifier U4A are electrically connected; the ninth resistor R35 is electrically connected between the output terminal of the operational amplifier U4 and the reverse speed input terminal E / AIN(-) of the brushless DC motor control chip U5; the tenth resistor R25 and the fourth capacitor C25 are connected in series between the reverse speed input terminal E / AIN(-) and the error output terminal E / OUT of the brushless DC motor control chip U5.

[0074] The signal processing circuit 8 includes a three-phase (U / V / W) voltage signal processing circuit, referenced. Figure 9 Resistor R103 is a pull-up resistor, resistor R106 is a current-limiting resistor, resistor R111 and capacitor C83 form an RC filter circuit, resistor R97 is a current-limiting resistor, and resistors R102 and R112 are voltage divider resistors. The inputs are three-phase Hall signals: HALL U IN, HALL V IN, and HALL W IN. The corresponding three-phase pulse signals, HALL U, HALL V, and HALL W, are input to pins 8, 9, and 10 of the brushless DC motor control chip U5, respectively. It should be noted that... Figure 9The circuit diagram shown is merely an example of the input Hall signal for one phase (U) of the three-phase circuit. In actual use, the signal processing circuit 8 will input the three-phase Hall signals through different Hall chips. That is, there will be three identical circuits used to input Hall signals for different phases, so that three-phase pulse signals will be output from the three Hall chips. Reference Figure 4 In the speed control circuit 9, the eighth resistor R36 and the third capacitor C34 form an RC integrator circuit. The tenth resistor R25 and the fourth capacitor C25 form an RC integrator circuit. The ninth resistor R35 is a current-limiting resistor.

[0075] Specifically, when the fuel pump motor body 12 is operating, the signal processing module 8 acquires the three-phase Hall signal generated by the fuel pump motor body 12 in real time. This three-phase Hall signal is then sent to transistor V10 via pull-up resistor R103 and current-limiting resistor R106 to achieve level flipping. After level flipping, the three-phase Hall signal is sent to transistor V7 for a second level flip, thus converting the three-phase Hall signal into a three-phase pulse signal and sending it to the fuel pump motor controller 11. Upon receiving the three-phase pulse signal, the brushless DC motor control chip U5 outputs a speed frequency signal at its speed output terminal TACH-OUT, based on the three-phase pulse signal. The speed frequency signal is sent to the speed control circuit 9. The speed control circuit 9 converts the received speed frequency signal into a speed signal, i.e., a speed voltage signal, after passing through the eighth resistor R36 and the third capacitor C34. The speed voltage signal is then input to the inverted speed input terminal E / AIN(-) after passing through the operational amplifier U4A. The brushless DC motor control chip U5 compares the received speed voltage signal with the target speed voltage signal to ensure that the conversion of the fuel pump motor body 12 is always within the preset motor speed range of the target speed.

[0076] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0077] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A fuel pump motor speed control system, characterized in that, It includes a fuel pump motor, a drive module, a signal processing module, and a speed control circuit; The fuel pump motor includes a fuel pump motor controller and a fuel pump motor body; the fuel pump motor controller is electrically connected to the fuel pump motor body and the drive module respectively, and the drive module is electrically connected to the fuel pump motor body. The fuel pump motor controller is used to obtain the target speed of the fuel pump motor body and output a drive pulse signal to the drive module according to the target speed; The drive module is used to convert the drive pulse signal into a drive voltage signal when the drive pulse signal is high, and send the drive voltage signal to the fuel pump motor body to make the fuel pump motor body work. The fuel pump motor controller is also used to receive the rotational speed of the fuel pump motor body when the fuel pump motor body is working, and adjust the duty cycle of the drive pulse signal sent to the drive module when the rotational speed is outside the preset motor speed range of the target speed, so that the rotational speed of the fuel pump motor body is within the preset motor speed range of the target speed. The fuel pump motor controller includes a brushless DC motor control chip. The signal processing module is electrically connected between the fuel pump motor body and the fuel pump motor controller; the speed control circuit is electrically connected to the fuel pump motor controller. The signal processing module is used to acquire the three-phase Hall signal of the fuel pump motor body when the fuel pump motor body is working, and to perform a second level flip on the three-phase Hall signal to convert it into a three-phase pulse signal and send it to the fuel pump motor controller. The fuel pump motor controller is also used to output the rotational speed frequency signal of the fuel pump motor body according to the three-phase pulse signal; The speed control circuit is used to convert the speed frequency signal into a speed signal and send it to the fuel pump motor controller so that the fuel pump motor controller can receive the speed of the fuel pump motor body. The speed control circuit includes an eighth resistor, a ninth resistor, a tenth resistor, an operational amplifier, a third capacitor, and a fourth capacitor; The eighth resistor and the third capacitor are connected in series between the speed output terminal and the ground terminal of the brushless DC motor control chip; the series connection point of the eighth resistor and the third capacitor is respectively between the speed input terminal of the brushless DC motor control chip and the positive input terminal of the operational amplifier; the negative input terminal and the output terminal of the operational amplifier are electrically connected; the ninth resistor is electrically connected between the output terminal of the operational amplifier and the reverse speed input terminal of the brushless DC motor control chip; the tenth resistor and the fourth capacitor are connected in series between the reverse speed input terminal and the error output terminal of the brushless DC motor control chip.

2. The control system according to claim 1, characterized in that, It also includes a power module; The power module is electrically connected to the fuel pump motor controller, the fuel pump motor body and the drive module respectively; The power module is used to convert the unstable input DC control voltage into a stable DC output voltage to power the fuel pump motor controller and the drive module.

3. The control system according to claim 1, characterized in that, The driving voltage signal is a DC driving voltage signal, and the system also includes a three-phase inverter circuit; The three-phase inverter circuit is electrically connected between the drive module and the fuel pump motor body; The three-phase inverter circuit is used to convert the DC drive voltage signal into an AC drive voltage signal so that the fuel pump motor body can work.

4. The control system according to claim 3, characterized in that, It also includes a current sampling circuit; The current sampling circuit is electrically connected between the three-phase inverter circuit and the fuel pump motor controller; the current sampling circuit is used to collect the output current of the three-phase inverter circuit, and amplify the output current before inputting it to the fuel pump motor controller. The fuel pump motor controller is also used to receive the output current, and based on the output current and a preset current threshold, control the drive pulse signal to output a low level when the output current is greater than or equal to the preset current threshold.

5. The control system according to claim 4, characterized in that, The current sampling circuit includes a first resistor, a differential amplifier, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a first capacitor, and a second capacitor; The first resistor is electrically connected between the current output terminal and the ground terminal of the three-phase inverter circuit, and is connected in series between the second and third resistors; the other end of the second resistor is electrically connected to the positive input terminal of the differential amplifier, and the other end of the third resistor is electrically connected to the negative input terminal of the differential amplifier; the first capacitor is connected in parallel between the positive and negative input terminals of the differential amplifier; the output terminal of the differential amplifier is electrically connected to one end of the sixth resistor, and the other end of the sixth resistor is electrically connected to the fourth and seventh resistors respectively; one end of the fifth resistor is electrically connected to the other end of the seventh resistor, and the other end of the seventh resistor is grounded; the other ends of the fourth and fifth resistors are both electrically connected to the fuel pump motor controller, and the second capacitor is connected in parallel between the other ends of the fifth resistor and the other end of the fifth resistor.

6. The control system according to claim 1, characterized in that, It also includes a target speed protection module; The target speed protection module is electrically connected to the fuel pump motor controller; The target speed protection module is used to control the target speed protection module to output a high-level soft start signal and input it to the fuel pump motor controller when the target speed is greater than the preset target speed, based on the target speed and in combination with the preset target speed. The fuel pump motor controller is also configured to output a high-level drive pulse signal after receiving the high-level soft-start signal.

7. The control system according to claim 1, characterized in that, It also includes a target speed input circuit; The target speed input circuit is electrically connected to the fuel pump motor controller; The fuel pump motor controller obtains the target speed of the fuel pump motor body through the target speed input circuit.

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