Fuel pump motor rotating speed control system

Abstract

The invention discloses a rotating speed control system for a fuel pump motor. The rotating speed control system comprises the fuel pump motor and a driving module, the fuel pump motor controller is used for acquiring a target rotating speed of the fuel pump motor body and outputting a driving pulse signal to the driving module according to the target rotating speed; the driving module is used for converting the driving pulse signal into a driving voltage signal when the driving pulse signal is at a high level, and sending the driving voltage signal to the fuel pump motor body, so that the fuel pump motor body works; the fuel pump motor controller is further used for receiving the rotating speed of the fuel pump motor body when the fuel pump motor body works and adjusting the duty ratio of the driving pulse signal sent to the driving module according to the rotating speed and the target rotating speed when the rotating speed is out of the preset motor rotating speed range of the target rotating speed. The rotating speed of the fuel pump motor body is within the preset motor rotating speed range of the target rotating speed. By means of the system, accurate control over the rotating speed of the fuel pump motor body is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of aircraft engines, and in particular to a fuel pump motor speed control system. Background Art

[0002] In recent years, the research of multi-electric / hybrid-electric aircraft engine technology has set off a research boom internationally, and people have conducted research on its key components to varying degrees. The aircraft engine fuel pump motor control system with the electric fuel pump motor as the core architecture is one of the key components in the development of multi-electric / hybrid-electric engines, and is also regarded by the industry as a major change in the aircraft engine fuel pump motor control system. The aircraft engine fuel pump motor controller is an important component of the aircraft engine. It is responsible for controlling the working state of the fuel pump to ensure that the engine obtains the appropriate amount of fuel supply. The fuel pump motor is usually installed in the fuel tank and is responsible for transporting fuel from the fuel tank to the engine. The control of the fuel amount needs to be determined according to the speed of the fuel pump motor.

[0003] The existing method for controlling the speed of the fuel pump motor is usually to obtain the relevant parameters of the fuel pump through software control, and the controller controls the speed of the fuel pump motor by processing the parameters. However, this method requires a lot of design and timely update of a large amount of code to achieve speed control, with complex logic, high labor consumption, slow operation speed and poor reliability. Summary of the invention

[0004] The invention provides a fuel pump motor speed control system, which uses a pure hardware structure to achieve accurate control of the fuel pump motor speed, does not require software code writing, has a simple design, a simple control method, and high reliability.

[0005] The present invention provides a fuel pump motor speed control system, comprising 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 the fuel pump motor body and the drive module respectively, 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 a driving pulse signal to the driving module according to the target speed;

[0008] The driving module is used for converting the driving pulse signal into a driving voltage signal when the driving pulse signal is at a high level, and sending the driving 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 according to the rotational speed and the target speed, when the rotational speed is outside the preset motor speed range of the target speed, adjust the duty cycle of the drive pulse signal sent to the drive module so that the rotational speed of the fuel pump motor body is within the preset motor speed range of the target speed.

[0010] Optionally, the system further includes 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 input unstable 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 further 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 to enable the fuel pump motor body to work.

[0016] Optionally, the system further includes 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 and input it into 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 resistor and the third resistor; 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 input terminal and the negative input terminal 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 resistor and the seventh resistor 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 end of the fourth resistor and the other end of the fifth resistor are both electrically connected to the fuel pump motor controller, and the second capacitor is connected in parallel between the other end of the fifth resistor and the other end of the fifth resistor.

[0021] Optionally, the system further 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 according to the target speed and the preset target speed when the target speed is greater than 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 further includes 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 further includes 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 obtain the three-phase Hall signal of the fuel pump motor body when the fuel pump motor body is working, and perform secondary level flipping on the three-phase Hall signal, 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 a speed frequency signal of the fuel pump motor body according to 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 receives 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 points of the eighth resistor and the third capacitor are respectively connected 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.

[0036] The technical solution of the present invention is to electrically connect the fuel pump motor controller to the fuel pump motor body and the drive module respectively, and the drive module is electrically connected to the fuel pump motor body; so that the fuel pump motor controller obtains the target speed of the fuel pump motor body, and outputs a drive pulse signal to the drive module according to the target speed; when the drive pulse signal is at a high level, the drive module converts the drive pulse signal into a drive voltage signal, and sends the drive voltage signal to the fuel pump motor body to make the fuel pump motor body work; when the fuel pump motor body is working, the fuel pump motor controller receives the speed of the fuel pump motor body, and when the speed is outside the preset motor speed range of the target speed, adjusts the duty cycle of the drive pulse signal sent to the drive module, so that the speed of the fuel pump motor body is within the preset motor speed range of the target speed. Utilizing the above system, the speed of the fuel pump motor is accurately controlled through a pure hardware structure, thereby realizing accurate control of the speed of the aircraft engine, without the need to write software code, with simple design, simple control method and high reliability.

[0037] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0039] Figure 1 A schematic diagram of the structure of a fuel pump motor speed control system provided by an embodiment of the present invention;

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

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

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

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

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

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

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

[0047] Fig. 9 A circuit diagram of a signal processing module provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0048] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work 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 and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0050] In one embodiment, Figure 1 The schematic diagram of the structure of a fuel pump motor speed control system provided by an embodiment of the present invention is applicable to the case where the speed of the fuel pump body in the aircraft engine system is accurately controlled within a preset speed range of the target speed by using the hardware structure, 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 at a 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 according to the speed and the target speed, when the speed is outside the preset motor speed range of the target speed, adjust the duty ratio of the drive pulse signal sent to the drive module 2 to make the speed of the fuel pump motor body 12 within the preset motor speed range of the target speed.

[0051] Among them, the fuel pump motor controller 11 is the core control system of the fuel pump motor, which is used to obtain 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 the 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 chip. The fuel pump motor body 12 is a structure that transports 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 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, so that the fuel pump motor controller 11 can obtain the target speed of the fuel pump motor body 12, wherein the target speed of the fuel pump motor body 12 can be finally determined by the engine controller through the relevant parameters of the engine, which is essentially a target speed voltage value. After the fuel pump motor controller 11 obtains the target speed, it will output a drive pulse signal to the drive module 2 according to the target speed. After the drive module 2 receives the drive pulse signal, it will confirm whether the output drive pulse signal is a high level signal or a low level signal. When the drive pulse signal is at a low level, the drive module 2 stops working, and it is also unable to output a drive voltage signal to the fuel pump motor body 12 to drive the fuel pump motor body 12 to work. At this time, the fuel pump motor body 12 does not work and there is no speed output. Only when the driving pulse signal is at a high level, the driving module 2 will convert the high-level driving pulse signal into a driving voltage signal and send it to the fuel pump motor body 12. After receiving the driving 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 when it is working, 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, and the fuel pump motor body 12 is kept working under the driving pulse signal. When the speed is not within the preset motor speed range of the target speed, such as the speed is higher than the preset motor speed range of the target speed, or the speed is 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. If the driving pulse signal is continued to work, too much or too little fuel may be delivered to the aircraft engine, causing the speed of the aircraft engine to be too fast or too slow, which has a certain degree of impact on the performance of the aircraft engine. At this time, the fuel pump motor controller 11 will adjust the duty cycle of the drive pulse signal output to the drive module 2, and obtain the adjusted speed of the fuel pump motor body 12, and determine whether the speed of the fuel pump motor body 12 is adjusted to 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 completed, 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 will continue to be adjusted until the speed is within the preset motor speed range of the target speed, then the adjustment is completed, and the final adjusted drive pulse signal is sent to the drive module 2. In this embodiment, the preset motor speed range can be 1%, which realizes the precise control of the speed of the fuel pump motor body 12.

[0053] In addition, after the speed adjustment of the fuel pump motor body 12 is completed, the speed of the fuel pump motor body 12 can be used to control the amount of fuel, so that the speed of the aircraft engine can be controlled according to the amount of fuel, so that the speed of the aircraft engine is within the preset engine speed range of the aircraft engine speed. In this embodiment, the preset engine speed range can be 0.5%, which realizes precise control of the aircraft engine speed.

[0054] The technical solution of the embodiment of the present invention is to electrically connect the fuel pump motor controller to the fuel pump motor body and the drive module respectively, and the drive module to the fuel pump motor body; so that the fuel pump motor controller obtains the target speed of the fuel pump motor body, and outputs a drive pulse signal to the drive module according to the target speed; when the drive pulse signal is at a high level, the drive module converts the drive pulse signal into a drive voltage signal, and sends the drive voltage signal to the fuel pump motor body to make the fuel pump motor body work; when the fuel pump motor body is working, the fuel pump motor controller receives the speed of the fuel pump motor body, and when the speed is outside the preset motor speed range of the target speed, adjusts the duty cycle of the drive pulse signal sent to the drive module, so that the speed of the fuel pump motor body is within the preset motor speed range of the target speed. Utilizing the above system, the speed of the fuel pump motor is precisely controlled through a pure hardware structure, thereby realizing precise control of the speed of the aircraft engine, without the need to write software code, with simple design, simple control method and high reliability.

[0055] In another alternative embodiment, Figure 2 A circuit diagram of a power module provided by an embodiment of the present invention, Figure 3 The schematic diagram of the structure of the second fuel pump motor speed control system provided by the embodiment of the present invention is shown in FIG. 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 is used to supply power to the fuel pump motor controller 11 and the drive module 2, so that the fuel pump motor controller 11, the fuel pump motor body 12 and the drive module 2 start working. Figure 2 , inductor L1 and inductor L2 are both filter inductors, capacitors C1-C8 and capacitors C10-C12 are all filter capacitors, resistors R1-R7 are all voltage divider resistors, U1 is a buck chip model XC8821FCC, and U2 is a three-terminal regulator model LM7805.

[0057] Specifically, refer to Figure 2 The input is an unstable DC voltage of 28V. The DC voltage passes through the filter inductor L1 and 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, the filter capacitor C10 and the filter capacitor C11 to become a stable DC voltage of 12V and output. A part of the stable 12V DC voltage is converted into a DC voltage of 5V after passing through the three-terminal regulator U2. The 12V DC voltage and 5V DC voltage generated after step-down are used to provide auxiliary power for the fuel pump motor controller 11 and the drive module 2, so that the fuel pump motor controller 11 and the drive module 2 can work normally.

[0058] Optionally, the fuel pump motor controller 11 includes a brushless DC motor control chip U5. Figure 4 A circuit diagram of a brushless DC motor control chip and some peripheral circuits provided by an embodiment of the present invention, Figure 5 A circuit diagram of a driving module provided by an embodiment of the present invention, referring 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 all bootstrap capacitors, diodes D3, D6 and D10 are all bootstrap diodes, capacitors C17, C13, C22, C28, C33 and C40 are all filter capacitors, and the remaining resistors are all voltage-dividing resistors. The input end of the drive chip U3 is the drive pulse signal output by 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 respectively input to the low-end drive pulse signal input end LIN of the drive module 2, and the drive pulse signals PDA, PDB and PDC of the upper half bridge are respectively input to the high-end drive pulse signal input end HIN of the drive module 2. After being processed by the drive chip, a suspended three-phase drive voltage signal is output to send the three-phase drive voltage signal to the fuel pump motor body 12 to make the fuel pump motor body 12 work.

[0059] Optional, Figure 6 A circuit diagram of a three-phase inverter circuit provided by an embodiment of the present invention, referring to Figure 3 and Figure 6 As shown, the driving voltage signal is a DC driving voltage signal, and the system also includes a three-phase inverter circuit 4; the three-phase inverter circuit 4 is electrically connected between the driving module 2 and the fuel pump motor body 12; the three-phase inverter circuit 4 is used to convert the DC driving voltage signal into an AC driving voltage signal to enable the fuel pump motor body 12 to work.

[0060] Among them, reference Figure 6 The on-resistances of the parallel MOS tubes Q8 and Q9 are both 1.2 mΩ. Similarly, the on-resistances of the MOS tubes Q10 to Q19 are all 1.2 mΩ. 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 driving voltage signal output by the driving module 2 into an AC driving voltage signal, and send the AC driving voltage signal to the fuel pump motor body 12 to enable the fuel pump motor body 12 to operate.

[0062] Optional, Figure 7 A circuit diagram of a current sampling circuit provided by an embodiment of the present invention, referring 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 and input 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 of the three-phase inverter circuit 4 and the ground terminal GND, 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 input terminal and the negative input terminal 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 end of the fourth resistor R333 and the other end 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 end of the fifth resistor R33 and the other end 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 dividing resistors, and the first capacitor C330 and the second capacitor C30 are both filter capacitors.

[0065] Specifically, the AC output current output by 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 the amplified AC output current signal is fed back to the fuel pump motor controller 11. After receiving the fed-back AC output current signal, the fuel pump motor controller 11 will compare the received AC output current with the preset current threshold, wherein the preset current threshold may be 120A, which may be set according to actual conditions and is not limited here. When the fuel pump motor controller 11 determines that the AC output current is less than the preset current threshold, indicating that the output current is within the normal range at this time, a high-level drive pulse signal will be output 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, indicating that the output current is too high and exceeds the preset current threshold, a low-level drive pulse signal will be output 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 further 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 of model AD620, a resistor R310, a resistor R15, a resistor R12, a resistor R17, a capacitor C15, a capacitor C210, and an operational amplifier U4B. The resistor R310, the resistor R15, and the resistor R17 are all voltage-dividing resistors, the resistor R12 and the capacitor C15 are RC filter circuits, and the operational amplifier U4B is used to amplify the input target speed signal.

[0068] Specifically, the positive input terminal and the negative input terminal of the differential amplifier U30 are the target speed signal input terminals, and 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, that is, the positive input terminal E / AIN(+).

[0069] Optional, Figure 8A circuit diagram of a target speed protection module provided by an embodiment of the present invention, referring 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 according to the target speed and the preset target speed when the target speed is greater than 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, resistor R77, resistor R79, resistor R80, resistor R82, resistor R84, resistor R86-resistor R89 ​​and resistor R93 are all voltage-dividing resistors, resistor R94 and capacitor C80 are RC filter circuits, capacitor C73, capacitor C76 and capacitor C78 are all filter capacitors, U11B and U11C are both comparators, and diode D1, diode D15 and diode D16 are all voltage-stabilizing diodes.

[0071] Specifically, after receiving the target speed input to the fuel pump motor controller 11, the target speed protection module 6 will compare the target speed with the preset target speed. It should be noted that when the target speed is input, it is essentially the input voltage value, so when the comparison is made, the target voltage value corresponding to the target speed is compared with the preset voltage threshold. In other words, the target speed signal input to the positive input terminal E / AIN(+), that is, the target voltage signal is input to the negative input terminal of the comparator U11B, and is compared with the voltage-dividing value of the voltage-dividing resistors R80 and R82 connected to the positive input terminal of the comparator U11B. The voltage-dividing value is the preset voltage threshold. When the target voltage is lower than the preset voltage threshold, the output terminal of the comparator U11B will output a high level, and the 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 MOS tube D9 to start. When the soft start signal input terminal SSTART of the brushless DC motor control chip U5 is turned on, the capacitor C29 starts to discharge, so that the voltage input to the soft start signal input terminal SSTART of the brushless DC motor control chip U5 is low level. When the soft start signal input terminal SSTART is low level, the PUA, PUB, PUC, PDA, PDB and PDC corresponding to the outputs of the 18th, 17th, 16th, 14th, 13th and 12th pins of the brushless DC motor control chip U5 are all low level, the drive module 2 stops working, the MOS tubes of the three-phase inverter circuit 4 are all turned off, and the fuel pump motor controller 11 has no output. This method can avoid the situation where the fuel pump motor controller 11 is mis-started and mis-output when the interference signal interferes with the target speed signal input to the positive input terminal E / AIN(+) of the brushless DC motor control chip U5.

[0072] Optional, Fig. 9 A circuit diagram of a signal processing module provided by an embodiment of the present invention, referring to Figure 3 , Figure 4 and Fig. 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 obtain the three-phase Hall signal of the fuel pump motor body 12 when the fuel pump motor body 12 is working, and perform a secondary level flip on the three-phase Hall signal, 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 and the ground terminal GND of the brushless DC motor control chip U5; 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. Fig. 9 , resistor R103 is a pull-up resistor, resistor R106 is a current limiting resistor, resistor R111 and capacitor C83 are RC filter circuits, resistor R97 is a current limiting resistor, resistor R102 and resistor R112 are both voltage divider resistors. The input ends are three-phase Hall signals, namely HALL U IN, HALL VIN and HALL W IN, and the corresponding three-phase pulse signals at the output ends, namely 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 Fig. 9The circuit diagram is only shown for example when a Hall signal of one phase (U) among the three phases is input. In actual use, the signal processing circuit 8 will input the input three-phase Hall signal through different Hall chips, that is, there will be three circuits with the same structure for inputting Hall signals of different phases to output three-phase pulse signals on three Hall chips. Figure 4 In the speed control circuit 9, the eighth resistor R36 and the third capacitor C34 form an RC integration circuit. The tenth resistor R25 and the fourth capacitor C25 form an RC integration circuit. The ninth resistor R35 is a current limiting resistor.

[0075] Specifically, when the fuel pump motor body 12 is working, the signal processing module 8 will obtain the three-phase Hall signal generated by the fuel pump motor body 12 in real time, and send the three-phase Hall signal to the transistor V10 through the pull-up resistor R103 and the current limiting resistor R106 to achieve level flipping. After the level flipping, the three-phase Hall signal will be sent to the transistor V7 to achieve secondary level flipping, thereby converting the three-phase Hall signal into a three-phase pulse signal and sending it to the fuel pump motor controller 11. After the brushless DC motor control chip U5 receives the three-phase pulse signal, it will output a speed frequency signal at the speed output terminal TACH-OUT of the brushless DC motor control chip U5 according to the three-phase pulse signal. The speed frequency signal will be sent to the speed control circuit 9, and the speed control circuit 9 will convert the received speed frequency signal into a speed signal, that is, a speed voltage signal, through the eighth resistor R36 and the third capacitor C34. The speed voltage signal is followed by the operational amplifier U4A and input to the reverse speed input terminal E / AIN(-). The brushless DC motor control chip U5 will compare 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 to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0077] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A fuel pump motor speed control system, characterized in that: Includes fuel pump motor and drive module; The fuel pump motor comprises 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 driving pulse signal to the driving module according to the target speed; The driving module is used for converting the driving pulse signal into a driving voltage signal when the driving pulse signal is at a high level, and sending the driving 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 based on the rotational speed and the target rotational speed, when the rotational speed is outside the preset motor speed range of the target speed, adjust the duty cycle of the drive pulse signal sent to the drive module so that the rotational speed of the fuel pump motor body is within the preset motor speed range of the target speed.

2. The control system according to claim 1, characterized in that: 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 supply module is used to convert the input unstable DC control voltage into a stable DC output voltage to supply power to 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 further comprises 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 driving voltage signal into an AC driving voltage signal to enable the fuel pump motor body to operate.

4. The control system according to claim 3, characterized in that: Also included is 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 and input it into 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 resistor and the third resistor; 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 input terminal and the negative input terminal 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 resistor and the seventh resistor 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 end of the fourth resistor and the other end of the fifth resistor are both electrically connected to the fuel pump motor controller, and the second capacitor is connected in parallel between the other end of the fifth resistor and the other end of the fifth resistor.

6. The control system according to claim 1, characterized in that: 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 according to the target speed and a preset target speed when the target speed is greater than the preset target speed; The fuel pump motor controller is also used to output a high-level driving pulse signal after receiving the high-level soft start signal.

7. The control system according to claim 1, characterized in that: Also included is 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.

8. The control system according to claim 1, characterized in that: The fuel pump motor controller includes a brushless DC motor control chip.

9. The control system according to claim 8, characterized in that: It also includes a signal processing module and a speed control circuit; 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 obtain the three-phase Hall signal of the fuel pump motor body when the fuel pump motor body is working, and perform secondary level flipping on the three-phase Hall signal, 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 a speed frequency signal of the fuel pump motor body according to the three-phase pulse signal; The speed control circuit is used for converting the speed frequency signal into a speed signal and sending it to the fuel pump motor controller, so that the fuel pump motor controller receives the speed of the fuel pump motor body.

10. The control system according to claim 9, characterized in that: 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.

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