Medium condition self-adaptive electric pump driving circuit

Abstract

The invention relates to the technical field of electric pump control, in particular to a medium condition self-adaptive electric pump driving circuit, which adopts a pure hardware simulation circuit method to realize stable and quick start and stable operation of an electric pump under different medium conditions, improves the adaptability of a system to complex and changeable environmental conditions and the robustness of the system, and is suitable for large-scale popularization and application. Meanwhile, participation of a CPU control chip is not needed, the complexity of system composition is reduced, and the system cost is reduced; the dependence of the system on a digital circuit and a core processor is reduced, and the anti-interference performance of the system on a complex electromagnetic environment is improved.

Description

Technical Field

[0001] The invention relates to the technical field of electric pump control, and in particular to a medium condition adaptive electric pump driving circuit. Background Art

[0002] The electric pump consists of a pump body, a motor (including cables) and a controller. The controller drives the motor, which drives the gears, impellers or other actuators in the pump to rotate at high speed, and outputs liquid with a certain flow rate and pressure. The liquid output by the electric pump includes coolant, fuel, hydraulic oil, lubricating oil, liquid carbon dioxide and other types of media.

[0003] Different liquid media have different viscosity coefficients at the same temperature. For example, at room temperature, the viscosity coefficient of a certain type of coolant is three times that of a certain type of aviation fuel. The same liquid medium has different viscosity coefficients at different temperatures. And the viscosity characteristics of liquid media have the characteristic of changing significantly with temperature. Generally, the lower the temperature, the higher the viscosity of the liquid. Taking a certain type of coolant as an example, at -40°C, the viscosity coefficient of this type of coolant is 70~80 times that of the normal temperature +20°C. Under the condition of the same flow rate and pressure output by the electric pump, the higher the viscosity coefficient means that the resistance to liquid flow is greater and the load of the electric pump is greater.

[0004] Electric pump control systems usually use a speed closed-loop control method, and the PID parameters of the closed-loop control determine the quality of the control effect. The obvious difference in the load of the electric pump system will have a certain impact on the effect of the control system with fixed PID parameters. The greater the load difference, the more significant the impact.

[0005] Normally, the electric pump system does not identify the medium conditions. For different medium liquids or different conditions of liquids at different temperatures, a set of control parameters is used. This method will greatly affect the control effect of the system. For example, the same set of parameters can run stably at room temperature. For the electric pump system under low temperature conditions of -40℃, it will cause slow startup, large speed fluctuations, slow speed regulation process, and even failure to converge the closed loop. The electric pumps used in military products have a large temperature range, and the conventional electric pump control system has poor system robustness under such conditions. The rest of the control method with temperature feedback uses the core processor (CPU) and temperature sensor. Through embedded software, the temperature sensor value is collected, and the control parameters are adjusted through internal preset logic processing. The defect of this design method is that the control system is complex and costly, and there are digital circuits that are easily interfered by complex electromagnetic environments. Once the program inside the core processor runs away or fails, the control of the electric pump system cannot be completed. Summary of the invention

[0006] In view of this, an object of the present invention is to provide a medium condition adaptive electric pump driving circuit to overcome the problems existing in the current prior art.

[0007] To achieve the above objectives, the present invention adopts the following technical solutions: The present application provides a medium condition adaptive electric pump driving circuit, comprising: A PID adjustment circuit is used to obtain current medium condition information and output a PID parameter value corresponding to the medium according to the medium condition information; A speed closed-loop circuit, used to set the PID parameters of the electric pump speed closed-loop according to the PID parameter value, determine the control information of the electric pump speed closed-loop, send the control signal containing the preset speed instruction to the driving core algorithm circuit, and dynamically adjust the control information sent to the driving core algorithm circuit according to the speed information of the electric pump fed back by the driving core algorithm circuit, so that the speed of the electric pump is maintained at the set speed of the electric pump; The driving core algorithm circuit is used to drive the electric pump to operate according to the control information, receive the speed information fed back by the electric pump, and send the speed information to the speed closed-loop circuit.

[0008] Furthermore, the medium condition adaptive electric pump driving circuit described above, the PID adjustment circuit includes: a medium sensor and a PID controller; The medium sensor is electrically connected to the PID controller; The PID controller is used to adjust the medium parameter value in real time according to the current medium condition information collected by the medium sensor, and send it to the speed closed-loop circuit.

[0009] Furthermore, in the medium condition adaptive electric pump driving circuit described above, the medium sensor includes: a temperature sensor and a medium viscosity sensor.

[0010] Furthermore, the medium condition adaptive electric pump driving circuit described above, driving the core algorithm circuit, includes: a motor driving chip; The first pin of the motor driving chip is connected to the speed closed-loop circuit for receiving the control information; The twelfth, thirteenth and fourteenth pins of the motor drive chip respectively output control signals of the three-phase lower tube, and the sixteenth, seventeenth and eighteenth pins respectively output control signals of the three-phase upper tube, so as to drive the electric pump to operate; The eighth pin, the ninth pin and the tenth pin of the motor drive chip receive the Hall signal fed back by the electric pump, and after internal calculation, feed back the speed information of the electric pump in the form of a voltage value through the twentieth pin to the speed closed-loop circuit.

[0011] Furthermore, in the medium condition adaptive electric pump driving circuit described above, the motor driving chip includes: a chip with model number UC2625.

[0012] Furthermore, the medium condition adaptive electric pump driving circuit described above, the speed closed-loop circuit includes: The in-phase input terminal of the operational amplifier U2B is connected to one end of the resistor R8, the other end of the resistor R8 is connected to the twentieth pin of the motor drive chip, the other end of the resistor R8 is also grounded through the capacitor C4, the inverting input terminal of the operational amplifier U2B is connected to one end of the resistor R11, the other end of the resistor R11 is connected to the output terminal of the operational amplifier U2B, the other end of the resistor R11 is also connected to one end of the parameter capacitor Ca1, the output terminal of the operational amplifier U2B is also connected to the inverting input terminal of the operational amplifier U2A through the parameter resistor Rx1, the other end of the parameter capacitor Ca1 is connected to the operational amplifier The inverting input terminal of the operational amplifier U2A is connected, the other end of the parameter capacitor Ca1 is also connected to one end of the parameter capacitor Ca2, the other end of the parameter capacitor Ca2 is connected to the output terminal of the operational amplifier U2A through the parameter resistor Rx2, the non-inverting input terminal of the operational amplifier U2A specifies the voltage, the positive power supply of the operational amplifier U2A is connected to the 5V voltage, the negative power supply of the operational amplifier U2A is grounded, the output terminal of the operational amplifier U2A is connected to one end of the resistor R7, the other end of the resistor R7 is connected to the first pin of the motor drive chip, and the other end of the resistor R7 is also grounded through the capacitor C8.

[0013] The beneficial effects of the present invention are: This application adopts a pure hardware analog circuit method to achieve smooth and fast startup and stable operation of the electric pump under different media conditions, which improves the adaptability of the system to complex and changeable environmental conditions and the robustness of the system. At the same time, it does not require the participation of the CPU control chip, reduces the complexity of the system composition, and reduces the system cost; reduces the system's dependence on digital circuits and core processors, and improves the system's anti-interference ability to complex electromagnetic environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 paying creative work.

[0015] Figure 1 This is a circuit diagram provided by an embodiment of a medium condition adaptive electric pump driving circuit of the present invention; Figure 2 The present invention is a schematic diagram of a speed closed-loop circuit and a driving core algorithm circuit structure provided by an embodiment of a medium condition adaptive electric pump driving circuit of the present invention. DETAILED DESCRIPTION

[0016] To make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described in detail below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0017] Figure 1 This is a circuit diagram of an embodiment of a medium condition adaptive electric pump drive circuit provided by the present invention. Figure 1 , this embodiment may include: PID adjustment circuit 1, used for obtaining current medium condition information and outputting PID parameter values ​​corresponding to the medium according to the medium condition information; The speed closed-loop circuit 2 is used to set the PID parameters of the electric pump speed closed-loop according to the PID parameter value, determine the control information, send the control signal of the preset speed command to the driving core algorithm circuit 3, and dynamically adjust the control information sent to the driving core algorithm circuit 3 according to the speed information of the electric pump fed back by the driving core algorithm circuit 3, so that the speed of the electric pump is maintained at the set speed of the electric pump; The driving core algorithm circuit 3 is used to drive the electric pump to operate according to the control information, receive the speed information fed back by the electric pump, and send the speed information to the speed closed-loop circuit 2.

[0018] It can be understood that the present embodiment adopts a pure hardware method to realize the medium condition adaptive electric pump drive, which satisfies the requirements of fast and stable control of the electric pump system under different temperatures and different medium conditions, thereby ensuring the high efficiency and reliability of the system; the pure hardware method does not require the participation of the CPU control chip, thus significantly improving the response speed of the controller, having independence, not relying on the CPU control instructions, reducing the complexity of the system control, being not easily affected by external environmental interference such as electromagnetic interference, having a low error rate, high reliability, and a simple system composition and low cost.

[0019] Preferably, the PID adjustment circuit 1 comprises: a medium sensor and a PID controller; The medium sensor is electrically connected to the PID controller; The PID controller is used to adjust the medium parameter value in real time according to the current medium condition information collected by the medium sensor and send it to the speed closed-loop circuit 2.

[0020] Preferably, the medium sensor includes: a temperature sensor and a medium viscosity sensor.

[0021] It is understandable that the PID adjustment circuit 1 has a variety of combinations and can be adjusted accordingly according to the actual use requirements of the system. For a system that does not change the medium type and only has operating conditions at different temperatures, the voltage value output by the temperature sensor can be used as the input of the PID adjustment circuit 1. For different voltage values, different resistance values ​​of Rx1 and Rx2 are connected to the speed closed-loop circuit 2 according to the preset logic of the internal circuit.

[0022] For control systems with different usage requirements for changing media scenarios, the medium viscosity sensor outputs a voltage value as the input of the PID adjustment circuit 1. For different voltage values, different resistance values ​​of Rx1 and Rx2 are connected to the speed closed-loop circuit 2 according to the preset logic of the internal circuit. The medium viscosity sensor is more expensive, but it will also improve the applicability of the system to a variety of usage scenarios.

[0023] Preferably, Figure 2 As shown, Figure 2 The present invention is a schematic diagram of a speed closed-loop circuit 2 and a driving core algorithm circuit 3 provided in an embodiment of a medium condition adaptive electric pump driving circuit. The driving core algorithm circuit 3 includes: a motor driving chip; The first pin of the motor driving chip is connected to the speed closed loop circuit 2 for receiving control information; The twelfth, thirteenth and fourteenth pins of the motor driver chip respectively output the control signals of the three-phase lower tube, and the sixteenth, seventeenth and eighteenth pins respectively output the control signals of the three-phase upper tube, which are used to drive the electric pump to operate; The eighth, ninth and tenth pins of the motor driver chip receive the Hall signal fed back by the electric pump, and after internal calculation, feed back the speed information of the electric pump in the form of a voltage value through the twentieth pin to the speed closed-loop circuit 2.

[0024] Preferably, the motor drive chip includes: a chip with model number UC2625.

[0025] It can be understood that the driving core algorithm circuit 3 is mainly composed of the motor driving chip U1, the peripheral interface configuration capacitors C1, C2, C3, C5, C6, C7 peripheral interface configuration resistors R1, R2, R3, R4, R5, R6, R9, and its core function is to change the duty cycle of the output PWM wave by receiving the voltage value containing the duty cycle information through the first pin of the chip, and control the opening and closing of the three-phase full-bridge power module, wherein the twelfth pin, the thirteenth pin and the fourteenth pin respectively output the control signal of the three-phase lower tube, and the sixteenth pin, the seventeenth pin and the eighteenth pin respectively output the control signal of the three-phase upper tube, and jointly realize the driving of the permanent magnet synchronous or DC brushless motor. The eighth pin, the ninth pin and the tenth pin receive the Hall signals HALLA, HALLB, and HALLC of the motor position feedback, and after internal calculation, the motor speed information is output in the form of a voltage value through the twentieth pin, that is, the Speed ​​signal. The driving core algorithm circuit 3 mainly completes the functions of receiving the duty cycle instruction, receiving the motor position feedback, outputting the motor drive signal, and outputting the motor speed information.

[0026] Preferably, the speed closed-loop circuit 2 comprises: The in-phase input terminal of the operational amplifier U2B is connected to one end of the resistor R8, the other end of the resistor R8 is connected to the twentieth pin of the motor driver chip, the other end of the resistor R8 is also grounded through the capacitor C4, the inverting input terminal of the operational amplifier U2B is connected to one end of the resistor R11, the other end of the resistor R11 is connected to the output terminal of the operational amplifier U2B, the other end of the resistor R11 is also connected to one end of the parameter capacitor Ca1, the output terminal of the operational amplifier U2B is also connected to the inverting input terminal of the operational amplifier U2A through the parameter resistor Rx1, and the other end of the parameter capacitor Ca1 is connected to the operational amplifier U2B. The inverting input terminal of the operational amplifier U2A is connected, the other end of the parameter capacitor Ca1 is also connected to one end of the parameter capacitor Ca2, the other end of the parameter capacitor Ca2 is connected to the output terminal of the operational amplifier U2A through the parameter resistor Rx2, the non-inverting input terminal of the operational amplifier U2A specifies the voltage, the positive power supply of the operational amplifier U2A is connected to the 5V voltage, the negative power supply of the operational amplifier U2A is grounded, the output terminal of the operational amplifier U2A is connected to one end of the resistor R7, the other end of the resistor R7 is connected to the first pin of the motor driver chip, and the other end of the resistor R7 is also grounded through the capacitor C8.

[0027] It can be understood that the speed closed-loop circuit 2 is mainly composed of an operational amplifier U2, filter resistors and capacitors R7, R8, C4, C8 and closed-loop parameter resistors and capacitors R11, Rx1, Rx2, Ca1, Ca2. The circuit uses the input speed information Speed ​​as feedback information, the command voltage Vref as given information, and the output voltage OUTA as a duty cycle command, and is connected to the driving core algorithm circuit 3. The speed closed-loop control logic is formed. The closed-loop principle is that when the motor speed Speed ​​voltage output by the driving core algorithm circuit 3 is less than the given voltage Vref, after being processed by the operational amplifier, the OUTA value increases on the existing basis, and after the duty cycle increases, the actual motor speed increases until the Speed ​​value is equal to Vref, and OUTA remains unchanged; when the Speed ​​voltage is greater than the given voltage Vref, the OUTA value decreases on the existing basis, the duty cycle decreases, and the actual motor speed decreases until the Speed ​​value is equal to Vref, and OUTA remains unchanged, so that the motor speed is always maintained near the given Vref value. When the external load changes and causes the speed to change, the speed can also be adjusted back to the given value through the closed-loop logic, that is, the speed closed-loop regulation is realized. In the speed closed-loop logic, there are three parameters that affect the closed-loop regulation effect, namely, proportional P, integral I and differential D, namely PID parameters. The proportional link is used to quickly respond to the deviation signal of the system, the integral link is used to eliminate the steady-state error, and the differential link is used to make adjustments in advance to suppress possible overshoot. According to the working principle of the operational amplifier, it can be deduced that the proportional parameter , integration parameter , differential parameters It can be seen that Rx1 and Rx2 in the speed closed-loop circuit 2 are important factors affecting the PID parameters, and are also key factors in the control effect of the closed-loop control system. By changing the resistance values ​​of Rx1 and Rx2, the PID parameters can be adjusted to adapt to systems with different load characteristics.

[0028] In specific practice, the temperature / medium viscosity sensor in the PID adjustment circuit 1 recognizes the current medium conditions, and connects the corresponding PID parameters Rx1 and Rx2 to the speed closed-loop circuit 2. The speed closed-loop circuit 2 constructed with Rx1, Rx2 and an operational amplifier controls the feedback speed in a closed-loop manner, and accordingly increases or decreases the duty cycle signal for controlling the motor speed, and outputs it to the driving core algorithm circuit 3. After calculation by the driving chip, six PWM wave signals for controlling the operation of the motor are generated to drive the motor to rotate and drive the electric pump to output liquid with a certain flow rate and pressure. When the medium characteristics change, the PID adjustment circuit 1 will connect different Rx1 and Rx2 to the speed closed-loop circuit 2 to adapt to the closed-loop control of the current system load state to ensure the rapid response and stability of the system.

[0029] It can be understood that the same or similar parts of the above embodiments can be referenced to each other, and the contents not described in detail in some embodiments can refer to the same or similar contents in other embodiments.

[0030] It should be noted that, in the description of the present invention, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of the present invention, unless otherwise specified, the meaning of "plurality" refers to at least two.

[0031] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code that includes one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present invention includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present invention belong.

[0032] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0033] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0034] In addition, each functional unit in each embodiment of the present invention may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0035] The storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disk, etc.

[0036] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0037] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A medium condition adaptive electric pump drive circuit, characterized in that: include: A PID adjustment circuit is used to obtain current medium condition information and output a PID parameter value corresponding to the medium according to the medium condition information; A speed closed-loop circuit, used to set the PID parameters of the electric pump speed closed-loop according to the PID parameter value, determine the control information of the electric pump speed closed-loop, send the control signal containing the preset speed instruction to the driving core algorithm circuit, and dynamically adjust the control information sent to the driving core algorithm circuit according to the speed information of the electric pump fed back by the driving core algorithm circuit, so that the speed of the electric pump is maintained at the set speed of the electric pump; The driving core algorithm circuit is used to drive the electric pump to operate according to the control information, receive the speed information fed back by the electric pump, and send the speed information to the speed closed-loop circuit.

2. The medium condition adaptive electric pump driving circuit according to claim 1, characterized in that: The PID adjustment circuit includes: a medium sensor and a PID controller; The medium sensor is electrically connected to the PID controller; The PID controller is used to adjust the medium parameter value in real time according to the current medium condition information collected by the medium sensor, and send it to the speed closed-loop circuit.

3. The medium condition adaptive electric pump driving circuit according to claim 2, characterized in that: The medium sensor includes: a temperature sensor and a medium viscosity sensor.

4. The medium condition adaptive electric pump driving circuit according to claim 3, characterized in that: Driving core algorithm circuit, including: motor driving chip; The first pin of the motor driving chip is connected to the speed closed-loop circuit for receiving the control information; The twelfth, thirteenth and fourteenth pins of the motor drive chip respectively output control signals of the three-phase lower tube, and the sixteenth, seventeenth and eighteenth pins respectively output control signals of the three-phase upper tube, so as to drive the electric pump to operate; The eighth pin, the ninth pin and the tenth pin of the motor drive chip receive the Hall signal fed back by the electric pump, and after internal calculation, feed back the speed information of the electric pump in the form of a voltage value through the twentieth pin to the speed closed-loop circuit.

5. The medium condition adaptive electric pump driving circuit according to claim 4, characterized in that: The motor drive chip includes: a chip with model number UC2625.

6. The medium condition adaptive electric pump driving circuit according to claim 5, characterized in that: The speed closed-loop circuit comprises: The in-phase input terminal of the operational amplifier U2B is connected to one end of the resistor R8, the other end of the resistor R8 is connected to the twentieth pin of the motor drive chip, the other end of the resistor R8 is also grounded through the capacitor C4, the inverting input terminal of the operational amplifier U2B is connected to one end of the resistor R11, the other end of the resistor R11 is connected to the output terminal of the operational amplifier U2B, the other end of the resistor R11 is also connected to one end of the parameter capacitor Ca1, the output terminal of the operational amplifier U2B is also connected to the inverting input terminal of the operational amplifier U2A through the parameter resistor Rx1, the other end of the parameter capacitor Ca1 is connected to the operational amplifier The inverting input terminal of the operational amplifier U2A is connected, the other end of the parameter capacitor Ca1 is also connected to one end of the parameter capacitor Ca2, the other end of the parameter capacitor Ca2 is connected to the output terminal of the operational amplifier U2A through the parameter resistor Rx2, the non-inverting input terminal of the operational amplifier U2A specifies the voltage, the positive power supply of the operational amplifier U2A is connected to the 5V voltage, the negative power supply of the operational amplifier U2A is grounded, the output terminal of the operational amplifier U2A is connected to one end of the resistor R7, the other end of the resistor R7 is connected to the first pin of the motor drive chip, and the other end of the resistor R7 is also grounded through the capacitor C8.

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