Driving circuit of oxygen production compressor

Abstract

The utility model provides a driving circuit of an oxygen production compressor. The driving circuit comprises a sampling module, a controller module, an MOS tube driving module and a three-phase full-bridge driving module, the three-phase full-bridge driving module comprises upper bridge arm MOS (Metal Oxide Semiconductor) tubes Q1, Q2 and Q3 and lower bridge arm MOS tubes Q4, Q5 and Q6, the sampling module comprises a phase current sampling unit and an MOS tube temperature sampling unit, and the phase current sampling unit comprises a differential amplification circuit consisting of a two-way operational amplifier N1 and is used for detecting two current changes in the three-phase full-bridge driving module; and the MOS tube temperature sampling unit comprises a thermistor RT1 and divider resistors R29 and R30, and is used for converting the temperature change of the MOS tube in the three-phase full-bridge driving module into a voltage signal and transmitting the voltage signal to the controller module. An external current sensor is omitted, corresponding driving signals are generated through the MOS tube driving circuit, connection and disconnection of MOS tubes of upper and lower bridge arms in the three-phase full-bridge driving circuit are controlled, and accurate detection and control of motor current are achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of motor drive, in particular to an oxygen generator compressor drive circuit. Background Art

[0002] With the continuous advancement of oxygen concentrator technology, compressors are increasingly adopting brushless DC motors as their core components to achieve more efficient and stable variable frequency control. Common drive methods for these motors include trapezoidal wave control based on back electromotive force and sinusoidal wave control based on phase current. Sine wave drive is favored for its smoother operation, lower torque ripple, and improved efficiency and noise performance.

[0003] In sinusoidal drive mode, accurately detecting and controlling the current in the motor windings is one of the key factors in ensuring motor performance. Traditionally, this process often relies on externally mounted current sensors or measurement through series resistors. However, both methods have certain limitations, as described below:

[0004] On the one hand, external current sensors are not only expensive and bulky, but also relatively complicated to install; at the same time, they may also introduce additional error sources, affecting the accuracy of the final results.

[0005] On the other hand, while using resistors for current monitoring is simple and straightforward, it can generate significant power loss at high currents, leading to severe heat generation and reduced overall system energy efficiency. Furthermore, because resistor values ​​vary with temperature, significant measurement deviations can occur under varying operating conditions.

[0006] Therefore, developing a new current detection solution that can maintain high accuracy and reduce energy consumption has become one of the urgent problems to be solved. Utility Model Content

[0007] The technical problem to be solved by the utility model is how to realize accurate detection of current without using an external current sensor, thereby controlling the efficient and stable operation of the oxygen generator compressor.

[0008] In order to solve the above technical problems, the present invention provides an oxygen compressor drive circuit, which includes a sampling module, a controller module, a MOS tube drive module and a three-phase full-bridge drive module; wherein:

[0009] The three-phase full-bridge driver module includes upper-arm MOS transistors Q1, Q2, Q3 and lower-arm MOS transistors Q4, Q5, Q6, wherein:

[0010] The upper bridge arm MOS transistor Q1 and the lower bridge arm MOS transistor Q4 are connected in series between the power supply VCC and GND, and the oxygen compressor VS1 is connected to the middle node VS1 between the upper bridge arm MOS transistor Q1 and the lower bridge arm MOS transistor Q4;

[0011] The upper bridge arm MOS transistor Q2 and the lower bridge arm MOS transistor Q5 are connected in series between the power supply VCC and GND, and the oxygen compressor VS2 is connected to the intermediate node VS2 between the upper bridge arm MOS transistor Q2 and the lower bridge arm MOS transistor Q5;

[0012] The upper bridge arm MOS transistor Q3 and the lower bridge arm MOS transistor Q6 are connected in series between the power supply VCC and GND, and the oxygen compressor VS3 is connected to the intermediate node VS3 between the upper bridge arm MOS transistor Q3 and the lower bridge arm MOS transistor Q6;

[0013] The sampling module includes a phase current sampling unit and a MOS tube temperature sampling unit, wherein:

[0014] The phase current sampling unit includes a differential amplifier circuit composed of a dual operational amplifier N1, which is used to detect the current changes of two of the three full-bridge drive modules;

[0015] The MOS tube temperature sampling unit includes a thermistor RT1 and voltage divider resistors R29 and R30, which are used to convert the temperature change of the MOS tube in the three-phase full-bridge drive module into a voltage signal and transmit it to the controller module.

[0016] Furthermore, the three-phase full-bridge drive module also includes resistors R1, R2, R3, R10, R11, and R12 and capacitors C1, C2, C3, C4, C5, and C6 to form an RC spike pulse absorption circuit.

[0017] Furthermore, the resistor R1 and the capacitor C1 are connected in series and then in parallel with the upper bridge arm MOS transistor Q1;

[0018] The resistor R2 is connected in series with the capacitor C2 and then connected in parallel with the upper bridge arm MOS transistor Q2;

[0019] The resistor R3 is connected in series with the capacitor C3 and then connected in parallel with the upper arm MOS tube Q3;

[0020] The resistor R10 is connected in series with the capacitor C4 and then connected in parallel with the lower bridge arm MOS tube Q4;

[0021] The resistor R11 is connected in series with the capacitor C5 and then connected in parallel with the lower bridge arm MOS transistor Q5;

[0022] The resistor R12 and the capacitor C6 are connected in series and then connected in parallel to the lower bridge arm MOS transistor Q5.

[0023] Furthermore, the three-phase full-bridge drive module also includes pull-down resistors R7, R8, R9, R16, R17, and R18, which are used to increase the shutdown speed of the upper-arm MOS tubes Q1, Q2, and Q3 and the lower-arm MOS tubes Q4, Q5, and Q6; wherein the pull-down resistors R7, R8, R9, R16, R17, and R18 are respectively connected between the G terminals and GND of the corresponding upper-arm MOS tubes Q1, Q2, and Q3 and the lower-arm MOS tubes Q4, Q5, and Q6.

[0024] Furthermore, the three-phase full-bridge drive module also includes resistors R4, R5, R6, R13, R14, and R15 for eliminating oscillation of the MOS tube, wherein the resistors R4, R5, R6, R13, R14, and R15 are respectively connected in series with the G ends of the corresponding upper arm MOS tubes Q1, Q2, and Q3 and the lower arm MOS tubes Q4, Q5, and Q6.

[0025] Furthermore, the controller module includes a controller, and the model of the controller is GD32E103CBT6.

[0026] Furthermore, the dual operational amplifier N1 includes an operational amplifier N1A and an operational amplifier N1B, wherein:

[0027] The differential amplifier circuit composed of the operational amplifier N1A is provided between the upper bridge arm MOS transistor Q1 and the lower bridge arm MOS transistor Q4;

[0028] The differential amplifier circuit composed of the operational amplifier N1B is provided between the upper bridge arm MOS transistor Q2 and the lower bridge arm MOS transistor Q5.

[0029] Furthermore, the phase current sampling unit further includes an RC filter circuit consisting of a resistor R21 and a capacitor C7, and a resistor R26 and a capacitor C8.

[0030] Furthermore, the MOS tube driving module includes chips N3, N5, and N6, and the models of the chips N3, N5, and N6 are SLM2181.

[0031] Furthermore, the MOS transistor driving module further includes bootstrap capacitors C9, C10, C11 and bootstrap diodes D1, D2, D3 to form bootstrap circuits respectively.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The utility model is an oxygen-generating compressor drive circuit based on phase current sampling based on the internal resistance of a MOS tube, which eliminates the need for an external current sensor, reduces system cost and complexity, and realizes accurate detection of the phase current by detecting the change in the voltage drop of the internal resistance of the MOS tube. At the same time, by detecting the change in the temperature of the MOS tube, temperature compensation is performed on the internal resistance of the MOS tube due to the temperature change, eliminating the influence of the temperature factor on the phase current detection, so that the oxygen-generating compressor drive circuit has a wider temperature application range.

[0034] Based on the obtained current signal and the preset control target, the controller calculates the required control quantity, outputs the corresponding PWM waveform, generates the corresponding drive signal through the MOS tube drive circuit, controls the conduction and shutdown of the upper and lower bridge arm MOS tubes in the three-phase full-bridge drive circuit, realizes the precise detection and control of the motor current, and improves the operating efficiency and control performance of the oxygen compressor. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a principle block diagram of the utility model;

[0036] Figure 2 This is a circuit diagram of the three-phase full-bridge drive module of the present utility model;

[0037] Figure 3 This is a circuit diagram of the phase current sampling unit of the present utility model;

[0038] Figure 4 This is a circuit diagram of the MOS tube temperature sampling unit of the present utility model;

[0039] Figure 5 This is a circuit diagram of the MOS tube driving module of the utility model;

[0040] Figure 6 This is a circuit diagram of the controller module of the present utility model. DETAILED DESCRIPTION

[0041] In order to make the technical solution and technical effect of the present invention clearer, the technical solution in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment. Obviously, the described embodiment is only a part of the embodiment of the present invention, not all of the embodiments.

[0042] The utility model aims to provide an oxygen generator compressor driving circuit, which can realize accurate detection of current without using an external current sensor, thereby controlling the efficient and stable operation of the oxygen generator compressor.

[0043] refer to Figure 1The circuit of the present invention mainly includes a sampling module, a controller module, a MOS tube driving module and a three-phase full-bridge driving module, wherein the sampling module includes a phase current sampling unit and a MOS tube temperature sampling unit.

[0044] The three-phase full-bridge drive module includes an upper-arm MOS tube and a lower-arm MOS tube, and controls the operation of the compressor by alternating conduction of the upper-arm MOS tube and the lower-arm MOS tube.

[0045] Specifically, refer to Figure 2 :

[0046] The three-phase full-bridge driver module includes upper-arm MOS transistors Q1, Q2, Q3 and lower-arm MOS transistors Q4, Q5, Q6; among which:

[0047] The upper bridge arm MOS transistor Q1 and the lower bridge arm MOS transistor Q4 are connected in series between the power supply VCC and GND, and the oxygen generator VS1 is connected to the intermediate node VS1 between the upper bridge arm MOS transistor Q1 and the lower bridge arm MOS transistor Q4;

[0048] The upper bridge arm MOS transistor Q2 and the lower bridge arm MOS transistor Q5 are connected in series between the power supply VCC and GND, and the oxygen generator VS2 is connected to the intermediate node VS2 between the upper bridge arm MOS transistor Q2 and the lower bridge arm MOS transistor Q5;

[0049] The upper bridge arm MOS transistor Q3 and the lower bridge arm MOS transistor Q6 are connected in series between the power supply VCC and GND, and the oxygen generator VS3 is connected to the middle node VS3 between the upper bridge arm MOS transistor Q3 and the lower bridge arm MOS transistor Q6.

[0050] The three-phase full-bridge driver module includes resistors R1, R2, R3, R10, R11, and R12, and capacitors C1, C2, C3, C4, C5, and C6, forming an RC spike absorption circuit. Furthermore, resistor R1 and capacitor C1 are connected in series and in parallel with the upper-arm MOS transistor Q1; resistor R2 and capacitor C2 are connected in series and in parallel with the upper-arm MOS transistor Q2; resistor R3 and capacitor C3 are connected in series and in parallel with the upper-arm MOS transistor Q3; resistor R10 and capacitor C4 are connected in series and in parallel with the lower-arm MOS transistor Q4; resistor R11 and capacitor C5 are connected in series and in parallel with the lower-arm MOS transistor Q5; and resistor R12 and capacitor C6 are connected in series and in parallel with the lower-arm MOS transistor Q5. This design absorbs spikes generated by the rapid switching of the MOS transistors, improving the circuit's electromagnetic compatibility.

[0051] The three-phase full-bridge driver module also includes pull-down resistors R7, R8, R9, R16, R17, and R18, which are used to increase the shutdown speed of the upper-arm MOS transistors Q1, Q2, Q3 and the lower-arm MOS transistors Q4, Q5, and Q6; wherein the pull-down resistors R7, R8, R9, R16, R17, and R18 are respectively connected between the G terminals and GND of the corresponding upper-arm MOS transistors Q1, Q2, Q3 and lower-arm MOS transistors Q4, Q5, and Q6. That is, the pull-down resistor R7 is connected between the G terminal of the upper-arm MOS transistor Q1 and GND; the pull-down resistor R8 is connected between the G terminal of the upper-arm MOS transistor Q2 and GND; the pull-down resistor R9 is connected between the G terminal of the upper-arm MOS transistor Q3 and GND; the pull-down resistor R16 is connected between the G terminal of the lower-arm MOS transistor Q4 and GND; the pull-down resistor R17 is connected between the G terminal of the lower-arm MOS transistor Q5 and GND; and the pull-down resistor R18 is connected between the G terminal of the lower-arm MOS transistor Q6 and GND.

[0052] The three-phase full-bridge driver module also includes resistors R4, R5, R6, R13, R14, and R15, which are connected in series with the G terminals of the corresponding upper-arm MOS transistors Q1, Q2, and Q3, and lower-arm MOS transistors Q4, Q5, and Q6, respectively. This design is used to eliminate MOS transistor oscillation.

[0053] The phase current sampling unit is used to detect the voltage drop across the internal resistance of the MOS tube and convert the current signal into a voltage signal and transmit it to the controller.

[0054] Specifically, refer to Figure 3 :

[0055] The phase current sampling unit includes a differential amplifier circuit composed of a dual operational amplifier N1, which is used to detect current changes in two of the three full-bridge drive modules. Furthermore, the dual operational amplifier N1 includes an operational amplifier N1A and an operational amplifier N1B. The differential amplifier circuit composed of operational amplifier N1A is arranged between the upper-arm MOS transistor Q1 and the lower-arm MOS transistor Q4; the differential amplifier circuit composed of operational amplifier N1B is arranged between the upper-arm MOS transistor Q2 and the lower-arm MOS transistor Q5.

[0056] When the upper-arm MOS tube Q1 and the lower-arm MOS tube Q5 are turned on and the other MOS tubes are turned off, the voltage change on the internal resistance of the lower-arm MOS tube Q5 will be amplified by a suitable multiple through the differential amplifier circuit composed of the dual-channel operational amplifier N1A and transmitted to pin 13 of the controller N4;

[0057] When the upper-arm MOS tube Q2 and the lower-arm MOS tube Q4 are turned on and the other MOS tubes are turned off, the voltage change on the internal resistance of the lower-arm MOS tube Q4 will be amplified by an appropriate multiple through the differential amplifier circuit composed of the dual operational amplifier N1B and transmitted to pin 14 of the controller N4.

[0058] The phase current sampling unit further includes an RC filter circuit consisting of a resistor R21 and a capacitor C7, and a resistor R26 and a capacitor C8, which is used to eliminate noise and interference and improve the accuracy of the voltage signal output to the controller N1.

[0059] The MOS tube temperature sampling unit is used to collect the temperature of the MOS tube in the three-phase full-bridge driver module, and convert its temperature change into a voltage signal and transmit it to the controller module.

[0060] Specifically, refer to Figure 4 :

[0061] The MOS tube temperature sampling unit includes thermistor RT1 and voltage divider resistors R29 and R30. This design is used to convert the temperature change of the MOS tube in the three-phase full-bridge driver module into a voltage signal and transmit it to pin 15 of controller N1.

[0062] The MOS tube driver module is used to drive the MOS tubes in the three-phase full-bridge driver module to turn on and off.

[0063] Specifically, refer to Figure 5 :

[0064] The MOS transistor driver module includes chips N3, N5, and N6. Chips N3, N5, and N6 are used to improve the controller's driving capability and have built-in dead-zone protection, which can increase the switching frequency of the MOS transistor while preventing direct conduction between the upper and lower bridge arms. Preferably, the model of chips N3, N5, and N6 is SLM2181.

[0065] The MOS tube driver module also includes bootstrap capacitors C9, C10, C11 and bootstrap diodes D1, D2, and D3, which respectively form bootstrap circuits to provide sufficient gate drive voltage for the MOS tubes in the three full-bridge driver modules to ensure that they can be turned on and off normally.

[0066] The controller module is used to calculate the required control quantity based on the collected temperature signal, current signal and preset control target, and generate a drive signal for controlling the MOS tube drive module.

[0067] Specifically, refer to Figure 6 :

[0068] The controller module includes a controller, preferably a GD32E103CBT6 controller. Pins 13 and 14 of the controller are AD sampling ports for collecting phase currents I_V and I_U; pin 15 of the controller is an AD sampling port for collecting MOS tube temperature information; and pins 26, 27, 28, 29, 30, and 31 of the controller output PWM waves for driving the MOS tube on and off.

[0069] This utility model is a circuit for driving an oxygen compressor based on phase current sampling using the internal resistance of a MOS tube. By detecting changes in the voltage drop from the internal resistance of the MOS tube, accurate phase current detection is achieved. Simultaneously, by detecting changes in the temperature of the MOS tube, temperature compensation is performed for changes in the internal resistance of the MOS tube due to temperature changes, eliminating the influence of temperature factors on phase current detection. This allows the oxygen compressor drive circuit to have a wider temperature range of application.

[0070] The controller calculates the required control quantity based on the obtained current signal and the preset control target, outputs the corresponding PWM waveform, generates the corresponding drive signal through the MOS tube drive circuit, and controls the conduction and shutdown of the upper and lower bridge arm MOS tubes in the three full-bridge drive module, thereby realizing the drive control of the motor.

[0071] Compared with existing technologies, this solution eliminates the need for an external current sensor, reducing system cost and complexity while also improving system reliability and stability. Furthermore, by collecting MOS tube temperature data and performing temperature compensation on its internal resistance, the impact of temperature fluctuations on the MOS tube's internal resistance is eliminated, extending the circuit's temperature range. By utilizing high-precision detection and processing circuits and advanced chip control algorithms, precise detection and control of motor current are achieved, improving compressor operating efficiency and control performance.

[0072] Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An oxygen compressor drive circuit, characterized in that: The circuit includes a sampling module, a controller module, a MOS tube driving module and a three-phase full-bridge driving module; wherein: The three-phase full-bridge driver module includes upper-arm MOS transistors Q1, Q2, Q3 and lower-arm MOS transistors Q4, Q5, Q6, wherein: The upper bridge arm MOS transistor Q1 and the lower bridge arm MOS transistor Q4 are connected in series between the power supply VCC and GND, and the oxygen compressor VS1 is connected to the middle node VS1 between the upper bridge arm MOS transistor Q1 and the lower bridge arm MOS transistor Q4; The upper bridge arm MOS transistor Q2 and the lower bridge arm MOS transistor Q5 are connected in series between the power supply VCC and GND, and the oxygen compressor VS2 is connected to the intermediate node VS2 between the upper bridge arm MOS transistor Q2 and the lower bridge arm MOS transistor Q5; The upper bridge arm MOS transistor Q3 and the lower bridge arm MOS transistor Q6 are connected in series between the power supply VCC and GND, and the oxygen compressor VS3 is connected to the intermediate node VS3 between the upper bridge arm MOS transistor Q3 and the lower bridge arm MOS transistor Q6; The sampling module includes a phase current sampling unit and a MOS tube temperature sampling unit, wherein: The phase current sampling unit includes a differential amplifier circuit composed of a dual operational amplifier N1, which is used to detect the current changes of two of the three full-bridge drive modules; The MOS tube temperature sampling unit includes a thermistor RT1 and voltage divider resistors R29 and R30, which are used to convert the temperature change of the MOS tube in the three-phase full-bridge drive module into a voltage signal and transmit it to the controller module.

2. The oxygen compressor driving circuit according to claim 1, characterized in that: The three-phase full-bridge drive module further includes resistors R1, R2, R3, R10, R11, and R12 and capacitors C1, C2, C3, C4, C5, and C6 to form an RC spike pulse absorption circuit.

3. The oxygen compressor driving circuit according to claim 2, characterized in that: The resistor R1 is connected in series with the capacitor C1 and then connected in parallel with the upper arm MOS transistor Q1; The resistor R2 is connected in series with the capacitor C2 and then connected in parallel with the upper bridge arm MOS transistor Q2; The resistor R3 is connected in series with the capacitor C3 and then connected in parallel with the upper arm MOS tube Q3; The resistor R10 is connected in series with the capacitor C4 and then connected in parallel with the lower bridge arm MOS tube Q4; The resistor R11 is connected in series with the capacitor C5 and then connected in parallel with the lower bridge arm MOS transistor Q5; The resistor R12 and the capacitor C6 are connected in series and then connected in parallel to the lower bridge arm MOS transistor Q5.

4. The oxygen compressor driving circuit according to claim 3 or 1, characterized in that: The three-phase full-bridge drive module also includes pull-down resistors R7, R8, R9, R16, R17, and R18, which are used to increase the turn-off speed of the upper-arm MOS transistors Q1, Q2, and Q3 and the lower-arm MOS transistors Q4, Q5, and Q6; wherein the pull-down resistors R7, R8, R9, R16, R17, and R18 are respectively connected between the G terminals and GND of the corresponding upper-arm MOS transistors Q1, Q2, and Q3 and the lower-arm MOS transistors Q4, Q5, and Q6.

5. The oxygen compressor driving circuit according to claim 4, characterized in that: The three-phase full-bridge drive module also includes resistors R4, R5, R6, R13, R14, and R15 for eliminating oscillation of the MOS tube, wherein the resistors R4, R5, R6, R13, R14, and R15 are respectively connected in series with the G ends of the corresponding upper-arm MOS tubes Q1, Q2, and Q3 and the lower-arm MOS tubes Q4, Q5, and Q6.

6. The oxygen compressor driving circuit according to claim 1, characterized in that: The controller module includes a controller, and the model of the controller is GD32E103CBT6.

7. The oxygen compressor driving circuit according to claim 1, characterized in that: The dual operational amplifier N1 includes an operational amplifier N1A and an operational amplifier N1B, wherein: The differential amplifier circuit composed of the operational amplifier N1A is provided between the upper bridge arm MOS transistor Q1 and the lower bridge arm MOS transistor Q4; The differential amplifier circuit composed of the operational amplifier N1B is provided between the upper bridge arm MOS transistor Q2 and the lower bridge arm MOS transistor Q5.

8. The oxygen compressor driving circuit according to claim 1, characterized in that: The phase current sampling unit further includes an RC filter circuit consisting of a resistor R21 and a capacitor C7, and a resistor R26 and a capacitor C8.

9. The oxygen generator compressor driving circuit according to claim 1, characterized in that: The MOS tube driving module includes chips N3, N5, and N6, and the models of the chips N3, N5, and N6 are SLM2181.

10. The oxygen compressor driving circuit according to claim 9, characterized in that: The MOS tube driving module further includes bootstrap capacitors C9, C10, C11 and bootstrap diodes D1, D2, D3, which respectively form bootstrap circuits.

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