Low-cost driving circuit for air compressor of ECAS system

Abstract

The utility model discloses a low-cost driving circuit for an air compressor of an ECAS system, and the low-cost driving circuit comprises a high-side driving control circuit which carries out the high-side driving control of the air compressor through a PWM signal outputted by an MCU; the low-side driving control circuit is used for carrying out low-side driving control on the air compressor by utilizing the PWM signal output by the MCU; the low-side driving control circuit is connected with a low-side protection circuit, and the low-side protection circuit performs current sampling on the driving control circuit, performs low-side overcurrent protection and transmits a sampling signal to the MCU; according to the utility model, the MCU is connected with the high-side driving control circuit and the low-side driving control circuit, so that the PWM signal output by the MCU is utilized to carry out high-side and low-side driving control on the air compressor; the protection circuit is arranged, high-low side overcurrent protection can be carried out, the structure is simple, control is easy, safety and reliability are achieved, the requirement for circuit layout is low, and the production cost of the high-low side driving circuit of the air compressor of the ECAS system is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of ECAS system air compressor drive circuits, in particular to a low-cost ECAS system air compressor drive circuit. Background Art

[0002] The electronic-controlled air suspension system ECAS (electronic-controlled air suspension) system is mainly composed of electronic control unit ECU, distribution valve, height sensor, air tank, air compressor and other components. The air compressor used in the ECAS system includes brushless motor, intake and exhaust system, desiccant, etc. At present, the driving circuit scheme of the air compressor is most often implemented by special high-side and low-side driver chips, which are expensive and have relatively simple control. Therefore, it is necessary to design an air compressor driving circuit that is low-cost, easy to implement, flexible in control, and has a wider range of applications.

[0003] The patent document with document number CN116846292A discloses a high-low side drive control method, circuit, device, equipment and storage medium. The method controls the high-low side drive chip based on an enable control signal and a low-level control signal; the high-low side drive chip is controlled by setting an external circuit to achieve the functional safety design of the high-low side drive output. It can be seen from this scheme that the high-low side drive control utilizes the control of the high-low side drive chip, which is expensive and the control is relatively simple. Utility Model Content

[0004] The utility model aims to provide an air compressor driving circuit which has low cost, is easy to realize, has flexible control and has a wider application range.

[0005] The purpose of the utility model can be achieved by the following technical solution: a low-cost driving circuit of an ECAS system air compressor, including a micro control unit MCU, the MCU is connected with:

[0006] The high-side drive control circuit uses the PWM signal output by the MCU to control the high-side drive of the air compressor;

[0007] The low-side drive control circuit uses the PWM signal output by the MCU to control the low-side drive of the air compressor; the low-side drive control circuit is connected to a low-side protection circuit, which samples the current of the drive control circuit and performs low-side overcurrent protection, and transmits the sampling signal to the MCU at the same time;

[0008] The high-side overcurrent protection control circuit uses the overcurrent protection signal output by the MCU to perform high-side overcurrent protection.

[0009] Further: the high-side drive control circuit structure is:

[0010] The microcontroller unit MCU is connected to the gate g2 of the dual MOS tube U1 through R9, D2, and g2 is pulled down to the ground through the resistor R2 and connected to the source s2;

[0011] The drain d2 of the dual MOS tube U1 is connected to the base b1 of the dual triode U2 through the resistor R3, and R3 is connected to the decoupling capacitor C1 through the resistor R1 and then connected to the high-side ground HS_GND;

[0012] The high-side 15V power supply HS_15V is connected to the decoupling capacitor C1 and the emitter e1 of U2 through D1;

[0013] One end of R6 is connected to the drain d1 of the dual-path MOS tube U1, and the other end is connected to the emitter e2 of the dual-path triode U2 and the gate g of the MOS tube Q1;

[0014] The gate g1 of U1 is pulled down to the high-side ground HS_GND through R5; the base b2 of U2 is pulled down to the high-side ground HS_GND through R7, and is connected to the resistor R4 and the anode of the diode D3 at the same time, and the other end of R4 is connected to the collector c1 of U2;

[0015] The cathode of diode D3 is connected to the gate g of MOS tube Q1; the collector c2 of U2 is connected to the high-side ground HS_GND through the pull-down resistor R8;

[0016] The resistor R10 and the capacitor C3 are connected in parallel between the gate g and the source e of the MOS tube Q1;

[0017] Capacitors C2 and C4 are connected in series and then in parallel between the drain d and source e of the MOS tube Q1;

[0018] The source electrode e of the MOS tube Q1 and the drain electrode d of the MOS tube Q2 are connected to a half-bridge driving circuit composed of the U phase of the motor U3.

[0019] Further: the low-side drive control circuit structure is:

[0020] The microcontroller unit MCU is connected to the gate g2 of the dual MOS tube U4 in sequence through R12, D6, and g2 is pulled down to the ground GND through the resistor R13 and connected to the source s2 of U4;

[0021] The drain d2 of the dual MOS tube U4 is connected to the base b1 of the dual triode U5 through the resistor R14, and R14 is connected to the decoupling capacitor C5 through the resistor R11 and then to the ground GND;

[0022] The 15V power supply is connected to the decoupling capacitor C5 and the emitter e1 of U5 through D5;

[0023] One end of R17 is connected to the drain d1 of the dual-way MOS tube U4, and the other end is connected to the emitter e2 of the dual-way triode U5 and the gate g of the MOS tube Q2; the gate g1 of U4 is pulled down to the ground GND through R16;

[0024] The base b2 of U5 is pulled down to ground GND through R18 and connected to the anode of resistor R15 and diode D7 at the same time. The other end of R15 is connected to the collector c1 of U5.

[0025] The cathode of diode D7 is connected to the gate g of MOS tube Q2; the collector c2 of U5 is grounded to GND through the pull-down resistor R19; the resistor R20 and the capacitor C7 are connected in parallel between the gate g and the source e of MOS tube Q2; the capacitors C6 and C8 are connected in series and connected in parallel between the drain d and the source e of MOS tube Q2;

[0026] The source electrode e of the MOS tube Q1 and the drain electrode d of the MOS tube Q2 are connected to a half-bridge driving circuit composed of the U phase of the motor U3.

[0027] Further: the low side protection circuit structure is:

[0028] One end of the sampling resistor R21 is connected to the source electrode e of the MOS tube Q2 and one end of the overcurrent protection circuit module, and the other end of the sampling resistor R21 is grounded GND;

[0029] The other end of the overcurrent protection circuit module is connected to the gate g1 of the dual-path MOS tube U4 through the diode D9, and is also connected to the MCU overcurrent signal sampling port.

[0030] Further: the high side protection circuit structure is:

[0031] The MCU high-side overcurrent protection control tube port is connected to the gate g1 of the dual MOS tube U1.

[0032] Furthermore: the sampling resistor R21 is a thin film resistor with a precision of 1%.

[0033] Beneficial effects of the utility model:

[0034] 1. The utility model connects the high-side drive control circuit and the low-side drive control circuit through the MCU, and uses the PWM signal output by the MCU to control the high and low side drives of the air compressor; a protection circuit is provided to perform high and low side overcurrent protection, and the utility model has a simple structure, is easy to control, is safe and reliable, has low requirements on circuit layout, and reduces the production cost of the high and low side drive circuits of the air compressor of the ECAS system.

[0035] 2. The utility model converts the high-precision thin film resistor R21 into a small voltage signal with high sampling accuracy, which can better realize the current sampling of the flyback power supply circuit, is beneficial to the circuit overcurrent protection, and improves the safety and reliability of the flyback power supply circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 The utility model is a structural schematic diagram of a low-cost driving circuit of an ECAS system air compressor. DETAILED DESCRIPTION

[0037] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar symbols throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0038] like Figure 1 As shown, the utility model discloses a low-cost driving circuit for an ECAS system air compressor, including a microcontroller unit MCU, and the MCU is connected with:

[0039] The high-side drive control circuit uses the PWM signal output by the MCU to control the high-side drive of the air compressor;

[0040] The low-side drive control circuit uses the PWM signal output by the MCU to control the low-side drive of the air compressor; the low-side drive control circuit is connected to a low-side protection circuit, which samples the current of the drive control circuit and performs low-side overcurrent protection, and transmits the sampling signal to the MCU at the same time;

[0041] The high-side overcurrent protection control circuit uses the overcurrent protection signal output by the MCU to perform high-side overcurrent protection.

[0042] The high-side drive control circuit structure is:

[0043] The microcontroller unit MCU is connected to the gate g2 of the dual MOS tube U1 through R9, D2, and g2 is pulled down to the ground through the resistor R2 and connected to the source s2;

[0044] The drain d2 of the dual MOS tube U1 is connected to the base b1 of the dual triode U2 through the resistor R3, and R3 is connected to the decoupling capacitor C1 through the resistor R1 and then connected to the high-side ground HS_GND;

[0045] The high-side 15V power supply HS_15V is connected to the decoupling capacitor C1 and the emitter e1 of U2 through D1;

[0046] One end of R6 is connected to the drain d1 of the dual-path MOS tube U1, and the other end is connected to the emitter e2 of the dual-path triode U2 and the gate g of the MOS tube Q1;

[0047] The gate g1 of U1 is pulled down to the high-side ground HS_GND through R5; the base b2 of U2 is pulled down to the high-side ground HS_GND through R7, and is connected to the resistor R4 and the anode of the diode D3 at the same time, and the other end of R4 is connected to the collector c1 of U2;

[0048] The cathode of diode D3 is connected to the gate g of MOS tube Q1; the collector c2 of U2 is connected to the high-side ground HS_GND through the pull-down resistor R8;

[0049] The resistor R10 and the capacitor C3 are connected in parallel between the gate g and the source e of the MOS tube Q1;

[0050] Capacitors C2 and C4 are connected in series and then in parallel between the drain d and source e of the MOS tube Q1;

[0051] The source electrode e of the MOS tube Q1 and the drain electrode d of the MOS tube Q2 are connected to a half-bridge driving circuit composed of the U phase of the motor U3.

[0052] The low-side drive control circuit structure is:

[0053] The microcontroller unit MCU is connected to the gate g2 of the dual MOS tube U4 in sequence through R12, D6, and g2 is pulled down to the ground GND through the resistor R13 and connected to the source s2 of U4;

[0054] The drain d2 of the dual MOS tube U4 is connected to the base b1 of the dual triode U5 through the resistor R14, and R14 is connected to the decoupling capacitor C5 through the resistor R11 and then to the ground GND;

[0055] The 15V power supply is connected to the decoupling capacitor C5 and the emitter e1 of U5 through D5;

[0056] One end of R17 is connected to the drain d1 of the dual-way MOS tube U4, and the other end is connected to the emitter e2 of the dual-way triode U5 and the gate g of the MOS tube Q2; the gate g1 of U4 is pulled down to the ground GND through R16;

[0057] The base b2 of U5 is pulled down to ground GND through R18 and connected to the anode of resistor R15 and diode D7 at the same time. The other end of R15 is connected to the collector c1 of U5.

[0058] The cathode of diode D7 is connected to the gate g of MOS tube Q2; the collector c2 of U5 is grounded to GND through the pull-down resistor R19; the resistor R20 and the capacitor C7 are connected in parallel between the gate g and the source e of MOS tube Q2; the capacitors C6 and C8 are connected in series and connected in parallel between the drain d and the source e of MOS tube Q2;

[0059] The source electrode e of the MOS tube Q1 and the drain electrode d of the MOS tube Q2 are connected to a half-bridge driving circuit composed of the U phase of the motor U3.

[0060] The low side protection circuit structure is:

[0061] One end of the sampling resistor R21 is connected to the source electrode e of the MOS tube Q2 and one end of the overcurrent protection circuit module, and the other end of the sampling resistor R21 is grounded GND;

[0062] The other end of the overcurrent protection circuit module is connected to the gate g1 of the dual-path MOS tube U4 through the diode D9, and is also connected to the MCU overcurrent signal sampling port.

[0063] The high side protection circuit structure is:

[0064] The MCU high-side overcurrent protection control tube port is connected to the gate g1 of the dual MOS tube U1.

[0065] The sampling resistor R21 is a thin film resistor with a precision of 1%.

[0066] After adopting the above structure, when controlling the air compressor:

[0067] In the first step, the high-side control pin of the microcontroller unit MCU outputs a high level in the PWM state, and drives the gate g2 of the dual MOS tube U1 through R9 and D2. The drain d2 and source s2 of the dual MOS tube U1 are turned on and connected to the high-side ground HS_GND, and the base b1 of the dual triode U2 is pulled down to the high-side ground HS_GND through the resistor R3, so that the emitter e1 and collector c1 of the dual triode U2 are turned on, and the voltage after the high-side 15V power supply (HS_15V) is filtered by the diode D1 and the decoupling capacitor C1 passes through the emitter e1, collector c1, resistor R4, and diode D3 of the dual triode U2 in turn to the gate of the MOS tube Q1, and the MOS tube Q1 is turned on.

[0068] In the second step, the high-side control pin of the microcontroller unit MCU outputs a low level in the PWM state, the gate g2 of the dual MOS tube U1 is connected to the high-side ground HS_GND through the pull-down resistor R2, the drain d2 and source s2 of the dual MOS tube U1 are not conducting, the emitter e1 and collector c1 of the dual triode U2 cannot be conducting, the high-side 15V power supply (HS_15V) cannot pass through the diode D1, the emitter e1 of the dual triode U2, the collector c1, the resistor R4, and the diode D3 to the gate of the MOS tube Q1, and there is no voltage on the gate of the MOS tube Q1, so it is not conducting; the PWM working mode of the high-side MOS tube Q1 is realized through the first and second steps.

[0069] In the third step, the low-side control pin of the microcontroller unit MCU outputs a high level in the PWM state, and drives the gate g2 of the dual MOS tube U4 through R12 and D6. The drain d2 and source s2 of the dual MOS tube U4 are connected to the ground GND after being turned on, and the base b1 of the dual triode U5 is pulled down to the ground GND through the resistor R15, so that the emitter e1 and collector c1 of the dual triode U2 are turned on, and the low-side 15V voltage after being filtered by the diode D5 and the decoupling capacitor C5 passes through the emitter e1, collector c1, resistor R15, and diode D4 of the dual triode U5 in turn to reach the gate of the MOS tube Q2, and the MOS tube Q2 is turned on.

[0070] In the fourth step, the low-side control pin of the microcontroller unit MCU outputs a low level in the PWM state, the gate g2 of the dual MOS tube U4 is connected to the low-side GND through the pull-down resistor R13, the drain d2 and the source s2 of the dual MOS tube U4 are not conducting, the emitter e1 and the collector c1 of the dual triode U5 cannot be conducting, the low-side 15V cannot pass through the diode D5, the emitter e1 of the dual triode U5, the collector c1, the resistor R15, and the diode D4 to the gate of the MOS tube Q2, and there is no voltage on the gate of the MOS tube Q2 and thus it is not conducting; the PWM working mode of the low-side MOS tube Q1 is realized through the third and fourth steps.

[0071] In the fifth step, when the motor has an overcurrent, the voltage signal generated by the current sampled by the sampling resistor R21 outputs an overcurrent feedback signal (high level) through the overcurrent protection chip. This high level signal is input to the gate g1 of the dual-path MOS tube U4 through the diode D9, thereby realizing the rapid conduction of d1 and s1 of the dual-path MOS tube U4. The gate of the MOS tube Q2 passes through the resistor R17 in turn, and the drain d1 and source s1 of the dual-path MOS tube U4 are connected to GND, thereby realizing the rapid shutdown protection of the MOS tube Q2 when overcurrent occurs.

[0072] In the sixth step, the voltage signal generated by the current sampled by the sampling resistor R21 outputs the overcurrent feedback signal (high level) through the overcurrent protection chip and is sent to the MCU overcurrent signal sampling port at the same time. The MCU high-side overcurrent protection control port outputs a high-level signal, which is input to the gate g1 of the dual-channel MOS tube U1 to achieve rapid conduction of d1 and s1 of the dual-channel MOS tube U1. The gate of the MOS tube Q1 passes through the resistor R6 in turn, and the drain d1 and source s1 of the dual-channel MOS tube U1 are connected to HS_GND, thereby achieving rapid shutdown protection of the MOS tube Q1 when overcurrent occurs.

[0073] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent substitutions or changes according to the technical scheme and concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

[0074] It should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0075] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present utility model, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0076] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0077] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

Claims

1. A low-cost drive circuit for an ECAS system air compressor, characterized in that: Including micro control unit MCU, MCU is connected with: The high-side drive control circuit uses the PWM signal output by the MCU to control the high-side drive of the air compressor; The low-side drive control circuit uses the PWM signal output by the MCU to control the low-side drive of the air compressor; the low-side drive control circuit is connected to a low-side protection circuit, which samples the current of the drive control circuit and performs low-side overcurrent protection, and transmits the sampling signal to the MCU at the same time; The high-side overcurrent protection control circuit uses the overcurrent protection signal output by the MCU to perform high-side overcurrent protection.

2. The low-cost driving circuit of an ECAS system air compressor according to claim 1, characterized in that: The high-side drive control circuit structure is: The microcontroller unit MCU is connected to the gate g2 of the dual MOS tube U1 through R9, D2, and g2 is pulled down to the ground through the resistor R2 and connected to the source s2; The drain d2 of the dual MOS tube U1 is connected to the base b1 of the dual triode U2 through the resistor R3, and R3 is connected to the decoupling capacitor C1 through the resistor R1 and then connected to the high-side ground HS_GND; The high-side 15V power supply HS_15V is connected to the decoupling capacitor C1 and the emitter e1 of U2 through D1; One end of R6 is connected to the drain d1 of the dual-path MOS tube U1, and the other end is connected to the emitter e2 of the dual-path triode U2 and the gate g of the MOS tube Q1; The gate g1 of U1 is pulled down to the high-side ground HS_GND through R5; the base b2 of U2 is pulled down to the high-side ground HS_GND through R7, and is connected to the resistor R4 and the anode of the diode D3 at the same time, and the other end of R4 is connected to the collector c1 of U2; The cathode of diode D3 is connected to the gate g of MOS tube Q1; the collector c2 of U2 is connected to the high-side ground HS_GND through the pull-down resistor R8; The resistor R10 and the capacitor C3 are connected in parallel between the gate g and the source e of the MOS tube Q1; Capacitors C2 and C4 are connected in series and then in parallel between the drain d and source e of the MOS tube Q1; The source electrode e of the MOS tube Q1 and the drain electrode d of the MOS tube Q2 are connected to a half-bridge driving circuit composed of the U phase of the motor U3.

3. The low-cost driving circuit of an ECAS system air compressor according to claim 1, characterized in that: The low-side drive control circuit structure is: The microcontroller unit MCU is connected to the gate g2 of the dual MOS tube U4 through R12, D6 in sequence, and g2 is pulled down to the ground GND through the resistor R13 and connected to the source s2 of U4; The drain d2 of the dual MOS tube U4 is connected to the base b1 of the dual triode U5 through the resistor R14, and R14 is connected to the decoupling capacitor C5 through the resistor R11 and then to the ground GND; The 15V power supply is connected to the decoupling capacitor C5 and the emitter e1 of U5 through D5; One end of R17 is connected to the drain d1 of the dual-way MOS tube U4, and the other end is connected to the emitter e2 of the dual-way triode U5 and the gate g of the MOS tube Q2; the gate g1 of U4 is pulled down to the ground GND through R16; The base b2 of U5 is pulled down to ground GND through R18 and connected to the anode of resistor R15 and diode D7. The other end of R15 is connected to the collector c1 of U5. The cathode of diode D7 is connected to the gate g of MOS tube Q2; the collector c2 of U5 is grounded to GND through the pull-down resistor R19; the resistor R20 and the capacitor C7 are connected in parallel between the gate g and the source e of MOS tube Q2; the capacitors C6 and C8 are connected in series and connected in parallel between the drain d and the source e of MOS tube Q2; The source electrode e of the MOS tube Q1 and the drain electrode d of the MOS tube Q2 are connected to a half-bridge driving circuit composed of the U phase of the motor U3.

4. The low-cost driving circuit of an ECAS system air compressor according to claim 1, characterized in that: The low side protection circuit structure is: One end of the sampling resistor R21 is connected to the source electrode e of the MOS tube Q2 and one end of the overcurrent protection circuit module, and the other end of the sampling resistor R21 is grounded GND; The other end of the overcurrent protection circuit module is connected to the gate g1 of the dual-path MOS tube U4 through the diode D9, and is also connected to the MCU overcurrent signal sampling port.

5. The low-cost driving circuit of an ECAS system air compressor according to claim 1, characterized in that: The high side protection circuit structure is: The MCU high-side overcurrent protection control tube port is connected to the gate g1 of the dual MOS tube U1.

6. The low-cost driving circuit of an ECAS system air compressor according to claim 4, characterized in that: The sampling resistor R21 is a thin film resistor with a precision of 1%.

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