A vehicle air conditioning compressor control circuit and control method

Abstract

This invention relates to the field of vehicle air conditioning control technology, and more particularly to a vehicle air conditioning compressor control circuit and control method. The control circuit includes: an air conditioning controller, a vehicle controller, and a compressor; the air conditioning controller is connected to the vehicle controller via a switch button, and the vehicle controller is connected to the compressor via an integrated power supply. When the switch button is closed, the vehicle controller controls the integrated power supply to provide high-voltage power to the compressor; the air conditioning controller is also connected to the vehicle controller via a three-state pressure switch, and the vehicle controller is also directly connected to the compressor. When the switch button is closed, the vehicle controller controls the compressor to start and stop. This invention solves the problem that frequent high-voltage disconnection and pre-charging of the compressor due to the disconnection of the three-state pressure switch signal, which affects the compressor's lifespan.

Description

Technical Field

[0001] This invention relates to the field of vehicle air conditioning control technology, and in particular to a vehicle air conditioning compressor control circuit and control method. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] In existing control methods for air conditioning compressors in new energy commercial vehicles, the main technical solution is as follows: the air conditioning controller is electrically connected to the air conditioning compressor and the fan motor in sequence, and a three-state switch is connected between the air conditioning compressor and the air conditioning controller. Figure 1 As shown. The three-state pressure switch refers to the automotive air conditioning pressure switch, a control element in the air conditioning control system used to protect the air conditioning compressor. After the vehicle is powered by high voltage, the air conditioning controller can normally supply 12V power. Pressing the air conditioning controller's power control button, and then pressing the A / C button, the air conditioning controller outputs a signal through the three-state pressure switch to the integrated power supply and the air conditioning compressor. The air conditioning contactor in the integrated power supply closes, the air conditioning compressor starts working, and the condenser fan starts working simultaneously.

[0004] However, the drawback of this control method is that when the three-state pressure switch signal is disconnected, the compressor will frequently disconnect the high pressure and frequently precharge, which will affect the life of the air conditioner compressor. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a vehicle air conditioning compressor control circuit that solves the problem of frequent high-pressure disconnection and frequent pre-charging of the compressor due to the disconnection of the three-state pressure switch signal, which in turn affects the compressor's lifespan.

[0006] To achieve the above objectives, the embodiments of the present invention provide the following technical solutions:

[0007] A vehicle air conditioning compressor control circuit includes: an air conditioning controller, a vehicle controller, and a compressor; the air conditioning controller is connected to the vehicle controller via a switch button, and the vehicle controller is connected to the compressor via an integrated power supply; when the switch button is closed, the vehicle controller controls the integrated power supply to provide high-voltage power to the compressor; the air conditioning controller is also connected to the vehicle controller via a three-state pressure switch, and the vehicle controller is also directly connected to the compressor; when the switch button is closed, the vehicle controller controls the compressor to start and stop.

[0008] Preferably, the three-state pressure switch includes a high-low pressure switch and a medium pressure switch. The A3 pin of the air conditioning controller is connected to the high-low pressure switch via the switch button and then to the A-5J pin of the vehicle controller. The B12 pin of the air conditioning controller is connected to the B-5G pin of the vehicle controller via the medium pressure switch.

[0009] Preferably, it also includes a power relay, wherein the A-5A pin of the vehicle controller is connected to the power relay, and the power relay is connected to the A12 pin of the air conditioning controller for supplying power to the air conditioning controller.

[0010] Preferably, the integrated power supply includes an air conditioning contactor, the vehicle controller is connected to the air conditioning contactor via a high-voltage battery, the air conditioning contactor is then connected to the compressor, and the vehicle controller can control the air conditioning contactor to close to supply power to the compressor.

[0011] Preferably, the vehicle controller is also connected to a condenser fan control circuit, which connects condenser fan 1 and condenser fan 2. The condenser fan control circuit includes a high-speed condenser fan relay and a low-speed condenser fan relay. The high-speed condenser fan relay is connected to condenser fan 1, and the low-speed condenser fan relay is connected to condenser fan 2.

[0012] Preferably, the condenser fan control circuit further includes a condenser fan high / low speed switching relay, which is used to switch the operation of condenser fan 1 and condenser fan 2.

[0013] This invention also provides a control method for the vehicle air conditioning compressor control circuit as described above. The air conditioning controller outputs two switching signals. The first switching signal controls the integrated power supply to provide high-voltage power to the front end of the compressor via the vehicle controller. The second switching signal is transmitted to the vehicle controller via the three-state pressure switch to control the compressor to start.

[0014] Preferably, after receiving the second control signal, the vehicle controller controls the compressor to start when it confirms that the battery charge is greater than a predetermined value and the compressor is powered by high voltage.

[0015] Preferably, before the air conditioner controller outputs a switch signal, it determines whether the heating, ventilation and air conditioning fans are working. When the heating, ventilation and air conditioning fans are working, the air conditioner controller outputs a switch signal.

[0016] Preferably, the vehicle controller stops the compressor after a predetermined time has elapsed since it no longer receives the on signal from the air conditioning controller.

[0017] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

[0018] 1. This invention divides the on signal output of the air conditioning controller into two paths. The first path, a switch signal, controls the integrated power supply via the vehicle controller to provide high-voltage power to the compressor front end. The second path, a switch signal, is transmitted to the vehicle controller via the three-state pressure switch to control the compressor startup. Even when the three-state pressure switch signal is disconnected, the high-voltage power to the compressor front end will not be disconnected. This ensures that unless the air conditioning is manually turned off, the electric compressor front end will maintain a high voltage state. This solves the problem of frequent high-voltage disconnection and pre-charging of the compressor due to the disconnection of the three-state pressure switch, thus affecting the compressor's lifespan and extending its service life.

[0019] 2. In existing technologies, the air conditioner can still be turned on normally when the SOC (State of Charge) of the power battery is low, which will consume the power of the high-voltage battery too quickly and affect its lifespan. In this invention, the vehicle controller will only output a low level through a pin when it confirms that the battery power is greater than a predetermined value (15%). When the SOC of the high-voltage battery is too low, there is an air conditioner start protection, and at the same time, a soft stop protection for the electric compressor can be realized, extending the lifespan of the electric compressor.

[0020] Advantages of additional aspects of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

[0021] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0022] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0023] Figure 1 This is a schematic diagram of the existing air conditioner compressor control method;

[0024] Figure 2 This is a schematic diagram of the air conditioner compressor control circuit provided in an embodiment of the present invention;

[0025] The distances or dimensions between parts have been exaggerated to show their positions; the diagram is for illustrative purposes only. Detailed Implementation

[0026] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0027] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this disclosure. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms “comprising” and / or “including” are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0028] Where there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0029] Terminology Explanation:

[0030] CAN message: refers to a frame in which the sending unit transmits data to the receiving unit.

[0031] Example 1

[0032] A three-state pressure switch refers to an automotive air conditioning pressure switch (sensor). The air conditioning pressure switch is a control element in the air conditioning control system. Because it operates under high, low, and medium pipeline pressures respectively, it is called a "three-state pressure switch." A three-state pressure switch is a protective switch, consisting of a high-pressure switch, a low-pressure switch, and a medium-pressure switch. The three-state pressure switch is installed on the high-pressure pipeline, and its functions are as follows: (1) Low-pressure switch: When there is a leak in the air conditioning system or low refrigerant levels, it forcibly cuts off the compressor's control circuit to prevent damage to the compressor, causing the compressor to stop working. (2) Medium-pressure switch: When the condensing pressure is too high, it forcibly makes the condenser fan rotate at high speed to reduce the high-pressure and increase the cooling effect. (3) High-pressure switch: To prevent excessive system pressure from causing a system explosion, it forcibly stops the compressor. When the air conditioning high-pressure is abnormally high, the high-pressure switch opens, cutting off the compressor's control circuit and causing the air conditioning system to stop working.

[0033] Existing control connection methods such as Figure 1 As shown, the air conditioner controller is electrically connected to the air conditioner compressor and the fan motor in sequence. A three-state switch is connected between the air conditioner compressor and the air conditioner controller. When the three-state pressure switch signal is disconnected, it will cause the compressor to frequently disconnect the high pressure and frequently precharge, which will affect the life of the air conditioner compressor.

[0034] To address the above-mentioned technical problems, this invention proposes a vehicle air conditioning compressor control circuit, such as... Figure 2As shown, it includes: an air conditioning controller, a vehicle controller, and a compressor; the air conditioning controller is connected to the vehicle controller via a switch button, and the vehicle controller is connected to the compressor via an integrated power supply. When the switch button is closed, the vehicle controller controls the integrated power supply to provide high-voltage power to the compressor; the air conditioning controller is also connected to the vehicle controller via a three-state pressure switch, and the vehicle controller is also directly connected to the compressor. When the switch button is closed, the vehicle controller controls the compressor to start and stop.

[0035] This invention splits the on signal output of the air conditioning controller into two paths. The first path, a switch signal, controls the integrated power supply via the vehicle controller to provide high-voltage power to the compressor's front end. The second path, a switch signal, is transmitted to the vehicle controller via a three-state pressure switch to control the compressor's start-up. Even when the three-state pressure switch signal is off, the high-voltage power to the compressor's front end remains uninterrupted. This ensures that unless the air conditioning is manually turned off, the electric compressor's front end will maintain a high voltage state. This solves the problem of frequent high-voltage disconnection and pre-charging caused by the three-state pressure switch, which affects the compressor's lifespan and extends its service life.

[0036] By deeply participating in the control of the air conditioning compressor through the vehicle controller, the following processes are achieved: air conditioning start signal input, compressor pre-charge and start working, condenser fan (i.e., condenser blower) low-speed operation, condenser fan high-speed operation, and air conditioning power-off process:

[0037] Air conditioning on signal input: After the vehicle's high voltage is ready, the vehicle controller outputs a high level. This high level controls the air conditioning panel power relay to supply power to the air conditioning controller. A high level input via the A-4M pin of the vehicle controller causes the controller to receive this signal and control the integrated power supply air conditioning contactor to close via a CAN message. At this time, pressing the A / C button on the air conditioning controller will cause a pin on the controller to output an A / C switch signal.

[0038] After the compressor is pre-charged, it starts to work: The A / C switch signal output by a certain pin of the air conditioning controller has two lines. One line controls the integrated power supply air conditioning contactor to close, so that the high voltage power supply at the front end of the air conditioning electric compressor is completed; the other line, line 2, is transmitted to the vehicle controller through the air conditioning three-state pressure switch. After the vehicle controller receives this signal and confirms that the battery power is greater than 15% and the air conditioning main contactor is closed, it outputs a low level to the electric compressor, and the electric compressor starts to work.

[0039] The operation process between the two A / C switch signals and the high / low pressure switch and medium pressure switch is as follows: After the A / C button is turned on, when the air conditioning high pressure line pressure is between (0.226±0.03)MPa and (2.25±0.2)MPa, the high / low pressure switch terminals of the three-state pressure switch are normally closed, that is, pins 1 and 4 are normally open. At this time, the A / C switch signal is transmitted to the A-5J pin of the vehicle controller through the high / low pressure switch terminals. When the line pressure is ≥1.52±0.1MPa, the medium pressure switch terminal of the three-state pressure switch is closed, that is, pins 2 and 3 are connected. At this time, the B-5G pin of the vehicle controller receives the high-speed fan operation signal and controls the condenser fan to operate at high speed.

[0040] The condenser fan operates at low speed: When the vehicle controller receives a compressor start signal or when the motor or electronic control system has a heat dissipation requirement, the vehicle controller controls the condenser fan to operate at low speed.

[0041] The high / low speed switching of the condenser fan is as follows: During air conditioning operation, when the pipeline pressure is ≥1.52±0.1MPa, the medium pressure switch terminal of the three-state pressure switch is closed. At this time, after the vehicle controller B-5G pin receives the high-speed operation signal of the fan, the vehicle controller B-5B pin controls the high-speed relay of the condenser fan and the high / low speed conversion relay of the condenser fan to work. At this time, the condenser fan works at high speed to achieve the purpose of rapid heat dissipation. As the condenser fan runs at high speed, the pipeline pressure drops accordingly. When the pipeline pressure drops to 1.22±0.12MPa, the medium pressure switch terminal of the three-state pressure switch is opened, and the condenser fan continues to run at low speed.

[0042] The condenser fan operates at high speed: When the air conditioning pipe pressure is high, the vehicle controller controls the condenser fan to operate at high speed to achieve the purpose of heat dissipation.

[0043] The air conditioning power-off process is as follows: after the vehicle controller does not receive the air conditioning on signal, it delays for 3 seconds and sends a disconnect command to the air conditioning contactor to control the compressor to stop.

[0044] Specifically, the control system for the fixed-frequency compressor of the air conditioner for new energy commercial vehicles includes a vehicle controller, an air conditioner controller, an air conditioner controller power relay, an electric compressor, an integrated power supply, a high-voltage battery, a high-speed relay for the condenser fan, a low-speed relay for the condenser fan, a high-low speed conversion relay for the condenser fan, and a three-state pressure switch.

[0045] The vehicle controller control circuit includes pins B-3L, A-5A, A-4M, A-5J, B-5G, B-1F, A-5H, A-4H, B-3B, B-5B, A-5M, and B-1L, with pin B-3L grounded. Pin A-5A is connected to the air conditioning panel relay, controlling the relay to supply power to the air conditioning controller. Pin A-4M is connected to pin A3 of the air conditioning controller, and the switch signal output from pin A3 of the air conditioning controller is sent to pin A-4M of the vehicle controller. Pin A-5J is connected to pin 4 of the high / low voltage switch of the three-state pressure switch. Pin B-5G is connected to pin 3 of the three-state pressure switch. Pin B-1F is connected to pin D1 of the electric compressor. When the integrated power supply air conditioning contactor is closed and the compressor start / stop signal is input (i.e., A-5J has a high-level input), pin B-1F... The output is low to the compressor D1 pin; pins A-5H and A-4H are communication line pins, connected to the integrated power supply J1 and J2 pins and the high-voltage battery G1 and G2 pins respectively, to realize CAN communication between the vehicle controller, the integrated power supply, and the high-voltage battery; pin B-3B is connected to the condenser fan low-speed relay. When there is a compressor start / stop signal input (i.e., A-5J has a high-level input) or when the motor or electronic control has a heat dissipation requirement, pin B-3B outputs a low level, and the condenser fan operates at low speed; pin B-5B is connected to the condenser fan high-speed relay and the condenser fan high-low speed conversion relay respectively. When the vehicle controller pin B-5G has a high-speed fan enable signal input, pin B-5B outputs a low level, and the condenser fan operates at high speed; pin A-5M is connected to the IGN power supply; and pin B-1L is connected to a constant 12V power supply.

[0046] The air conditioning controller control circuit includes pins C1, C6, A2, A12, and B12, with pin A12 grounded. Pin A2 is connected to the air conditioning controller power relay. When the vehicle is powered by high voltage, the vehicle controller A-5A outputs a high level to control the air conditioning controller power relay to supply power to pin A2 and pin D2 of the electric compressor. Pins C1 and C6 are connected to the front evaporator temperature sensor, which feeds back the front evaporator temperature to the air conditioning controller. The signal from pin A3 is divided into an A / C switch signal, outputting in two paths. One path connects to pin 1 of the high / low voltage switch of the three-state pressure switch. The low-pressure switch pin 4 connects to the vehicle controller pin A-5J to control the compressor's start and stop. The second line connects to the vehicle controller pin A-4M. Upon receiving this signal, the vehicle controller controls the air conditioning contactor within the integrated power supply to close via a CAN message. Pin B12 connects to the medium-pressure switch pin 2 of the three-state pressure switch. When the pipeline pressure is ≥1.52±0.1MPa, the medium-pressure switch closes, and the signal travels through the medium-pressure switch pin 3 to the vehicle controller pin B-5G, which is the high-speed fan enable signal input. Upon receiving this signal, the vehicle controller controls the condenser fan to operate at high speed.

[0047] The integrated power control circuit includes pins J1 to J9, of which pins J6 to J9 are high-voltage pins; pins J6 and J7 are connected to electric compressor pins D5 and D6 respectively, serving as the positive and negative input pins of the high-voltage power supply; pins J8 and J9 are connected to high-voltage battery pins G6 and G7 respectively, serving as the positive and negative input pins of the high-voltage power supply; pin J5 is grounded; pin J3 is connected to the IGN power supply; and J4 is connected to a constant 12V power supply.

[0048] The electric compressor control circuit includes pins D1, D2, D3, D5, and D6, with pin D3 grounded.

[0049] The high-voltage battery control circuit includes pins G1 to G5, G6, and G7, with pin G5 grounded; pin G3 connected to the IGN power supply; and pin G4 connected to a constant 12V power supply.

[0050] Example 2

[0051] This embodiment relates to a control method for a fixed-frequency compressor used in the air conditioning of new energy commercial vehicles, including:

[0052] Step S01: After the vehicle is connected to high voltage, the high voltage is ready. The vehicle controller outputs a high level from pin A-5A. This high level controls the power relay KA of the air conditioning panel to supply power to the air conditioning controller, so that the air conditioning controller can be powered normally.

[0053] Step S02: After turning on the power control button of the air conditioner controller, press the A / C button. At this time, a certain pin of the air conditioner controller outputs a high level, which is the A / C switch signal. This signal is divided into two paths.

[0054] It should be noted that when the A / C button is pressed, the air conditioning controller will only output a high level after the front HVAC (heating, ventilation and air conditioning) fan has started blowing air. This can effectively prevent the compressor from frequently starting and stopping due to the front HVAC fan's frost protection caused by the inability to expel cold air.

[0055] Step S03: The A / C switch signal sent from the air conditioning controller pin goes directly to the A-4M pin of the vehicle controller. After receiving this signal, the vehicle controller controls the air conditioning contactor K1 to close via CAN message, so that the high voltage power supply to the front end of the air conditioning electric compressor is completed.

[0056] Step S04: The A / C switch signal from the air conditioning controller pin passes through the air conditioning three-state pressure switch. When the air conditioning pipe pressure is within the normal range, the signal is transmitted to the A-5J pin of the vehicle controller, which is the air conditioning compressor start / stop signal. When the A-5J pin of the vehicle controller receives a high level and the air conditioning contactor K1 is closed, the B-1F pin of the vehicle controller outputs a low level to the electric compressor. Upon receiving this signal, the compressor starts working.

[0057] Specifically, the vehicle controller will only output a low level through the B-1F pin when it confirms that the battery charge is greater than 15%.

[0058] Step S05: When the vehicle controller receives a compressor start signal input, i.e., when A-5J has a high-level input, or when the motor or electronic control has a heat dissipation requirement, pin B-3B outputs a low level to control the condenser fan to run at low speed.

[0059] Step S06: When the air conditioning pipe pressure is high, the sensor detects that the oil pressure in the air conditioning pipe is high and sends a signal to the vehicle controller. That is, when there is a low level input on the B-5G pin, the vehicle controller controls the B-5B pin and the B-3B pin to output a low level together, controlling the condenser fan to run at high speed to achieve the purpose of heat dissipation.

[0060] It is worth mentioning that the low-level signal input to the B-5G tube is output by the air conditioner controller. It will only be connected when the pipeline pressure reaches a certain value after passing through the medium-pressure pin of the three-state pressure switch.

[0061] Step S07: If the vehicle controller does not receive the air conditioning on signal, that is, after the vehicle controller pin A-4M is not input, it will send a disconnect command to the multi-function air conditioning contactor K1 after a 3-second delay, and the air conditioning will be turned off.

[0062] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

[0063] Finally, it should be noted that, unless otherwise specified, the embodiments of the present invention and the various features thereof can be combined with each other, all of which are within the protection scope of the present invention. Furthermore, all or part of the steps in the above methods can be executed in a computer system such as a set of computer-executable instructions, and although the steps are listed in the order 1, 2, 3…, in some cases, the steps shown or described may be performed in a different order than that shown here.

Claims

1. A vehicle air conditioning compressor control circuit, characterized by, include: Air conditioning controller, vehicle controller, and compressor; The air conditioning controller outputs two switching signals. The first switching signal controls the integrated power supply of the vehicle controller to supply high voltage power to the front end of the compressor. The second switch signal is transmitted to the vehicle controller via a three-state pressure switch to control the compressor to start; when the three-state pressure switch signal is disconnected, the high voltage at the front end of the compressor will not be disconnected, and the front end of the electric compressor will always maintain a high voltage state; The air conditioning controller is connected to the vehicle controller via a switch button. The vehicle controller is connected to the compressor via an integrated power supply. When the switch button is closed, the vehicle controller controls the integrated power supply to provide high-voltage power to the compressor. The air conditioning controller is also connected to the vehicle controller via a three-state pressure switch. The vehicle controller is also directly connected to the compressor. When the switch button is closed, the vehicle controller controls the compressor to start and stop. The vehicle controller is also connected to a condenser fan control circuit, which connects condenser fan one and condenser fan two. The condenser fan control circuit includes a high-speed condenser fan relay and a low-speed condenser fan relay. The high-speed condenser fan relay is connected to condenser fan one, and the low-speed condenser fan relay is connected to condenser fan two. The condenser fan control circuit also includes a condenser fan high / low speed switching relay, which is used to switch the operation of condenser fan one and condenser fan two.

2. The vehicle air conditioning compressor control circuit as described in claim 1, characterized in that, The three-state pressure switch includes a high-low pressure switch and a medium pressure switch. The A3 pin of the air conditioning controller is connected to the high-low pressure switch via the switch button and then to the A-5J pin of the vehicle controller. The B12 pin of the air conditioning controller is connected to the B-5G pin of the vehicle controller via the medium pressure switch.

3. The vehicle air conditioning compressor control circuit as described in claim 1, characterized in that, It also includes a power relay, with the A-5A pin of the vehicle controller connected to the power relay, and the power relay connected to the A12 pin of the air conditioning controller to supply power to the air conditioning controller.

4. The vehicle air conditioning compressor control circuit as described in claim 1, characterized in that, The integrated power supply includes an air conditioning contactor. The vehicle controller is connected to the air conditioning contactor via a high-voltage battery. The air conditioning contactor is then connected to the compressor. The vehicle controller can control the air conditioning contactor to close and supply power to the compressor.

5. A control method using the vehicle air conditioning compressor control circuit as described in any one of claims 1-4, characterized in that, After receiving the second switch signal, the vehicle controller controls the compressor to start when it confirms that the battery power is greater than a predetermined value and the compressor is powered by high voltage.

6. The control method as described in claim 5, characterized in that, Before the air conditioner controller outputs a switch signal, it determines whether the heating, ventilation and air conditioning fans are working. When the heating, ventilation and air conditioning fans are working, the air conditioner controller outputs a switch signal.

7. The control method as described in claim 5, characterized in that, After the vehicle controller fails to receive the air conditioning controller's on signal for a predetermined time, it controls the compressor to stop.

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