Anti-reverse connection pre-charge system, controller and control method of electric compressor

Abstract

The embodiment of the application provides a reverse connection prevention pre-charging system, a controller and a control method of an electric compressor, which comprise: a power supply circuit composed of a positive line and a negative line; a reverse connection prevention diode and a reverse connection prevention pre-charging negative connection end arranged in the negative line; the reverse connection prevention pre-charging negative connection end is connected with a power supply negative pole; the reverse connection prevention diode can be configured to prevent reverse connection of a power supply and block reverse current from flowing from the reverse connection prevention pre-charging negative connection end to the positive line. The application relates to the field of electric compressors. The reverse connection prevention diode is arranged in the negative line, and when the power supply is reversely connected, the reverse connection prevention diode can reliably block reverse current from flowing from the reverse connection prevention pre-charging negative connection end to the positive line, so that the circuit is protected from damage and the safety and reliability of the system are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of electric compressor, in particular to the anti-reverse connection pre-charge system, controller and control method of electric compressor. BACKGROUND

[0002] In the field of electric compressor, especially in the electric compressor applied to electric vehicle air conditioning system or refrigerated transport equipment, the anti-reverse connection pre-charge system is a key component to ensure the safety of the circuit. The system is mainly used to prevent short circuit or component damage caused by reverse connection of power supply (such as battery pack), and to suppress the impact of transient impact current on bus capacitor at the initial power-on to avoid system failure. In the prior art, the anti-reverse connection pre-charge circuit usually arranges an anti-reverse connection diode on the positive line of the power supply circuit, for example, by connecting the anti-reverse connection diode in series on the positive line to block the reverse current. Although this configuration can achieve basic reverse connection protection, it has obvious limitations: first, the positive line is the high-voltage side, which is not conducive to the integration of low-loss switching elements (such as NMOS transistors), because these elements usually take the negative pole as the reference ground, resulting in complex circuit design and increased cost; second, during normal operation, the voltage drop of the diode will cause continuous power consumption, reducing the system efficiency; third, the arrangement of components on the positive line is easy to interfere with the voltage sampling accuracy, affecting the accurate judgment of the connection state of the power supply. These defects limit the performance of electric compressors in efficient and reliable applications, and it is urgent to optimize the pre-charge system with anti-reverse connection diode arrangement to solve the deficiencies of the prior art. SUMMARY

[0003] According to the embodiments of the present application, the anti-reverse connection pre-charge system, controller and control method of electric compressor are provided to solve the technical problems in the background art.

[0004] In the first aspect of the present application, an anti-reverse connection pre-charge system of electric compressor is provided.

[0005] The anti-reverse connection pre-charge system of electric compressor, the power supply circuit, is composed of a positive line and a negative line;

[0006] An anti-reverse connection diode and an anti-reverse connection pre-charge negative connection end arranged in the negative line;

[0007] The anti-reverse connection pre-charge negative connection end is connected with the negative pole of the power supply;

[0008] The anti-reverse connection diode can be configured to prevent reverse connection of the power supply and block the reverse current flowing from the anti-reverse connection pre-charge negative connection end to the positive line.

[0009] Preferably, a pre-charge resistor is further included, which is arranged in the negative line and connected in series with the anti-reverse connection diode, and is configured to suppress the transient impact current at the initial power-on;

[0010] The anti-reverse connection diode is turned on when the power supply is connected in forward direction, supporting the bus capacitor group to be charged by the pre-charge resistor; and is turned off when the power supply is connected in reverse direction, preventing the circuit from running.

[0011] Preferably, a relay and a driving unit are further included, the relay is arranged in the negative line, in parallel with the series combination of the anti-reverse connection diode and the pre-charge resistor;

[0012] The driving unit is provided with a level output end connected with the control end of the relay, and is configured to output a control level through the level output end when receiving a start signal, so as to make the relay switch to the on state and bypass the anti-reverse connection diode and the pre-charge resistor, so as to reduce the circuit impedance in normal operation.

[0013] Preferably, a control unit is further included, the control unit is connected with the driving unit and is configured to detect the power supply connection state and generate the start signal;

[0014] When the control unit detects that the power supply is connected in reverse direction, the driving unit is prevented from outputting the control level, so as to make the relay remain in the off state, ensuring that the anti-reverse connection diode blocks the reverse current and prevents the circuit from running;

[0015] When the control unit detects that the power supply is connected in forward direction, the start signal is generated to trigger the driving unit to control the relay to be turned on.

[0016] Preferably, the positive line includes a first positive connection end connected with the positive pole of the power supply and a second positive connection end connected with the load;

[0017] The negative line includes a first negative connection end connected with the negative pole of the power supply or the anti-reverse connection pre-charge negative connection end, and a second negative connection end connected with the load;

[0018] A control unit and a trigger switch are further included;

[0019] The control unit is connected with the trigger switch and the driving unit, and is configured to receive a trigger signal and generate the start signal;

[0020] The anti-reverse connection diode and the pre-charge resistor are arranged in series in the negative line, and are turned on to support the bus capacitor group to be charged when the power supply is connected in forward direction, and are turned off to prevent the circuit from running when the power supply is connected in reverse direction;

[0021] The relay is connected in parallel with the series combination of the anti-reverse connection diode and the pre-charge resistor, and is configured to switch the circuit path after receiving the control level, bypassing the anti-reverse connection diode and the pre-charge resistor;

[0022] The control unit is further configured to detect the matching condition between the trigger signal and the circuit state, and prevent the relay from being turned on if the trigger signal exists but the circuit state is abnormal, so as to avoid the compressor from running under unstable conditions.

[0023] Preferably, the application further comprises a voltage sampling terminal and a current detection unit, wherein the voltage sampling terminal is connected with the positive line and configured to detect the input voltage of the positive line and generate the start signal.

[0024] The current detection unit is configured to detect the circuit current value in the pre-charging stage and evaluate whether the current value meets the preset standard.

[0025] The control unit is connected with the current detection unit and configured to monitor the matching condition between the trigger signal and the current value detected by the current detection unit.

[0026] If the current value is lower than the preset threshold, it is determined that the trigger mechanism is invalid, and a fault code is generated to prevent the high-voltage circuit from running.

[0027] In the second aspect of the application, an electric compressor controller is provided, comprising an anti-reverse pre-charging system, and a high-voltage input voltage sampling terminal, a driving circuit, a self-locking circuit, a bus capacitor and a micro control unit.

[0028] The voltage sampling terminal is connected with the positive line and configured to detect the input voltage.

[0029] The signal output terminal of the driving circuit is connected with the relay and configured to output a driving level to control the relay to switch the circuit path when the input voltage meets the preset condition.

[0030] The self-locking circuit is connected with the control terminal of the driving circuit and the relay, and configured to enter a self-locking state after receiving the control signal of the micro control unit, to provide the current required for driving the relay in cooperation with the micro control unit, and to prevent the relay from being accidentally disconnected due to the failure of the micro control unit or external interference.

[0031] In the third aspect of the application, a control method of an electric compressor is provided.

[0032] The method comprises the following steps:

[0033] Collecting the input voltage of the positive line of the high-voltage loop;

[0034] Detecting the current value in the circuit when the input voltage meets the preset range;

[0035] When all the detection parameters meet the preset conditions, sending a driving signal to the control port of the relay to trigger the relay to act, and switching the high-voltage loop from the anti-reverse pre-charging path to the main loop path.

[0036] Preferably, the bus capacitor group voltage value is collected in real time after power-on, and whether the power reverse connection exists is judged based on the theoretical RC charging time, if the reverse connection is detected, a fault notification is generated or the relay is disconnected;

[0037] In the pre-charging process, if the voltage or current value detected does not match the preset value, or if the relay sticking or component damage is detected, a fault code is generated and the high-voltage circuit is prevented from running to prevent the pre-charging resistor from overheating or damage;

[0038] The theoretical RC charging time is calculated according to the pre-charging resistor and the time constant of the bus capacitor group, and is used to verify the normality of the charging curve;

[0039] The control unit is further configured to, when the trigger signal exists, evaluate the effectiveness of the trigger mechanism in combination with the voltage and current detection results, and if an abnormality is detected, a fault protection mechanism is started.

[0040] Preferably, after sending a driving signal to the control port of the relay, the self-locking circuit is activated to enter a working state, cooperates with the micro control unit to provide a driving current, and maintains stable operation of the relay to enhance the anti-interference ability of the circuit;

[0041] If the relay sticking or the pre-charging resistor has an overheating risk, a fault protection mechanism is started to disconnect the high-voltage circuit to prevent component damage.

[0042] One or more technical solutions provided in the present application have at least the following technical effects or advantages:

[0043] The anti-reverse connection pre-charging system of the electric compressor provided by the present application realizes significant technical improvement by arranging an anti-reverse connection diode in the negative line. Specifically:

[0044] Effectively prevent reverse connection of power supply: the anti-reverse connection diode is arranged in the negative line, and when the power supply is reversely connected, the reverse current can be reliably blocked from flowing from the anti-reverse connection pre-charging negative connection end to the positive line, protecting the circuit from damage and improving the safety and reliability of the system.

[0045] Convenient integration of low-loss components: the negative line as a reference ground facilitates the integration of NMOS transistors or other low-loss switching elements, simplifying circuit design, reducing on-resistance and manufacturing cost, and improving overall system efficiency compared to positive line arrangement.

[0046] Reduce normal operation power consumption: by arranging the negative line, it is convenient for subsequent bypassing of the diode path through relays and other components, avoiding continuous power consumption caused by diode voltage drop, and suitable for high-load or long-time running electric compressor applications.

[0047] It is to be understood that the description of the summary section is not intended to identify key or essential features of embodiments of the application, nor is it intended to limit the scope of the application. Other BRIEF DESCRIPTION OF DRAWINGS

[0048] The above and other features, aspects, and advantages of embodiments of the present application will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. In the drawings, like reference numerals refer to like elements, wherein:

[0049] Figure 1 An application scenario of the reverse connection prevention pre-charge circuit is shown;

[0050] Figure 2 A schematic diagram of the reverse connection prevention pre-charge circuit is shown;

[0051] Figure 3 A schematic diagram of the relay driving circuit is shown;

[0052] Figure 4 A schematic diagram of the self-locking circuit is shown;

[0053] Figure 5 A flow chart of the control method is shown;

[0054] Figure 6 A perspective connection structure schematic diagram of the reverse connection prevention pre-charge system of the electric compressor according to an embodiment of the present application is shown;

[0055] Figure 7 An exploded view of the reverse connection prevention pre-charge system of the electric compressor according to an embodiment of the present application is shown;

[0056] Figure 8 A connection structure schematic diagram of the inner container, the cold air pipeline and the partition plate of the reverse connection prevention pre-charge system of the electric compressor according to an embodiment of the present application is shown;

[0057] Figure 9 A connection structure schematic diagram of the control assembly and the cold air pipeline of the reverse connection prevention pre-charge system of the electric compressor according to an embodiment of the present application is shown;

[0058] Figure 10 A connection structure schematic diagram of the control assembly of the reverse connection prevention pre-charge system of the electric compressor according to an embodiment of the present application is shown;

[0059] Figure 11 An exploded view of the trigger assembly of the reverse connection prevention pre-charge system of the electric compressor according to an embodiment of the present application is shown;

[0060] Figure 12 A planar schematic diagram of the trigger assembly of the reverse connection prevention pre-charge system of the electric compressor according to an embodiment of the present application is shown.

[0061] The reference signs are as follows:

[0062] 1-battery pack, 2-motor, 3-bus capacitor group, 4-anti-reverse connection pre-charging circuit, 401-anti-reverse connection diode, 402-pre-charging resistor, 403-relay, 5-driving unit, 6-controller, 7-self-locking circuit, 8-control assembly, 801-handle, 802-rotating plate, 803-groove body, 804-clamping piece, 805-main shaft, 9-trigger assembly, 901-pressing plate, 902-pad plate, 903-sliding rod, 904-spring, 905-baffle, 907-branch pipe, 908-main pipe, 909-trigger switch, 910-air outlet, 911-bracket, 913-shaft body, 10-carriage, 11-refrigeration assembly, 12-inner container, 13-cold air pipeline, 14-baffle, 15-NPN triode, 16-PNP triode. DETAILED DESCRIPTION

[0063] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0064] In addition, the term “and / or” in this document merely describes an association relationship of associated objects, and indicates that there can be three relationships, for example, A and / or B can represent the three cases of existence of A alone, existence of A and B simultaneously, and existence of B alone. In addition, the character “ / ” in this document generally represents an “or” relationship between the front and rear associated objects.

[0065] As shown in Figure 1 , Figure 2 and Figure 3 , the anti-reverse connection pre-charging system of the electric compressor includes the anti-reverse connection pre-charging circuit 4 and other structures, specifically, the anti-reverse connection pre-charging circuit 4 includes a control unit, a trigger switch 909, a voltage sampling end, a current detection unit, an anti-reverse connection diode 401, a pre-charging resistor 402, a relay 403 and a driving unit, which collectively realize the functions of power reverse connection protection, transient impact current suppression and safe operation of the system in the refrigerated truck application.

[0066] The power supply circuit is composed of a positive line and a negative line. The positive line includes a first positive connection end and a second positive connection end. The first positive connection end is connected to the positive electrode of the battery pack 1, and the second positive connection end is connected to the positive electrode end (i.e., the load positive electrode end) of the motor 2. The negative line includes a first negative connection end (i.e., an anti-reverse pre-charging negative connection end) and a second negative connection end. The first negative connection end is connected to the negative electrode of the battery pack 1, and the second negative connection end is connected to the negative electrode end (i.e., the load negative electrode end) of the motor 2.

[0067] The control unit is connected to the drive unit and is configured to detect the connection state of the battery pack 1 and generate a start signal. Specifically, the control unit determines whether the battery pack 1 is connected in forward or reverse direction by detecting the voltage polarity of the first positive connection end and the first negative connection end. When the control unit detects that the battery pack 1 is connected in reverse direction, it prevents the drive unit from outputting a control level (e.g., high level), causing the relay 403 to remain in an open state, ensuring that the anti-reverse diode 401 blocks reverse current and prevents the circuit from operating. When the control unit detects that the battery pack 1 is connected in forward direction, it generates a start signal to trigger the drive unit to output a control level through its level output end, driving the relay 403 to switch to a conductive state.

[0068] The trigger switch 909 is arranged at the bottom of each chamber of the refrigerated truck and is electrically connected to the first negative connection end (i.e., the anti-reverse pre-charging negative connection end) in the negative line. The trigger switch 909 is configured to close the switch by the gravity of the goods itself when the goods are placed at the bottom of the chamber, generating a trigger signal. The trigger signal and the start signal generated by the power supply circuit are jointly input to the control unit, which is used to activate the drive unit to output a control level, causing the relay 403 to switch to a conductive state. The control unit is connected to the trigger switch 909 and the drive unit and is configured to receive the trigger signal and generate the start signal, while detecting the matching condition of the trigger signal and the circuit state. Specifically, the control unit detects the matching between the closed state of the trigger switch 909 and the input voltage of the positive line. If the trigger switch 909 is closed and the input voltage meets the preset range (e.g., within the normal working voltage range), the trigger relay 403 is triggered to switch the high-voltage circuit from the anti-reverse pre-charging path to the main circuit path, while allowing the refrigerant outlet to be mechanically opened under the gravity of the goods to release cold air; if the trigger switch 909 is not closed (e.g., no goods are placed) or the input voltage is abnormal (e.g., exceeds the preset range), the control unit prevents the relay 403 from being conductive, and generates a fault code to prevent the high-voltage circuit from operating, preventing the compressor from starting under the condition of no goods or abnormal power supply.

[0069] The anti-reverse diode 401 and the pre-charge resistor 402 are connected in series in the negative line. The anode of the anti-reverse diode 401 is connected to the first negative connection end, and the cathode is connected to one end of the pre-charge resistor 402, and the other end of the pre-charge resistor 402 is connected to the downstream of the negative line (i.e. towards the second negative connection end). The trigger switch 909 is connected in series with the anti-reverse diode 401 and the pre-charge resistor 402, which ensures that the reverse current is blocked when the power supply is reversely connected, protecting the circuit and the refrigerant outlet control mechanism. The anti-reverse diode 401 is configured to prevent reverse connection of the battery pack 1. When the battery pack 1 is connected in the forward direction, the anti-reverse diode 401 is turned on, allowing current to flow through the pre-charge resistor 402 to pre-charge the bus capacitor bank 3; when the battery pack 1 is reversely connected, the anti-reverse diode 401 is cut off, blocking the reverse current from flowing from the first negative connection end to the positive line, preventing the circuit from running. The pre-charge resistor 402 is configured to limit the current by its resistance value at the initial power-on stage, to suppress the impact of transient impulse current on the bus capacitor bank 3, until the voltage of the bus capacitor bank 3 approaches the voltage of the battery pack 1.

[0070] The relay 403 is arranged in the negative line, connected in parallel with the series combination of the anti-reverse diode 401 and the pre-charge resistor 402. Specifically, the two ends of the relay 403 are connected to the anode of the anti-reverse diode 401 and the other end of the pre-charge resistor 402 downstream, respectively. The drive unit has a level output end connected to the control end of the relay 403, which is configured to output a control level through the level output end when receiving the start signal of the control unit, to drive the relay 403 to switch to the conduction state. At this time, the current bypasses the anti-reverse diode 401 and the pre-charge resistor 402, and directly flows through the relay 403, to reduce the circuit impedance in normal operation and improve system efficiency.

[0071] The voltage sampling end is connected to the positive line, specifically to the first positive connection end or the second positive connection end, configured to detect the input voltage of the positive line and transmit the detection result to the control unit to assist in judging the power connection state or generating the start signal. The current detection unit is arranged in the negative line, configured to detect the current value of the circuit during the pre-charge stage and evaluate whether the current value meets the preset standard (e.g. a preset current threshold range). The control unit is connected to the current detection unit, configured to monitor the matching state between the trigger signal and the current value detected by the current detection unit. If the current value is lower than the preset threshold (e.g. due to failure of the trigger mechanism or abnormal connection), the control unit determines that the trigger mechanism is failed, generates a fault code, and prevents the high-voltage circuit from running to protect the system safety.

[0072] In practical applications, when the battery pack 1 is connected in the positive direction and powered on, the control unit detects the input voltage through the voltage sampling terminal, and judges whether the circuit is in normal operating conditions in combination with the closed state of the trigger switch 909 and the current value of the current detection unit. If the trigger switch 909 is closed due to the gravity of the goods, the input voltage is within the preset range, and the pre-charge current is normal, the control unit generates a start signal to drive the relay 403 to close, switches the circuit to the main loop path, and at the same time allows the refrigerant outlet to open to release cold air; if the battery pack 1 is connected in the reverse direction, the trigger switch 909 is not closed, the input voltage is abnormal, or the pre-charge current is below the threshold, the control unit prevents the relay 403 from conducting, and generates a fault code to suspend the operation of the high-voltage circuit to prevent the compressor from starting under unsafe or unstable conditions.

[0073] The anti-reverse connection pre-charge system of the present application significantly reduces power consumption compared to the traditional positive line configuration by innovatively configuring the anti-reverse connection diode 401, the pre-charge resistor 402, and the relay 403 in the negative line. The reason is that the negative line serves as the reference ground, facilitating the integration of NMOS or similar low-loss components, simplifying circuit design and improving efficiency. In normal operation, the relay 403 is turned on, bypassing the path of the anti-reverse connection diode 401 and the pre-charge resistor 402, directly conducting the negative main loop, effectively avoiding the continuous voltage drop power consumption of the diode and resistor. In addition, the negative line configuration does not interfere with the voltage sampling of the positive line, ensuring sampling accuracy and improving the stability of system control. The trigger switch 909 is linked with the gravity of the goods, and in combination with voltage and current detection, only activates the main loop and the refrigerant outlet when the safety conditions are met, further improving the intelligence and safety of the refrigerated truck system.

[0074] As shown in Figures 5 to 12 The anti-reverse connection pre-charge system of the present application significantly reduces power consumption compared to the traditional positive line configuration by innovatively configuring the anti-reverse connection diode 401, the pre-charge resistor 402, and the relay 403 in the negative line. The reason is that the negative line serves as the reference ground, facilitating the integration of NMOS or similar low-loss components, simplifying circuit design and improving efficiency. In normal operation, the relay 403 is turned on, bypassing the path of the anti-reverse connection diode 401 and the pre-charge resistor 402, directly conducting the negative main loop, effectively avoiding the continuous voltage drop power consumption of the diode and resistor. In addition, the negative line configuration does not interfere with the voltage sampling of the positive line, ensuring sampling accuracy and improving the stability of system control. The trigger switch 909 is linked with the gravity of the goods, and in combination with voltage and current detection, only activates the main loop and the refrigerant outlet when the safety conditions are met, further improving the intelligence and safety of the refrigerated truck system.

[0075] The refrigeration assembly 11 is arranged on the vehicle compartment 10 and communicates with the cold air pipeline 13, and is used to provide cold air to maintain a low-temperature environment in the vehicle compartment 10. The inner container 12 is laid in the interior of the vehicle compartment 10 and constitutes the inner wall of the refrigeration space. The at least one partition 14 divides the space enclosed by the vehicle compartment 10 and the inner container 12 into at least two chambers, which are used to separate the storage of different goods. The cold air pipeline 13 is connected with the refrigeration assembly 11 and is configured to deliver cold air to each chamber.

[0076] At least two trigger assemblies 9 are arranged at the bottom of the at least two chambers respectively, each of which comprises a pressing plate 901, an air outlet hole 910, a linkage mechanism, a bracket 911, a shaft body 913, a torsional spring 912, a baffle 905, a plurality of branch pipes 907, a plurality of main pipes 908, a backing plate 902 and a trigger switch 909.

[0077] The plurality of main pipes 908 are in communication with the cold air pipeline 13, for guiding the cold air from the refrigeration assembly 11 to the chambers. Each of the main pipes 908 is in communication with the plurality of branch pipes 907 respectively, and the openings of the branch pipes 907 are used for releasing the cold air into the chambers. The pressing plate 901 is in sliding connection with the inner container 12 and can move in the vertical direction under the gravity of the goods. The backing plate 902 is fixedly connected to the inner container 12 and serves as a support structure of the trigger assembly 9. The bracket 911 is fixed to the inner container 12 and is in rotational connection with the shaft body 913. The shaft body 913 is fixedly connected to the baffle 905, which can rotate around the shaft body 913 to cover or open the openings of the branch pipes 907. The air outlet hole 910 is processed on the pressing plate 901 and is located corresponding to the openings of the branch pipes 907 to ensure the smooth release of the cold air. The trigger switch 909 is fixed to the backing plate 902, and its trigger end corresponds to the bottom end face of the pressing plate 901, which is configured to be triggered when the pressing plate 901 is pressed down to generate a trigger signal.

[0078] The linkage mechanism comprises a slide rod 903 and a spring 904. The top end of the slide rod 903 is fixedly connected to the bottom of the pressing plate 901, and the bottom end thereof is in sliding fit with the top end of the baffle 905. The spring 904 is sleeved on the slide rod 903, and the two ends thereof are connected with the backing plate 902 and the pressing plate 901 respectively, which is configured to provide a reset force to maintain the initial position of the pressing plate 901. The torsional spring 912 is sleeved on the shaft body 913, and the two ends thereof are connected with the shaft body 913 and the bracket 911 respectively, which is configured to drive the baffle 905 to reset to cover the openings of the branch pipes 907.

[0079] In actual use, when the goods are placed on the pressing plate 901, the gravity of the goods makes the pressing plate 901 slide towards the backing plate 902, pushing the slide rod 903 to move downward. The bottom end of the slide rod 903 drives the baffle 905 to rotate around the shaft body 913, opening the openings of the branch pipes 907, so that the cold air is released into the chambers through the air outlet hole 910. At the same time, the bottom end face of the pressing plate 901 triggers the trigger switch 909 to generate a trigger signal, which is transmitted to the control unit of the anti-reverse connection pre-charging circuit 4 to activate the high-voltage loop switching (such as driving the relay 403 to conduct). When the goods are removed, the reset force of the spring 904 and the torsional spring 912 makes the pressing plate 901 and the baffle 905 return to the initial position, closing the openings of the branch pipes 907 and disconnecting the trigger switch 909 to stop the output of the trigger signal.

[0080] The control assembly 8 comprises a groove body 803, a rotating plate 802, a main shaft 805, a handle 801 and a clamping piece 804.

[0081] The groove 803 is machined on the pressing plate 901, constituting a recess for accommodating the rotating plate 802. The main shaft 805 is in sliding connection with the groove 803, allowing the rotating plate 802 to move along the main shaft 805 within the groove 803. The rotating plate 802 is arranged within the groove 803, with its top end surface initially flush with the top end surface of the pressing plate 901. The handle 801 is in rotational connection with the rotating plate 802, facilitating the operator to lift and rotate the rotating plate 802. The clamping piece 804 is fixedly connected to the inner container 12, configured to cooperate with the rotating plate 802 to achieve positioning.

[0082] In actual use, when it is necessary to lock or adjust the pressing plate 901, the operator lifts the rotating plate 802 through the handle 801, and rotates the rotating plate 802 to disengage it from the groove 803. Then, the pressing plate 901 is pressed downward, causing the rotating plate 802 to slide along the main shaft 805 to the position of the clamping piece 804, and be positioned by being rotated and embedded into the clamping piece 804, thereby fixing the position of the pressing plate 901 and preventing it from accidentally triggering the trigger switch 909 or opening the branch pipe 907 due to the gravity of the goods. This design facilitates locking the system when there is no goods or maintenance, improving the safety of operation.

[0083] It is worth mentioning that: the trigger assembly 9 uses the gravity of the goods to drive the pressing plate 901 to link the baffle 905 and the trigger switch 909, only opening the opening of the branch pipe 907 to release cold air when the goods exist, and activating the high-pressure circuit, avoiding the compressor from running when there is no goods, and significantly reducing the energy consumption of the system. At the same time, through the way of pressure triggering the opening of the cold air port, it ensures that only the chamber with goods is targeted for refrigeration, without affecting the normal refrigeration of other chambers, improving the resource utilization efficiency and overall refrigeration performance of the refrigerated truck. The control assembly 8 provides the function of manually fixing the pressing plate 901 through the locking mechanism of the rotating plate 802 and the clamping piece 804, facilitating the locking of the system when there is no goods or maintenance, preventing accidental triggering, improving the safety in the non-working state, and reducing the risk of operation. The reverse connection pre-charging circuit 4 is configured with a negative line, reducing the circuit impedance and power consumption during normal operation, and combining with the signal of the trigger switch 909, starting the circuit only after the goods trigger, that is, the circuit will start only after one trigger switch 909 is contacted. Ensure that the refrigerated truck operates under safe voltage and current conditions, avoid damage in the case of reverse connection of the power supply or abnormal state, and improve the reliability and durability of the system. The above beneficial effects realize the intelligent and low-energy consumption operation of the refrigerated truck through the integration of the gravity of the goods and the circuit control, which is suitable for multi-chamber refrigerated transportation scenarios, improving the overall economy and practicality.

[0084] In addition, another embodiment of the present application provides an electric compressor controller, comprising an anti-reverse pre-charging circuit 4, a high-voltage input voltage sampling terminal, a driving circuit, a self-locking circuit 7, a bus capacitor group 3 and a micro control unit (MCU). The controller realizes power reverse connection protection and transient impact current suppression by integrating the anti-reverse pre-charging circuit 4, and ensures the stable operation of the relay 403 by combining the self-locking mechanism, thereby enhancing the system reliability and safety. The structure and function of the electric compressor controller are described in detail as follows:

[0085] The anti-reverse pre-charging circuit 4 comprises an anti-reverse diode 401, a pre-charging resistor 402, a relay 403 and a driving unit, which are arranged in the negative line and used for preventing the battery pack 1 from being reversely connected and suppressing the impact of transient impact current on the bus capacitor group 3 in the initial power-on period. The anti-reverse diode 401 and the pre-charging resistor 402 are connected in series in the negative line, and the relay 403 is connected in parallel with the series combination. The specific working principle is as described in the foregoing embodiment: when the battery pack 1 is connected in the forward direction, the anti-reverse diode 401 is turned on, and the current flows through the pre-charging resistor 402 to pre-charge the bus capacitor group 3; when the relay 403 is turned on, the current bypasses the anti-reverse diode 401 and the pre-charging resistor 402 and directly flows through the main circuit, thereby reducing the circuit impedance.

[0086] The high-voltage input voltage sampling terminal is connected with the positive line, specifically connected with the first positive connection end (connected with the positive pole of the battery pack 1) or the second positive connection end (connected with the positive terminal of the motor 2), and configured to detect the input voltage of the positive line in real time and transmit the detection result to the micro control unit. The input voltage is used to judge the power connection state (forward or reverse connection) and whether the preset condition (for example, the voltage value is within the normal working range) is met, thereby providing a basis for subsequent circuit control.

[0087] The signal output end of the driving circuit is connected with the control end of the relay 403, and configured to output a driving level (for example, a high level) to control the relay 403 to switch the circuit path when the micro control unit confirms that the input voltage meets the preset condition (for example, the voltage value is within the preset range and the power is connected in the forward direction). The driving circuit comprises an NPN triode, which generates a driving level by turning on after receiving the control signal of the micro control unit, thereby driving the relay 403 to switch from the off state to the on state, so as to bypass the anti-reverse diode 401 and the pre-charging resistor 402 and reduce the circuit impedance in the normal operation.

[0088] Referring to the drawings Figure 4which shows a schematic diagram of the self-locking circuit 7. The self-locking circuit 7 includes a PNP transistor connected to the driving circuit and the control end of the relay 403, configured to enter a self-locking state after receiving the control signal of the micro control unit. The self-locking circuit 7 works with the micro control unit to provide the stable current required to drive the relay 403, and prevent the accidental disconnection of the relay 403 caused by micro control unit failure or external interference (such as electromagnetic interference or signal jitter). Specifically, when the micro control unit sends a control signal to activate the driving circuit, the self-locking circuit 7 forms a self-locking path through the conduction of the PNP transistor, maintaining the conduction state of the relay 403 until the micro control unit explicitly sends a disconnection signal or the power is turned off. The introduction of the self-locking circuit 7 significantly improves the anti-interference ability and operational stability of the system.

[0089] The bus capacitor group 3 is connected between the battery pack 1 and the motor 2, configured to filter and stabilize the power supply voltage, reducing the impact of voltage fluctuations on the motor 2. In the initial power-on period, the anti-reverse connection pre-charging circuit 4 limits the current through the pre-charging resistor 402 to protect the bus capacitor group 3 from transient impact current.

[0090] The micro control unit is connected to the high-voltage input voltage sampling end, the driving circuit and the self-locking circuit 7, configured to receive the detection results of the high-voltage input voltage sampling end, judge the power connection state and voltage condition, and generate corresponding control signals. The micro control unit controls the driving circuit to output the driving level according to whether the input voltage meets the pre-set conditions (such as the voltage value being within the safe range and being a positive connection) and other trigger signals (such as the signal triggering the switch 909), and maintains the stable state of the relay 403 through the self-locking circuit 7. If an abnormal situation is detected (such as reverse connection, voltage out of range or missing trigger signal), the micro control unit prevents the driving circuit and the self-locking circuit 7 from acting, keeps the relay 403 disconnected, and generates a fault code to suspend the high-voltage circuit operation.

[0091] The electric compressor controller of the present application significantly improves the safety and stability of the system by integrating the anti-reverse connection pre-charging circuit 4, the driving circuit and the self-locking circuit 7. The anti-reverse connection pre-charging circuit 4 is arranged in the negative line, taking advantage of the characteristics of the negative as the reference ground, facilitating the integration of low-loss elements (such as NMOS), and bypassing the anti-reverse connection diode 401 and the pre-charging resistor 402 through the relay 403, reducing the power consumption during normal operation. The high-voltage input voltage sampling end and the micro control unit work together to monitor the power state in real time, ensuring that the high-voltage loop is activated only under safe conditions. The self-locking circuit 7 realizes the self-locking function through the PNP transistor, effectively preventing the accidental disconnection of the relay 403 caused by micro control unit failure or external interference, enhancing the anti-interference ability and operational reliability of the system.

[0092] As Figure 5In addition, another embodiment of the present application provides a control method for an electric compressor, which is applied to the above-mentioned electric compressor controller. The controller includes an anti-reverse connection pre-charge circuit 4, a high-voltage input voltage sampling terminal, a driving circuit, a self-locking circuit 7, a bus capacitor group 3, and a micro control unit (MCU). The control method realizes power reverse connection protection, transient impact current suppression, and system stable operation by real-time monitoring of voltage and current, combined with self-locking mechanism and fault protection strategy. Referring to the accompanying drawings Figure 5 The steps and functions of the control method are described in detail as follows:

[0093] Collecting high-voltage loop input voltage:

[0094] The input voltage of the positive line is collected in real time through the high-voltage input voltage sampling terminal. The sampling terminal is connected to the first positive connection terminal (connected to the positive of the battery pack 1) or the second positive connection terminal (connected to the positive terminal of the motor 2). The micro control unit receives the input voltage data and determines whether it is within the preset range (for example, the rated working voltage range, such as 100V to 400V, which is determined according to the system design). If the input voltage is out of the preset range or the polarity is abnormal (for example, indicating reverse connection of the power supply), the micro control unit generates a fault notification, prevents subsequent operation, and keeps the relay 403 in the open state, ensuring that the anti-reverse connection diode 401 blocks the reverse current and prevents the circuit from running.

[0095] Detecting pre-charge phase current value:

[0096] When the input voltage meets the preset range and it is confirmed that the power supply is connected in the forward direction, the control method detects the current value in the negative line through the current detection unit arranged in the series path of the anti-reverse connection diode 401 and the pre-charge resistor 402. The micro control unit evaluates whether the detected current value meets the preset standard (for example, the expected current range based on the theoretical RC charging curve). The theoretical RC charging time calculates the time constant (τ = R × C) according to the resistance value of the pre-charge resistor 402 and the capacitance value of the bus capacitor group 3, which is used to verify the normality of the pre-charge curve. If the current value deviates from the preset standard (for example, too high or too low), it indicates that there may be component damage or circuit abnormality, and the micro control unit generates a fault code to suspend the operation of the high-voltage circuit to prevent the pre-charge resistor 402 from overheating or damage.

[0097] Monitoring bus capacitor voltage and power supply connection state:

[0098] After power-on, the control method collects the voltage value of the bus capacitor group 3 in real time through the voltage sampling terminal, and judges whether the charging process is normal based on the theoretical RC charging time. If the voltage rising curve of the bus capacitor group 3 deviates from the theoretical curve (for example, the voltage rises too fast or too slow), or the voltage polarity is detected to be abnormal (indicating that the power is reversely connected), the micro control unit generates a fault notification, and keeps or disconnects the relay 403 through the drive circuit to prevent the high-voltage circuit from running. The anti-reverse connection diode 401 is cut off when reversely connected, ensuring that reverse current cannot flow through the circuit, protecting the system safety.

[0099] Trigger signal and circuit state evaluation:

[0100] The micro control unit receives the trigger signal from the trigger switch 909, and evaluates the effectiveness of the trigger mechanism in combination with the voltage and current detection results. The trigger switch 909 is arranged at the bottom of the refrigerated truck cavity, configured to be closed under the gravity of the goods, generating a trigger signal. If the trigger signal exists, and the input voltage and current values all meet the preset conditions (for example, the voltage is within the preset range, and the current conforms to the theoretical charging curve), the micro control unit confirms that the trigger mechanism is effective, and enters the next step of operation; If the trigger signal is missing (for example, no goods) or the voltage and current are abnormal (for example, the relay 403 is stuck or the pre-charging resistor 402 is overheated), the micro control unit starts the fault protection mechanism, generates a fault code, and prevents the relay 403 from conducting, preventing the compressor from running under unstable conditions.

[0101] Drive relay switching circuit path:

[0102] When all detection parameters (including input voltage, current value, bus capacitor voltage and trigger signal) meet the preset conditions, the micro control unit sends a control signal to the drive circuit. The signal output end of the drive circuit is connected with the control end of the relay 403, and outputs a drive level (for example, high level, driving NPN triode to conduct), triggering the relay 403 to switch from the off state to the on state, and switching the high-voltage loop from the anti-reverse connection pre-charging path (through the anti-reverse connection diode 401 and the pre-charging resistor 402) to the main loop path (through the relay 403). This switching bypasses the anti-reverse connection diode 401 and the pre-charging resistor 402, reduces the circuit impedance during normal operation, and improves the system efficiency.

[0103] Activate the self-locking circuit to enhance stability:

[0104] After sending the drive signal to the control port of the relay 403, the micro control unit activates the self-locking circuit 7 to enter the working state. Referring to the accompanying drawings Figure 4The self-locking circuit 7 includes a PNP transistor connected to the driving circuit and the control end of the relay 403. After receiving the control signal of the micro control unit, the self-locking circuit 7 forms a self-locking path through the conduction of the PNP transistor, and cooperates with the micro control unit to provide the stable current required for driving the relay 403. The self-locking circuit 7 ensures that the relay 403 maintains the conduction state during normal operation, prevents the accidental opening of the relay 403 due to micro control unit failure or external interference (such as electromagnetic interference or signal jitter), and enhances the anti-interference ability of the circuit.

[0105] Fault protection mechanism:

[0106] During pre-charging or normal operation, the micro control unit continuously monitors the circuit state. If an abnormal situation is detected, such as relay 403 sticking (judged by abnormal current or voltage), pre-charging resistor 402 overheating (inferred by current value or temperature sensor feedback), component damage or other circuit state deviating from the preset standard, the micro control unit immediately starts the fault protection mechanism, generates a fault code and disconnects the relay 403 through the driving circuit, suspending the operation of the high-voltage circuit. At the same time, the micro control unit can output a fault notification through the external interface to prompt the operator to check or maintain, so as to prevent further damage to the pre-charging resistor 402 or other components.

[0107] The control method ensures that the system only operates in a safe and stable condition by monitoring the input voltage, current and bus capacitor voltage in real time, combined with trigger signal verification, significantly improving the reliability and safety of the electric compressor. The reverse connection pre-charging circuit 4 is arranged in the negative line, which cooperates with the theoretical RC charging time evaluation to effectively prevent the damage of reverse connection and transient impulse current to the bus capacitor group 3. The self-locking circuit 7 realizes stable driving through the PNP transistor, prevents the accidental opening of the relay 403 due to interference, and improves the anti-interference ability. The fault protection mechanism identifies problems such as relay sticking, pre-charging resistor overheating or component damage in time through multi-parameter monitoring and fault code generation, and protects the system from further damage.

[0108] The above specific embodiments do not constitute a limitation on the protection scope of the present application. Those skilled in the art should understand that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A reverse-connection pre-charge system for an electric compressor, characterized in that, include: The power supply circuit consists of a positive wire and a negative wire; The reverse polarity protection diode (401) and the reverse polarity protection pre-charged negative terminal are arranged in the negative line; The anti-reverse connection pre-charge negative terminal is connected to the negative terminal of the power supply. The reverse connection protection diode (401) can be configured to prevent reverse connection of the power supply and block reverse current from flowing from the reverse connection protection precharge negative terminal to the positive terminal; It also includes a pre-charge resistor (402), which is arranged in the negative line and connected in series with the anti-reverse connection diode (401); It also includes a high-voltage input voltage sampling terminal and a current detection unit; It also includes a control unit; The current detection unit is configured to detect the circuit current value during the pre-charging stage and evaluate whether the current value meets a preset standard. The control unit is connected to the current detection unit and configured to monitor the matching status between the trigger signal and the current value detected by the current detection unit; The current value being lower than the preset threshold is due to the failure of the trigger component (9) or abnormal connection. Based on this, the control unit determines that the trigger component (9) has failed and generates a fault code to prevent the high-voltage circuit from operating. The anti-reverse connection pre-charge system is applied to a refrigerated truck, which includes a compartment (10), a refrigeration component (11), an inner liner (12), a cold air duct (13), at least one partition (14), and at least two triggering components (9); the refrigeration component (11) is installed on the compartment (10) and is connected to the cold air duct (13); the inner liner (12) is laid inside the compartment (10); at least one partition (14) divides the space enclosed by the compartment (10) and the inner liner (12) into at least two chambers; At least two of the triggering components (9) are respectively disposed at the bottom of at least two of the chambers. Each triggering component (9) includes a pressure plate (901), an air outlet (910), a linkage mechanism, a bracket (911), a shaft (913), a torsion spring (912), a baffle (905), multiple branch pipes (907), multiple main pipes (908), a pad (902), and a trigger switch (909). Multiple main pipes (908) are connected to the cold air duct (13), and the multiple main pipes (908) are used to guide cold air from the refrigeration component (11) to each of the chambers; each main pipe (908) is connected to multiple branch pipes (907), and the opening of the branch pipe (907) is used to release cold air into the chamber; the pressure plate (901) is slidably connected to the inner liner (12); the pad (902) is fixedly connected to the inner liner (12); the bracket (911) is fixedly connected to the inner liner (12) and rotatably connected to the shaft (913); the shaft (913) is rotatably connected to the inner liner (12); 3) Fixedly connected to the baffle (905), the baffle (905) can rotate around the shaft (913) to cover or open the openings of the multiple branch pipes (907); the air outlet (910) is machined on the pressure plate (901), and the position of the air outlet (910) corresponds to the opening of the branch pipe (907); the trigger switch (909) is fixed on the pad (902), the trigger end of the trigger switch (909) corresponds to the bottom end face of the pressure plate (901), and the trigger switch (909) is configured to be triggered when the pressure plate (901) is pressed down to generate a trigger signal; The linkage mechanism includes a slide rod (903) and a spring (904); the top end of the slide rod (903) is fixedly connected to the bottom of the pressure plate (901), and the bottom end of the slide rod (903) slides against the top end of the baffle (905); the spring (904) is sleeved on the slide rod (903), and the two ends of the spring (904) are respectively connected to the pad (902) and the pressure plate (901); the torsion spring (912) is sleeved on the shaft (913), and the two ends of the torsion spring (912) are respectively connected to the shaft (913) and the bracket (911).

2. The reverse connection protection pre-charge system for the electric compressor according to claim 1, characterized in that: It also includes a relay (403) and a drive unit, wherein the relay (403) is arranged in the negative line and connected in parallel with the series combination of the anti-reverse connection diode (401) and the pre-charge resistor (402); The drive unit has a level output terminal, which is connected to the control terminal of the relay (403). It is configured to output a control level through the level output terminal when a start signal is received, so that the relay (403) switches to the on state, bypassing the anti-reverse connection diode (401) and the pre-charge resistor (402) to reduce the circuit impedance during normal operation.

3. The reverse connection protection pre-charge system for the electric compressor according to claim 2, characterized in that: The control unit is connected to the drive unit and is configured to detect the power connection status and generate the start signal. When the control unit detects a reverse power connection, it prevents the drive unit from outputting a control level, keeps the relay (403) in the open state, and ensures that the reverse connection protection diode (401) blocks the reverse current and prevents the circuit from operating. When the control unit detects a positive power connection, it generates the start signal, which triggers the drive unit to control the relay (403) to turn on.

4. The reverse connection protection pre-charge system for the electric compressor according to claim 3, characterized in that: The positive wire includes a first positive terminal connected to the positive terminal of the power supply and a second positive terminal connected to the load. The negative wire includes a first negative connection terminal connected to the negative terminal of the power supply or the reverse connection pre-charge negative connection terminal, and a second negative connection terminal connected to the load. The control unit is connected to the trigger switch (909) and the drive unit, and is configured to receive the trigger signal and generate the start signal; The reverse connection protection diode (401) and the pre-charge resistor (402) are connected in series in the negative line. When the power supply is connected in the forward direction, the diode is turned on to support the charging of the bus capacitor bank (3), and when the power supply is connected in the reverse direction, the diode is turned off to prevent the circuit from operating. The relay (403) is connected in parallel with the series combination of the anti-reverse connection diode (401) and the pre-charge resistor (402), and is configured to switch the circuit path after receiving the control level, bypassing the anti-reverse connection diode (401) and the pre-charge resistor (402). The control unit is configured to detect the matching between the trigger signal and the circuit state. If the trigger signal is present but the circuit state is abnormal, the relay (403) is prevented from being turned on to avoid the compressor from operating under unstable conditions.

5. The reverse connection protection pre-charge system for the electric compressor according to claim 4, characterized in that, The high-voltage input voltage sampling terminal is connected to the positive line and is configured to detect the input voltage of the positive line and output a voltage sampling signal to the control unit for generating the start signal.

6. An electric compressor controller, characterized in that, The system includes the reverse connection protection precharge system of any one of claims 1-5, as well as the drive circuit, the self-locking circuit (7), the bus capacitor bank (3), and the microcontroller unit; The high-voltage input voltage sampling terminal is connected to the positive line and is configured to detect the input voltage. The signal output terminal of the drive circuit is connected to the relay (403) in the reverse connection precharge system and is configured to output a drive level to control the relay (403) to switch the circuit path when the input voltage meets the preset conditions. The self-locking circuit (7) is connected to the control terminal of the drive circuit and the relay (403) and is configured to enter a self-locking state after receiving the control signal from the microcontroller unit.

7. A control method for an electric compressor, applied to the electric compressor controller of claim 6, characterized in that, include: Collect the input voltage of the positive line of the high-voltage circuit; When the input voltage meets the preset range, the current value in the detection circuit is detected. When all detection parameters meet the preset conditions, a drive signal is sent to the control port of the relay (403) to trigger the relay (403) to switch the high voltage circuit from the anti-reverse connection pre-charge path to the main circuit path.

8. The control method according to claim 7, characterized in that, Also includes: After power-on, the voltage value of the bus capacitor bank (3) is collected in real time, and the power supply is reversed based on the theoretical RC charging time. If the reverse connection is detected, a fault notification is generated or the relay (403) is disconnected. During the pre-charging process, if the voltage or current value is detected to be inconsistent with the preset value, or if the relay (403) is detected to be stuck or the component is damaged, a fault code is generated and the high voltage circuit is stopped from operating to prevent the pre-charging resistor (402) from overheating or being damaged. The theoretical RC charging time is calculated based on the time constant of the pre-charging resistor (402) and the bus capacitor bank (3) and is used to verify the normality of the charging curve. The microcontroller unit is configured to evaluate the effectiveness of the trigger component (9) in conjunction with the voltage and current detection results when the trigger signal is present, and to activate the fault protection mechanism if an abnormality is detected.

9. The control method according to claim 7, characterized in that, Also includes: After sending a drive signal to the control port of the relay (403), the self-locking circuit (7) is activated and enters the working state, working together with the microcontroller unit to provide drive current.

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