Current-limiting output control method, device and equipment of rectification module and medium

Abstract

The invention discloses a current-limiting output control method and device of a rectification module, equipment and a medium, and belongs to the technical field of electronic circuits. The method comprises the following steps: detecting output current after the rectification module is started; when a current-limiting trigger event is detected, carrying out current-limiting control on the output current of the rectifier module by adopting sliding-mode control; after the current limiting control reaches a preset sliding mode surface, PID control is adopted to carry out current stabilization control on the output current of the rectification module; and when it is identified that the current-limiting output ending condition is satisfied, ending the output current control of the rectification module. According to the technical scheme, the output current of the rectifier module can be quickly limited through the connection of sliding mode control and PID control, so that the response speed of an inter-electrode fault is improved, the fault current is timely and effectively limited, and the operation safety of power electronic equipment is ensured.

Description

Technical Field

[0001] The present application belongs to the field of electronic circuit technology, and specifically relates to a current limiting output control method, device, equipment and medium for a rectifier module. Background Art

[0002] With the rapid development of new energy technologies and the continuous advancement of power electronics technology, low-voltage DC distribution systems have gradually become a hot topic in research and application. Especially in power consumption scenarios dominated by DC loads and equipped with distributed photovoltaic and energy storage devices, low-voltage DC distribution systems have attracted widespread attention due to their high efficiency, stability and economic advantages.

[0003] At present, the urban power grid is still dominated by AC power, so in the process of converting AC power into DC power, an efficient AC / DC rectifier module is needed to provide a reliable power supply point. At present, the industry generally adopts high-frequency rectification to achieve this function, which has the advantages of small size, high efficiency and fast response speed. However, an important problem of low-voltage DC distribution system is that the switchgear used in its distribution network is a mechanical DC switch. The action time of mechanical switches is usually at the millisecond (ms) level, while the action speed of power electronic equipment is at the microsecond (us) level. This difference in time scale leads to the fact that in multi-level distribution networks, when faults such as inter-pole short circuits occur, power electronic equipment can quickly detect faults and respond, but mechanical switches cannot cut off fault currents in a short time. For example, when a short circuit fault occurs at a node, the upstream power electronic equipment will quickly detect the fault and start the protection mechanism, but due to the slow action time of the mechanical switch, the fault current cannot be cut off in time, resulting in the continued increase of the fault current, which may cause serious damage to the entire distribution network. In addition, this time difference may also cause false operation between protection devices, further affecting the stability and reliability of the system.

[0004] Therefore, how to effectively limit the fault current when an inter-pole fault occurs and ensure the coordinated work between power electronic equipment and mechanical switches has become a key issue that needs to be urgently solved in low-voltage DC distribution systems. Summary of the invention

[0005] The embodiments of the present application provide a current limiting output control method, device, equipment and medium for a rectifier module, with the aim of solving the problem that in the event of an inter-pole fault, the fault current cannot be limited in a timely and effective manner, resulting in potential safety hazards in the operation of power electronic equipment.

[0006] In a first aspect, an embodiment of the present application provides a current limiting output control method for a rectifier module, the method comprising:

[0007] After the rectifier module is started, the output current is detected;

[0008] When a current limiting trigger event is detected, a sliding mode control is used to perform current limiting control on the output current of the rectifier module;

[0009] After the current limiting control reaches the preset sliding mode surface, the output current of the rectifier module is controlled by PID control to stabilize the current;

[0010] When it is identified that the current limiting output termination condition is met, the output current control of the rectifier module is terminated.

[0011] Furthermore, the output current of the rectifier module is limited by using sliding mode control, including:

[0012] Obtain a preset sliding surface;

[0013] According to the current output current of the rectifier module, the output current of the rectifier module is limited and controlled in the form of an exponential approach law.

[0014] Furthermore, according to the current output current of the rectifier module, the output current of the rectifier module is limited in the form of an exponential approach law, including:

[0015] The form of the exponential reaching law is as follows:

[0016]

[0017] Among them, ∈>0, k>0, and both are design parameters, sgn(s) is the sign function; ∈ is used to determine the approach speed of the system when it is far away from the preset sliding surface, and k is used to determine the approach speed of the system when it is close to the preset sliding surface.

[0018] Furthermore, after reaching the preset sliding surface, PID control is used to perform steady current control on the output current of the rectifier module, including:

[0019] After reaching the preset sliding mode surface, a smooth switching function is used to switch from sliding mode control to PID control to perform steady current control on the output current of the rectifier module.

[0020] Furthermore, when a current limiting triggering event is detected, a sliding mode control is used to perform current limiting control on the output current of the rectifier module, including:

[0021] When it is detected that the output current of the rectifier module exceeds a preset current threshold, it is determined that a current limiting trigger event is detected, and sliding mode control is used to perform current limiting control on the output current of the rectifier module.

[0022] Further, when it is identified that the current limiting output termination condition is met, the output current control of the rectifier module is terminated, including:

[0023] When it is identified that the current limiting time reaches the set time, the output current control of the rectifier module is terminated.

[0024] Furthermore, before identifying that the current limiting duration reaches the set duration, the method further includes:

[0025] When it is identified that the fault is resolved, the normal current output of the rectifier module is restored.

[0026] In a second aspect, an embodiment of the present application provides a current limiting output control device for a rectifier module, the device comprising:

[0027] A current detection unit is used to detect the output current after the rectifier module is started;

[0028] A first current limiting control unit, configured to use sliding mode control to perform current limiting control on the output current of the rectifier module when a current limiting triggering event is detected;

[0029] A second current limiting control unit, used to use PID control to perform a steady current control on the output current of the rectifier module after the current limiting control reaches a preset sliding mode surface;

[0030] The current limiting termination unit is used to terminate the output current control of the rectifier module when it is identified that the current limiting output termination condition is met.

[0031] In a third aspect, an embodiment of the present application provides an electronic device, which includes a processor, a memory, and a program or instruction stored in the memory and executable on the processor, wherein the program or instruction, when executed by the processor, implements the steps of the method described in the first aspect.

[0032] In a fourth aspect, an embodiment of the present application provides a readable storage medium, on which a program or instruction is stored, and when the program or instruction is executed by a processor, the steps of the method described in the first aspect are implemented.

[0033] In a fifth aspect, an embodiment of the present application provides a chip, comprising a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is used to run a program or instruction to implement the method described in the first aspect.

[0034] In the embodiment of the present application, the rectifier module performs output current detection after startup; when a current limiting trigger event is detected, the output current of the rectifier module is controlled by sliding mode control; after the current limiting control reaches the preset sliding mode surface, the output current of the rectifier module is controlled by PID control to stabilize the current; when it is identified that the current limiting output termination condition is met, the output current control of the rectifier module is terminated. The above technical scheme can achieve rapid output current limitation of the rectifier module by connecting the sliding mode control and the PID control in an emergency situation when an inter-pole fault or other fault occurs, so as to improve the response speed of the inter-pole fault, realize timely and effective limitation of the fault current, and ensure the safe operation of the power electronic equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a flow chart of a current limiting output control method of a rectifier module provided in Embodiment 1 of the present application;

[0036] Figure 2 It is a flow chart of a current limiting output control method of a rectifier module provided in Embodiment 2 of the present application;

[0037] Figure 3 It is a structural schematic diagram of a current limiting output control device of a rectifier module provided in Embodiment 3 of the present application;

[0038] Figure 4 It is a schematic diagram of the structure of the electronic device provided in Example 4 of the present application. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical scheme and advantages of the present application clearer, the specific embodiments of the present application are further described in detail below in conjunction with the accompanying drawings. It is understood that the specific embodiments described herein are only used to explain the present application, rather than to limit the present application. It should also be noted that, for the convenience of description, only the part related to the present application but not all of the content is shown in the accompanying drawings. Before discussing the exemplary embodiments in more detail, it should be mentioned that some exemplary embodiments are described as processes or methods depicted as flow charts. Although the flow chart describes each operation (or step) as a sequential process, many of the operations therein can be implemented in parallel, concurrently or simultaneously. In addition, the order of each operation can be rearranged. The process can be terminated when its operation is completed, but it can also have additional steps not included in the accompanying drawings. The process can correspond to a method, a function, a procedure, a subroutine, a subprogram, etc.

[0040] The following will be combined with the drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the present application belong to the scope of protection of this application.

[0041] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0042] In the following, in conjunction with the accompanying drawings, the current limiting output control method, device, equipment and medium of the rectifier module provided in the embodiments of the present application are described in detail through specific embodiments and their application scenarios.

[0043] Embodiment 1

[0044] Figure 1 1 is a flow chart of a current limiting output control method of a rectifier module provided in Embodiment 1 of the present application. Figure 1 As shown, the specific steps include:

[0045] S101, after the rectifier module is started, output current detection is performed;

[0046] First, the present application is applicable to the scenario of output current limiting control in the case of inter-pole fault or other fault conditions. Based on the above usage scenarios, it can be understood that the execution subject of the present application can be a rectifier output control system.

[0047] An AC / DC rectifier module is a circuit or device unit that can convert alternating current (AC) into direct current (DC). A common example is a rectifier bridge circuit composed of semiconductor devices such as diodes. The alternating current has a direction and magnitude that changes periodically. Through the action of the rectifier module, according to a specific circuit topology, this alternating current is processed into a fixed-direction direct current, so as to provide appropriate power for various electronic devices and circuit systems that require DC power supply in the future. For example, in a computer power supply, the external input mains power is alternating current, and the AC / DC rectifier module inside the power supply will first convert it into direct current, and then after further voltage stabilization and other processing, it will be supplied to the computer's motherboard, hard disk and other components.

[0048] It means that the rectifier module starts working. After the input power (usually AC power input) is turned on, the electronic components and circuits inside the module start to operate, and the input AC power is converted accordingly according to the established rectification principle, from the initial standby or unpowered state to the normal operation and DC output state. For example, some industrial high-power AC / DC rectifier modules may need to close the corresponding switch when starting, connect the three-phase AC power, and then the control circuit, power conversion circuit, etc. in the module are powered on and start working.

[0049] Output current detection can ensure power safety and normal operation of equipment. By detecting the output current, it can be found in time whether the current exceeds the rated current range that the module itself or the subsequently connected load can withstand. If the current is too large, it may mean that the load has a short circuit or other fault conditions. Long-term overcurrent state will damage the electronic components inside the rectifier module (such as the power diode may burn out due to overheating), and may also cause damage to other devices connected to it. If the current is too small, it may mean that the load is not connected normally or the module itself has problems such as partial circuit failure, affecting the normal operation of the entire power supply system. Output current detection can also achieve precise power management and control. Understanding the output current situation helps to optimize the control of the entire power supply system. For example, in some power supply systems with adjustable output power, the working state of the rectifier module is dynamically adjusted according to the feedback of the output current size, so that the output voltage, power and other parameters remain stable to meet the power demand of different loads under different working conditions.

[0050] The detection method may include the use of a current sensor (such as a Hall current sensor), which is based on the Hall effect principle. When current passes through, a corresponding electrical signal (such as a voltage signal) will be generated on its sensing element, and the electrical signal is in a certain proportional relationship with the measured current. This electrical signal is processed by a subsequent conditioning circuit (such as amplification, filtering, etc.) and then transmitted to the detection circuit or controller, thereby converting the actual output current value. The indirect measurement method can calculate the current size by detecting other electrical quantities associated with the current. For example, the power and voltage at the output end of the rectifier module are detected, and the current value is calculated based on the power calculation formula when the power and voltage are known.

[0051] S102, when a current limiting triggering event is detected, using sliding mode control to perform current limiting control on the output current of the rectifier module;

[0052] In this embodiment, the current limiting triggering event may be an event of an output current increase, such as an inter-electrode short circuit fault.

[0053] Sliding Mode Control (SMC) is a variable structure control method. Its core idea is to design a suitable switching function to force the system's state trajectory to reach and maintain a pre-set sliding surface within a limited time, and the system has the desired dynamic characteristics on this sliding surface, such as stability, robustness, etc. Even if the system has uncertain factors such as external interference and internal parameter changes, as long as certain conditions are met, the system can still operate stably according to the design requirements.

[0054] The preset sliding surface is the target output current of the control. It can be understood that through sliding mode control, the current after the increase can reach the sliding surface current in a short time, thereby realizing the rapid current limiting of the output current interruption.

[0055] On the basis of the above technical solution, optionally, it is characterized in that when a current limiting trigger event is detected, a sliding mode control is used to perform current limiting control on the output current of the rectifier module, including:

[0056] When it is detected that the output current of the rectifier module exceeds a preset current threshold, it is determined that a current limiting trigger event is detected, and sliding mode control is used to perform current limiting control on the output current of the rectifier module.

[0057] Among them, in the normal operation stage, after the rectifier module is started, the output voltage is gradually increased through the soft start strategy until it reaches the predetermined stable voltage. After the system reaches the predetermined stable voltage, the output port is opened to allow the load to be connected. Under rated power, the increase and decrease of the load is judged by real-time monitoring of the change of the output current Iactual, so as to use the PID controller to adjust the PWM duty cycle and control the output current Iout.

[0058] In this solution, specifically, a current threshold Iset is set. When the detected output current Iactual exceeds the threshold, it is determined that a current limiting trigger event exists. The selection of the threshold Iset should be determined based on the characteristics of the system's maximum normal operating current and fault current, and is given by the user. When it is detected that Iactual>Iset, the current limiting strategy is immediately started. The fault information is transmitted to the upper control system through the high-speed communication interface, and the current limiting control program is started. It should be noted that Iset will be smaller than 1.2*Irated, for example, it can be 1.05 times or 1.1 times of Irated.

[0059] In this embodiment, optionally, sliding mode control is used to limit the output current of the rectifier module, including:

[0060] Obtain a preset sliding surface;

[0061] According to the current output current of the rectifier module, the output current of the rectifier module is limited and controlled in the form of an exponential approach law.

[0062] The sliding surface is preset, and the sliding surface s is defined as the difference between the output current Iout and the target current 1.2*Irated:

[0063] s = Iout - 1.2Irated;

[0064] Where Irated is the rated current. The sliding surface s represents the deviation between the output current and the target current limit current. When s=0, it means that the output current has reached the target current limit current.

[0065] It should be noted that 1.2 times of Irated is a data obtained through a large amount of experimental data and creative labor statistics. This output current can not only avoid damaging the load electronic devices, but also meet the needs of heat control, and will not cause the electronic devices to malfunction due to fluctuations caused by control.

[0066] In order to achieve fast current limiting, an exponential reaching law is selected, which can provide a larger reaching speed when the system state is far away from the sliding mode surface, and gradually reduce the reaching speed when approaching the sliding mode surface, thereby reducing the chattering phenomenon.

[0067] Through such an arrangement, this embodiment can provide a greater approach speed through sliding mode control when the system state is far away from the sliding mode surface, thereby achieving rapid current limiting, reducing the duration of the fault current, and improving the safety of the system.

[0068] In the above technical solution, optionally, according to the current output current of the rectifier module, the output current of the rectifier module is limited in the form of an exponential approach law, including:

[0069] The form of the exponential reaching law is as follows:

[0070]

[0071] Among them, ∈>0, k>0, and both are design parameters, sgn(s) is the sign function; ∈ is used to determine the approach speed of the system when it is far away from the preset sliding surface, and k is used to determine the approach speed of the system when it is close to the preset sliding surface.

[0072] In this scheme, the dynamic model of the system is assumed to be:

[0073]

[0074] Among them, f(Iout,u) is the nonlinear function of the system, u is the control input, and d is the external disturbance.

[0075] According to the sliding surface and reaching law, the expression of the controller u is solved.

[0076] First, the derivative of the sliding surface s is calculated:

[0077]

[0078] According to the convergence law:

[0079]

[0080] Substituting the derivative of the sliding surface into the reaching law:

[0081]

[0082] According to the dynamic model of the system:

[0083]

[0084] Combining the above two equations, we get the expression of the control input u:

[0085] f(Iout,u)+d=-∈sgn(s)-ks;

[0086] The external disturbance d is small and can be ignored, and the control input u is solved as:

[0087] u=f-1 (-∈sgn(s)-ks);

[0088] Assume f(Iout,u)=aIout+bu, then:

[0089]

[0090] Through such a setting, the present scheme can realize rapid limitation of the output current in the event of a short circuit fault, and in the process of limiting the output current, it can also control it at a certain rate, thereby improving the limiting speed and control accuracy of the output current and ensuring the safe and stable operation of the electronic and electrical equipment.

[0091] S103, after the current limiting control reaches a preset sliding surface, using PID control to perform a steady current control on the output current of the rectifier module;

[0092] Sliding mode control is mainly used to achieve current limiting control of output current. It can quickly respond to the current change trend, limit the current within a safe range, and make the system state reach the preset sliding mode surface. When this sliding mode surface is reached, in order to make the output current more stable and accurately maintain near the desired value, PID control can be used for steady current control to give full play to its advantages in stable control.

[0093] PID control, namely proportional, integral and differential control, is a classic control strategy based on feedback. It performs proportional, integral and differential operations on the system error (the difference between the actual output and the expected output), and combines the operation results to form a control signal, which acts on the controlled object to adjust its output and make the system output as close to the expected output as possible.

[0094] When the sliding mode control makes the output current of the rectifier module reach the preset sliding mode surface, the current has been limited to an appropriate range. The goal of PID control is to allow this current to be stably maintained near the desired steady current value, without being disturbed by external factors such as load fluctuations and slight changes in grid voltage, to ensure a stable and reliable DC current supply for subsequent loads.

[0095] This solution uses PID control as a connection to effectively suppress the impact of various interference factors on the output current. By reasonably adjusting the parameters of the three links of proportion, integration, and differentiation, the output current of the rectifier module can be kept highly stable during the operation after reaching the sliding surface, reducing current fluctuations, providing a stable DC power supply for the load, and reducing the risk of damage to the load equipment due to unstable current. With the help of the integral link to eliminate steady-state errors and the precise control of the current change trend by the differential link, PID control can accurately stabilize the output current near the desired steady current value, meet the high-precision requirements for current steady current control, and is particularly suitable for some application scenarios that require strict power supply current accuracy, such as power supply for high-precision electronic instruments and equipment. In addition, the principle of PID control is relatively intuitive and simple. In practical applications, it can be adjusted through some conventional debugging methods. Engineering and technical personnel can easily optimize the control effect according to the actual operation of the rectifier module and the control objectives.

[0096] In one embodiment, optionally, after the current limiting control reaches a preset sliding mode surface, PID control is used to perform a steady current control on the output current of the rectifier module, including:

[0097] After reaching the preset sliding mode surface, a smooth switching function is used to switch from sliding mode control to PID control to perform steady current control on the output current of the rectifier module.

[0098] In order to achieve a smooth transition and avoid the adverse effects of such switching, this scheme introduces a smooth switching function to coordinate the conversion between the two control strategies to ensure the continuity and stability of the output current steady-state control of the rectifier module.

[0099] When switching from sliding mode control to PID control, if there is no smooth transition, the control signal may suddenly jump, which will cause the working state of the power switch devices in the rectifier module to change sharply, and then cause the output current to appear instantaneous peaks or valleys, affecting the stability of power supply and the normal operation of the load. The smooth switching function can make the transition process of this control mode continuous and smooth, allowing the system to smoothly transition from the current limiting state under sliding mode control to the steady current state under PID control.

[0100] By gradually adjusting the proportion of the two control strategies, the system can maintain stable operation during the switching period, and will not cause unstable phenomena such as oscillation and loss of control due to control switching, ensuring that the output current of the rectifier module can continue to be reasonably and effectively controlled and maintained within the expected safe and stable range.

[0101] The smooth switching function itself should be continuous during the switching process, and no discontinuity should occur, so as to ensure that the control signal will not produce sudden jumps when switching. Specifically, it can be designed as a function that changes continuously with time or system state variables, such as the common use of functions with continuous characteristics such as exponential functions and trigonometric functions. Specifically, a switching factor can be set, and its value range is usually between 0 and 100. When it is 0, it means that sliding mode control is fully adopted; when it reaches 100, it means that it is completely switched to PID control. In the process of switching from sliding mode control to PID control, the value of the switching factor gradually increases from the beginning to 100.

[0102] This solution can avoid system instability problems that may be caused by sudden changes in control methods by using a smooth switching function, so that the rectifier module can continue to operate stably during the entire current control process, and the output current smoothly transitions and stabilizes near the desired steady current value, reducing the risk of adverse effects on load equipment and improving the reliability of the entire power supply system. Through reasonable smooth switching, the fast current limiting capability of sliding mode control and the high-precision steady current capability of PID control can be fully utilized, and their respective advantages can be brought into play at different stages to achieve better output current control effects and better meet the needs of various loads for stable DC power supply.

[0103] In this solution, specifically, when the system state s approaches or reaches the sliding surface s=0, it can be considered that the system has entered the sliding surface. At this time, the smooth switching function is used To smoothly switch from sliding mode control to PID control. The function of the smooth switching function is to smoothly transition the control input from sliding mode control to PID control when the system state is close to the sliding surface, avoiding instability caused by sudden changes.

[0104] The PID controller monitors the output current in real time and dynamically adjusts the control output to ensure that the output current is stable within 1.2Irated. The expression of the PID controller is:

[0105]

[0106] Among them, e=1.2Irated-Iout, Kp, Ki and Kd are proportional, integral and differential coefficients respectively.

[0107] S104, when it is identified that the current limiting output termination condition is met, terminate the output current control of the rectifier module.

[0108] Among them, when it is identified that the conditions for terminating the current limiting output are met, for example, when a certain current limiting control duration is met, or when other termination control conditions are met, such as receiving a control instruction from the back end that the fault circuit has been isolated, the output current control of the rectifier module can be terminated.

[0109] Specifically, after the above steps, the PID controller is used to ensure that the output current is stabilized at 1.2Irated to prevent the fault current from continuing to rise. In the current limiting state, the fault current is continuously monitored to ensure that the system operates stably in the current limiting state.

[0110] When the fault is removed, the system automatically returns to normal operation. Alternatively, by real-time monitoring of the output current, when the output current drops to the normal range, the normal control strategy is restored. In addition, if the fault duration exceeds the set maximum current limiting output time t, the module shuts down the output.

[0111] In this embodiment, optionally, when it is identified that the current limiting output termination condition is met, the output current control of the rectifier module is terminated, including:

[0112] When it is identified that the current limiting time reaches the set time, the output current control of the rectifier module is terminated.

[0113] In this solution, the set duration can be 5 seconds, or longer or shorter, but it is generally set to more than 3 seconds. This is because when the IGBT (Insulated Gate Bipolar Transistor) three-phase full-bridge rectifier circuit continuously outputs 1.2Irated, the heat will increase. Therefore, a certain duration needs to be set to control the current limiting duration. In addition, considering the protection removal time, assuming there are three levels of circuits, the reaction time of each level has a range of 0.5 seconds, and the three levels will be around 1.5 seconds. It will take more than 1 second for the circuit breaker to detect the fault current and for the switch to trip. Therefore, the faulty part can generally be removed within 3 seconds.

[0114] This solution ensures the safety of the working environment of electronic devices by designing the set duration, which is beneficial to providing protection for the stable operation of electronic circuits.

[0115] Based on the above technical solutions, optionally, before identifying that the current limiting duration reaches the set duration, the method further includes:

[0116] When it is identified that the fault is resolved, the normal current output of the rectifier module is restored.

[0117] In another possible case, before it is identified that the current limiting duration reaches a set duration, if it is identified that the fault is resolved, the normal current output of the rectifier module can be restored.

[0118] In summary, this solution can not only quickly limit the current when a fault occurs, but also automatically restore to normal operation after the fault is resolved, or shut down the rectifier module after the fault duration exceeds the set time, providing a flexible current limiting strategy and improving the reliability and safety of the system.

[0119] The technical solution provided in this embodiment detects the output current after the rectifier module is started; when a current limiting trigger event is detected, the output current of the rectifier module is limited by sliding mode control; after the current limiting control reaches the preset sliding mode surface, the output current of the rectifier module is controlled by PID control to stabilize the current; when it is identified that the current limiting output termination condition is met, the output current control of the rectifier module is terminated. The above technical solution can achieve rapid output current limitation of the rectifier module by connecting the sliding mode control and the PID control in an emergency situation when an inter-pole fault or other fault occurs, so as to improve the response speed of the inter-pole fault, achieve timely and effective limitation of the fault current, and ensure the safe operation of power electronic equipment.

[0120] Embodiment 2

[0121] In order to enable those skilled in the art to understand the present solution more clearly, the present application also provides a preferred embodiment.

[0122] Figure 2 is a flow chart of the current limiting output control method of the rectifier module provided in the second embodiment of the present application. Figure 2 As shown, the specific steps include:

[0123] S1: Normal operation status, and current detection.

[0124] S2, fault detection, that is, identifying whether Iactual>Iset exists. If so, execute S3, if not, execute S1.

[0125] S3, sliding mode control to achieve rapid current limiting.

[0126] S4: The system enters the sliding surface and begins to smoothly transition to PID high-precision steady flow control.

[0127] S5. While continuing the current limiting output, check whether the fault is cleared, that is, Iactual<Iset. If so, execute S6; if not, execute S7.

[0128] S6. After the fault is eliminated, normal power supply is restored.

[0129] S7, determine whether the current limiting output time satisfies t<5s, if not, continue to execute S5, if satisfied, execute S8.

[0130] S8. Turn off the rectifier module.

[0131] End the process.

[0132] Through such a setting, the sliding mode control of this scheme can provide a larger approach speed when the system state is far away from the sliding mode surface, thereby achieving rapid current limiting, reducing the duration of the fault current, and improving the safety of the system. PID control takes over after the system enters the sliding mode surface to ensure that the output current is stable within the target value, achieving high-precision steady current control, and improving the control accuracy and stability of the system. This algorithm can not only quickly limit the current when a fault occurs, but also automatically restore to normal operation after the fault is removed, or shut down the rectifier module after the fault duration exceeds the set time, providing a flexible current limiting strategy and improving the reliability and safety of the system.

[0133] The present invention is further described below through the description of a specific implementation mode. Assuming that the output rated power of the rectifier module is 20kW, the rated voltage is 750V, and the duration of the current limiting output is 5s, the implementation is as follows:

[0134] Normal operating status:

[0135] After the rectifier module is started, the output voltage is gradually increased through the soft start strategy until it reaches 750V.

[0136] After the system reaches 750V, the output port is opened to allow load access.

[0137] At a rated power of 20kW, the increase or decrease of the load is determined by real-time monitoring of the output current Iactual, and the PID controller is used to adjust the PWM duty cycle to control the output current Iout.

[0138] Fault detection and current limiting strategy startup:

[0139] Set the current threshold Iset = 30A;

[0140] When the detected output current Iactual exceeds 30A, it is judged as a fault current.

[0141] The fault information is transmitted to the upper control system through the high-speed communication interface to start the current limiting control program.

[0142] Sliding mode control for fast current limiting:

[0143] The sliding surface s is defined as the difference between the output current Iout and the target current 32A:

[0144] s = Iout - 32;

[0145] Select the exponential reaching law, the reaching law is in the form of:

[0146]

[0147] Among them, ∈ = 10, k = 1;

[0148] Assume the dynamic model of the system is:

[0149]

[0150] Where a=-1, b=1;

[0151] According to the sliding surface and reaching law, the expression of the controller u is solved:

[0152] u=-(∈sgn(s)+ks+aIout);

[0153] Substitute specific parameters:

[0154] u=-(10sgn(s)+s-Iout);

[0155] The system enters the sliding surface and begins to smoothly transition to PID high-precision steady flow control:

[0156] When the system state s approaches or reaches the sliding mode surface s=0, a smooth switching function (s)=arctan(s) is used to smoothly switch from sliding mode control to PID control.

[0157] The PID controller monitors the output current in real time and dynamically adjusts the control output to ensure that the output current is stable within 32A.

[0158] The system maintains the maximum current Irated output until the fault is resolved and normal operation is restored, or the rectifier module is turned off after the maximum current limit output time is continued for 5 seconds.

[0159] Through the PID controller, the output current is ensured to be stable at 32A to prevent the fault current from continuing to rise.

[0160] In the current limiting state, the fault current continues to be monitored to ensure that the system operates stably in the current limiting state.

[0161] When the fault is removed, the system automatically returns to normal operation. By real-time monitoring of the output current, when the output current drops to the normal range, the normal control strategy is restored.

[0162] If the fault lasts for more than 5 seconds, the rectifier module will be shut down.

[0163] This solution implements a current limiting output control algorithm for the AC / DC rectifier module when an inter-pole fault occurs. Specifically, it is a current limiting control strategy for the AC / DC rectifier circuit based on three-phase PFC (power factor correction) plus full-bridge LLC.

[0164] Embodiment 3

[0165] Figure 3 Schematic diagram of the structure of the current limiting output control device of the rectifier module provided in the fourth embodiment of the present application. Figure 3 As shown, the device comprises:

[0166] The current detection unit 301 is used to detect the output current after the rectifier module is started;

[0167] A first current limiting control unit 302, configured to use sliding mode control to perform current limiting control on the output current of the rectifier module when a current limiting triggering event is detected;

[0168] A second current limiting control unit 303, configured to use PID control to perform a steady current control on the output current of the rectifier module after the current limiting control reaches a preset sliding mode surface;

[0169] The current limiting termination unit 304 is used to terminate the output current control of the rectifier module when it is identified that the current limiting output termination condition is met.

[0170] The technical solution provided in this embodiment detects the output current after the rectifier module is started; when a current limiting trigger event is detected, the output current of the rectifier module is limited by sliding mode control; after the current limiting control reaches the preset sliding mode surface, the output current of the rectifier module is controlled by PID control to stabilize the current; when it is identified that the current limiting output termination condition is met, the output current control of the rectifier module is terminated. The above technical solution can achieve rapid output current limitation of the rectifier module by connecting the sliding mode control and the PID control in an emergency situation when an inter-pole fault or other fault occurs, so as to improve the response speed of the inter-pole fault, achieve timely and effective limitation of the fault current, and ensure the safe operation of power electronic equipment.

[0171] The current limiting output control device of the rectifier module in the embodiment of the present application can be a device, or a component, an integrated circuit, or a chip in a terminal. The device can be a mobile electronic device or a non-mobile electronic device. Exemplarily, the mobile electronic device can be a mobile phone, a tablet computer, a laptop computer, a PDA, an in-vehicle electronic device, a wearable device, an ultra-mobile personal computer (ultra-mobile personal computer, UMPC), a netbook or a personal digital assistant (personal digital assistant, PDA), etc., and the non-mobile electronic device can be a server, a network attached storage (Network Attached Storage, NAS), a personal computer (personal computer, PC), a television (television, TV), a teller machine or a self-service machine, etc., which is not specifically limited in the embodiment of the present application.

[0172] The current limiting output control device of the rectifier module in the embodiment of the present application may be a device having an operating system. The operating system may be an Android operating system, an IOS operating system, or other possible operating systems, which are not specifically limited in the embodiment of the present application.

[0173] The current limiting output control device of the rectifier module provided in the embodiment of the present application can implement each process implemented in the above method embodiment, and will not be described again here to avoid repetition.

[0174] Embodiment 4

[0175] like Figure 4 As shown, an embodiment of the present application also provides an electronic device 400, including a processor 401, a memory 402, and a program or instruction stored in the memory 402 and executable on the processor 401. When the program or instruction is executed by the processor 401, each process of the current limiting output control device embodiment of the above-mentioned rectifier module is implemented, and the same technical effect can be achieved. To avoid repetition, it will not be repeated here.

[0176] It should be noted that the electronic devices in the embodiments of the present application include the mobile electronic devices and non-mobile electronic devices mentioned above.

[0177] Embodiment 5

[0178] An embodiment of the present application also provides a readable storage medium, on which a program or instruction is stored. When the program or instruction is executed by a processor, the various processes of the embodiment of the current limiting output control device of the above-mentioned rectifier module are implemented, and the same technical effect can be achieved. To avoid repetition, it will not be repeated here.

[0179] The processor is a processor in the electronic device described in the above embodiment. The readable storage medium includes a computer readable storage medium, such as a computer read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0180] Embodiment 6

[0181] An embodiment of the present application further provides a chip, which includes a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is used to run programs or instructions to implement the various processes of the embodiment of the current limiting output control device of the above-mentioned rectifier module, and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0182] It should be understood that the chip mentioned in the embodiments of the present application can also be called a system-level chip, a system chip, a chip system or a system-on-chip chip, etc.

[0183] It should be noted that, in this article, the terms "comprise", "include" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise one..." do not exclude the presence of other identical elements in the process, method, article or device including the element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in reverse order according to the functions involved, for example, the described method may be performed in an order different from that described, and various steps may also be added, omitted, or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0184] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a computer software product, which is stored in a storage medium (such as ROM / RAM, a disk, or an optical disk), and includes a number of instructions for a terminal (which can be a mobile phone, a computer, a server, or a network device, etc.) to execute the methods described in each embodiment of the present application.

[0185] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

[0186] The above are only preferred embodiments of the present application and the technical principles used. The present application is not limited to the specific embodiments described herein, and various obvious changes, readjustments and substitutions that can be made by those skilled in the art will not deviate from the scope of protection of the present application. Therefore, although the present application is described in more detail through the above embodiments, the present application is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present application, and the scope of the present application is determined by the scope of the claims.

Claims

1. A current limiting output control method for a rectifier module, characterized in that: The method comprises: After the rectifier module is started, the output current is detected; When a current limiting trigger event is detected, a sliding mode control is used to perform current limiting control on the output current of the rectifier module; After the current limiting control reaches the preset sliding mode surface, the output current of the rectifier module is controlled by PID control to stabilize the current; When it is identified that the current limiting output termination condition is met, the output current control of the rectifier module is terminated.

2. The current limiting output control method of the rectifier module according to claim 1, characterized in that: The output current of the rectifier module is limited by sliding mode control, including: Obtain a preset sliding surface; According to the current output current of the rectifier module, the output current of the rectifier module is limited and controlled in the form of an exponential approach law.

3. The current limiting output control method of the rectifier module according to claim 2, characterized in that: According to the current output current of the rectifier module, the output current of the rectifier module is limited in the form of an exponential approach law, including: The form of the exponential reaching law is as follows: Among them, ∈>0, k>0, and both are design parameters, sgn(s) is the sign function; ∈ is used to determine the approach speed of the system when it is far away from the preset sliding surface, and k is used to determine the approach speed of the system when it is close to the preset sliding surface.

4. The current limiting output control method of the rectifier module according to claim 1, characterized in that: After the current limiting control reaches the preset sliding surface, the output current of the rectifier module is controlled by PID control, including: After reaching the preset sliding mode surface, a smooth switching function is used to switch from sliding mode control to PID control to perform steady current control on the output current of the rectifier module.

5. The current limiting output control method of the rectifier module according to claim 1, characterized in that: When a current limiting trigger event is detected, the output current of the rectifier module is limited by using sliding mode control, including: When it is detected that the output current of the rectifier module exceeds a preset current threshold, it is determined that a current limiting trigger event is detected, and sliding mode control is used to perform current limiting control on the output current of the rectifier module.

6. The current limiting output control method of the rectifier module according to claim 1, characterized in that: When it is identified that the current limiting output termination condition is met, the output current control of the rectifier module is terminated, including: When it is identified that the current limiting time reaches the set time, the output current control of the rectifier module is terminated.

7. The current limiting output control method of the rectifier module according to claim 6, characterized in that: Before identifying that the current limiting duration reaches the set duration, the method further includes: When it is identified that the fault is resolved, the normal current output of the rectifier module is restored.

8. A current limiting output control device for a rectifier module, characterized in that: The device comprises: A current detection unit is used to detect the output current after the rectifier module is started; A first current limiting control unit, configured to use sliding mode control to perform current limiting control on the output current of the rectifier module when a current limiting triggering event is detected; A second current limiting control unit, used to use PID control to perform a steady current control on the output current of the rectifier module after the current limiting control reaches a preset sliding mode surface; The current limiting termination unit is used to terminate the output current control of the rectifier module when it is identified that the current limiting output termination condition is met.

9. An electronic device, characterized in that: It includes a processor, a memory, and a program or instruction stored in the memory and executable on the processor, wherein when the program or instruction is executed by the processor, the steps of the current limiting output control method of the rectifier module as described in any one of claims 1 to 7 are implemented.

10. A readable storage medium, characterized in that: The readable storage medium stores a program or instruction, and when the program or instruction is executed by the processor, the steps of the current limiting output control method of the rectifier module as described in any one of claims 1-7 are implemented.

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