Control method of power supply circuit, processing unit, power supply circuit and storage medium

Abstract

The invention provides a control method of a power supply circuit, a processing unit, the power supply circuit and a storage medium. The type of an input voltage signal on the electromagnetic compatibility unit is detected, and whether the first input voltage on the electromagnetic compatibility unit obtained through sampling of the voltage sampling unit is continuously reduced or not is detected; and if the input voltage signal is a direct-current voltage signal and the first input voltage is not continuously reduced, controlling the switch unit to be closed so as to ensure that the charging current of the power factor correction capacitor is smaller than the preset current after the current limiting unit is short-circuited. The charging current of the power factor correction capacitor is less than the preset current after the current limiting unit is short-circuited; the phenomenon of air switch error protection or power plug ignition corresponding to the power supply circuit is avoided, and the power failure risk of the whole power supply system is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of power supplies, and particularly relates to a control method for a power supply circuit, a processing unit, a power supply circuit, and a storage medium. Background Art

[0002] In an AC-DC / DC-DC power supply circuit, to meet the requirements of high power factor and high efficiency, a relatively common solution is the scheme of EMI circuit + relay (parallel current-limiting resistor) + PFC (power factor correction capacitor). After power-on, the input voltage first charges the power factor correction capacitor through the current-limiting resistor, thereby limiting the charging current of the power factor correction capacitor. Then, the relay is controlled to close, thereby short-circuiting the current-limiting resistor, and then the input voltage is output with high efficiency.

[0003] However, in actual situations, when the staff inserts the power supply circuit into the corresponding power supply port (such as the jack provided by the PDU), there may be situations such as shaking, resulting in the power supply circuit being first connected to the power supply, then disconnected, and finally connected again. The prior art usually completes the closing of the relay during the first connection to the power supply. During the process of the power supply circuit being disconnected and then connected again, the power factor correction capacitor discharges first and then charges, resulting in the charging current of the power factor correction capacitor not passing through the current-limiting resistor during the recharging process, resulting in a very large charging current. There may be phenomena such as false protection of the air switch or arcing of the power supply plug corresponding to the power supply circuit, ultimately causing a risk of power outage in the entire power supply system. Summary of the Invention

[0004] Aiming at the deficiencies in the prior art, the present application provides a control method for a power supply circuit, a processing unit, a power supply circuit, and a storage medium.

[0005] In a first aspect, in one embodiment, the present application provides a control method for a power supply circuit. The control method for the power supply circuit is used to perform switching control on the power supply circuit. The power supply circuit includes an electromagnetic compatibility unit, a power factor correction capacitor, a current-limiting unit, a switching unit, a voltage sampling unit, and a processing unit. The current-limiting unit is connected in series between the electromagnetic compatibility unit and the power factor correction capacitor. The switching unit is connected in parallel with the current-limiting unit. The voltage sampling unit is connected to the electromagnetic compatibility unit. The processing unit is respectively connected to the switching unit and the voltage sampling unit. For the processing unit, the control method for the power supply circuit includes:

[0006] After the power supply circuit is connected to the power supply,

[0007] Detect the type of the input voltage signal on the electromagnetic compatibility unit;

[0008] Detect whether the first input voltage on the electromagnetic compatibility unit sampled by the voltage sampling unit continuously decreases;

[0009] If the input voltage signal type is a DC voltage signal and the first input voltage does not continuously decrease, then control the switch unit to close to ensure that after the current limiting unit is short-circuited, the charging current of the power factor correction capacitor is less than the preset current.

[0010] In one embodiment, detecting whether the first input voltage on the electromagnetic compatibility unit sampled by the voltage sampling unit continuously decreases includes:

[0011] Detecting whether the first input voltage sampled at a target time on the electromagnetic compatibility unit is less than the first input voltage sampled at the previous time of the target time. If so, perform counting or timing;

[0012] If the cumulative count value obtained by continuous counting is not less than the preset value or the cumulative timing value obtained by continuous timing is not less than the first preset timing value, it is determined that the first input voltage on the electromagnetic compatibility unit continuously decreases; otherwise, it is determined that the first input voltage on the electromagnetic compatibility unit does not continuously decrease.

[0013] In one embodiment, detecting the input voltage signal type on the electromagnetic compatibility unit includes:

[0014] Detecting the second input voltage on the electromagnetic compatibility unit sampled by the voltage sampling unit;

[0015] Determine the input voltage signal type on the electromagnetic compatibility unit according to the second input voltage.

[0016] In one embodiment, the second input voltage includes a positive input voltage and a negative input voltage; determining the input voltage signal type on the electromagnetic compatibility unit according to the second input voltage includes:

[0017] Determine the input voltage phase according to the positive input voltage and the negative input voltage;

[0018] If the input voltage phase does not change within the second preset time value, it is determined that the input voltage signal type is a DC voltage signal;

[0019] If the input voltage phase changes within the second preset time value, it is determined that the input voltage signal type is an AC voltage signal.

[0020] In one embodiment, the second input voltage includes a positive input voltage or a negative input voltage; determining the input voltage signal type on the electromagnetic compatibility unit according to the second input voltage includes:

[0021] Determine the input voltage amplitude according to the positive input voltage and the negative input voltage;

[0022] If the input voltage amplitude continuously exceeds the preset amplitude within the third preset time value, it is determined that the input voltage signal type is a DC voltage signal;

[0023] If the amplitude of the input voltage does not continuously exceed the preset amplitude within the third preset value, determine that the type of the input voltage signal is an AC voltage signal.

[0024] In one embodiment, if the first input voltage does not continuously decrease, controlling the switch unit to close includes:

[0025] If the first input voltage does not continuously decrease and the type of the input voltage signal does not change within the fourth preset value, control the switch unit to close.

[0026] In one embodiment, after the step of detecting the type of the input voltage signal on the electromagnetic compatibility unit, for the processing unit, the control method of the power supply circuit further includes:

[0027] If the type of the input voltage signal is an AC voltage signal and the type of the input voltage signal does not change within the fourth preset value, control the switch unit to close.

[0028] In a second aspect, in one embodiment, the present application provides a processing unit, including a memory and a processor; the memory stores a computer program, and the processor is configured to run the computer program in the memory to execute the steps in the control method of the power supply circuit in any of the above embodiments.

[0029] In a third aspect, in one embodiment, the present application provides a power supply circuit, including an electromagnetic compatibility unit, a power factor correction capacitor, a current limiting unit, a switch unit, and a voltage sampling unit. The power supply circuit further includes the processing unit in any of the above embodiments.

[0030] In a fourth aspect, in one embodiment, the present application provides a storage medium storing a computer program, and the computer program is loaded by a processor to execute the steps in the control method of the power supply circuit in any of the above embodiments.

[0031] Through the control method, processing unit, power supply circuit and storage medium of the above power supply circuit, when the power supply circuit disconnects the connection with the power supply, the filter capacitor and power factor correction capacitor in the electromagnetic compatibility unit will discharge. Based on this principle, after the power supply circuit is connected to the power supply, the type of the input voltage signal on the electromagnetic compatibility unit is detected, and whether the first input voltage on the electromagnetic compatibility unit continuously decreases is detected. If the input voltage signal type is a DC voltage signal and the first input voltage does not continuously decrease, it indicates that the first input voltage is not obtained based on the discharge of the filter capacitor in the electromagnetic compatibility unit and belongs to that provided by a real DC power supply. Thus, on this basis, the switch unit is controlled to close to short-circuit the current limiting unit. It can ensure that after the current limiting unit is short-circuited, the charging current of the power factor correction capacitor is less than the preset current, avoid the phenomenon of false protection of the air switch or arcing of the power plug corresponding to the power supply circuit, and thus reduce the power outage risk of the entire power supply system. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those skilled in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0033] Figure 1 FIG. is a schematic structural diagram of a power supply circuit provided by an embodiment of the present application;

[0034] Figure 2 FIG. is a schematic flowchart of a control method for a power supply circuit provided by an embodiment of the present application;

[0035] Figure 3 FIG. is a relay control timing diagram provided by an embodiment of the present application;

[0036] Figure 4 FIG. is a schematic structural diagram of an electromagnetic compatibility unit provided by an embodiment of the present application;

[0037] Figure 5 FIG. is a schematic structural diagram of a current limiting unit and a switch unit provided by an embodiment of the present application;

[0038] Figure 6 FIG. is a schematic structural diagram of a resistor voltage dividing unit provided by an embodiment of the present application;

[0039] Figure 7 FIG. is a schematic structural diagram of an analog-to-digital converter provided by an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0040] The following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application.

[0041] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation to the present application. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of the described features. In the description of the present application, "a plurality" means two or more, unless otherwise specifically defined. In the present application, the term "exemplary" is used to mean "serving as an example, illustration, or description". Any embodiment described as "exemplary" in the present application is not necessarily to be construed as more preferred or more advantageous than other embodiments. In order for any person skilled in the art to implement and use the present application, the following description is given. In the following description, details are set forth for the purpose of explanation. It should be understood that those of ordinary skill in the art can recognize that the present application can be implemented without these specific details. In other instances, well-known structures and processes are not described in detail to avoid unnecessary details from obscuring the description of the present application. Therefore, the present application is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed in the present application.

[0042] In a first aspect, in one embodiment, the present application provides a control method for a power supply circuit, and the control method for the power supply circuit is used to perform switching control on the power supply circuit.

[0043] As Figure 1 shown, the power supply circuit includes an electromagnetic compatibility unit, a power factor correction capacitor, a current limiting unit, a switching unit, a voltage sampling unit, and a processing unit. The current limiting unit is connected in series between the electromagnetic compatibility unit and the power factor correction capacitor. The switching unit is connected in parallel with the current limiting unit. The voltage sampling unit is connected to the electromagnetic compatibility unit. The processing unit is respectively connected to the switching unit and the voltage sampling unit.

[0044] Among them, the electromagnetic compatibility (EMC) unit refers to a series of circuit design techniques adopted in electronic systems or electrical equipment, which are used to improve the electromagnetic compatibility of equipment, reduce electromagnetic interference and enhance the anti-interference ability of the circuit unit. Generally, the EMC unit can include several parts such as filters, terminal impedance matching, grounding and shielding, interference suppression circuits, isolators, power noise suppression, ground wire routing, and electromagnetic radiation control.

[0045] Filters are used to prevent unwanted frequency components from entering or leaving the equipment. Common filters include low-pass filters, high-pass filters, band-pass filters, and band-stop filters, etc.

[0046] Terminal impedance matching is to match the impedance of the signal source and the load by adjusting the input and output impedance of the circuit, so as to reduce reflection and interference.

[0047] Good grounding and shielding designs can reduce the propagation of electromagnetic interference and the degree of interference on sensitive circuits. This includes using appropriate grounding techniques, effective shielding materials and structures, etc.

[0048] Interference suppression circuits use special circuit design techniques, such as differential mode circuits, common mode circuits, balanced circuits, etc., to suppress the propagation and influence of electromagnetic interference signals.

[0049] Isolators are used to isolate the propagation of interference and mutual influence between different circuits. Common isolators include optocouplers, transformer isolation, etc.

[0050] Power noise is a common interference source in electronic equipment. Taking appropriate measures such as power filtering, voltage regulation techniques, and decoupling capacitors can reduce the impact of power noise on the equipment.

[0051] Reasonable ground wire routing can reduce the interference and propagation of ground loops and reduce common mode interference.

[0052] By taking measures such as reasonable PCB layout, trace routing, and component arrangement, etc., the occurrence and propagation of electromagnetic radiation can be reduced, and the interference to surrounding equipment can be lowered.

[0053] Among them, the current limiting unit is mainly used to limit the magnitude of the flowing current, thereby limiting the charging current of the power factor correction capacitor.

[0054] Among them, the switching unit is mainly used to short-circuit the current limiting unit when in the closed state, so as to output the connected power supply with high efficiency.

[0055] Among them, the Power Factor Correction Capacitor (abbreviated as PFC capacitor) is a capacitor used to improve the power factor of the power system. In an AC circuit, the power factor of a load device refers to the ratio of the actual power to the apparent power, which reflects the balance relationship between the useful power and the useless power (i.e., reactive power) in the circuit. The main function of the power factor correction capacitor is to improve the power factor by compensating the reactive power of the load circuit. It converts the reactive power in the circuit into useful power, reduces the flow of reactive power in the circuit, and improves the efficiency of the power system. The benefits of using power factor correction capacitors include improving energy utilization efficiency, reducing power losses, increasing the capacity of the power system, and reducing the load on power equipment.

[0056] The power factor correction capacitor can reduce the flow of reactive power in the power system, improve the utilization rate of active power, and thus improve the overall energy utilization efficiency of the power system.

[0057] By improving the power factor, the power factor correction capacitor can reduce the transmission losses and line current in the power system, and reduce the energy consumption of the power supply and load devices.

[0058] The power factor correction capacitor can reduce the reactive power demand of the power system, thus releasing additional power system capacity and extending the service life of power equipment.

[0059] By improving the power factor, the power factor correction capacitor can reduce the load on power equipment and improve the stability and reliability of the power system.

[0060] Among them, the voltage sampling unit may include a resistor voltage division unit and an analog-to-digital converter.

[0061] Among them, the processing unit may be a DSP (Digital Signal Processor).

[0062] For the processing unit, as Figure 2 shown, the control method of the power supply circuit includes:

[0063] Step 101, after the power supply circuit is connected to the power supply, detect the type of the input voltage signal on the electromagnetic compatibility unit and detect whether the first input voltage on the electromagnetic compatibility unit sampled by the voltage sampling unit continuously decreases.

[0064] Among them, the input voltage signal types include AC voltage signals and DC voltage signals. It can be understood that the AC voltage signal and the DC voltage signal have different current change situations, including the amplitude change of the current or the phase change of the current.

[0065] Specifically, taking the phase as an example, the input current includes a positive input current and a negative input current. Based on the positive input current and the negative input current, the phase of the input current is determined. If the phase of the input current remains positive or remains negative (i.e., does not change within a certain period of time), it can be determined that the type of the input voltage signal is a DC voltage signal. On the contrary, if the phase of the input current alternates continuously between positive and negative, it can be determined that the type of the input voltage signal is an AC voltage signal. The duration needs to be determined according to the period of the AC voltage signal. For example, the duration can be set to be slightly greater than the period of the AC voltage signal.

[0066] Similarly, taking the amplitude of the current as an example, if the input current continuously exceeds a preset current, it can be determined that the type of the input voltage signal is a DC voltage signal. On the contrary, if the input current does not continuously exceed the preset current, it can be determined that the type of the input voltage signal is an AC voltage signal. The preset current needs to be determined according to the current peaks of the DC voltage signal and the AC voltage signal. The duration needs to be determined according to the period of the AC voltage signal, so as to accurately distinguish between the AC voltage signal and the DC voltage signal based on the preset current and the corresponding duration. For example, the duration can be set to be slightly greater than the period of the AC voltage signal.

[0067] Among them, for current sampling, it can be obtained through relevant conversion operations on the voltage sampled by the voltage sampling unit in the power supply circuit. For example, operations are performed using Ohm's law and circuit characteristics.

[0068] Among them, when the connected DC power supply or AC power supply is disconnected from the power supply circuit, the filter capacitor and the power factor correction capacitor in the electromagnetic compatibility unit will discharge. In this case, through the detection in step 101 above, it is easy to obtain the detection result that the type of the input voltage signal is a DC voltage signal. However, the detected DC voltage signal is not provided by the real DC power supply. When the subsequent real DC power supply or AC power supply is reconnected, since the power factor correction capacitor has discharged a part of the charge, it will be recharged. If the switch unit has been controlled to be closed before, the charging current used to charge the power factor correction capacitor is very large at this time. In response to this situation, in this step, the characteristic that the voltage decreases continuously during the capacitor discharge process is used to judge the change trend of the first input voltage. If the detected first input voltage continuously decreases, it can be determined that the currently detected DC voltage signal is not provided by the real DC power supply, so the switch unit is not controlled to be closed.

[0069] Step 102, if the type of the input voltage signal is a DC voltage signal and the first input voltage does not continuously decrease, control the switch unit to close to ensure that after the current limiting unit is short-circuited, the charging current of the power factor correction capacitor is less than the preset current.

[0070] Among them, if the first input voltage does not continuously decrease, it can be determined that the detected DC voltage signal is provided by a real DC power supply, and the power factor correction capacitor does not experience discharging and then recharging. At this time, closing the control switch unit is not likely to generate a very large charging current.

[0071] It should be noted that although it can be determined that the power factor correction capacitor is not in a discharging state when the first input voltage does not continuously decrease, it is not necessarily in a fully charged state and may also be in a charging state. In view of this situation, in this embodiment, relevant preconditions can be set in the control method to avoid closing the control switch unit when the power factor correction capacitor is in a charging state. Specifically, the time required to execute the above steps can be set longer so that the power factor correction capacitor can be fully charged within the execution time of the above steps; or after the power supply circuit is connected to the power supply, the above steps are executed after a certain delay so that the power factor correction capacitor can be fully charged within the delay time.

[0072] Among them, it should be emphasized that the control methods implemented in this embodiment can all rely on the hardware structure of the power supply circuit itself without the need to additionally increase the hardware cost.

[0073] Through the control method of the above power supply circuit, when the power supply circuit disconnects from the power supply, the filter capacitor and the power factor correction capacitor in the electromagnetic compatibility unit will both discharge. Based on this principle, after the power supply circuit is connected to the power supply, the type of the input voltage signal on the electromagnetic compatibility unit is detected and whether the first input voltage on the electromagnetic compatibility unit continuously decreases is detected. If the input voltage signal type is a DC voltage signal and the first input voltage does not continuously decrease, it indicates that the first input voltage is not obtained based on the discharge of the filter capacitor in the electromagnetic compatibility unit and is provided by a real DC power supply; thus, on this basis, the control switch unit is closed to short-circuit the current limiting unit. It can ensure that after the current limiting unit is short-circuited, the charging current of the power factor correction capacitor is less than the preset current; avoid the phenomenon of false protection of the air switch or arcing of the power supply plug corresponding to the power supply circuit, thereby reducing the power outage risk of the entire power supply system.

[0074] In one embodiment, detecting whether the first input voltage on the electromagnetic compatibility unit sampled by the voltage sampling unit continuously decreases includes:

[0075] Detecting whether the first input voltage sampled at the target moment on the electromagnetic compatibility unit is less than the first input voltage sampled at the previous moment of the target moment. If so, perform counting or timing.

[0076] Among them, the decrease in the first input voltage is determined based on the comparison result between two adjacent first input voltages. As mentioned in the above embodiments, when detecting the type of the input voltage signal, the input voltage on the electromagnetic compatibility unit can be detected first, then relevant operations can be performed on the input voltage to obtain the corresponding input current, and finally, based on the input current, it can be determined whether the input voltage signal type is a DC voltage signal or an AC voltage signal. The input voltage obtained during the detection of the input voltage signal type can also be applied to the "process of determining whether the DC voltage signal is a real detection". Therefore, the target moment can refer to the current moment (i.e., after completing the detection of the input voltage signal type, voltage sampling is performed again), or it can refer to a certain historical moment (i.e., the input voltage required for the "process of detecting the input voltage signal type" and the input voltage required for the "process of determining whether the DC voltage signal is provided by a real DC power supply" are sampled simultaneously), as long as it meets the premise of "after the power circuit is connected to the power supply".

[0077] Among them, the first input voltage can be obtained by sampling based on a preset sampling frequency. Then, it can be directly counted when the first input voltage sampled at the target moment is less than the first input voltage sampled at the previous moment of the target moment, or timed according to the sampling period corresponding to the preset sampling frequency.

[0078] If the cumulative count value obtained by continuous counting is not less than the preset value or the cumulative timing value obtained by continuous timing is not less than the first preset timing value, it is determined that the first input voltage on the electromagnetic compatibility unit decreases continuously; otherwise, it is determined that the first input voltage on the electromagnetic compatibility unit does not decrease continuously.

[0079] Among them, continuous counting refers to counting without interruption. For example, if it is detected at the first moment that the first input voltage is less than the previous one, the count is 1; if it is detected at the second moment that the first input voltage is less than the previous one, the count is 2; if it is detected at the third moment that the first input voltage is not less than the previous one, the counting stops; if it is detected at the third moment that the first input voltage is less than the previous one, the count is 3, and so on. The specific method of continuous timing is the same. As long as the situation of not less than occurs, the timing stops. The specific details can refer to continuous counting and will not be elaborated here.

[0080] Among them, the preset value can be 3, that is, when the cumulative count value obtained by continuous counting reaches 3, it can be determined that the first input voltage on the electromagnetic compatibility unit decreases continuously. If the cumulative count value obtained by continuous counting reaches 2, but the situation of not less than occurs during the third detection, the cumulative count value is fixed at 2, which does not meet the requirement of continuous decrease.

[0081] In one embodiment, detecting the type of the input voltage signal on the electromagnetic compatibility unit includes:

[0082] Detect the second input voltage on the electromagnetic compatibility unit sampled by the voltage sampling unit.

[0083] Determine the type of the input voltage signal on the electromagnetic compatibility unit according to the second input voltage.

[0084] As mentioned in the above embodiments, the input voltage on the electromagnetic compatibility unit can be detected first, and then relevant operations can be performed on the input voltage to obtain the corresponding input current. Finally, the type of the input voltage signal can be detected according to the input current. However, this method is relatively complex in calculation, and errors will be introduced in the process of performing relevant operations on the input voltage to obtain the corresponding input current, which may affect the judgment accuracy. Therefore, in this embodiment, in view of this situation, the type of the input voltage signal can be directly detected according to the sampled second input voltage. Since the second input voltage is directly sampled by the voltage sampling unit and no relevant operations are required, the calculation complexity can be reduced and the judgment accuracy can be improved.

[0085] As mentioned in the above embodiments, the input voltage required for the "detection process of the type of the input voltage signal" and the input voltage required for the "detection process of determining whether the DC voltage signal is provided by a real DC power supply" are sampled simultaneously. That is, in this embodiment, the second input voltage sampled and the first input voltage sampled in the above embodiments can be the same voltage. The "first" and "second" only represent the application of this voltage in different steps or stages. In other words, after the power supply circuit is connected to the power supply, the electromagnetic compatibility unit is voltage-sampled by the voltage sampling unit to obtain the target input voltage, and then the target input voltage is applied as the second input voltage to the "detection process of the type of the input voltage signal", and the target input voltage is applied as the first input voltage to the "detection process of determining whether the DC voltage signal is provided by a real DC power supply".

[0086] In one embodiment, the second input voltage includes a positive input voltage and a negative input voltage; determining the type of the input voltage signal on the electromagnetic compatibility unit according to the second input voltage includes:

[0087] Determine the input voltage phase according to the positive input voltage and the negative input voltage.

[0088] The voltage sampling unit can perform positive voltage sampling and negative voltage sampling respectively. It should be noted that in this embodiment, the type of the input voltage signal can be either a DC voltage signal or an AC voltage signal. Therefore, the positive input voltage here can correspond to the voltage output from the positive pole of the DC voltage signal or the voltage output from the live wire of the AC voltage signal, and the negative input voltage can correspond to the voltage output from the negative pole of the DC voltage signal or the voltage output from the neutral wire of the AC voltage signal.

[0089] Among them, the positive input voltage is used as the minuend, and the negative input voltage is used as the subtrahend, so as to determine the difference between the positive input voltage and the negative input voltage. If the difference is positive, the input voltage phase is a positive phase; if the difference is negative, the input voltage phase is a negative phase.

[0090] If the input voltage phase does not change within the second preset value, it is determined that the input voltage signal type is a DC voltage signal.

[0091] If the input voltage phase changes within the second preset value, it is determined that the input voltage signal type is an AC voltage signal.

[0092] Among them, since the phase change situations of DC voltage signals and AC voltage signals are different, the input voltage signal type can be detected through the obtained input voltage phase. Specifically, the phase of a DC voltage signal does not change and is always a positive phase or a negative phase, while the phase of an AC voltage signal alternates within its cycle. The second preset value can be set according to the cycle of the AC voltage signal and can be set to be slightly larger than the cycle of the AC voltage signal, such as 24 ms. When the input voltage phase does not change within 24 ms, that is, it is always a positive phase or always a negative phase, this obviously does not conform to the phase change situation of an AC voltage signal, so the input voltage signal type can be determined as a DC voltage signal. When the input voltage phase changes within 24 ms, that is, first a positive phase and then a negative phase; or first a negative phase and then a positive phase; this obviously does not conform to the phase change situation of a DC voltage signal, so the input voltage signal type can be determined as an AC voltage signal.

[0093] In one embodiment, the second input voltage includes the positive input voltage or the negative input voltage; according to the second input voltage, determining the input voltage signal type on the electromagnetic compatibility unit includes:

[0094] Determine the input voltage amplitude according to the positive input voltage and the negative input voltage;

[0095] If the input voltage amplitude continuously exceeds the preset amplitude within the third preset value, it is determined that the input voltage signal type is a DC voltage signal.

[0096] As mentioned in the above embodiment, the corresponding input voltage phase can be determined through the difference between the positive input voltage and the negative input voltage, so as to determine the input voltage signal type according to the input voltage phase. In addition to the difference in phase change between DC voltage signals and AC voltage signals, there is also a difference in amplitude change. Therefore, in this embodiment, the characteristic that DC voltage signals and AC voltage signals are different in amplitude change can also be used to detect the input voltage signal type.

[0097] Among them, the amplitude refers to the degree of voltage swing of the voltage relative to the true ground or the reference ground. The negative input voltage in this embodiment can be understood as the voltage of the true ground or the reference ground. Therefore, the positive input voltage can be used as the minuend, and the negative input voltage can be used as the subtrahend to determine the difference between the positive input voltage and the negative input voltage. Finally, the absolute value of this difference is used as the input voltage amplitude.

[0098] Among them, the preset amplitude can be set to be slightly less than the voltage amplitude of the DC voltage signal. For example, the preset amplitude is set to 40V. Similarly, the third preset time value can also be set according to the period of the AC voltage signal, and can be set to be slightly greater than the period of the AC voltage signal. For example, it is set to 24ms. If the input voltage amplitude continuously exceeds 40V within 24ms, it can be determined that the input voltage signal type is a DC voltage signal.

[0099] If the input voltage amplitude does not continuously exceed the preset amplitude within the third preset time value, it is determined that the input voltage signal type is an AC voltage signal.

[0100] Among them, similarly, if the input voltage amplitude does not continuously exceed 40V within 24ms, it can be determined that the input voltage signal type is an AC voltage signal.

[0101] Specifically, when it is detected that the input voltage amplitude is greater than 40V, the voltage rising flag is determined to be 1. When the input voltage amplitude is less than 30V, the voltage rising flag is determined to be 0. If the voltage rising flag continuously remains 1 within 24ms, it is determined that the input voltage signal type is a DC voltage signal; otherwise, it is determined that the input voltage signal type is an AC voltage signal.

[0102] In one embodiment, if the first input voltage does not continuously decrease, the control switch unit is controlled to close, including:

[0103] If the first input voltage does not continuously decrease and the input voltage signal type does not change within the fourth preset time value, the control switch unit is controlled to close.

[0104] Among them, as mentioned in the above embodiments, when the first input voltage does not continuously decrease, although it can be determined that the power factor correction capacitor is not in a discharging state, it is not necessarily in a fully charged state and may still be in a charging state. Therefore, relevant preconditions can be set in the control method to avoid closing the switch unit when the power factor correction capacitor is in a charging state. For example, the time required to execute the above steps can be set longer so that the power factor correction capacitor can be fully charged within the execution time of the above steps; or after the power supply circuit is connected to the power supply, the above steps are executed after a certain delay so that the power factor correction capacitor can be fully charged within the delay time. However, there are certain problems with these methods. Setting the execution time longer will affect the processing speed of the modification processing unit itself and may cause related problems; setting the delay time does not necessarily guarantee that the power factor correction capacitor is fully charged, and it is also possible that the power factor correction capacitor discharges during the delay time, resulting in the power factor correction capacitor still being in a charging state after it is subsequently determined that the connected DC power supply is real.

[0105] To address the above problems, this embodiment sets an additional control condition, that is, the type of the input voltage signal does not change within the fourth preset time value. In this way, not only is it ensured that the connected DC voltage signal is real, but also it is ensured that the power factor correction capacitor is fully charged based on the connected real DC voltage signal. After these conditions are met, the power factor correction capacitor is necessarily fully charged, and thus the switch unit can be reliably controlled to close.

[0106] Among them, it can be understood that the fourth preset time value is greater than the first preset time value used to determine whether the first input voltage continuously decreases. In this embodiment, the fourth preset time value can be set to 500 ms. It should be noted that the fourth preset time value can include multiple first preset time values. For example, if it includes 10 first preset time values, then among the 10 first preset time values, if the detection result corresponding to each first preset time value is not continuously decreasing, the switch unit is controlled to close; if the detection result corresponding to a certain first preset time value is continuously decreasing, the process stops and the above steps are re-executed.

[0107] Among them, in addition to determining whether the type of the input voltage signal does not change within the fourth preset time value, in other embodiments, it can also be achieved through the corresponding preset type count. For example, each time the type of the input voltage signal is detected as a DC voltage signal, the count is incremented by 1 until the count value is greater than the preset type count, and then the switch unit is controlled to close; if the type of the input voltage signal is detected as an AC voltage signal, the count stops and the above steps are re-executed.

[0108] In one embodiment, after the step of detecting the type of input voltage signal on the electromagnetic compatibility unit, for the processing unit, the control method of the power supply circuit further includes:

[0109] If the type of input voltage signal is an AC voltage signal and the type of input voltage signal does not change within the fourth preset value, then control the switch unit to close.

[0110] Among them, similar to the corresponding embodiment of the above DC voltage signal, the judgment of setting the fourth preset value for the AC voltage signal is also to ensure that the power factor correction capacitor is fully charged before the switch unit closes. For details, reference can be made to the above embodiment and will not be elaborated here.

[0111] It should be added that for the DC voltage signal, since the DC voltage signal will also be detected due to the capacitor discharge, the detected DC voltage signal is not provided by the real DC power supply. Therefore, it is necessary to judge the authenticity of the DC power supply by detecting whether the first input voltage continuously decreases. And capacitor discharge cannot cause an AC voltage signal to be detected. Therefore, when an AC voltage signal is detected, it must be real. On this basis, only the judgment condition of the fourth preset value needs to be set.

[0112] Among them, as Figure 3 shown, after adopting the control method in this embodiment, the input voltage and input current enter from the mark 1 in Figure 3 . From mark 1 to mark 5, the connected AC power supply is disconnected, resulting in the power factor correction capacitor starting to discharge and the corresponding PFC voltage decreasing. During this process, the control signal of the relay is always at a low level, that is, the relay is not controlled to close. From mark 5 to mark 8, the AC power supply is reconnected, the power factor correction capacitor starts to charge, and the corresponding PFC voltage rises until it reaches the peak value, that is, the power factor correction capacitor is fully charged. At this time, the control signal of the relay is at a high level, that is, the relay is controlled to close.

[0113] In a second aspect, in one embodiment, the present application provides a processing unit, including a memory and a processor; the memory stores a computer program, and the processor is configured to run the computer program in the memory to execute the following steps:

[0114] After the power supply circuit is connected to the power supply,

[0115] Detect the type of input voltage signal on the electromagnetic compatibility unit;

[0116] Detect whether the first input voltage on the electromagnetic compatibility unit sampled by the voltage sampling unit continuously decreases;

[0117] If the input voltage signal type is a DC voltage signal and the first input voltage does not continuously decrease, the control switch unit is closed to ensure that after the current limiting unit is short-circuited, the charging current of the power factor correction capacitor is less than the preset current.

[0118] Through the above processing unit, when the power supply circuit disconnects from the power supply, the filter capacitor and the power factor correction capacitor in the electromagnetic compatibility unit will both discharge. Based on this principle, after the power supply circuit is connected to the power supply, the type of the input voltage signal on the electromagnetic compatibility unit is detected and whether the first input voltage on the electromagnetic compatibility unit continuously decreases is detected. If the input voltage signal type is a DC voltage signal and the first input voltage does not continuously decrease, it indicates that the first input voltage is not obtained based on the discharge of the filter capacitor in the electromagnetic compatibility unit and belongs to that provided by a real DC power supply; thus, on this basis, the control switch unit is closed to short-circuit the current limiting unit. It can ensure that after the current limiting unit is short-circuited, the charging current of the power factor correction capacitor is less than the preset current; avoid the phenomenon of false protection of the air switch or arcing of the power plug corresponding to the power supply circuit, thereby reducing the power outage risk of the entire power supply system.

[0119] In a third aspect, as Figure 1 shown, in one embodiment, the present application provides a power supply circuit, including an electromagnetic compatibility unit, a power factor correction capacitor, a current limiting unit, a switch unit, a voltage sampling unit, and the power supply circuit further includes the processing unit in any of the above embodiments.

[0120] Through the above power supply circuit, when the power supply circuit disconnects from the power supply, the filter capacitor and the power factor correction capacitor in the electromagnetic compatibility unit will both discharge. Based on this principle, after the power supply circuit is connected to the power supply, the type of the input voltage signal on the electromagnetic compatibility unit is detected and whether the first input voltage on the electromagnetic compatibility unit continuously decreases is detected. If the input voltage signal type is a DC voltage signal and the first input voltage does not continuously decrease, it indicates that the first input voltage is not obtained based on the discharge of the filter capacitor in the electromagnetic compatibility unit and belongs to that provided by a real DC power supply; thus, on this basis, the control switch unit is closed to short-circuit the current limiting unit. It can ensure that after the current limiting unit is short-circuited, the charging current of the power factor correction capacitor is less than the preset current; avoid the phenomenon of false protection of the air switch or arcing of the power plug corresponding to the power supply circuit, thereby reducing the power outage risk of the entire power supply system.

[0121] As Figure 4 shown, in one embodiment, the electromagnetic compatibility unit includes a fuse F1, a varistor VDR1, a rectifier bridge BD1, and a filter composed of a capacitor CX1, an inductor LF1, a capacitor CY1, a capacitor CY2, an inductor LF2, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a capacitor CX2, a capacitor GC3, and a capacitor GC4.

[0122] As Figure 5 shown, in one embodiment, the switch unit includes a relay RLY1, the current limiting unit includes a resistor THR1 and a resistor THR3, and the DC signal rectified by the rectifier bridge BD1 charges the power factor correction capacitor C1 through the resistor THR1 and the resistor THR3.

[0123] Among them, as Figure 5 shown, the power supply circuit further includes a resistor THR2, an inductor L1, a capacitor C2, a resistor FB1, a resistor R7, a MOS transistor Q1, a resistor R6, a resistor R27, a resistor NTC2, a diode D2, a diode D3, a diode D1, a capacitor C3, a capacitor C4, a resistor R26, a diode D4, a capacitor C6, a triode Q8, a capacitor C5, a resistor R24, a resistor R9, a resistor R10, a resistor R11, a resistor R12, a resistor R13, a resistor R14.

[0124] In one embodiment, the voltage sampling unit includes a resistor voltage dividing unit and an analog-to-digital converter. As Figure 6 shown, the resistor voltage dividing unit includes a resistor R15, a resistor R16, a resistor R17, a resistor R18, a resistor R19, a resistor R20. As Figure 7 shown, the analog-to-digital converter CU10 is connected to the resistor voltage dividing unit through a resistor CR41, a diode CD38, a resistor CR42, a resistor CR43, a capacitor CC31, and a resistor CR36, a diode CD42, a resistor CR35, a resistor CR37, a capacitor CC30.

[0125] Fourthly, in one embodiment, the present application provides a storage medium storing a computer program, and the computer program is loaded by a processor to execute the following steps:

[0126] After the power supply circuit is connected to the power supply,

[0127] detect the type of the input voltage signal on the electromagnetic compatibility unit;

[0128] detect whether the first input voltage on the electromagnetic compatibility unit sampled by the voltage sampling unit continuously decreases;

[0129] If the input voltage signal type is a DC voltage signal and the first input voltage does not continuously decrease, then control the switch unit to close to ensure that after the current limiting unit is short-circuited, the charging current of the power factor correction capacitor is less than a preset current.

[0130] Through the above storage medium, when the power circuit disconnects the connection with the power supply, the filter capacitor and the power factor correction capacitor in the electromagnetic compatibility unit will both discharge. Based on this principle, after the power circuit is connected to the power supply, the type of the input voltage signal on the electromagnetic compatibility unit is detected, and whether the first input voltage on the electromagnetic compatibility unit continuously decreases is detected. If the input voltage signal type is a DC voltage signal and the first input voltage does not continuously decrease, it indicates that the first input voltage is not obtained based on the discharge of the filter capacitor in the electromagnetic compatibility unit and is provided by a real DC power supply. Therefore, on this basis, the switch unit is controlled to close to short-circuit the current limiting unit. It can ensure that after the current limiting unit is short-circuited, the charging current of the power factor correction capacitor is less than the preset current, avoid the phenomenon of false protection of the air switch or arcing of the power plug corresponding to the power circuit, and thus reduce the power outage risk of the entire power supply system.

[0131] Those of ordinary skill in the art can understand that any reference to a memory, storage, database, or other medium used in the various embodiments provided in this application may include non-volatile and / or volatile memories. Non-volatile memories may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memories may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink), DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and Rambus dynamic RAM (RDRAM), etc.

[0132] Since the computer program stored in the storage medium can execute the steps in the control method of the power circuit in any one of the embodiments provided in this application, the beneficial effects that can be achieved by the control method of the power circuit in any one of the embodiments provided in this application can be realized. For details, see the previous embodiments and will not be elaborated here.

[0133] In the above embodiments, the descriptions of the various embodiments have their own focuses. For the parts not detailed in a certain embodiment, reference can be made to the detailed descriptions of other embodiments above, and will not be elaborated here.

[0134] The above has introduced in detail a control method, a processing unit, a power supply circuit and a storage medium provided by the present application. Specific examples are used in this article to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application; at the same time, for those skilled in the art, according to the idea of the present application, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present application.

[0135] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

Claims

1. A control method for a power supply circuit, characterized in that, The control method of the power supply circuit is used to perform switching control on the power supply circuit. The power supply circuit includes an electromagnetic compatibility unit, a power factor correction capacitor, a current limiting unit, a switching unit, a voltage sampling unit, and a processing unit. The current limiting unit is connected in series between the electromagnetic compatibility unit and the power factor correction capacitor. The switching unit is connected in parallel with the current limiting unit. The voltage sampling unit is connected to the electromagnetic compatibility unit. The processing unit is respectively connected to the switching unit and the voltage sampling unit; For the processing unit, the control method of the power supply circuit includes: After the power supply circuit is connected to the power supply, detect the type of the input voltage signal on the electromagnetic compatibility unit; detect whether the first input voltage on the electromagnetic compatibility unit sampled by the voltage sampling unit continuously decreases; If the input voltage signal type is a DC voltage signal and the first input voltage does not continuously decrease, control the switching unit to close to ensure that after the current limiting unit is short-circuited, the charging current of the power factor correction capacitor is less than a preset current.

2. The control method of the power supply circuit according to claim 1, characterized in that The detection of whether the first input voltage on the electromagnetic compatibility unit sampled by the voltage sampling unit continuously decreases includes: detect whether the first input voltage sampled at a target time on the electromagnetic compatibility unit is less than the first input voltage sampled at the previous time of the target time. If so, perform counting or timing; If the cumulative count value obtained by continuous counting is not less than a preset value or the cumulative timing value obtained by continuous timing is not less than a first preset timing value, determine that the first input voltage on the electromagnetic compatibility unit continuously decreases. Otherwise, determine that the first input voltage on the electromagnetic compatibility unit does not continuously decrease.

3. The control method of the power supply circuit according to claim 1, characterized in that The detection of the type of the input voltage signal on the electromagnetic compatibility unit includes: detect the second input voltage on the electromagnetic compatibility unit sampled by the voltage sampling unit; determine the type of the input voltage signal on the electromagnetic compatibility unit according to the second input voltage.

4. The control method of the power supply circuit according to claim 3, wherein The second input voltage includes a positive input voltage and a negative input voltage. The determination of the type of the input voltage signal on the electromagnetic compatibility unit according to the second input voltage includes: determine the input voltage phase according to the positive input voltage and the negative input voltage; If the input voltage phase does not change within a second preset timing value, determine that the input voltage signal type is a DC voltage signal; If the input voltage phase changes within the second preset timing value, determine that the input voltage signal type is an AC voltage signal.

5. The control method of the power supply circuit according to claim 3, characterized in that, The second input voltage includes a positive input voltage or a negative input voltage. The determination of the type of the input voltage signal on the electromagnetic compatibility unit according to the second input voltage includes: determine the input voltage amplitude according to the positive input voltage and the negative input voltage; If the input voltage amplitude continuously exceeds a preset amplitude within a third preset timing value, determine that the input voltage signal type is a DC voltage signal; If the amplitude of the input voltage does not continuously exceed the preset amplitude within the third preset value, it is determined that the type of the input voltage signal is an AC voltage signal.

6. The control method of the power supply circuit according to claim 1, characterized in that, The control of the switch unit to close when the first input voltage does not continuously decrease includes: If the first input voltage does not continuously decrease and the type of the input voltage signal does not change within the fourth preset value, control the switch unit to close.

7. The control method of the power supply circuit according to claim 1, characterized in that, After the step of detecting the type of the input voltage signal on the electromagnetic compatibility unit, for the processing unit, the control method of the power supply circuit further includes: If the type of the input voltage signal is an AC voltage signal and the type of the input voltage signal does not change within the fourth preset value, control the switch unit to close.

8. A processing unit, characterized in that, Including a memory and a processor; the memory stores a computer program, and the processor is configured to run the computer program in the memory to execute the steps in the control method of the power supply circuit according to any one of claims 1 to 7.

9. A power supply circuit, comprising an electromagnetic compatibility unit, a power factor correction capacitor, a current limiting unit, a switching unit, and a voltage sampling unit, characterized in that, The power supply circuit further includes the processing unit according to claim 8.

10. A storage medium, characterized in that, The storage medium stores a computer program, and the computer program is loaded by a processor to execute the steps in the control method of the power supply circuit according to any one of claims 1 to 7.

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