Control method and control system for a power supply circuit

Abstract

The application relates to the technical field of electronic circuits, and provides a control method and a control system of a power supply circuit. The control method of the power supply circuit comprises an LLC circuit, and the load type of the LLC circuit is determined according to an output power parameter of the LLC circuit by collecting the output power parameter. Since the output power parameter can be used to indicate the load type of the power supply circuit, the load type of the LLC circuit can be determined according to the output power parameter. When the load type is light load, a control strategy of variable-frequency modulation and fixing a phase-shifting angle at a first preset phase-shifting angle is adopted, and when the load type is medium load, a control strategy of phase-shifting modulation and fixed frequency is adopted. Based on this, the change mode of the driving signal of the LLC circuit can be dynamically adjusted according to the load type / load condition by adopting the corresponding control strategy, and then the LLC circuit is driven to work by using the driving signal, so that the power supply circuit can output power meeting the current load type / load condition to supply power for the load, thereby widening the application range of the power supply circuit.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electronic circuits, and particularly relates to a control method and a control system of a power supply circuit. BACKGROUND

[0002] At present, most power supply circuits usually comprise a voltage conversion circuit and an LLC circuit.

[0003] The LLC circuit is a widely used switching power supply topology, and currently a variable frequency modulation control strategy is usually adopted for the LLC circuit. However, the load of the power supply is usually dynamically changed, when the load gradually increases, only using the variable frequency modulation control strategy to control the LLC circuit is easy to cause the overall efficiency of the power supply circuit to be low, and even a serious heating phenomenon occurs, which affects the service life of the power supply. That is, only using the variable frequency modulation control strategy cannot meet the power supply demand of different load types. Therefore, how to provide a power supply circuit control scheme capable of dynamically adapting to different loads is a problem to be solved. SUMMARY

[0004] The application aims to provide a control method and a control system of a power supply circuit, which can dynamically adapt to the power supply demand of different loads and widen the application range of the power supply circuit.

[0005] The first aspect of the application embodiment provides a control method of a power supply circuit, the power supply circuit comprising an LLC circuit, and the control method comprising:

[0006] collecting an output power parameter of the LLC circuit;

[0007] determining a load type of the LLC circuit according to the output power parameter, and determining a corresponding LLC circuit control strategy according to the load type;

[0008] when the load type is light load, adopting a control strategy of variable frequency modulation and fixing a phase shift angle at a first preset phase shift angle;

[0009] when the load type is medium load, adopting a control strategy of phase shift modulation and fixed frequency.

[0010] The power supply circuit control method provided by the embodiment of the present application, wherein the power supply circuit comprises an LLC circuit, the output power parameter of the LLC circuit is collected, the load type of the LLC circuit can be determined according to the output power parameter, the LLC circuit control strategy corresponding to the load type can be determined, and the control strategy is adopted when the load type is light load, the frequency modulation is adopted and the phase shift angle is fixed at the first preset phase shift angle, and the control strategy is adopted when the load type is medium load, the phase shift modulation is adopted and the frequency is fixed. Based on this, the change mode of the drive signal of the LLC circuit can be dynamically adjusted according to the load type / load condition, and the LLC circuit is driven by the drive signal, the power meeting the current load type / load condition can be output to supply power for the load, and the application range of the power supply circuit is widened.

[0011] The second aspect of the embodiment of the present application provides a power supply circuit control system, which is applicable to the power supply circuit control method of the first aspect, the power supply circuit comprises an LLC circuit, and the control system comprises:

[0012] The sampling unit is used for collecting the output power parameter of the LLC circuit.

[0013] The control unit is used for determining the load type of the LLC circuit according to the output power parameter, and determining the LLC circuit control strategy corresponding to the load type.

[0014] The drive unit is controlled by the control unit, and outputs the drive signal to the LLC circuit based on the LLC circuit control strategy.

[0015] The control unit is further used for controlling the drive unit by adopting the control strategy of adopting the frequency modulation and fixing the phase shift angle at the first preset phase shift angle when the load type is light load, and controlling the drive unit by adopting the control strategy of adopting the phase shift modulation and fixing the frequency when the load type is medium load.

[0016] It can be understood that the beneficial effects of the second aspect can be referred to the related description of the first aspect, and will not be repeated here. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 A use environment schematic diagram of the power supply circuit control method provided by the embodiment of the present application;

[0018] Figure 2 An implementation flowchart of the power supply circuit control method provided by the embodiment of the present application;

[0019] Figure 3 An implementation flowchart of the power supply circuit control method provided by another embodiment of the present application;

[0020] Figure 4 A specific circuit diagram of the LLC circuit in the embodiment of the present application is a full-bridge LLC circuit;

[0021] Figure 5 An implementation flowchart of a control method of a power supply circuit provided by another embodiment of the present application is provided;

[0022] Figure 6 A structural schematic diagram of a power supply circuit provided by the embodiment of the present application is provided;

[0023] Figure 7 A structural schematic diagram of an electronic device provided by the embodiment is provided;

[0024] Figure 8 A structural schematic diagram of a control system of a power supply circuit provided by the embodiment is provided. DETAILED DESCRIPTION

[0025] In order to make the technical problems to be solved by the present application, the technical solutions and beneficial effects clearer, the present application will be further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0026] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0027] It should be understood that the terms "length", "width", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the present application and simplify the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0028] In addition, the terms "first", "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0029] LLC circuits, also known as LLC resonant converters, are a commonly used switching power supply topology. They can employ frequency conversion modulation control strategies. However, the load is not static. As the load gradually increases, especially when the operating range from half-load to full-load has not yet reached the resonant point, frequency conversion modulation can cause excessive switching losses in the MOSFETs of the LLC circuit, leading to low overall power supply efficiency and even severe overheating. Therefore, when the load is dynamically changing, frequency conversion modulation alone cannot meet the power supply requirements of different load types. Thus, providing a power supply circuit control scheme that can adapt to dynamic loads is a pressing issue that needs to be addressed.

[0030] To address the aforementioned technical problems, this embodiment provides a power supply circuit control method that can dynamically adapt to the power supply requirements of different loads in an LLC circuit, thus broadening the applicability of the power supply circuit. For a better understanding of the power supply circuit control method provided in this embodiment, please refer to [reference needed]. Figure 1 This diagram illustrates an application environment for a power supply circuit control method. (Example:) Figure 1 As shown, the power supply circuit includes at least a voltage conversion circuit and an LLC circuit. It is understood that... Figure 1 The power supply circuit shown is for illustrative purposes only; in actual implementation, the power supply circuit may include branches or modules with other functions. Therefore, Figure 1 The power supply circuit shown does not constitute a limitation on the implementation of the control method for the power supply circuit provided in this embodiment.

[0031] exist Figure 1 In this circuit, a voltage conversion circuit can be used to connect to the input power supply. The voltage conversion circuit can boost or buck the input power supply to obtain the target voltage, and the LLC circuit supplies power to the load based on this target voltage.

[0032] Figure 2 A flowchart illustrating the implementation of a power supply circuit control method according to an embodiment of this application is shown. Figure 2 As shown, the control method for the power supply circuit includes the following steps:

[0033] 110: Collect the output power parameters of the LLC circuit.

[0034] In step 110, the output power parameter refers to the power parameter when the LLC circuit supplies power to the load. After collecting the output current and output voltage, the output power is obtained by multiplying the output current and output voltage, and the output power is used as the output power parameter of the LLC circuit.

[0035] In a specific implementation, the output power parameter of the LLC circuit can be obtained by using a sampling circuit. For example, an ADC sampling circuit is used to sample the output end and / or the output node of the LLC circuit, and then the output power parameter can be obtained.

[0036] The output power parameter of the LLC circuit can be obtained by using an AD sampling circuit to sample the output power of the LLC circuit. For example, a current sampling circuit and / or a voltage sampling circuit is used to sample the output node of the LLC circuit, and then the corresponding output power parameter is obtained.

[0037] In another embodiment, the step 110 can include the following steps:

[0038] The current and voltage parameters of the LLC circuit in the continuous N periods are collected to obtain N output current measurement values and N output voltage measurement values; the output current value of the LLC circuit is obtained based on the N output current measurement values, and the output voltage value of the LLC circuit is obtained based on the N output voltage measurement values; and the output power of the LLC circuit is calculated as the output power parameter by using the output voltage value and the output current value.

[0039] In this embodiment, the N periods refer to N periods of the driving signal of the LLC circuit. Here, N can be an integer greater than 1. In a specific implementation, the power supply circuit further includes an AD sampling circuit, and when the output current measurement value and the output voltage measurement value are obtained, the current sampling circuit is used to sample the current of the LLC circuit, and the N periods are continuously sampled to obtain the N output current measurement values. At the same time, the voltage sampling circuit is used to sample the voltage of the LLC circuit, and the N periods are continuously sampled to obtain the N output voltage measurement values. Here, since the current measurement value is the instantaneous output current of the LLC circuit, it cannot be directly equated to the output current of the LLC circuit. Similarly, the voltage measurement value is the instantaneous output voltage of the LLC circuit, and it cannot be directly equated to the output voltage of the LLC circuit.

[0040] For example, in a specific implementation, the average of the N output current measurement values and the average of the N output voltage measurement values can be obtained by averaging the N output current measurement values and the N output voltage measurement values, respectively, and then the average current value and the average voltage value are used as the output voltage value and the output current value of the LLC circuit, respectively.

[0041] As an example, the above-mentioned obtaining the output current value of the LLC circuit based on the N output current measurement values and obtaining the output voltage value of the LLC circuit based on the N output voltage measurement values include:

[0042] The N output current measurement values and the N output voltage measurement values are subjected to a de-extreme operation respectively to obtain N-2 output current sample values and N-2 output voltage sample values. The N-2 output current sample values and the N-2 output voltage sample values are subjected to an average operation respectively to obtain the output voltage value and the output current value of the LLC circuit.

[0043] As an embodiment, the output power of the LLC circuit is calculated by using the output voltage value and the output current value as the output electric energy parameter, including:

[0044] The product of the output voltage value and the output current value is calculated to obtain the output power of the LLC circuit as the output electric energy parameter.

[0045] In the embodiment, the N output current measurement values are subjected to a de-extreme operation, specifically, the maximum and the minimum of the N output current measurement values are removed. Similarly, the N output voltage measurement values are subjected to a de-extreme operation, specifically, the maximum and the minimum of the N output voltage measurement values are removed. In this way, by subjecting the N output current measurement values and the N output voltage measurement values to a de-extreme operation respectively, the current values with large deviations in the N output current measurement values can be removed, and the voltage values with large deviations in the N output voltage measurement values can be removed, and then N-2 output current sample values and N-2 output voltage sample values with stronger coupling are obtained. Then, the N-2 output current sample values and the N-2 output voltage sample values are subjected to an average operation respectively, and the real and smooth output current curve and the output voltage curve can be obtained, so that the two sets of average values are taken as the output current value and the output voltage value of the LLC circuit.

[0046] It is easy to understand that by calculating the product of the output voltage value and the output current value at the same time, the output power of the LLC circuit at different times can be obtained, and by taking the output power of the LLC circuit at different times as the output electric energy parameter, the actual power demand of the load of the LLC circuit at different times can be represented.

[0047] In some embodiments, considering that the output voltage value and the output current value corresponding to any two time instants are not equal, the output power corresponding to the two time instants can be equal, so the input voltage can be considered when calculating the output power. For example, a first weight value corresponding to the influence degree of the input voltage on the output power is determined, and a second weight value corresponding to the influence degree of the output voltage on the output power is determined, and the first weight value and the second weight value are different. In this way, in the case that the output voltage value and the output current value corresponding to any two time instants are not equal, the output power corresponding to the two time instants calculated is also necessarily not equal. Based on this, the output power of the LLC circuit at different time instants is used as the output energy parameter, which can represent the actual power demand of the load of the LLC circuit at different time instants.

[0048] 120: determining the load type of the LLC circuit according to the output energy parameter, and determining the corresponding LLC circuit control strategy according to the load type.

[0049] According to the output energy parameter, the load type of the LLC circuit can be determined. Here, the load type can be various, and the LLC circuit control strategy corresponding to different load types is different.

[0050] In step 120, the load type can be used to distinguish the power demand degree of the load. For example, the load type can include light load, medium load and heavy load. Accordingly, the power demand of the light load is low, the power demand of the medium load is high, and the power demand of the heavy load is the highest. It is easy to understand that different load types can correspond to different LLC circuit control strategies. At the same time, the output energy parameter can be used as a basis for determining the load type.

[0051] In specific implementation, when determining the load type of the LLC circuit according to the output energy parameter of the LLC circuit, the corresponding relationship between different load types and the output energy parameter can be established in advance, and then when the output energy parameter of the LLC circuit is obtained, the corresponding load type can be determined from the corresponding relationship.

[0052] In this embodiment, by constructing a preset mapping list, the information in the preset mapping list describes the corresponding relationship between the output energy parameter and the load type. Since the information in the preset mapping list is used to describe the corresponding relationship between the output energy parameter and the load type, the corresponding load type can be directly determined from the preset mapping list according to the output energy parameter. Similarly, the corresponding relationship between the load type and the LLC circuit control strategy can also be established in advance, and then when the load type is determined, the corresponding LLC circuit control strategy can be determined according to the load type. In some embodiments, the information in the preset mapping list can also be used to describe the corresponding relationship among the output energy parameter, the load type and the LLC circuit control strategy.

[0053] 121: When the load type is light load, a control strategy of variable frequency modulation and fixing the phase shift angle at a first preset phase shift angle is adopted.

[0054] In step 121, the variable frequency modulation refers to performing variable frequency modulation on the driving signal corresponding to the LLC circuit, and during the variable frequency modulation, the phase shift angle of the driving signal is fixed at the first preset phase shift angle.

[0055] In a specific implementation, the first preset phase shift angle can be an optimal phase shift angle of the driving signal of the LLC circuit.

[0056] 122: When the load type is medium load, a control strategy of phase shift modulation and fixed frequency is adopted.

[0057] In step 122, the phase shift modulation refers to performing phase shift modulation on the driving signal corresponding to the LLC circuit, and during the phase shift modulation, the frequency of the driving signal is fixed.

[0058] The above scheme can determine the load type of the LLC circuit according to the output power parameter, when the load type is light load, a control strategy of variable frequency modulation and fixing the phase shift angle at a first preset phase shift angle is adopted, and when the load type is medium load, a control strategy of phase shift modulation and fixed frequency is adopted. In this way, the corresponding control strategy can be dynamically adjusted according to the load type / load condition to indicate the change mode of the driving signal of the LLC circuit, and then the LLC circuit is driven by the driving signal to work, which can output power meeting the current load type / load condition to supply power for the load, thereby widening the application range of the power supply circuit.

[0059] In another embodiment of the present application, before step 110, there can further be a step of: in response to a preset operation of controlling the LLC circuit to output power, controlling the LLC circuit to output power according to a preset strategy.

[0060] In this embodiment, the preset strategy includes that the LLC circuit works based on a first preset phase shift angle and a first preset frequency.

[0061] Specifically, controlling the LLC circuit to output power according to the preset strategy can be understood as generating an initial driving signal according to the first preset phase shift angle and the first preset frequency to drive / control the LLC circuit.

[0062] In a specific implementation, the control unit can be connected with the driving circuit, and when the LLC circuit is controlled to output electric energy according to the preset strategy, the control unit can generate a corresponding control instruction according to the preset strategy to instruct the driving circuit to generate a corresponding initial driving signal to drive the LLC circuit to work. Alternatively, the driving circuit can be integrated in the control unit, and when the LLC circuit is controlled to output electric energy according to the preset strategy, the control unit can generate a corresponding initial driving signal to drive the LLC circuit to work through the driving circuit according to the preset strategy.

[0063] It is easy to understand that, since the preset strategy includes that the LLC circuit works based on the first preset phase shift angle and the first preset frequency, when the LLC circuit is controlled to output electric energy according to the preset strategy, it can be understood that the LLC circuit is controlled to work in a mode of the first preset phase shift angle and the first preset frequency, an initial environment for identifying the load type is constructed, and an implementation basis for collecting the output electric energy parameter of the LLC circuit is provided.

[0064] Figure 3 An implementation flowchart of a control method of a power supply circuit provided by another embodiment of the application is shown, as shown in the figure, and further includes step 123, specifically:

[0065] 123: When the load type is heavy load, a control strategy of frequency modulation and fixing the phase shift angle to the second preset phase shift angle is adopted.

[0066] In step 123, frequency modulation refers to frequency modulation of the driving signal corresponding to the LLC circuit, and during the frequency modulation, the phase shift angle of the driving signal is fixed at the second preset phase shift angle and does not change.

[0067] In a specific implementation, the frequency range / interval of the frequency modulation in step 123 is different from the frequency range / interval of the frequency modulation in step 130.

[0068] For example, the frequency modulation in step 121 is in a first frequency modulation range, and the frequency modulation in step 123 is in a second frequency modulation range. Specifically, the first frequency modulation range can be from the first preset frequency fmax to the second preset frequency f1, and the second frequency modulation range can be from the second preset frequency f1 to the third preset frequency fmin.

[0069] For example, the first frequency modulation range f1 ∈ [fmax, f1), and the second frequency modulation range f2 ∈ (f1, fmin].

[0070] As an example, step 121 can specifically include:

[0071] When the load type is light load and the load type switches from light load to medium load, a control strategy of fixing the phase shift angle at the first preset phase shift angle and frequency modulation of the frequency from the first preset frequency to the second preset frequency is adopted.

[0072] When the load type is light load and the load type switches from light load to no load, the control strategy of fixing the phase shift angle at the first preset phase shift angle and frequency modulation from the second preset frequency to the first preset frequency is adopted.

[0073] The first preset frequency is greater than the second preset frequency.

[0074] In this embodiment, the first preset frequency can be the maximum driving frequency of the LLC circuit. It can also be understood as the maximum driving frequency that the LLC circuit can withstand. When the load type is light load and the load type switches from light load to medium load, it means that the load of the LLC circuit is increasing, that is, the electricity demand is increasing, and at this time it is still in the light load type. When the load type is light load and the load type switches from light load to no load, it means that the load of the LLC circuit is decreasing, that is, the electricity demand is decreasing, and at this time it is still in the light load type. The second preset frequency can be any intermediate frequency between the maximum driving frequency and the minimum driving frequency of the LLC circuit.

[0075] Exemplarily, the first preset phase shift angle is 30°, and the frequency modulation is taken as an example with the first frequency modulation range being from the first preset frequency to the second preset frequency. The first frequency modulation range f1∈[fmax, f1), fmax is the first preset frequency, which is also the maximum frequency, and f1 is the second preset frequency, which is also the fixed frequency. When the LLC circuit is controlled / driven by the control strategy of frequency modulation and fixing the phase shift angle at the first preset phase shift angle, specifically, a driving signal with frequency change is generated at the first preset phase shift angle of 30°, and the frequency change range of the driving signal is within the first frequency modulation range. Since the first frequency modulation range can be from the first preset frequency fmax to the second preset frequency f1, during the process of changing the load type from light load to medium load, the load increases and the electricity demand also increases, and when frequency modulation is performed, it can be frequency modulated from the first preset frequency fmax to the second preset frequency f1. During the process of changing the load type from light load to no load, the load decreases and the electricity demand also decreases, and when frequency modulation is performed, it can be frequency modulated from the second preset frequency f1 to the first preset frequency fmax, which can reduce the output power of the LLC circuit.

[0076] As an embodiment, step 122 can specifically include:

[0077] When the load type is medium load and the load type switches from medium load to heavy load, the control strategy of fixing the LLC circuit switching frequency at the second preset frequency and phase shift modulation of the phase shift angle from the first preset phase shift angle to the second preset phase shift angle is adopted.

[0078] When the load type is medium load and the load type switches from medium load to light load, the control strategy of fixing the switching frequency of the LLC circuit at the second preset frequency and phase-modulating the phase shift angle from the second preset phase shift angle to the first preset phase shift angle is adopted.

[0079] The first preset phase shift angle is greater than the second preset phase shift angle.

[0080] In the embodiment, when the load type is medium load and the load type switches from medium load to heavy load, it indicates that the load of the LLC circuit is increasing, that is, the power demand is increasing, and at this time, the load type is still medium load. When the load type is medium load and the load type switches from medium load to light load, it indicates that the load of the LLC circuit is decreasing, that is, the power demand is decreasing, and at this time, the load type is still medium load.

[0081] Based on the above examples, taking the first preset phase shift angle as 30° and the second preset phase shift angle as 0° and the second preset frequency f1 as an example. The driving signal is generated at the second preset frequency f1, and the phase shift angle of the driving signal changes between the first preset phase shift angle and the second preset phase shift angle. In the process of changing the load type from medium load to heavy load, the load increases, and the power demand also increases. When phase-modulating, the phase shift angle can be phase-modulated from the first preset phase shift angle 30° to the second preset phase shift angle 0°, so that the LLC circuit can provide more power for the load. In the process of changing the load type from medium load to light load, the load decreases, and the power demand also decreases. When phase-modulating, the phase shift angle can be phase-modulated from the second preset phase shift angle 0° to the first preset phase shift angle 30°, so that the LLC circuit can reduce the output power.

[0082] As an example, the step 123 can specifically include:

[0083] When the load type switches from medium load to heavy load, the control strategy of fixing the phase shift angle at the second preset phase shift angle and frequency-modulating the frequency from the second preset frequency to the third preset frequency is adopted.

[0084] When the load type is heavy load and the load type switches from heavy load to medium load, the control strategy of fixing the phase shift angle at the second preset phase shift angle and frequency-modulating the frequency from the third preset frequency to the second preset frequency is adopted.

[0085] The second preset frequency is greater than the third preset frequency.

[0086] In the embodiment, the second preset phase shift angle can be smaller than the first preset phase shift angle. The third preset frequency can be the minimum driving frequency of the LLC circuit, which can also be understood as the minimum driving frequency of the LLC circuit. When the load type is switched from the medium load to the heavy load and the load type is the heavy load, it indicates that the load of the LLC circuit is increasing, that is, the power demand is increasing, at this time, it is just from the medium load type to the heavy load type. When the load type is the heavy load and the load type is switched from the heavy load to the medium load, it indicates that the load of the LLC circuit is decreasing, that is, the power demand is decreasing, at this time, it is still in the heavy load type.

[0087] Exemplarily, the second preset phase shift angle is 0°, the frequency modulation is in the second frequency range, and the second frequency range includes the second preset frequency to the third preset frequency. The second frequency range f2 ∈ (f1, fmin], f1 is the second preset frequency, which is also a fixed frequency, and fmin is the third preset frequency, which is also the minimum frequency. When the LLC circuit is controlled / driven by the control strategy of adopting the frequency modulation and fixing the phase shift angle at the second preset phase shift angle, specifically, the driving signal with frequency change is generated at the second preset phase shift angle of 0°, and the frequency change range of the driving signal is in the second frequency range. Since the second frequency range can be from the second preset frequency f1 to the third preset frequency fmin, when the load type is changed from the medium load to the heavy load, the load increases, the power demand also increases, and when the frequency modulation is performed, the frequency modulation can be performed from the second preset frequency f1 to the third preset frequency fmin, so that the LLC circuit can provide more power for the load. During the process of changing the load type from the heavy load to the medium load, the load decreases, the power demand also decreases, and when the frequency modulation is performed, the frequency modulation can be performed from the third preset frequency fmin to the second preset frequency f1, so that the LLC circuit can reduce the output power. Taking the fixed frequency f1 as an example.

[0088] In actual use, after any one of steps 121, 122 and 123 is executed, different control strategies can be switched according to whether the actual output power of the LLC circuit meets the load type, or according to the change of the load type. For example, after step 121 is executed, steps 122 and 123 can be sequentially executed.

[0089] Figure 4 A specific circuit diagram of the LLC circuit in the embodiment of the application is shown. As shown in Figure 4 The input power supply can be connected to the voltage conversion circuit through the first input terminal V1+ and the second input terminal V1-, and the full-bridge LLC circuit can be connected to the load through the first output terminal V2+ and the second output terminal V2-. In Figure 4In this circuit, the voltage conversion circuit specifically includes a switching transistor S1, an inductor L, capacitors C1 and C2, and a diode D1. One end of capacitor C1 is connected to inductor L, which is used to connect to the first input terminal V1+. The other end of inductor L is connected to the first terminal of switching transistor S1. The other end of capacitor C1 is connected to the second terminal of switching transistor S1, which is used to connect to the second input terminal V1-. The anode of diode D1 is connected to the first terminal of switching transistor S1. Capacitor C2 is connected between the cathode of diode D1 and the second terminal of switching transistor S1.

[0090] exist Figure 4 In this circuit, the full-bridge LLC circuit includes a transformer Lm, a first switch Q1, a second switch Q2, a third switch Q3, a fourth switch Q4, diodes D2 and D3, and a capacitor C4. In the actual implementation, all switches are MOSFETs, with their first terminals all being drains, their second terminals all being sources, and their control terminals all being gates. For example... Figure 4 As shown, the source of the first switch Q1 and the source of the third switch Q3 are connected to one end of capacitor C2. The drain of the second switch Q2 and the drain of the fourth switch Q4 are connected to the other end of capacitor C2. The drain of the first switch Q1 and the source of the second switch Q2 are connected to one end of inductor Lr. The other end of inductor Lr is connected to one end of capacitor C3. The other end of capacitor C3 is connected to the primary winding N1 of transformer Lm. The other end of the primary winding N1 of transformer Lm is connected to the source of the fourth switch Q4. The source of the fourth switch Q4 is connected to the drain of the third switch Q3. One end of the secondary winding N2 of transformer Lm is connected to the anode of diode D2. The other end of the secondary winding N2 is connected to the anode of diode D3. The cathodes of diodes D2 and D3 are connected to the first end of capacitor C4 to form the first output terminal V2+. The neutral point of the secondary winding N2 is connected to the second end of capacitor C4 to form the second output terminal V2-. In this embodiment, the drive signals for the first switch Q1 and the fourth switch Q4 are in phase, the drive signals for the second switch Q2 and the third switch Q3 are in phase, while the control signals for the first switch Q1 and the second switch Q2 are complementary, and the control signals for the third switch Q3 and the fourth switch Q4 are complementary. In conjunction with any of the above embodiments, as one example, the control method provided in this embodiment may further include: employing a fixed duty cycle control strategy for the LLC circuit. For example, the duty cycle of the drive signal for the LLC circuit can be 50%.

[0091] Figure 5 This illustration shows a flowchart of the implementation of a power supply circuit control method according to another embodiment of this application. Figure 2 or Figure 3 The difference in the illustrated embodiment is that, Figure 5 The illustrated embodiment further includes steps 510 to 520, specifically:

[0092] 510: re-executing the step of collecting the output power parameter of the LLC circuit.

[0093] The re-executing the step of collecting the output power parameter of the LLC circuit can be understood as re-executing the step 110.

[0094] 520: based on the output power parameter and the current driving signal of the LLC circuit, determining to take a new control strategy when the load type changes.

[0095] In the embodiment, since the output power parameter is used to indicate the load type of the power supply circuit, and in actual use, the output power parameter can intuitively reflect the degree of change of the load type, and at the same time, the current driving signal of the LLC circuit can also reflect the power supply adaptation degree between the power supply circuit and the load, so the load type can be determined based on the output power parameter and the current driving signal of the LLC circuit whether the load type changes.

[0096] Taking the output power parameter of the LLC circuit as an example, when the output power of the LLC circuit changes from a higher power value to a lower power value, and the driving signal of the LLC circuit also changes accordingly, it can be indicated that the energy consumption of the load changes from high to low, for example, the load type changes from medium load to light load, or from heavy load to medium load, or from heavy load to light load.

[0097] As an embodiment, the step 520 specifically includes a step A and / or a step B. Here, the step A and the step B can be parallel steps or sequential steps. When the step A is executed, the step B can no longer be executed, or when the step A is executed, the step B is executed, which is not limited here. Specifically:

[0098] Step A: if it is determined according to the output power parameter that the load type changes from heavy load to medium load, and the frequency of the current driving signal of the LLC circuit is at a fixed frequency, and the difference between the phase of the current driving signal and the second preset phase shift angle is not less than a preset phase hysteresis interval, then a phase shift modulation and fixed frequency control strategy is taken as the new control strategy.

[0099] In the embodiment, in order to avoid the control unit frequently switching the control strategy of the LLC circuit, when judging whether the control strategy needs to be switched, a preset phase hysteresis interval is set, that is, when the difference between the phase of the driving signal and the phase shift threshold is equal to or greater than the preset phase hysteresis interval, it indicates that the load state has stabilized, and at this time, switching the control strategy of the LLC circuit will not cause the control strategy to be switched back. Here, the preset phase hysteresis interval can be understood as a threshold range of the difference between the phase of the current driving signal and the phase shift threshold.

[0100] It is easy to understand that considering the fluctuation of the driving signal or the output power of the LLC circuit in actual use, in order to avoid misjudgment, the actual output power parameter of the LLC circuit is combined to determine whether the load type is changed, and the control strategy of the driving signal is combined, so that the switching control strategy meets the actual use demand.

[0101] Exemplarily, taking the second preset phase shift angle of 0° as an example, the preset phase hysteresis interval can be set to 5°, that is, when the phase of the current driving signal is 5°, the difference between the second preset phase shift angle 0° is 5°, which is not less than the preset phase hysteresis interval 5°, and the control strategy of phase shift modulation and fixed frequency is taken as the new control strategy to control the LLC circuit to work.

[0102] Step B: If it is determined according to the power parameter that the load type changes from medium load to light load, and the phase of the current driving signal for controlling the LLC circuit is the first preset phase shift angle, and the difference between the frequency of the current driving signal and the fixed frequency is not less than the preset frequency hysteresis interval, the control strategy of variable frequency modulation and fixing the phase shift angle at the first preset phase shift angle is taken as the new control strategy.

[0103] In the embodiment, in order to avoid that the control unit frequently switches the control strategy of the LLC circuit, when judging whether the control strategy needs to be switched, a preset frequency hysteresis interval is further set. That is, if the frequency of the current driving signal is the fixed frequency, and the difference between the frequency of the current driving signal and the fixed frequency is equal to or greater than the preset frequency hysteresis interval, it indicates that the load state has been stable, and at this time, switching the control strategy of the LLC circuit will not cause the switching of the control strategy. Here, the preset frequency hysteresis interval can be understood as a threshold range of the difference between the frequency of the current driving signal and the fixed frequency.

[0104] Exemplarily, taking the fixed frequency f1 as an example, the preset frequency hysteresis interval can be set to X, that is, when the frequency of the current driving signal is f, the difference X1 between the fixed frequency f1 is not less than the preset frequency hysteresis interval X, and the first preset variable frequency strategy is executed as the control strategy to control the LLC circuit to work.

[0105] The above scheme sets the preset phase hysteresis interval and / or the preset frequency hysteresis interval, which not only can avoid the frequent switching of the control mode of the LLC circuit, but also can provide a basis for realizing that the LLC circuit adapts to different control modes according to different loads, and can further improve the flexibility and scientific degree of the power supply circuit.

[0106] The embodiment of the present application further provides a power supply circuit. As shown in Figure 6 The power supply circuit 100 provided by the embodiment of the present application comprises:

[0107] The direct current source 10 is used to provide a direct current voltage.

[0108] The voltage conversion circuit 20 is connected with the direct current source 10, and is configured to perform voltage conversion on the direct current voltage to obtain a target voltage.

[0109] The LLC circuit 30 is connected with the voltage conversion circuit 20, and is configured to supply power to the load 110 based on the target voltage.

[0110] The control unit 40 is connected with the LLC circuit 30. The control unit 40 is configured to implement the steps of the control method of the power supply circuit provided in the above embodiments.

[0111] In a specific implementation, the direct current source 10 refers to a power supply that can output direct current, such as a battery, a DC-DC circuit, etc. The voltage conversion circuit 20 can be a boost circuit, a buck circuit, etc., which is not limited here.

[0112] As shown in Figure 7 , the electronic device 200 provided by the embodiment of the present application includes the power supply circuit 100 in the above embodiments.

[0113] It can be understood that the power supply circuit 100 and the electronic device 200 provided by the embodiment of the present application, the improvement points and the specific implementation manners related to the present application have been described in detail in the embodiments of the control method of the corresponding power supply circuit, and therefore, the specific implementation manners are described in the embodiments of the Figures 1 to 5 control method of the corresponding power supply circuit, and therefore, the specific implementation manners are described in the embodiments of the Figures 1 to 5 and Figures 1 to 5 , and the related descriptions in the embodiments are not repeated here.

[0114] As shown in Figure 8 , the control system of the power supply circuit provided by the embodiment of the present application is applicable to the control method of the power supply circuit in any of the above embodiments. The power supply circuit includes an LLC circuit, and the control system includes:

[0115] The sampling unit 810 is configured to collect an output power parameter of the LLC circuit.

[0116] The control unit 820 is configured to determine a load type of the LLC circuit according to the output power parameter, and determine a corresponding LLC circuit control strategy according to the load type.

[0117] The driving unit 830 is controlled by the control unit to output a driving signal to the LLC circuit based on the corresponding LLC circuit control strategy.

[0118] The control unit 810 is further configured to, when the load type is light load, adopt a variable-frequency modulation and fix a phase shift angle at a first preset phase shift angle control strategy to control the driving unit, and when the load type is medium load, adopt a phase shift modulation and fix a frequency control strategy to control the driving unit.

[0119] It can be understood that the power supply circuit control system provided by the embodiment, the improvement points and the specific implementation manners related to the present application have been described in detail in the Figures 1 to 5 The embodiments of the corresponding power supply circuit control method are described in detail, and therefore, for details, refer to Figures 1 to 5 , and Figures 1 to 5 The related descriptions in the corresponding embodiments are not repeated here.

[0120] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above functional units and modules is taken as an example for illustration, and in actual application, the above functions can be completed by different functional units and modules according to needs, that is, the internal structure of the device is divided into different functional units or modules to complete all or part of the functions described above. Each functional unit and module in the embodiment can be integrated in one processing unit, or each unit can exist physically, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or in the form of a software functional unit.

[0121] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can still be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A control method of a power supply circuit including an LLC circuit, characterized by, The control method comprises: acquiring an output electrical energy parameter of the LLC circuit; determining a load type of the LLC circuit according to the output electrical energy parameter, and determining a corresponding LLC circuit control strategy according to the load type; when the load type is light load and the load type switches from light load to medium load, adopting a control strategy of fixing a phase shift angle at a first preset phase shift angle and frequency modulation from a first preset frequency to a second preset frequency; when the load type is light load and the load type switches from light load to no load, adopting a control strategy of fixing the phase shift angle at the first preset phase shift angle and frequency modulation from the second preset frequency to the first preset frequency; wherein the first preset frequency is greater than the second preset frequency; when the load type is medium load, adopting a control strategy of phase shift modulation and fixed frequency; when the load type is heavy load, adopting a control strategy of frequency modulation and fixing the phase shift angle at a second preset phase shift angle.

2. The control method of a power supply circuit according to claim 1, characterized by, The control strategy when the load type is medium load, adopting a control strategy of phase shift modulation and fixed frequency, comprises: when the load type is medium load and the load type switches from medium load to heavy load, adopting a control strategy of fixing the LLC circuit switching frequency at the second preset frequency and phase shift modulation of the phase shift angle from the first preset phase shift angle to the second preset phase shift angle; when the load type is medium load and the load type switches from medium load to light load, adopting a control strategy of fixing the LLC circuit switching frequency at the second preset frequency and phase shift modulation of the phase shift angle from the second preset phase shift angle to the first preset phase shift angle; wherein the first preset phase shift angle is greater than the second preset phase shift angle.

3. The control method of a power supply circuit according to claim 1, characterized by, The control strategy when the load type is heavy load, adopting a control strategy of frequency modulation and fixing the phase shift angle at a second preset phase shift angle, comprises: when the load type switches from medium load to heavy load, adopting a control strategy of fixing the phase shift angle at the second preset phase shift angle and frequency modulation from the second preset frequency to a third preset frequency; when the load type is heavy load and the load type switches from heavy load to medium load, adopting a control strategy of fixing the phase shift angle at the second preset phase shift angle and frequency modulation from the third preset frequency to the second preset frequency; wherein the second preset frequency is greater than the third preset frequency.

4. The control method of a power supply circuit according to claim 1, characterized by, The acquisition of the output electrical energy parameter of the LLC circuit comprises: acquiring current and voltage parameters of the LLC circuit in consecutive N cycles to obtain N output current measurement values and N output voltage measurement values; obtaining an output current value of the LLC circuit based on the N output current measurement values, and obtaining an output voltage value of the LLC circuit based on the N output voltage measurement values; using the output voltage value and the output current value, the output power of the LLC circuit is calculated as the output electrical energy parameter.

5. The control method of a power supply circuit according to claim 4, characterized by The obtaining of the output current value of the LLC circuit based on the N output current measurement values, and the obtaining of the output voltage value of the LLC circuit based on the N output voltage measurement values, comprises: respectively, to obtain N-2 output current sample values and N-2 output voltage sample values; respectively, to obtain N-2 output current sample values and N-2 output voltage sample values; The output power of the LLC circuit is calculated as the output electrical energy parameter, including: The output power of the LLC circuit is calculated as the output electrical energy parameter, including:

6. A control method of a power supply circuit according to any one of claims 1 to 5, characterized by Before the step of collecting the output electrical energy parameter of the LLC circuit, further comprising: In response to a preset operation of controlling the output electrical energy of the LLC circuit, the LLC circuit outputs electrical energy according to a preset strategy; wherein the preset strategy includes that the LLC circuit works based on the first preset phase shift angle and the first preset frequency.

7. A control method of a power supply circuit according to any one of claims 1 to 5, characterized by The control method further comprises: The LLC circuit adopts a fixed duty ratio control strategy.

8. A control system of a power supply circuit, adapted to the control method of the power supply circuit according to any one of claims 1 to 7, the power supply circuit including an LLC circuit, characterized by The control system comprises: a sampling unit for collecting the output electrical energy parameter of the LLC circuit; a control unit for determining the load type of the LLC circuit according to the output electrical energy parameter, and determining the corresponding LLC circuit control strategy according to the load type; a driving unit controlled by the control unit, which outputs a driving signal to the LLC circuit based on the corresponding LLC circuit control strategy; The control unit is further configured to: when the load type is light load and the load type switches from light load to medium load, adopt a control strategy of fixing the phase shift angle at the first preset phase shift angle and frequency modulation from the first preset frequency to the second preset frequency; when the load type is light load and the load type switches from light load to no load, adopt a control strategy of fixing the phase shift angle at the first preset phase shift angle and frequency modulation from the second preset frequency to the first preset frequency, the first preset frequency being greater than the second preset frequency; when the load type is medium load, adopt a control strategy of phase shift modulation and fixed frequency; when the load type is heavy load, adopt a control strategy of frequency modulation and fixing the phase shift angle at the second preset phase shift angle.

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