CN113991980A - Control method and controller of switching power supply and switching power supply - Google Patents
Control method and controller of switching power supply and switching power supply Download PDFInfo
- Publication number
- CN113991980A CN113991980A CN202111598581.XA CN202111598581A CN113991980A CN 113991980 A CN113991980 A CN 113991980A CN 202111598581 A CN202111598581 A CN 202111598581A CN 113991980 A CN113991980 A CN 113991980A
- Authority
- CN
- China
- Prior art keywords
- power supply
- switching power
- voltage
- current
- output current
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M3/00—Conversion of dc power input into dc power output
- H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
- H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
- H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
- H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
- H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M3/33507—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of the output voltage or current, e.g. flyback converters
- H02M3/33523—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of the output voltage or current, e.g. flyback converters with galvanic isolation between input and output of both the power stage and the feedback loop
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Dc-Dc Converters (AREA)
Abstract
The invention discloses a control method of a switching power supply, a controller and the switching power supply, wherein after the output current of the switching power supply is detected, whether the output current of the switching power supply is larger than an output current threshold value is judged, if yes, the maximum frequency of a control signal of a switching tube is adjusted from a first frequency to a second frequency, the maximum value of the peak current of a primary winding is adjusted from the first current to the second current, meanwhile, constant current control is turned off, and the controller of the switching power supply is allowed to enter a continuous conduction mode. The output power of the switching power supply is increased under the condition that other parameters of the switching power supply are fixed, so that the switching power supply enters a peak power mode. Compared with the method that only the peak current output by the switching power supply to the primary winding of the transformer is increased, the working pressure of the transformer is reduced. In addition, whether the switching power supply needs to enter a peak power mode or not is judged by detecting the output current of the switching power supply, and the method is more accurate.
Description
Technical Field
The invention relates to the field of power supply control, in particular to a control method of a switching power supply, a controller and the switching power supply.
Background
The intelligent sound box or the internet of things equipment and other equipment work at a normal working power most of the time, but the equipment needs to work at a peak power for a short time, and the peak power is generally twice or even higher than the normal working power. When the equipment needs to work under the peak power, if the peak current output by the switching power supply is increased by only increasing the power of the equipment, the working pressure of a transformer in the switching power supply can be increased.
Disclosure of Invention
The invention aims to provide a control method and a controller of a switching power supply and the switching power supply, which increase the output power of the switching power supply under the condition that other parameters of the switching power supply are fixed by improving the working frequency of the switching power supply, the current output by the switching power supply to a primary winding of a transformer and allowing the controller of the switching power supply to enter a continuous conduction mode, so that the switching power supply enters a peak power mode. Compared with the method that only the peak current output by the switching power supply to the primary winding of the transformer is increased, the working pressure of the transformer is reduced. In addition, whether the switching power supply needs to enter a peak power mode or not is judged by detecting the output current of the switching power supply, and the method is more accurate.
In order to solve the technical problem, the invention provides a control method of a switching power supply, which is applied to a controller in the switching power supply, the switching power supply further comprises a first rectification module, a transformer and a second rectification module which are sequentially connected, the transformer comprises a primary winding, a secondary winding and an auxiliary winding, one end of the primary winding is connected with an output end of the first rectification module, the other end of the primary winding is connected with one end of a switching tube, the other end of the switching tube is grounded through a sampling resistor, and a control end of the switching tube is connected with the controller in the switching power supply, the control method comprises the following steps:
detecting the output current of the switching power supply;
judging whether the output current of the switching power supply is greater than an output current threshold value or not;
if so, adjusting the maximum frequency of the control signal of the switching tube from a first frequency to a second frequency, adjusting the maximum value of the peak current of the primary winding from a first current to a second current, and allowing to enter a continuous conduction mode.
Preferably, the detecting the output current of the switching power supply includes:
detecting a first voltage representing the current output by the switching power supply, wherein the magnitude of the first voltage is in positive correlation with the magnitude of the output current of the switching power supply;
judging whether the output current of the switching power supply is larger than an output current threshold value or not, comprising the following steps:
carrying out differential amplification on the first voltage and a first reference voltage to obtain a second voltage, wherein the second voltage is in negative correlation with the first voltage;
judging whether the second voltage is smaller than a second reference voltage;
and if the second voltage is smaller than the second reference voltage, judging that the output current of the switching power supply is larger than the output current threshold value.
Preferably, detecting a first voltage indicative of a current output by the switching power supply comprises:
detecting a median voltage of voltages at two ends of the sampling resistor;
obtaining the conducting duty ratio of the secondary winding based on the sampling voltage of the auxiliary winding;
and multiplying the median voltage by the duty ratio to obtain a first voltage.
Preferably, after adjusting the maximum frequency of the control signal of the switching tube from a first frequency to a second frequency and adjusting the maximum value of the peak current of the primary winding from a first current to a second current to allow the continuous conduction mode, the method further includes:
judging whether a first preset time is reached;
and if the first preset time is reached, adjusting the maximum frequency of a control signal of the switching tube from a second frequency to a first frequency, adjusting the maximum value of the peak current of the primary winding from a second current to a first current so as to realize constant voltage and constant current control and continue for a second preset time, and returning to the step of detecting the output current of the switching power supply after the second preset time.
In order to solve the technical problem, the invention further provides a controller in the switching power supply, the switching power supply further comprises a first rectification module, a transformer and a second rectification module which are sequentially connected, the transformer comprises a primary winding, a secondary winding and an auxiliary winding, one end of the primary winding is connected with the output end of the first rectification module, the other end of the primary winding is connected with one end of a switching tube, the other end of the switching tube is grounded through a sampling resistor, and the control end of the switching tube is connected with the controller in the switching power supply;
the controller in the switching power supply includes:
a memory for storing a computer program;
and the processor is used for realizing the steps of the control method of the switching power supply when executing the computer program.
In order to solve the technical problem, the invention further provides a controller in the switching power supply, the switching power supply further comprises a first rectification module, a transformer and a second rectification module which are sequentially connected, the transformer comprises a primary winding, a secondary winding and an auxiliary winding, one end of the primary winding is connected with the output end of the first rectification module, the other end of the primary winding is connected with one end of a switching tube, the other end of the switching tube is grounded through a sampling resistor, and the control end of the switching tube is connected with the controller in the switching power supply;
the controller in the switching power supply includes:
the output current detection module is used for detecting the output current of the switching power supply;
the comparison module is used for judging whether the output current of the switching power supply is larger than an output current threshold value or not;
and the processor is used for adjusting the maximum frequency of the control signal of the switching tube from a first frequency to a second frequency when the output current of the switching power supply is greater than the output current threshold value, adjusting the maximum value of the peak current of the primary winding from the first current to the second current, and allowing the switching power supply to enter a continuous conduction mode.
Preferably, the output current detection module is specifically configured to detect a first voltage representing a current output by the switching power supply, where a magnitude of the first voltage is in positive correlation with a magnitude of the output current of the switching power supply;
the comparison module comprises:
the differential amplifier is used for carrying out differential amplification on the first voltage and a first reference voltage to obtain a second voltage, and the second voltage is in negative correlation with the first voltage;
the comparator is used for judging whether the second voltage is smaller than the second reference voltage or not; and when the second voltage is smaller than the second reference voltage, determining that the output current of the switching power supply is larger than the output current threshold value.
Preferably, the output current detection module includes:
the median sampling module is used for detecting the median voltage of the voltages at the two ends of the sampling resistor;
the duty ratio detection module is used for obtaining the conduction duty ratio of the secondary winding based on the sampling voltage of the auxiliary winding;
and the multiplier is used for multiplying the median voltage and the duty ratio to obtain a first voltage.
Preferably, the output current detection module further includes:
and the buffer is arranged between the median sampling module and the multiplier and is used for isolating the median sampling module and the multiplier.
In order to solve the technical problem, the invention further provides a switching power supply, which comprises the controller, and further comprises a first rectification module, a transformer and a second rectification module which are sequentially connected, wherein the transformer comprises a primary winding, a secondary winding and an auxiliary winding, one end of the primary winding is connected with the output end of the first rectification module, the other end of the primary winding is connected with one end of a switching tube, the other end of the switching tube is grounded through a sampling resistor, and the control end of the switching tube is connected with the controller in the switching power supply.
The application provides a control method of a switching power supply, a controller and the switching power supply, after the output current of the switching power supply is detected, whether the output current of the switching power supply is larger than an output current threshold value is judged, if yes, the maximum frequency of a control signal of a switching tube is adjusted from a first frequency to a second frequency, the maximum value of the peak current of a primary winding is adjusted from the first current to the second current, meanwhile, constant current control is turned off, and the controller of the switching power supply is allowed to enter a continuous conduction mode. The maximum working frequency of the switching power supply, the peak current output to the primary winding of the transformer by the switching power supply and the permission of the controller of the switching power supply to enter the continuous conduction mode are improved, so that the output power of the switching power supply is increased under the condition that other parameters of the switching power supply are fixed, and the switching power supply enters the peak power mode. Compared with the method that only the peak current output by the switching power supply to the primary winding of the transformer is increased, the working pressure of the transformer is reduced. In addition, whether the switching power supply needs to enter a peak power mode or not is judged by detecting the output current of the switching power supply, and the method is more accurate.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed in the prior art and the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.
Fig. 1 is a flowchart of a control method of a switching power supply according to the present invention;
fig. 2 is a schematic structural diagram of a switching power supply provided in the present invention;
fig. 3 is a schematic structural diagram of a controller in a switching power supply according to the present invention;
fig. 4 is a schematic structural diagram of a controller in another switching power supply provided by the present invention;
fig. 5 is a graph of the relationship between the current output to the load and the frequency and peak current of the power supply according to the present invention.
Detailed Description
The core of the invention is to provide a control method, a controller and a switching power supply of the switching power supply, and the control method, the controller and the switching power supply increase the output power of the switching power supply under the condition that other parameters of the switching power supply are fixed by improving the working frequency of the switching power supply, the peak current output by the switching power supply to a primary winding of a transformer and allowing the controller of the switching power supply to enter a continuous conduction mode, so that the switching power supply enters a peak power mode. Compared with the method that only the peak current output by the switching power supply to the primary winding of the transformer is increased, the working pressure of the transformer is reduced. In addition, whether the switching power supply needs to enter a peak power mode or not is judged by detecting the output current of the switching power supply, and the method is more accurate.
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Fig. 1 is a flowchart of a control method of a switching power supply provided by the present invention, fig. 2 is a schematic structural diagram of a switching power supply provided by the present invention, the control method is applied to a controller 21 in the switching power supply, the switching power supply further includes a first rectification module 22, a transformer 23, and a second rectification module 24 that are sequentially connected, the transformer 23 includes a primary winding 231, a secondary winding 232, and an auxiliary winding 233, one end of the primary winding 231 is connected to an output end of the first rectification module 22, the other end of the primary winding 231 is connected to one end of a switching tube 25, the other end of the switching tube 25 is grounded through a sampling resistor 26, a control end of the switching tube 25 is connected to the controller 21 in the switching power supply, and the control method includes:
s11: detecting the output current of the switching power supply;
s12: judging whether the output current of the switching power supply is greater than an output current threshold value or not;
s13: if so, the maximum frequency of the control signal of the switching tube 25 is adjusted from the first frequency to the second frequency, and the maximum value of the peak current of the primary winding 231 is adjusted from the first current to the second current, so as to allow the continuous conduction mode to be entered.
Considering that devices such as smart speakers or internet of things devices operate at a normal operating power most of the time, these devices may need to operate at a peak power briefly, and the peak power is generally twice or even higher than the normal operating power. Therefore, when the device needs to operate at the peak power, the switching power supply needs to output the peak power in a short time, so that the normal operation of the device is ensured.
Firstly, the output current of the switching power supply is detected, whether the output current of the switching power supply is larger than a current threshold or not is judged, and if yes, the fact that the current output current is too large is proved, and the switching power supply needs to be converted into a peak power mode. There are three methods for increasing the output power of the switching power supply, which are to increase the maximum frequency of the control signal output to the switching tube 25, increase the peak current of the primary winding 231, and change the discontinuous conduction mode to the continuous conduction mode. If only one of them is adjusted, for example, the power of the device is increased by only increasing the current output by the switching power supply, the operating pressure of the transformer 23 in the switching power supply is increased. Therefore, when the output power of the switching power supply is increased, the maximum frequency of the control signal output to the switching tube 25 is adjusted from the first frequency to the second frequency, the peak current of the primary winding 231 is increased, and the switching power supply is allowed to enter the continuous conduction mode from the discontinuous conduction mode, so that the output power of the switch with energy can be increased better, and a larger working pressure is not applied to the transformer 23 in the switching power supply.
On the basis of the above-described embodiment:
as a preferred embodiment, detecting the output current of the switching power supply includes:
detecting a first voltage representing the current output by the switching power supply, wherein the magnitude of the first voltage is in positive correlation with the magnitude of the output current of the switching power supply;
judging whether the output current of the switching power supply is larger than the output current threshold value or not, comprising the following steps:
carrying out differential amplification on the first voltage and the first reference voltage to obtain a second voltage, wherein the second voltage is in negative correlation with the first voltage;
judging whether the second voltage is smaller than a second reference voltage;
and if the second voltage is smaller than the second reference voltage, judging that the output current of the switching power supply is larger than the output current threshold value.
The method comprises the steps of detecting a first voltage which is in positive correlation with the magnitude of the output current of the switching power supply, and carrying out differential amplification on the first voltage and a first reference voltage to obtain a second voltage, wherein the second voltage is in negative correlation with the first voltage, namely the second voltage is in negative correlation with the magnitude of the output current of the switching power supply.
And converting the judgment of whether the output current of the switching power supply is greater than the output current threshold into judgment of whether the second voltage is less than the second reference voltage, if the second voltage is less than the second reference voltage, judging that the output current of the switching circuit is greater than the output current threshold, and if the second voltage is greater than the second reference voltage, judging that the output current of the switching circuit is less than the output current threshold.
In addition, the switching power supply adjusts the maximum frequency of the control signal output to the switching tube 25 and the peak current of the primary winding 231 according to the second voltage, and the second voltage plays a feedback role to realize the constant voltage and constant current output control of the switching power supply at the normal working power.
The second voltage obtained by checking, dividing and amplifying the first voltage and the first reference voltage can play a feedback role, and the constant voltage and constant current output control of the switching power supply is ensured. And comparing the second voltage with a second reference voltage to judge whether the output current of the switching power supply is greater than an output current threshold value or not, thereby carrying out subsequent control.
As a preferred embodiment, detecting a first voltage indicative of a current output by the switching power supply comprises:
detecting the median voltage of the voltages across the sampling resistor 26;
the duty ratio of the conduction of the secondary winding 232 is obtained based on the sampling voltage of the auxiliary winding 233;
and multiplying the median voltage by the duty ratio to obtain a first voltage.
The duty ratio of the secondary winding 232 conduction obtained by the median voltage of the voltages at the two ends of the sampling resistor 26 and the sampling voltage of the auxiliary winding 233 is multiplied, so as to obtain a first voltage representing the current output by the switching power supply, and the first voltage is in positive correlation with the current output by the switching power supply.
As a preferred embodiment, after adjusting the maximum frequency of the control signal of the switching tube 25 from the first frequency to the second frequency, and adjusting the maximum value of the peak current of the primary winding 231 from the first current to the second current, and allowing the continuous conduction mode to be entered, the method further includes:
judging whether a first preset time is reached;
if the first preset time is reached, the maximum frequency of the control signal of the switching tube 25 is adjusted from the second frequency to the first frequency, the maximum value of the peak current of the primary winding 231 is adjusted from the second current to the first current, so that the constant-voltage constant-current control is realized, the second preset time is continued, and the step of detecting the output current of the switching power supply is returned after the second preset time.
Considering that the switching power supply can damage the switching power supply in the peak power mode after working for a long time, a first preset time is set, the switching power supply can output the peak power within the first preset time, and the switching power supply can recover to the power of normal work after exceeding the first preset time.
Further, it is considered that even if the switching power supply is restored to the constant voltage and constant current control output after the first preset time, the switching power supply will be restored to the peak power mode if the large load connected to the output terminal of the second rectification module 24 of the switching power supply is not disconnected from the switching power supply. Therefore, a second preset time is set, the switching power supply will not enter the peak power mode within the second preset time, and the step of detecting the output current of the switching power supply is returned until the second preset time, so as to continuously judge whether the output current of the current switching power supply is greater than the output current threshold value.
The first preset time is set to ensure that the switching power supply is not in the peak power mode for a long time, and the second preset time can reserve certain interval time between two times of output peak power modes.
Fig. 3 is a schematic structural diagram of a controller in a switching power supply provided by the present invention, where the switching power supply further includes a first rectification module 22, a transformer 23, and a second rectification module 24, which are connected in sequence, the transformer 23 includes a primary winding 231, a secondary winding 232, and an auxiliary winding 233, one end of the primary winding 231 is connected to an output end of the first rectification module 22, the other end of the primary winding 231 is connected to one end of a switching tube 25, the other end of the switching tube 25 is grounded through a sampling resistor 26, and a control end of the switching tube 25 is connected to the controller in the switching power supply;
the controller in the switching power supply includes:
a memory 31 for storing a computer program;
and a processor 32 for implementing the steps of the control method of the switching power supply when executing the computer program.
For the introduction of the controller in the switching power supply provided by the present invention, please refer to the above embodiments, which are not described herein again.
Fig. 2 is a schematic structural diagram of a switching power supply provided by the present invention, fig. 4 is a schematic structural diagram of a controller in another switching power supply provided by the present invention, the switching power supply further includes a first rectification module 22, a transformer 23, and a second rectification module 24, which are connected in sequence, the transformer 23 includes a primary winding 231, a secondary winding 232, and an auxiliary winding 233, one end of the primary winding 231 is connected to an output end of the first rectification module 22, the other end of the primary winding 231 is connected to one end of a switching tube 25, the other end of the switching tube 25 is grounded through a sampling resistor 26, and a control end of the switching tube 25 is connected to the controller in the switching power supply;
the controller in the switching power supply includes:
an output current detection module 41, configured to detect an output current of the switching power supply;
a comparing module 42, configured to determine whether an output current of the switching power supply is greater than an output current threshold;
and the processor 43 is configured to adjust the maximum frequency of the control signal of the switching tube 25 from the first frequency to the second frequency and adjust the maximum value of the peak current of the primary winding 231 from the first current to the second current when the output current of the switching power supply is greater than the output current threshold, so as to allow the continuous conduction mode to be entered.
For the introduction of the controller in the switching power supply provided by the present invention, please refer to the above embodiments, which are not described herein again.
As a preferred embodiment, the output current detection module 41 is specifically configured to detect a first voltage representing a current output by the switching power supply, where a magnitude of the first voltage is positively correlated with a magnitude of an output current of the switching power supply;
the comparison module 42 includes:
the differential amplifier is used for carrying out differential amplification on the first voltage and the first reference voltage to obtain a second voltage, and the second voltage is in negative correlation with the first voltage;
the comparator is used for judging whether the second voltage is smaller than the second reference voltage or not; and when the second voltage is smaller than the second reference voltage, determining that the output current of the switching power supply is larger than the output current threshold value.
The first voltage is connected to the inverting input terminal of the differential amplifier, and the first reference voltage is connected to the non-inverting input terminal of the differential amplifier. The second voltage is connected to the inverting input of the comparator, and the second reference voltage is connected to the inverting input of the comparator.
The comparator includes, but is not limited to, outputting a high level at the second voltage less than the second reference voltage and outputting a low level at the second voltage greater than the second reference voltage.
In addition, the comparing module 42 includes, but is not limited to, a differential amplifier and a comparator, and may also be an integrator for integrating and filtering, which is not limited herein.
As a preferred embodiment, the output current detection module 41 includes:
a median sampling module for detecting a median voltage of voltages at both ends of the sampling resistor 26;
the duty ratio detection module is used for obtaining the conduction duty ratio of the secondary winding 232 based on the sampling voltage of the auxiliary winding 233;
and the multiplier is used for multiplying the median voltage by the duty ratio to obtain a first voltage.
Preferably, the output current detection module 41 further includes:
and the buffer is arranged between the median sampling module and the multiplier and is used for isolating the median sampling module from the multiplier.
It should be noted that the median sampling module is implemented by a switch.
In order to prevent the modules from interfering with each other, a buffer is provided to isolate the median sampling module from the multiplier.
Fig. 2 is a schematic structural diagram of a switching power supply provided by the present invention, which includes the above-mentioned controller 21, and further includes a first rectification module 22, a transformer 23, and a second rectification module 24 that are connected in sequence, where the transformer 23 includes a primary winding 231, a secondary winding 232, and an auxiliary winding 233, one end of the primary winding 231 is connected to an output end of the first rectification module 22, the other end of the primary winding 231 is connected to one end of a switching tube 25, the other end of the switching tube 25 is grounded through a sampling resistor 26, and a control end of the switching tube 25 is connected to the controller 21 in the switching power supply.
For the introduction of the switching power supply provided by the present invention, please refer to the above embodiments, which are not described herein.
In this specification, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.
Those of skill would further appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both, and that the various illustrative components and steps have been described above generally in terms of their functionality in order to clearly illustrate this interchangeability of hardware and software. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (10)
1. A control method of a switching power supply is characterized in that the control method is applied to a controller in the switching power supply, the switching power supply further comprises a first rectification module, a transformer and a second rectification module which are sequentially connected, the transformer comprises a primary winding, a secondary winding and an auxiliary winding, one end of the primary winding is connected with an output end of the first rectification module, the other end of the primary winding is connected with one end of a switching tube, the other end of the switching tube is grounded through a sampling resistor, and a control end of the switching tube is connected with the controller in the switching power supply, and the control method comprises the following steps:
detecting the output current of the switching power supply;
judging whether the output current of the switching power supply is greater than an output current threshold value or not;
if so, adjusting the maximum frequency of the control signal of the switching tube from a first frequency to a second frequency, adjusting the maximum value of the peak current of the primary winding from a first current to a second current, and allowing to enter a continuous conduction mode.
2. The method for controlling the switching power supply according to claim 1, wherein detecting the output current of the switching power supply comprises:
detecting a first voltage representing the current output by the switching power supply, wherein the magnitude of the first voltage is in positive correlation with the magnitude of the output current of the switching power supply;
judging whether the output current of the switching power supply is larger than an output current threshold value or not, comprising the following steps:
carrying out differential amplification on the first voltage and a first reference voltage to obtain a second voltage, wherein the second voltage is in negative correlation with the first voltage;
judging whether the second voltage is smaller than a second reference voltage;
and if the second voltage is smaller than the second reference voltage, judging that the output current of the switching power supply is larger than the output current threshold value.
3. The method of controlling a switching power supply according to claim 2, wherein detecting a first voltage indicative of a current output by the switching power supply comprises:
detecting a median voltage of voltages at two ends of the sampling resistor;
obtaining the conducting duty ratio of the secondary winding based on the sampling voltage of the auxiliary winding;
and multiplying the median voltage by the duty ratio to obtain a first voltage.
4. The method of controlling a switching power supply according to any one of claims 1 to 3, wherein the step of adjusting the maximum frequency of the control signal of the switching tube from a first frequency to a second frequency and the maximum value of the peak current of the primary winding from the first current to the second current, after allowing the continuous conduction mode to be entered, further comprises:
judging whether a first preset time is reached;
and if the first preset time is reached, adjusting the maximum frequency of a control signal of the switching tube from a second frequency to a first frequency, adjusting the maximum value of the peak current of the primary winding from a second current to a first current so as to realize constant voltage and constant current control and continue for a second preset time, and returning to the step of detecting the output current of the switching power supply after the second preset time.
5. A controller in a switching power supply is characterized by further comprising a first rectifying module, a transformer and a second rectifying module which are sequentially connected, wherein the transformer comprises a primary winding, a secondary winding and an auxiliary winding, one end of the primary winding is connected with the output end of the first rectifying module, the other end of the primary winding is connected with one end of a switching tube, the other end of the switching tube is grounded through a sampling resistor, and the control end of the switching tube is connected with the controller in the switching power supply;
the controller in the switching power supply includes:
a memory for storing a computer program;
processor for implementing the steps of the method for controlling a switching power supply according to any one of claims 1 to 4 when executing said computer program.
6. A controller in a switching power supply is characterized by further comprising a first rectifying module, a transformer and a second rectifying module which are sequentially connected, wherein the transformer comprises a primary winding, a secondary winding and an auxiliary winding, one end of the primary winding is connected with the output end of the first rectifying module, the other end of the primary winding is connected with one end of a switching tube, the other end of the switching tube is grounded through a sampling resistor, and the control end of the switching tube is connected with the controller in the switching power supply;
the controller in the switching power supply includes:
the output current detection module is used for detecting the output current of the switching power supply;
the comparison module is used for judging whether the output current of the switching power supply is larger than an output current threshold value or not;
and the processor is used for adjusting the maximum frequency of the control signal of the switching tube from a first frequency to a second frequency when the output current of the switching power supply is greater than the output current threshold value, adjusting the maximum value of the peak current of the primary winding from the first current to the second current, and allowing the switching power supply to enter a continuous conduction mode.
7. The controller in the switching power supply according to claim 6, wherein the output current detection module is specifically configured to detect a first voltage representing a current output by the switching power supply, and a magnitude of the first voltage is positively correlated with a magnitude of the output current of the switching power supply;
the comparison module comprises:
the differential amplifier is used for carrying out differential amplification on the first voltage and a first reference voltage to obtain a second voltage, and the second voltage is in negative correlation with the first voltage;
the comparator is used for judging whether the second voltage is smaller than the second reference voltage or not; and when the second voltage is smaller than the second reference voltage, determining that the output current of the switching power supply is larger than the output current threshold value.
8. The controller in a switching power supply according to claim 7, wherein said output current detection module comprises:
the median sampling module is used for detecting the median voltage of the voltages at the two ends of the sampling resistor;
the duty ratio detection module is used for obtaining the conduction duty ratio of the secondary winding based on the sampling voltage of the auxiliary winding;
and the multiplier is used for multiplying the median voltage and the duty ratio to obtain a first voltage.
9. The controller in a switching power supply according to claim 7, wherein said output current detection module further comprises:
and the buffer is arranged between the median sampling module and the multiplier and is used for isolating the median sampling module and the multiplier.
10. A switching power supply, comprising the controller according to any one of claims 5 to 9, and further comprising a first rectification module, a transformer and a second rectification module connected in sequence, wherein the transformer comprises a primary winding, a secondary winding and an auxiliary winding, one end of the primary winding is connected to the output end of the first rectification module, the other end of the primary winding is connected to one end of a switching tube, the other end of the switching tube is grounded through a sampling resistor, and the control end of the switching tube is connected to the controller in the switching power supply.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111598581.XA CN113991980A (en) | 2021-12-24 | 2021-12-24 | Control method and controller of switching power supply and switching power supply |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111598581.XA CN113991980A (en) | 2021-12-24 | 2021-12-24 | Control method and controller of switching power supply and switching power supply |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113991980A true CN113991980A (en) | 2022-01-28 |
Family
ID=79734309
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111598581.XA Pending CN113991980A (en) | 2021-12-24 | 2021-12-24 | Control method and controller of switching power supply and switching power supply |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113991980A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114421781A (en) * | 2022-03-31 | 2022-04-29 | 深圳市芯茂微电子有限公司 | Control method of resonant converter |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20140192563A1 (en) * | 2013-01-08 | 2014-07-10 | Inno-Tech Co., Ltd. | Dual-mode switching power control device |
| CN104272572A (en) * | 2012-03-26 | 2015-01-07 | 夏普株式会社 | Switching power supply circuit and led illumination device |
| US20150103566A1 (en) * | 2013-10-14 | 2015-04-16 | Texas Instruments Incorporated | Systems and Methods of CCM Primary-Side Regulation |
| US9621053B1 (en) * | 2014-08-05 | 2017-04-11 | Flextronics Ap, Llc | Peak power control technique for primary side controller operation in continuous conduction mode |
| JP2017103870A (en) * | 2015-11-30 | 2017-06-08 | シャープ株式会社 | Switching power supply device |
| CN206575319U (en) * | 2016-03-10 | 2017-10-20 | 半导体元件工业有限责任公司 | Switched-mode power supply and its control circuit |
| CN110336466A (en) * | 2019-06-17 | 2019-10-15 | 无锡博通微电子技术有限公司 | A kind of inverse-excitation type digital switch power circuit with primary feedback and peak power |
-
2021
- 2021-12-24 CN CN202111598581.XA patent/CN113991980A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104272572A (en) * | 2012-03-26 | 2015-01-07 | 夏普株式会社 | Switching power supply circuit and led illumination device |
| US20140192563A1 (en) * | 2013-01-08 | 2014-07-10 | Inno-Tech Co., Ltd. | Dual-mode switching power control device |
| US20150103566A1 (en) * | 2013-10-14 | 2015-04-16 | Texas Instruments Incorporated | Systems and Methods of CCM Primary-Side Regulation |
| US9621053B1 (en) * | 2014-08-05 | 2017-04-11 | Flextronics Ap, Llc | Peak power control technique for primary side controller operation in continuous conduction mode |
| JP2017103870A (en) * | 2015-11-30 | 2017-06-08 | シャープ株式会社 | Switching power supply device |
| CN206575319U (en) * | 2016-03-10 | 2017-10-20 | 半导体元件工业有限责任公司 | Switched-mode power supply and its control circuit |
| CN110336466A (en) * | 2019-06-17 | 2019-10-15 | 无锡博通微电子技术有限公司 | A kind of inverse-excitation type digital switch power circuit with primary feedback and peak power |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114421781A (en) * | 2022-03-31 | 2022-04-29 | 深圳市芯茂微电子有限公司 | Control method of resonant converter |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10720835B2 (en) | Limiting average current in a peak-controlled boost converter | |
| US10231050B2 (en) | Method for limiting amplifier input current to avoid low voltage conditions | |
| US20200359123A1 (en) | Headset charging system and headset charging method | |
| CN100592237C (en) | Intelligent switch power source power detection and control device | |
| US20170310122A1 (en) | Charging apparatus and charging control circuit thereof and charging control method | |
| CN108233545B (en) | Wireless charging receiving circuit, electronic equipment and wireless charging method | |
| CN113991980A (en) | Control method and controller of switching power supply and switching power supply | |
| CN107959358B (en) | Control method of wireless charging device and wireless charging device | |
| US11522391B2 (en) | Method and apparatus for detecting objects in charging area of wireless charging transmitter | |
| CN117439283A (en) | Method and circuit for mitigating saturation in a wireless power system | |
| KR102472738B1 (en) | How to Limit Amplifier Input Current to Avoid Low Voltage Conditions | |
| US8022672B2 (en) | Charger control circuit and charger control method | |
| CN107426859A (en) | A kind of adaptive fast response circuit, fast response method and LED drive circuit | |
| CN106411138B (en) | A kind of dynamic regulating circuit, system, method and Switching Power Supply | |
| CN112702291B (en) | Adaptive equalizer and adjusting range expanding method thereof | |
| CN115242227A (en) | Frequency control circuit suitable for PFM control chip and related device | |
| US9755525B2 (en) | Power converter circuit and power limit control circuit thereof | |
| CN111211591B (en) | Overvoltage protection method, overvoltage protection circuit and wireless charging system | |
| WO2020052375A1 (en) | Charging control method and apparatus, and terminal device | |
| US20240056001A1 (en) | Vibration-Driven Energy Harvesting Device | |
| US11804834B2 (en) | Electromagnetic interference regulator by use of capacitive parameters of field-effect transistor | |
| CN214153994U (en) | Overvoltage protection circuit and device | |
| JP2002300733A (en) | Full charge detecting method for battery | |
| GB2551621A (en) | Method for limiting amplifier input current to avoid low voltage conditions | |
| KR20110022136A (en) | Circuit for sensing input voltage |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20220128 |
|
| RJ01 | Rejection of invention patent application after publication |