CN114389454A - Secondary side control method and secondary side control system of isolated power supply - Google Patents
Secondary side control method and secondary side control system of isolated power supply Download PDFInfo
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- 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
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/10—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers
- H02H7/12—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers
- H02H7/1213—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers for DC-DC converters
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Abstract
A secondary side control method and a secondary side control system of an isolated power supply realize the accurate control of a secondary side on current parameters by adopting the mode control of a secondary side peak current; detecting the voltage at two ends of a secondary inductor of the transformer during the switching-on period of the primary power tube, acquiring primary inductive current information of the isolation power supply, judging whether the primary inductive current of the isolation power supply reaches a peak value according to the primary inductive current information of the isolation power supply, and switching off the primary power tube when the primary inductive current of the isolation power supply reaches the peak value; in addition, the output load current of the isolation power supply is calculated by obtaining the duty ratio of secondary follow current time occupying one switching period and the secondary peak current according to the voltage at two ends of the secondary winding of the transformer, so that the starting control of the primary power tube and the control of the peak current of the primary power tube are realized. Compared with a primary side peak current mode control mode, the method naturally offsets non-ideal factors of voltage transformation, and improves control precision; meanwhile, a sampling resistor is not required to be arranged, the problem of resistance loss of the traditional control scheme is solved, and the system efficiency is improved.
Description
Technical Field
The invention belongs to the technical field of switching power supplies, and relates to a secondary side control method and a secondary side control system of an isolation power supply.
Background
For a switching power supply topology structure, current information of an inductor or a transformer needs to be monitored, and particularly a control method of a peak current mode needs to sample a peak current to control the turn-off of a main MOS. An isolation power supply isolates a primary side and a secondary side through electromagnetism, as shown in fig. 1, the isolation power supply generally comprises a transformer I101, a secondary side diode I102 and a primary side power tube I108, and in order to obtain better current accuracy, a conventional architecture generally needs to use a primary side sampling resistor RCS2, i.e., I110, to obtain peak current information of a primary side inductor of the transformer. Meanwhile, the current of the inductor in the primary side of the transformer is controlled by the primary side sampling resistor, but the transmission ratio of the primary side current to the secondary side is influenced by parameters such as the turn ratio, the leakage inductance and the like of the transformer, and the equivalent turn ratio of the transformer cannot be accurately controlled by the production process, so that the output current of the secondary side cannot be accurately controlled by the primary side sampling resistor, and the influence of non-ideal factors of the transformer on the accuracy of the primary side control output current cannot be eliminated.
For the secondary side control architecture, the secondary side control part is difficult to accurately obtain the primary side inductive current information, so that the secondary side accurate control of the peak inductive current cannot be realized. Taking the flyback isolation switch power supply shown in fig. 1 as an example, a secondary side control architecture is used, the isolation power supply system includes a transformer I101, a secondary side diode I102, two voltage dividing resistors I103 and I104, a secondary side control unit I105, a primary side and secondary side signal transmission unit I106, a primary side control unit I107, and a primary side power tube I108, in order to obtain primary side information and a secondary side signal, a primary side sampling resistor R is usually further arranged on each of the primary side and the secondary sideCS2And secondary side sampling resistor RCS1. The two voltage division resistors I103 and I104 are used for sampling the output voltage of the power supply system to obtain the divided voltage which is output to the secondary side control unit I105 as a feedback signal FB; secondary sampling resistor RCS1For sampling output current, output current and secondary side sampling resistor RCS1The product of the self-resistance is converted into a SENSE1 voltage, and the SENSE1 voltage outputs the current information represented by the voltage to the secondary control unit I105 to be compared with the output voltage information contained in the feedback signal FB. The secondary control unit I105 controls the working mode of the whole power supply chip according to the input secondary current and voltage information, and transmits the secondary information to the primary control unit I107 through the primary and secondary signal transmission unit I106. The primary side control unit I107 is controlled by the secondary side control unit I105, and the signal of the secondary side control unit I105 controls the primary side control unit through the primary side and secondary side signal transmission unit I106I107, a primary side power tube I108 is turned on and the peak current of the primary side power tube I108 is controlled; but because it is controlled by the peak current mode, the primary side control unit I107 also passes through the primary side sampling resistor I110, i.e. RCS2The peak current of the primary inductor of the transformer is sampled and used for controlling the turn-off of the primary power tube I108.
It can be seen that in the conventional secondary side control architecture, two sampling resistors R are usually requiredCS1And RCS2Secondary side sampling resistor RCS1Sampling the output load information of the secondary side of the transformer, sampling the resistance R at the primary sideCS2The peak current information of the primary side inductance of the transformer is sampled, and the primary side and the secondary side are controlled according to the collected information.
Disclosure of Invention
Aiming at the problems that the system efficiency is reduced due to the fact that an isolation power supply of a traditional secondary control framework is provided with power consumption caused by a sampling resistor, and the secondary output current cannot be accurately controlled through a primary sampling resistor, the invention provides a secondary control method and a secondary control system without the sampling resistor, which are suitable for a switch power supply with a transformer, and comprise ACDC, DCDC and other isolation power supply control systems; according to the secondary side control system provided by the invention, the primary side inductive current is accurately detected by acquiring the secondary side voltage, and the primary side power tube is controlled according to the detection result, so that the influence of non-ideal factors of a transformer on the primary side control output current precision when the primary side sampling resistor controls the secondary side output current is solved, not only can high precision be realized, but also no power consumption is generated when the current flows through the resistor due to no need of setting the sampling resistor, so that the problem of low efficiency of a traditional secondary side control framework due to the adoption of the sampling resistor is solved, and the system efficiency is improved.
The technical scheme of the isolation power supply secondary side control method provided by the invention is as follows:
a secondary side control method of an isolation power supply is disclosed, wherein the isolation power supply is based on an interrupted current mode and comprises a transformer and a primary side power tube, the transformer comprises a primary side inductor and a secondary side inductor, and the primary side power tube is connected with the primary side inductor of the transformer in series; the secondary side control method of the isolation power supply comprises the steps of controlling the on and off of the primary side power tube, wherein the method for controlling the off of the primary side power tube comprises the following steps:
a1, detecting the voltages at two ends of the secondary inductor of the transformer during the turn-on period of the primary power tube, wherein the ratio of the input voltage of the isolation power supply to the voltages at two ends of the secondary inductor of the transformer is the turn ratio of the primary winding and the secondary winding of the transformer, and the primary inductive current of the isolation power supply is positively correlated with the input voltage of the isolation power supply, so that the primary inductive current information of the isolation power supply can be obtained by processing the detected voltages at two ends of the secondary inductor of the transformer;
a2, judging whether the primary side inductive current of the isolation power supply reaches the peak value according to the primary side inductive current information of the isolation power supply obtained in the step A1, and turning off the primary side power tube when the primary side inductive current of the isolation power supply reaches the peak value;
the method for controlling the opening of the primary side power tube comprises the following steps:
b1, detecting the voltage at two ends of the secondary side inductor of the transformer and acquiring the duty ratio D of the secondary side freewheeling time in one switching period;
b2, obtaining the peak voltage of the voltage at the two ends of the secondary inductor of the transformer and converting the peak voltage into secondary peak current LS_PKThen the output load current of the isolated power supply is
B3, sampling the output voltage of the isolation power supply to obtain a feedback voltage, processing the output load current of the isolation power supply to obtain a voltage signal containing the output load current information of the isolation power supply, comparing the voltage signal with the feedback voltage, and controlling the switching state of the primary side switching tube according to the comparison result.
Specifically, in the step a1, the detected voltage at two ends of the secondary inductor of the transformer is converted into a current signal, and then the first capacitor is charged, the voltage on the first capacitor is compared with a set threshold voltage, and when the voltage on the first capacitor is greater than the threshold voltage, it indicates that the primary inductor current of the isolation power supply reaches a peak value, and a signal for turning off the primary power tube is generated.
Specifically, the peak values of the primary side inductive currents corresponding to different output loads of the isolation power supply are also different, and the different peak values of the primary side inductive currents are adapted by three methods including, but not limited to:
the method comprises the steps of firstly, adjusting the capacitance value of the first capacitor;
adjusting the voltage value of the threshold voltage;
and thirdly, adjusting the proportionality coefficient of the voltage at the two ends of the secondary inductor of the transformer converted into the current signal.
Specifically, the primary side inductor current of the isolation power supply is controlled according to the output load current of the isolation power supply obtained in the step B2, so that the output load current of the isolation power supply is kept constant; and comparing the output load current of the isolation power supply with a set overload protection threshold current, and controlling the primary side switching tube to be kept off to realize output overload protection when the output load current exceeds the overload protection threshold current.
In order to realize the secondary side control method, the invention also provides a specific structure of the isolated power supply secondary side control system, and the technical scheme is as follows:
a secondary side control system of an isolation power supply is disclosed, wherein the isolation power supply is based on an interrupted current mode and comprises a transformer, a primary side power tube and a secondary side diode, one end of a primary side winding of the transformer is connected with an input voltage of the isolation power supply, and the other end of the primary side winding of the transformer is grounded after passing through the primary side power tube; one end of a secondary winding of the transformer is connected with the anode of the secondary diode, and the other end of the secondary winding of the transformer is grounded; the cathode of the secondary side diode outputs the output voltage of the isolation power supply, and the output voltage of the isolation power supply is sampled to obtain a feedback voltage;
the secondary side control system of the isolation power supply is used for controlling the on and off of the primary side power tube and comprises a primary side current detection module, an information processing unit and a control module,
the input end of the primary side current detection module is connected with the voltage at two ends of the secondary side inductor of the transformer and is used for generating an output signal containing the current information of the primary side inductor of the isolation power supply; the information processing unit is used for judging whether the primary side inductive current of the isolation power supply reaches a peak value according to the output signal of the primary side current detection module, and controlling the control module to switch off the primary side power tube when the primary side inductive current of the isolation power supply reaches the peak value;
the information processing unit is also used for calculating a duty ratio D of secondary freewheeling time in one switching period according to the voltage at two ends of the secondary inductor of the transformer detected by the primary current detection module, and calculating a secondary peak current L according to the peak voltage of the voltage at two ends of the secondary inductor of the transformer detected by the primary current detection moduleS_PKSo as to obtain an output load current of the isolated power supply of
Generating a voltage signal containing output load current information of the isolation power supply and outputting the voltage signal to the control module; and the control module compares the voltage signal containing the output load current information of the isolation power supply with the feedback voltage and controls the switching state of the primary side power tube according to the comparison result.
Specifically, the primary current detection module comprises a secondary voltage monitoring primary current unit, and the information processing unit comprises a peak inductor current comparator;
the input end of the secondary voltage monitoring primary current unit is connected with two ends of a secondary winding of the transformer and is used for acquiring voltages at two ends of a secondary inductor of the transformer, converting the voltages into corresponding currents and then charging a first capacitor;
and when the voltage of the first input end of the peak inductive current comparator is greater than that of the second input end of the peak inductive current comparator, the peak inductive current comparator generates a turn-off control signal and turns off the primary power tube through the control module.
Specifically, the primary side current detection module further includes a current programming modulation unit, and the current programming modulation unit is configured to adjust a capacitance value of the first capacitor to adjust a rising slope of a voltage at a first input terminal of the peak inductor current comparator.
Specifically, the primary side current detection module further includes a current programming modulation unit, and the current programming modulation unit is configured to adjust a voltage value of the peak inductor current threshold voltage.
Specifically, the primary side current detection module further comprises a current programming modulation unit, and the current programming modulation unit is configured to adjust a ratio coefficient of a voltage at two ends of the secondary side inductor of the transformer to a corresponding current, so as to adjust a rising slope of a voltage at a first input terminal of the peak inductor current comparator.
Specifically, the information processing unit further comprises a constant current control circuit and an output overload protection circuit, wherein the constant current control circuit controls the primary side inductive current of the isolation power supply according to the output load current of the isolation power supply, so that the output load current of the isolation power supply keeps constant; the output overload protection circuit compares the output load current of the isolation power supply with a set overload protection threshold current, and controls the primary side switching tube to be kept off through the control module to realize output overload protection when the output load current exceeds the overload protection threshold current.
The invention has the beneficial effects that: the invention adopts secondary side peak current mode control, compared with primary side peak current mode control, the invention can realize more accurate control of the maximum value of the output current load, naturally offset the non-ideal factors of voltage transformation, and realize accurate control of the secondary side on the current parameters; the method comprises the steps of extracting primary side inductance current peak value information by sampling voltages at two ends of a secondary winding of a transformer, realizing turn-off control of a primary side power tube, and realizing accurate sampling of primary side current of the transformer without a primary side sampling resistor; the output load current information is calculated by obtaining the secondary peak current information and the secondary on-time duty ratio, so that the starting control of the primary power tube and the control of the peak current of the primary power tube are realized, and the accurate sampling of the output current of the transformer is realized without a secondary sampling resistor; the problem of resistance loss caused by the arrangement of the sampling resistor in the traditional control scheme is solved, and the system efficiency is improved; the invention is easy to realize in the monolithic integrated circuit, and does not need to add extra chip external components and chip pins.
Drawings
The following description of various embodiments of the invention may be better understood with reference to the following drawings, which schematically illustrate major features of some embodiments of the invention. These figures and examples provide some embodiments of the invention in a non-limiting, non-exhaustive manner.
Fig. 1 is a structural diagram of a conventional isolated flyback switch control system, which uses resistance sampling to realize control.
Fig. 2 is an implementation architecture diagram of a secondary side control method and a secondary side control system for isolating a power supply according to a first embodiment of the present invention.
FIG. 3 is a specific implementation form of a secondary side control method and a secondary side control system of an isolated power supply according to a second embodiment of the present invention, wherein V is modulated by capacitor programmingCSThe rising slope of (c).
FIG. 4 is a specific implementation form of a secondary side control method and a secondary side control system for an isolated power supply according to a third embodiment of the present invention, wherein V is modulated by resistance programmingSETThe voltage value of (2).
FIG. 5 is a specific implementation form of a secondary side control method and a secondary side control system for an isolated power supply according to a third embodiment of the present invention, wherein V is modulated by resistance programmingCSThe rising slope of (c).
Detailed Description
The technical solution of the present invention is described in detail below with reference to the accompanying drawings and specific embodiments.
The specific details of the embodiments described below are provided to provide a better understanding of the embodiments of the invention and are not intended to limit the scope of the invention. It will be understood by those skilled in the art that embodiments of the present invention may be practiced without some of the details, steps, or with other methods, connections, and so forth. The invention is suitable for an isolated power supply with a transformer, comprises an ACDC (alternating current direct current converter), a DCDC (direct current) and other isolated power supply control systems, and is a secondary side control system. The secondary side mentioned in the present invention refers to the two isolated ends of the isolation transformer, respectively, relative to the primary side of the transformer, and the primary side and the secondary side of the transformer are sometimes also called the primary side and the secondary side, etc.
In the first embodiment, the invention is applied to a flyback isolated switching power supply as an example, but the invention is also applicable to other switching power supply systems which utilize a transformer to realize isolation. As shown in fig. 2, the isolation power supply includes a transformer I101, a primary power tube I108 and a secondary diode I102, the transformer I101 includes a primary winding and a secondary winding, one end of the primary winding of the transformer I101 is connected to an input voltage VIN of the isolation power supply, and the other end of the primary winding of the transformer I101 is grounded through the primary power tube I108; one end of a secondary winding of the transformer I101 is connected with the anode of a secondary diode I102, and the other end of the secondary winding is grounded; the cathode of the secondary diode I102 outputs the output voltage VOUT of the isolated power supply.
In order to perform accurate control, it is necessary to sample output load current information of an isolation power supply and peak current information of a primary inductor of a transformer, and as described in the background art, in a conventional secondary control architecture, real-time shutdown of a primary power tube is achieved by controlling a primary peak current through a secondary, and a primary sampling resistor R is required to be usedCS2Sampling transformer primary inductance peak current information, utilizing secondary side sampling resistor RCS1Load current information is sampled and output, so that two sampling resistors are needed, extra power consumption is increased by the sampling resistors, and the overall efficiency of the system is reduced. In order to solve the technical problem, the invention provides a novel secondary side control framework which can acquire output load current information and transformer primary side inductance peak current information without setting a sampling resistor and control the on-off of a primary side switching tube I108 according to the acquired information.
Firstly, describing the process of acquiring the peak current information of the primary inductance of the transformer to control the turn-off of the primary switching tube I108, as shown in FIG. 2, the secondary control system provided by the invention comprises a primary current detection module, an information processing unit I114 and a control module, wherein the primary current detection module is used for generating an output signal containing the primary inductance current information of the isolation power supply and comprises a secondary voltage detection primary current unit I112 and a current programming modulation unit I113; the information processing unit I114 processes the output signal of the primary side current detection module to generate a corresponding control signal; the control module controls the primary power tube I108 according to the control signal output by the information processing unit I114, and comprises a secondary control unit I105, a primary and secondary signal transmission unit I106 and a primary control unit I107.
The input end of the secondary voltage detection primary current unit I112 is connected with two ends of a secondary winding of the transformer and used for acquiring the voltage V at two ends of a secondary inductor of the transformer during the turn-on period of the primary power tube1-2And charging the first capacitor after converting into corresponding current, wherein the output signal of the primary side current detection module is the voltage V on the first capacitorCSVoltage V on the first capacitorCSThe information of the primary side inductance current of the isolated power supply is included, and the specific analysis is as follows.
According to the working principle of the isolation power supply, the relationship between the primary side inductance current Ip in the time domain and the input voltage VIN and the primary side inductance Lp of the isolation power supply is as follows:
lp is a constant and the value of ip (t) is related only to the time t and the input voltage VIN. In addition, the voltage difference V between two ends 1 and 2 of the secondary winding of the transformer is sampled at the switching-on moment of the primary side switching tube I1081-2Can derive V1-2VIN/N, where N is the transformer turn ratio, i.e., the ratio of the primary winding to the secondary winding of the transformer. Therefore, the voltage V at two ends of the secondary inductor of the detected transformer is detected1-2The processing can obtain information of the primary side inductor current Ip of the isolated power supply.
The following method is combined with the utilization of a primary sampling resistor R in the traditional secondary control frameworkCS2SamplingThe working process of the peak current information of the primary side inductance of the transformer is explained by the invention for the primary side sampling resistor RCS2Alternative effects of (a).
For traditional peak current control, a primary sampling resistor R is utilizedCS2Sampling current and converting into corresponding voltage signal VSENSE2The peak current information that can be obtained is expressed in terms of voltage as follows:
lp and R in the formulaCS2Is a constant, VSENSE2Is only related to the time t and the input voltage VIN, so if information of the input voltage VIN is available on the secondary side, the sum V can be generated on the secondary sideSENSE2The same time domain waveform also realizes the method for detecting the primary side current of the transformer by the secondary side.
The invention detects the voltage V at two ends of the secondary inductor of the transformer1-2Processing, converting into corresponding current, and charging the first capacitor to obtain a rising slope and a V1-2Proportional ramp waveform, i.e. voltage V across the first capacitorCS：
The peak values of primary side inductive currents corresponding to different output loads of the isolation power supply are different, and the adjustment of the K value can be suitable for different conditions. Different systems can calculate a reasonable K value according to the magnitude of the inductance current peak value which is set as required, so that the following relation is established:
under the above relationship, we can obtain:
i.e. with respect to the conventional primary sampling resistor RCS2If we set up
Then the setting of the value of K is equivalent to R in the conventional mannerCS2The setting of (3) can be set according to the maximum load requirement of practical application, thereby realizing different peak current control of different K pairs. And as shown in the above equation, once the system requirement is determined, K is a constant, so the K value in the present invention is equal to R in the conventional secondary control architectureCS2The function of (2) realizes the replacement.
The theory above can be essentially considered to be that the peak current of the primary side inductor is controlled by controlling the turn-on time of the primary side power tube I108, and for accurate control, the inductor current needs to reach 0 every switching period, and V is measured every timeCSThe waveform rising process of the invention needs to start from 0 voltage, so the invention is suitable for the isolated power supply of discontinuous current mode (DCM mode).
The magnitude of the K value is controlled by the current programming modulation unit I113, and three specific embodiments are given below to realize the adjustment of the K value, but the adjustment manner of the K value is not limited to the following three embodiments.
In the embodiment, the adjustment of the value K is achieved by adjusting the capacitance value of the first capacitor, as shown in fig. 3, which is a schematic diagram of the control architecture of the embodiment, wherein the primary side secondary side signal transmission unit I106 and the primary side control unit I107 of the control module are not shown in fig. 3, and are shown in fig. 2.
During the conduction period of the primary power tube I108, the voltage sampling interval control logic circuit I207 controls the voltage V at the two ends of the secondary winding of the transformer at the sampling corresponding moment1-2And converting the sampled voltage into current through a voltage-to-current conversion circuit I208 to charge a first capacitor, which may be a programmable capacitor I206 or a series of programmable capacitor arrays in this embodiment, wherein the capacitance of the first capacitor is controlled by a programmable modulation unit I113, and its magnitude determines V during the inductor current monitoringCSBy using the peak inductor current comparator I201 to VCSAnd a system set peak inductor current threshold voltage VCSPKAnd performing comparison to control the turn-off of the primary side power tube I108. Due to VCSAnd VCSPKThe comparison determines the turn-on time of the primary inductor, which in fact is the inductance of the first capacitor, and the corresponding turn-on time of the primary power tube, which is the peak current of the primary inductor. The appropriate peak current of the transformer can be controlled by reasonably setting the inductance value of the first capacitor, and compared with the traditional control mode with a sampling resistor, the first capacitor has the function equivalent to a primary sampling resistor RCS2。
The peak inductor current comparator I201 is used for comparing the current monitoring information V at the input endCSAnd a peak current target value V of the system controlCSPKThereby controlling the peak inductor current of the transformer. When the primary power tube is opened, the voltage V on the first capacitorCSWill rise from 0 to up when VCSIs equal to the system control target value VCSPKWhen the current reaches the peak value set by the system, the primary side power tube turn-off signal is fed back to the primary side control unit I107 through the primary side signal transmission unit I106 by the secondary side control unit I105 in the control module, so that the primary side power tube I108 is turned off, and the primary side inductive current is accurately controlled by the secondary side. In some embodiments, a capacitance reset control I209 is also provided to perform reset control on the first capacitance.
Example III by adjusting with VCSThe voltage value of the threshold voltage for comparison realizes adjustment of the K value, as shown in fig. 4 is a schematic diagram of the control architecture of the present embodiment, and compared with fig. 3 of the second embodiment, the current programming modulation unit I113 adopts the programming resistor I212 to realize control of the peak current threshold, which has a similar function as the capacitor programming in the second embodiment, and the system sets a peak current target value VCSPKThe voltage division resistance value V is obtained by dividing the voltage by the resistors I211 and I212SETAnd VCSFor comparison, I212 is a programming resistor, whose resistance value can be adjusted by the current programming modulation unit I113, thereby changing VSETThe resistance value of (2). At VCSUnder the condition of unchanged rising slope, V is changed by adjusting different resistance values of the programming resistor I212SETAnd VCSPKThe peak value inductance current detection is realized by different proportionality coefficients. The control of the peak current of the transformer is realized by controlling the turn-on time of the primary power tube, and in a closed loop system, the peak currents corresponding to different output loads are different, so the target value V of the peak current determined by the systemCSPKThe loop can be adjusted in real time in relation to the output load.
In the fourth embodiment, the voltage V at two ends of the secondary inductor of the transformer is adjusted1-2The difference between the embodiment and the third embodiment is that the current programming modulation unit I113 in the embodiment adjusts the resistance value of the resistor I213 through resistance programming, and the resistor I213 is used to control the voltage-to-current conversion scaling factor in the voltage-to-current conversion circuit I208, thereby controlling VCSTo achieve the desired control of the primary side power tube on-time.
The three embodiments described above provide the schemes that the current programming modulation unit I113 is programmed and controlled by different ways to obtain the K value, and theoretically, only the reasonable setting of the K value satisfies the requirement
The primary side sampling resistor R in the traditional secondary side control framework can be completely replacedCS2Thereby passing through the secondary side V1-2The voltage realizes real-time monitoring and control on the primary side inductive current and realizes accurate control on the turn-off of the primary side power tube I108. The invention controls the peak current of the primary side inductor and is also equivalent to the peak current of the secondary side inductor of flyback, and N is V due to individual difference of processing technology in actual batch application1-2If the ratio of the VIN and the VIN has a certain error, the invention passes through V1-2The controlled current information has a certain error corresponding to the primary side peak current, but if only the secondary side flyback peak current is considered, the influence of N just influencesCancellation is good. The secondary side sampling information has a certain error on the primary side inductance current information sampling, but when the secondary side sampling information is converted into the secondary side peak current through the turn ratio, the influence of the turn ratio on the secondary side peak current can be counteracted, so that the influence of the turn ratio micro-variation on the maximum output current capability of the system can be ignored, the control is considered to be approximate primary side peak inductance current control, and the influence of the deviation of N on the control system can be ignored. Compared with the accurate control of the primary side peak current, the method has more accurate control of the secondary side peak current, more effective and accurate control of the output full load capacity and more accurate and more advantageous control of the overload point.
The process of the present invention for obtaining the information of the output load current to control the on/off of the primary side switching tube I108 is described next, since the present invention is based on the discontinuous current mode to realize the control of DCM, the secondary side can pass through V1-2The secondary side inductance follow current time is easily obtained, and therefore the duty ratio D of the secondary side follow current time in the whole period is easily obtained. When the primary side inductive current reaches the peak value set by the system, the output load current calculation module I202 in the information processing unit I114 obtains the secondary side inductive current peak value according to the primary side inductive current peak value, and V is measured in each periodCSThe peak value sampling of the secondary side obtains the peak current of the secondary side, and theoretically, the peak current of the secondary side is obtained according to the previous relational expression:
LS_PK＝VCS_PK×K′
wherein VCS_PKIs V in the switching periodCSK' is a coefficient corresponding to the voltage to secondary peak current transition, which is also a constant related to K and Lp. The output load current can be derived:
therefore, the invention does not need the secondary side sampling resistor R of the traditional secondary side control frameworkCS1The output load current of the isolated power supply can be easily known, and the secondary side sampling resistor R is replacedCS1The function of (1).
Secondary sampling resistor R used in traditional secondary control frameworkCS1Sampling output current and summing RCS1The product of the self-resistance is converted into the voltage of the SENSE1, and the current information contained in the voltage of the SENSE1 is compared with the output voltage information contained in the feedback signal FB to control the opening of the primary power tube I108 and the peak current of the primary power tube I108. The feedback voltage FB is obtained by sampling the output voltage of the isolated power supply, and as shown in fig. 2, a resistance sampling mode may be adopted, and two voltage dividing resistors I103 and I104 are connected in series between the output voltage of the isolated power supply and ground, and a series point of the two voltage dividing resistors outputs the feedback voltage FB.
According to the invention, the secondary side inductance current peak value information and the secondary side conduction time duty ratio are obtained through the processing of the information processing unit I114, so that the output load current information can be calculated, and the more accurate the secondary side peak value current control is, the more accurate the maximum output load capacity Io is, and the whole performance parameters of the system can be improved. And then, the output load current information is used for generating a corresponding signal through calculation processing to replace a SENSE1 voltage in a traditional secondary side control framework to be compared with a feedback signal FB for system control, and several specific modes for system control by using the output load current information are given below. Firstly, a constant current function (namely, a CC function) can be realized by using the monitored load current information, the CC function unit I204 controls the primary side inductance current under the action of the secondary side control unit I105 according to the monitored load current information, and the closed-loop control ensures that the load current is constant. In addition, output overload protection can be realized by using the monitored current peak value information of the primary side inductor, when the monitored load current exceeds the set threshold current value of the output overload protection circuit I203, the output overload protection circuit I203 can output a signal of system error, the system can enter a protection state, and the primary side power tube is not allowed to be started by controlling the primary side power tube to be kept off, so that the abnormal state of the system is protected. In addition, other current related functions, such as internal line voltage compensation, output line compensation and the like, can be completed by utilizing the monitored load current information, the current related functions are common in the switching power supply and are not described one by one, and the method is characterized in that the functions are achieved by utilizing a secondary side to sample the load current and realizing no sampling resistor.
As described above, in an existing control system, it is usually necessary to sample peak current information of a primary inductor of a transformer and output load information of a secondary, the secondary control system implements closed-loop control on the entire power supply system by controlling the turn-on of a primary power tube and the peak current of the power tube, a primary signal transmission unit I106 in a control module is used to transmit a signal of a secondary control unit I105 to a primary control unit I107, so as to implement communication control of primary and secondary information, and the primary signal transmission unit I106 and the secondary signal transmission unit I106 can be implemented in various manners such as optical coupling, capacitive coupling isolation transmission, or transformer magnetic coupling isolation transmission.
In summary, in one aspect, the primary current monitoring unit I112 samples the voltage V across the secondary winding of the transformer during the conduction period of the primary power tube I1081-2The method for sampling and monitoring the transformer inductive current is realized by the correlation corresponding relation and the programming function of external programming control, and the monitoring information of the transformer peak inductive current can be obtained and processed without a current sampling resistor; on the other hand, the output load current information can be calculated through the secondary side peak current information and the secondary side on-time duty ratio, the primary side inductance current information and the output load current information are obtained without setting a sampling resistor and are used for carrying out peak current mode loop control, and the secondary side can accurately control the current. Compared with the traditional control mode, the invention can save the current sampling resistor and realize higher system efficiency.
In order to obtain the information of the peak current of the primary inductor of the transformer, control the turn-off of the primary switch tube I108, thereby controlling the peak current of the transformer and realizing the rough control of the output load current of the system, in the embodiment, the voltage V at two ends of the secondary winding of the transformer is used1-2Charging the first capacitor after converting into corresponding current, voltage V on the first capacitorCSIt represents the primary inductor current information of the isolated power supply and simultaneously utilizes the current programming modulation unitThe value K of the I113 is adjusted by combining with reasonable configuration of the secondary voltage monitoring primary current unit I112, so that the method can be suitable for various peak value settings of primary inductive current. Then VCSThe information is output to the information processing unit I114 for processing, and the information processing unit I114 receives VCSAfter the signal according to VCSThe peak value of the voltage-stabilizing resistor can realize that the primary side sampling resistor R is not neededCS2Meanwhile, a peak current mode control mode of the system is realized. When V isCSWhen the represented current information rises to the set peak current controlled by the closed loop of the system, the information processing unit I114 outputs a corresponding signal to send a signal for turning off the primary power tube I108 through the secondary control unit I105, so as to control the primary power tube I108 to be turned off. When in use
V produced by the inventionCSThe controlled turn-on time of the primary power tube is equivalent to that of a primary sampling resistor R in the traditional modeCS2Controlled on-time, so that R is not requiredCS2Under the condition, the secondary side can effectively obtain the information of the primary side inductive current, the real-time turn-off control of the primary side power tube I108 is realized, and the accurate control of the peak inductive current of the transformer is realized.
In order to obtain the information of the output load current to control the primary side switching tube I108 to be opened and control the peak current of the primary side power tube I108, the invention provides that the voltage V at two ends of the secondary winding of the transformer is used1-2Obtaining the follow current time of the secondary inductor so as to obtain a duty ratio D, and obtaining a peak value L of the secondary inductor current according to the peak value of the primary inductor current when the primary inductor current reaches a peak value set by a systemS_PKCombining D and LS_PKCalculating output load current
The output load current information is compared with the output voltage information to control the primary power tube I108 to be opened and control the peak current of the primary power tube I108, and the method can also be used for realizing the functions of output overload protection, constant current, line voltage compensation and the like.
Although the embodiment takes a flyback power supply as an example, the invention is not limited in scope, and is applicable to an isolated power supply including a transformer; in addition, the embodiment of the present invention has been described only by way of example for the adjustment of the K value and the application of the output load current, but it should be understood by those skilled in the art that other structures and methods may be applied to the present invention for realizing the respective possible functions, that variations and modifications are possible for the disclosed embodiment, that other possible alternative embodiments and equivalent variations of the devices in the embodiments may be made by those skilled in the art, and that insubstantial changes or modifications made by those skilled in the art without departing from the spirit of the present invention shall fall within the protection scope of the claims of the present invention.
Claims (10)
1. A secondary side control method of an isolation power supply is disclosed, wherein the isolation power supply is based on an interrupted current mode and comprises a transformer and a primary side power tube, the transformer comprises a primary side inductor and a secondary side inductor, and the primary side power tube is connected with the primary side inductor of the transformer in series; the method for controlling the secondary side of the isolation power supply is characterized by comprising the following steps of controlling the primary side power tube to be turned on and turned off:
a1, detecting the voltages at two ends of the secondary inductor of the transformer during the turn-on period of the primary power tube, wherein the ratio of the input voltage of the isolation power supply to the voltages at two ends of the secondary inductor of the transformer is the turn ratio of the primary winding and the secondary winding of the transformer, and the primary inductive current of the isolation power supply is positively correlated with the input voltage of the isolation power supply, so that the primary inductive current information of the isolation power supply can be obtained by processing the detected voltages at two ends of the secondary inductor of the transformer;
a2, judging whether the primary side inductive current of the isolation power supply reaches the peak value according to the primary side inductive current information of the isolation power supply obtained in the step A1, and turning off the primary side power tube when the primary side inductive current of the isolation power supply reaches the peak value;
the method for controlling the opening of the primary side power tube comprises the following steps:
b1, detecting the voltage at two ends of the secondary side inductor of the transformer and acquiring the duty ratio D of the secondary side freewheeling time in one switching period;
b2, obtaining the peak voltage of the voltage at the two ends of the secondary inductor of the transformer and converting the peak voltage into secondary peak current LS_PKThen the output load current of the isolated power supply is
B3, sampling the output voltage of the isolation power supply to obtain a feedback voltage, processing the output load current of the isolation power supply to obtain a voltage signal containing the output load current information of the isolation power supply, comparing the voltage signal with the feedback voltage, and controlling the switching state of the primary side switching tube according to the comparison result.
2. The secondary side control method of the isolated power supply of claim 1, wherein in the step a1, the detected voltage across the secondary side inductor of the transformer is converted into a current signal, then a first capacitor is charged, the voltage across the first capacitor is compared with a set threshold voltage, and when the voltage across the first capacitor is greater than the threshold voltage, it indicates that the primary side inductor current of the isolated power supply reaches a peak value, and a signal for turning off the primary side power tube is generated.
3. The method for controlling the secondary side of an isolated power supply of claim 2, wherein the peak value of the primary side inductor current is different for different output loads of the isolated power supply, and the different peak values of the primary side inductor current are adapted by three methods including but not limited to:
the method comprises the steps of firstly, adjusting the capacitance value of the first capacitor;
adjusting the voltage value of the threshold voltage;
and thirdly, adjusting the proportionality coefficient of the voltage at the two ends of the secondary inductor of the transformer converted into the current signal.
4. The secondary side control method of the isolated power supply according to any one of claims 1 to 3, wherein the primary side inductor current of the isolated power supply is controlled according to the output load current of the isolated power supply obtained in the step B2, so that the output load current of the isolated power supply is kept constant; and comparing the output load current of the isolation power supply with a set overload protection threshold current, and controlling the primary side switching tube to be kept off to realize output overload protection when the output load current exceeds the overload protection threshold current.
5. A secondary side control system of an isolation power supply is disclosed, wherein the isolation power supply is based on an interrupted current mode and comprises a transformer, a primary side power tube and a secondary side diode, one end of a primary side winding of the transformer is connected with an input voltage of the isolation power supply, and the other end of the primary side winding of the transformer is grounded after passing through the primary side power tube; one end of a secondary winding of the transformer is connected with the anode of the secondary diode, and the other end of the secondary winding of the transformer is grounded; the cathode of the secondary side diode outputs the output voltage of the isolation power supply, and the output voltage of the isolation power supply is sampled to obtain a feedback voltage;
it is characterized in that the secondary side control system of the isolation power supply is used for controlling the on-off of the primary side power tube and comprises a primary side current detection module, an information processing unit and a control module,
the input end of the primary side current detection module is connected with the voltage at two ends of the secondary side inductor of the transformer and is used for generating an output signal containing the current information of the primary side inductor of the isolation power supply; the information processing unit is used for judging whether the primary side inductive current of the isolation power supply reaches a peak value according to the output signal of the primary side current detection module, and controlling the control module to switch off the primary side power tube when the primary side inductive current of the isolation power supply reaches the peak value;
the information processing unit is also used for calculating a duty ratio D of secondary freewheeling time in one switching period according to the voltage at two ends of the secondary inductor of the transformer detected by the primary current detection module, and calculating a secondary peak current L according to the peak voltage of the voltage at two ends of the secondary inductor of the transformer detected by the primary current detection moduleS_PKThereby to makeObtaining an output load current of the isolated power supply as
Generating a voltage signal containing output load current information of the isolation power supply and outputting the voltage signal to the control module; and the control module compares the voltage signal containing the output load current information of the isolation power supply with the feedback voltage and controls the switching state of the primary side power tube according to the comparison result.
6. The secondary side control system of the isolated power supply of claim 5, wherein the primary side current detection module comprises a secondary side voltage monitoring primary side current unit, and the information processing unit comprises a peak inductor current comparator;
the input end of the secondary voltage monitoring primary current unit is connected with two ends of a secondary winding of the transformer and is used for acquiring voltages at two ends of a secondary inductor of the transformer, converting the voltages into corresponding currents and then charging a first capacitor;
and when the voltage of the first input end of the peak inductive current comparator is greater than that of the second input end of the peak inductive current comparator, the peak inductive current comparator generates a turn-off control signal and turns off the primary power tube through the control module.
7. The isolated power supply secondary side control system as claimed in claim 6, wherein the primary side current detection module further comprises a current programming modulation unit for adjusting a capacitance value of the first capacitor to adjust a rising slope of the voltage at the first input terminal of the peak inductor current comparator.
8. The isolated power supply secondary control system of claim 6, wherein the primary current detection module further comprises a current programming modulation unit, the current programming modulation unit configured to adjust the voltage value of the peak inductor current threshold voltage.
9. The isolated power supply secondary side control system of claim 6, wherein the primary side current detection module further comprises a current programming modulation unit, and the current programming modulation unit is configured to adjust a ratio coefficient of a voltage across the transformer secondary side inductor to a corresponding current, so as to adjust a rising slope of the voltage at the first input terminal of the peak inductor current comparator.
10. The secondary control system of the isolated power supply according to any one of claims 5 to 9, wherein the information processing unit further comprises a constant current control circuit and an output overload protection circuit, the constant current control circuit controls the primary side inductor current of the isolated power supply according to the output load current of the isolated power supply, so that the output load current of the isolated power supply is kept constant; the output overload protection circuit compares the output load current of the isolation power supply with a set overload protection threshold current, and controls the primary side switching tube to be kept off through the control module to realize output overload protection when the output load current exceeds the overload protection threshold current.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115226270A (en) * | 2022-09-16 | 2022-10-21 | 广东高斯宝电气技术有限公司 | Constant current control circuit of LED power supply |
| CN115912936A (en) * | 2023-01-03 | 2023-04-04 | 成都智融微电子有限公司 | Flyback switching power supply circuit, flyback switching power supply control method and power supply device |
| CN118137856A (en) * | 2024-05-08 | 2024-06-04 | 茂睿芯（深圳）科技有限公司 | Control device for switching power supply and switching power supply |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20060284567A1 (en) * | 2005-06-16 | 2006-12-21 | Active-Semi International Inc. | Primary side constant output voltage controller |
| CN101925237A (en) * | 2010-08-20 | 2010-12-22 | 杭州电子科技大学 | Primary constant-current control device of isolated type flyback converter |
| US20170033698A1 (en) * | 2015-07-31 | 2017-02-02 | Texas Instruments Incorporated | Flyback converter with secondary 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 |
| CN107579670A (en) * | 2017-09-19 | 2018-01-12 | 东南大学 | A kind of constant pressure output control system of synchronous rectification primary side feedback flyback power supply |
| CN108539986A (en) * | 2017-12-15 | 2018-09-14 | 杰华特微电子（杭州）有限公司 | A kind of inverse-excitation type switch power-supply |
| CN108667302A (en) * | 2017-03-28 | 2018-10-16 | 杰华特微电子（杭州）有限公司 | A kind of isolated switching circuit and its control method |
| CN109995254A (en) * | 2017-12-29 | 2019-07-09 | 东南大学 | A method of improving synchronous rectification primary side feedback flyback power supply dynamic property |
| US10622904B1 (en) * | 2019-03-26 | 2020-04-14 | Infineon Technologies Ag | Isolated feedback techniques for a flyback voltage converter |
-
2020
- 2020-10-21 CN CN202011131735.XA patent/CN114389454B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20060284567A1 (en) * | 2005-06-16 | 2006-12-21 | Active-Semi International Inc. | Primary side constant output voltage controller |
| CN101925237A (en) * | 2010-08-20 | 2010-12-22 | 杭州电子科技大学 | Primary constant-current control device of isolated type flyback converter |
| US9621053B1 (en) * | 2014-08-05 | 2017-04-11 | Flextronics Ap, Llc | Peak power control technique for primary side controller operation in continuous conduction mode |
| US20170033698A1 (en) * | 2015-07-31 | 2017-02-02 | Texas Instruments Incorporated | Flyback converter with secondary side regulation |
| CN108667302A (en) * | 2017-03-28 | 2018-10-16 | 杰华特微电子（杭州）有限公司 | A kind of isolated switching circuit and its control method |
| CN107579670A (en) * | 2017-09-19 | 2018-01-12 | 东南大学 | A kind of constant pressure output control system of synchronous rectification primary side feedback flyback power supply |
| CN108539986A (en) * | 2017-12-15 | 2018-09-14 | 杰华特微电子（杭州）有限公司 | A kind of inverse-excitation type switch power-supply |
| CN109995254A (en) * | 2017-12-29 | 2019-07-09 | 东南大学 | A method of improving synchronous rectification primary side feedback flyback power supply dynamic property |
| US10622904B1 (en) * | 2019-03-26 | 2020-04-14 | Infineon Technologies Ag | Isolated feedback techniques for a flyback voltage converter |
Non-Patent Citations (1)
| Title |
|---|
| 王归新，等: "双端DCM模式反激变换器变压器变比研究", 《电气开关》, vol. 55, no. 4, 15 August 2017 (2017-08-15), pages 30 - 32 * |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115226270A (en) * | 2022-09-16 | 2022-10-21 | 广东高斯宝电气技术有限公司 | Constant current control circuit of LED power supply |
| CN115226270B (en) * | 2022-09-16 | 2023-01-24 | 广东高斯宝电气技术有限公司 | Constant current control circuit of LED power supply |
| CN115912936A (en) * | 2023-01-03 | 2023-04-04 | 成都智融微电子有限公司 | Flyback switching power supply circuit, flyback switching power supply control method and power supply device |
| CN118137856A (en) * | 2024-05-08 | 2024-06-04 | 茂睿芯（深圳）科技有限公司 | Control device for switching power supply and switching power supply |
| CN118137856B (en) * | 2024-05-08 | 2024-08-16 | 茂睿芯（深圳）科技有限公司 | Control device for switching power supply and switching power supply |
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