WO2013060162A1 - Method and device for controlling resonant converter - Google Patents

Method and device for controlling resonant converter Download PDF

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Publication number
WO2013060162A1
WO2013060162A1 PCT/CN2012/077951 CN2012077951W WO2013060162A1 WO 2013060162 A1 WO2013060162 A1 WO 2013060162A1 CN 2012077951 W CN2012077951 W CN 2012077951W WO 2013060162 A1 WO2013060162 A1 WO 2013060162A1
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WO
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Prior art keywords
signal
analog
digital
compensation
compensation signal
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PCT/CN2012/077951
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French (fr)
Chinese (zh)
Inventor
王明金
万正海
张伟
刘辉
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中兴通讯股份有限公司
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Publication of WO2013060162A1 publication Critical patent/WO2013060162A1/en

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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
    • 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
    • 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
    • H02M3/337—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 in push-pull configuration
    • H02M3/3376—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 in push-pull configuration with automatic control of output voltage or current
    • 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
    • H02M1/0048—Circuits or arrangements for reducing losses
    • H02M1/0054—Transistor switching losses
    • H02M1/0058—Transistor switching losses by employing soft switching techniques, i.e. commutation of transistors when applied voltage is zero or when current flow is zero
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
    • Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Definitions

  • the present invention relates to the field of communications, and in particular to a control method and apparatus for a resonant converter.
  • BACKGROUND OF THE INVENTION High efficiency, high power and high density are an important development trend of power electronic products. LLC (abbreviation of Lr, Lm, Cr, which represents the resonant inductance, magnetizing inductance and resonant capacitance in the resonance parameters, respectively).
  • LLC abbreviation of Lr, Lm, Cr, which represents the resonant inductance, magnetizing inductance and resonant capacitance in the resonance parameters, respectively.
  • the resonant converter has outstanding advantages in terms of conversion efficiency and power density, and thus many switching power supply industry personnel Favor, specifically, the advantages of the LLC resonant converter include the following three points:
  • the operating frequency of the LLC resonant converter can be made relatively high, so that the volume of the converter can be effectively reduced, the cost of manufacturing the converter can be reduced, and the power density of the converter can be improved;
  • step S102 determining the operating state of the LLC resonant converter, if the LLC resonant converter is turned on and no fault occurs, step S104 is performed, otherwise, S112 is performed instead;
  • S104 The sampling circuit of the digital processor samples the output signal of the resonant conversion circuit;
  • S106 the digital processor compares according to the preset given amount and the sampled signal, thereby obtaining a voltage compensation control signal;
  • S108 The digital processor compares and obtains the obtained voltage compensation control signal to determine a control mode of the LLC resonant converter, and generates a corresponding pulse width modulation signal.
  • the pulse width modulation module in the digital processor blocks the driving circuit, and the LLC resonant circuit stops working, and the process ends. It can be seen from the above method that in an interrupt algorithm cycle, the digital processor needs to realize the voltage output of the compensation loop and convert the voltage output into a corresponding pulse width modulation signal to complete a complete DC/DC converter. With constant pressure, current limit, constant power and even current limit retraction. At present, the compensation loop is executed in the algorithm interrupt process of the digital processor. Due to the cost limitation, the frequency of the digital processor used in the control of the LLC resonant converter is generally not very high, and the maximum of the LLC resonant converter is high. The operating frequency is generally above 200KHz or even 300KHz.
  • the present invention provides a control method and apparatus for a resonant converter to at least solve the problem that it is difficult for a digital processor to perform a feedback control operation within a pulse width modulation period when the resonant converter operates at a high frequency.
  • the feedback control produces a delay problem.
  • a control method for a resonant converter comprising: sampling an analog output signal of a resonant conversion circuit; and obtaining a simulated compensation signal by the sampled signal through an analog compensation circuit; converting the analog compensation signal The digital compensation signal is input, and the resonance conversion circuit is feedback-controlled according to the digital compensation signal.
  • the step of obtaining the analog compensation signal by the sampled signal through the analog compensation circuit comprises: obtaining the voltage analog compensation signal by the sampled voltage signal through the voltage loop compensation circuit; or obtaining the sampled current signal through the current loop compensation circuit.
  • Current analog compensation signal Preferably, the step of obtaining the analog compensation signal by the sampled signal through the analog compensation circuit comprises: obtaining the voltage analog compensation signal by the sampled voltage signal through the voltage loop compensation circuit, and obtaining the sampled current signal through the current loop compensation circuit.
  • the current analog compensation signal is compared with the current analog compensation signal; if the voltage analog compensation signal is smaller than the current analog compensation signal, the voltage analog compensation signal is output as an analog compensation signal; otherwise, the current analog compensation signal is used as The analog compensation signal is output.
  • the step of converting the analog compensation signal into the digital compensation signal comprises: performing analog-to-digital conversion of the analog compensation signal to obtain a digital signal; comparing the value of the digital signal with a predetermined threshold; and generating the result according to the comparison by using a corresponding control method A pulse width modulated signal that is a digital compensation signal.
  • the step of generating a pulse width modulation signal as a digital compensation signal by using a corresponding control manner according to the result of the comparison comprises: generating a pulse width modulation as a digital compensation signal by using a phase shifting method when the digital signal is smaller than the first predetermined threshold a signal; when the digital signal is greater than or equal to the first predetermined threshold is less than the second predetermined threshold, using a phase shift modulation method to generate a pulse width modulation signal as a digital compensation signal; when the digital signal is greater than or equal to a second predetermined threshold, using a frequency modulation method to generate A pulse width modulated signal of a digitally compensated signal.
  • a control apparatus for a resonant converter comprising: a resonant conversion circuit configured to output an analog output signal; a sampling circuit configured to sample an analog output signal of the resonant conversion circuit; The circuit is configured to compensate the sampled signal to obtain an analog compensation signal; the digital processor is configured to convert the analog compensation signal into a digital compensation signal, and perform feedback control on the resonance conversion circuit according to the digital compensation signal.
  • the analog compensation circuit comprises: a voltage loop compensation circuit configured to compensate the sampled voltage signal to obtain a voltage analog compensation signal; or a current loop compensation circuit configured to compensate the sampled current signal to obtain a current analog compensation signal.
  • the analog compensation circuit comprises: a voltage loop compensation circuit, configured to compensate the obtained voltage signal to obtain a voltage analog compensation signal; and a current loop compensation circuit configured to compensate the sampled current signal to obtain a current analog compensation signal; , the voltage analog compensation signal is compared with the current analog compensation signal; if the voltage analog compensation signal is smaller than the current analog compensation signal, the voltage analog compensation signal is output as an analog compensation signal; otherwise, the current analog compensation signal is used as an analog compensation The signal is output.
  • the digital processor comprises: an analog to digital conversion unit configured to perform analog to digital conversion of the analog compensation signal to obtain a digital signal; a comparison unit configured to compare the value of the digital signal with a predetermined threshold; generating a unit, configured to compare The result obtained uses a corresponding control method to generate a pulse width modulated signal for feedback control.
  • the control device of the resonant converter further includes: a driving circuit configured to generate a control signal according to the pulse width modulation signal and output the signal to the resonance conversion circuit.
  • a digital-analog hybrid resonant converter control method is adopted, and the compensation of the loop is completed by the analog compensation circuit, so that the digital processor only needs to convert the output of the analog compensation circuit into a corresponding pulse width modulation signal. Therefore, the time for the digital processor to perform the feedback control operation is shortened, and the resonant circuit can be controlled in each pulse width modulation period, thereby solving the problem that the digital processor is difficult in the case where the resonant converter operates at a high frequency.
  • the delay of the feedback control caused by performing a feedback control operation in a pulse width modulation period achieves the purpose of controlling the resonant circuit in each pulse width modulation period, thereby ensuring the resonance The stability and real-time control of the circuit.
  • FIG. 1 is a flow chart of a control method of a resonant converter according to the prior art
  • FIG. 2 is a block diagram showing a preferred configuration of a control device for a resonant converter according to an embodiment of the present invention
  • FIG. 1 is a flow chart of a control method of a resonant converter according to the prior art
  • FIG. 2 is a block diagram showing a preferred configuration of a control device for a resonant converter according to an embodiment of the present invention
  • FIG. 1 is a flow chart of a control method of a resonant converter according to the prior art
  • FIG. 2 is a block diagram showing a preferred configuration of a control device for a resonant converter according to an embodiment of the present invention
  • FIG. 2 is a block diagram
  • FIG. 4 is a schematic diagram showing a relationship between a voltage control signal and a switching frequency corresponding to three control modes according to an embodiment of the present invention; A schematic diagram of the relationship between the voltage control signal and the duty ratio corresponding to the three control modes according to the embodiment of the present invention;
  • FIG. 6 is a preferred flowchart of the control device of the resonant converter according to the embodiment of the present invention; A preferred block diagram of a control method of a resonant converter according to an embodiment of the present invention;
  • FIG. 8 is a schematic diagram of a preferred voltage loop compensation circuit according to an embodiment of the present invention; 9 is a schematic diagram of a preferred current loop compensation circuit according to an embodiment of the present invention;
  • FIG. 10 is a schematic diagram of a pulse width modulation signal when operating in a frequency modulation interval according to an embodiment of the present invention
  • FIG. 11 is a diagram of an operation according to an embodiment of the present invention.
  • Fig. 12 is another preferred flow chart of the control method of the resonant converter according to an embodiment of the present invention.
  • the present invention provides a preferred control device for a resonant converter, the device comprising: a resonant converter circuit 202; a sampling circuit 204 directly connected to the resonant converter circuit 202, or through load and resonance
  • the conversion circuit 202 is connected; the analog compensation circuit 206 is connected to the sampling circuit 204; the digital processor 208 is connected to the analog compensation circuit 206; and the drive circuit 210 is connected to the resonance conversion circuit 202 and the digital processor 208.
  • the digital processor 208 includes: an analog-to-digital conversion unit 2082 connected to the analog compensation circuit 206; a generating unit 2086 connected to the driving circuit 210; a comparison unit 2084 connected to the analog-to-digital conversion unit 2082 and the generating unit 2086;
  • the unit 2088 is connected to the analog compensation circuit 206.
  • the compensation of the loop is accomplished by the analog compensation circuit 206 such that the digital processor 208 only needs to convert the output of the analog compensation circuit 206 to a corresponding pulse width modulated signal, thereby shortening the number.
  • the processor 208 interrupts the execution time of the algorithm, and solves the problem that the delay of the feedback control caused by the digital processor being difficult to perform a feedback control operation within one pulse width modulation period when the resonant converter operates at a high frequency. It achieves the purpose of controlling the resonant circuit in each pulse width modulation period, thereby ensuring the stability and real-time control of the resonant circuit.
  • the present invention provides a preferred method for controlling a resonant converter.
  • the sampling signal is used as a voltage signal as an example, but the present invention is not limited thereto. Therefore, the sampling signal may also be a current signal.
  • FIGS. 2 and 3 which includes steps S1-S8:
  • S1 At the beginning of each pulse width modulation period interrupt routine, the operating state of the LLC resonant converter is judged. If the LLC resonant converter is turned on and no fault occurs, step S2 is performed, otherwise, S8 is performed instead.
  • S2 The sampling circuit 204 samples the voltage analog output signal output from the resonance conversion circuit 202 to obtain a voltage ⁇ .
  • the analog compensation circuit 206 gives a given voltage signal V to a given voltage given by the given unit 2088. For comparison, the sampled voltage signal V is obtained based on the comparison result. Compensation is performed to obtain an analog compensation signal Vf , and then the resulting analog compensation signal is output to an analog to digital conversion unit 2082 in the digital processor 208.
  • the analog-to-digital conversion unit 2082 performs analog-to-digital conversion on the analog compensation signal to convert the analog compensation signal to a digital signal, and transmits the obtained digital signal to the comparison unit 2084.
  • the comparing unit 2084 compares the converted digital signal with a predetermined threshold.
  • the generating unit 2086 generates a pulse width modulation signal for the feedback control according to the result of the comparison by using a corresponding control manner.
  • the resonant converter 202 e.g., LLC resonant converter
  • the three phases of phase shifting and frequency modulation and the preset fixed voltage (or current, power, etc.) exist as shown in Figure 4-5. Based on the relationship shown in FIG.
  • the comparing unit 2084 may compare the converted digital signal with a predetermined threshold value, and may include: when the voltage control signal (for example, the digital signal converted in the above step S4) is smaller than the fixed voltage.
  • VI first predetermined threshold
  • the switching frequency of the LLC resonant converter works to keep the maximum value (fmax) unchanged, the phase shift duty ratio changes linearly with the voltage control signal, and the voltage control signal is smaller.
  • the smaller the phase shift duty ratio D is; when the voltage control signal (for example, the digital signal converted in S4) is greater than or equal to the fixed voltage VI but less than the fixed voltage V2 (second predetermined threshold), the frequency shifting phase shift control is used.
  • the phase duty ratio and the switching frequency both vary linearly with the voltage control signal.
  • FIG. 6 further shows a scheme for generating a pulse width modulation signal for the feedback control in the above steps S5 and S6. Specifically, as shown in FIG.
  • the sampling circuit 204 samples the analog compensation signal (Vf), compares the sampled digital signal with a predetermined threshold, and generates a pulse width modulation for the feedback control according to the comparison result using a corresponding control manner. signal.
  • the specific determining step includes: when the digital signal (VO is less than the first predetermined threshold (VI), generating a pulse width modulation signal as the digital compensation signal by using a phase shifting method; when the digital signal is greater than or equal to the first When the predetermined threshold is less than the second predetermined threshold (V2), the phase shift modulation method is used to generate the digital complement Compensating for a pulse width modulation signal of the signal; when the digital signal is greater than or equal to the second predetermined threshold, generating a pulse width modulation signal as the digital compensation signal by using a frequency modulation method.
  • the voltage loop compensation circuit gives a voltage signal given by the given unit 2088 to the quantized and sampled voltage signal. Compare and obtain the error; then pass through a double-zero, three-pole type III compensation amplifier to obtain an amplified and compensated voltage signal.
  • the transfer function of the type III compensation amplifier is as follows:
  • ⁇ ⁇ 1 and ⁇ ⁇ 2 correspond to the two zero position
  • ⁇ ⁇ 1 and ⁇ ⁇ 2 correspond to the two pole position
  • the other pole is the integral at the origin.
  • the digital signal is exemplified by a voltage signal, but does not constitute a limitation of the present invention, and the digital signal may also be a current signal or the like; further, the simulation in the above embodiment
  • the compensation circuit is described by taking a voltage loop compensation circuit as an example.
  • the present invention is not limited thereto, and the analog compensation circuit may further include a current loop compensation circuit, a constant power loop compensation circuit, and a retraction loop compensation circuit.
  • the above transfer function is equally applicable to current loop compensation current.
  • the current loop compensation circuit gives a given current to the given unit 2088 a given amount / g and the sampled current signal /. Compare and obtain the error; then pass through a double-zero, three-pole type III compensation amplifier to obtain an amplified and compensated current signal / .
  • the transfer function of the type III compensation amplifier is as follows:
  • FIG. 10 is a schematic diagram of a pulse width modulation signal when operating in a frequency modulation interval (using a frequency modulation control method).
  • Q1 and Q4 are the super forearm upper tube drive and the lag arm lower tube drive respectively (as shown by the solid line in Figure 10)
  • Q2 and Q3 are the super forearm lower tube drive and the lag arm upper tube drive respectively (as in Figure 10). Shown in dotted line).
  • the effective driving of Q1 and P Q4 (such as the corresponding solid line high level in Figure 10) is exactly the same; the effective driving of Q2 and Q3 (as shown by the corresponding dotted line in Figure 10) It's exactly the same.
  • the upper and lower tubes (Q1 and Q2, Q3 and Q4) of the same bridge arm are effectively driven by 180 degrees, and there is a dead zone in the middle. The dead time is a fixed value.
  • FIG. 11 is a schematic diagram of a pulse width modulation signal when operating in a phase shift interval (including a fixed frequency phase shift control method and a phase shift frequency modulation control method).
  • Q1 and Q4 are the super forearm upper tube drive and the lag arm lower tube drive respectively
  • Q2 and Q3 are the super forearm lower tube drive and the lag arm upper tube drive respectively.
  • the effective driving of Q1 and Q4 is shifted by a certain angle
  • the effective driving of Q2 and Q3 is also shifted by a certain angle. This angle is called the phase shifting angle.
  • the effective drive between the upper and lower tubes of the same bridge arm (for example, Q1 and Q2, Q3 and Q4) is 180 degrees apart, and there is a dead zone between the upper and lower tubes of the same bridge arm. This dead zone can prevent the same bridge arm. A straight-through occurs between the upper and lower tubes, and a soft switch can also be realized.
  • the dead time is not fixed, but changes with load characteristics (including output voltage and load size), and the corresponding relationship is determined by the characteristics of the LLC resonant converter.
  • the size of the dead zone is generally determined according to the size of the phase shift angle. The relationship between them is usually a nonlinear monotonous recursive relationship, that is, the larger the phase shift angle, the larger the dead zone.
  • the relationship between the phase shift angle and the dead zone can be converted into a linear relationship of segments by a straight line fitting method; a table of phase shift angles and dead zones can also be created, and the table can be used to obtain the dead.
  • the size of the area In short, with the flexible and variable characteristics of digital control, the primary switching tube of the transformer can also achieve soft switching when phase shifting or widening control.
  • the driving circuit 210 receives the pulse width modulation signal generated by the generating unit 2086 for feedback control, and amplifies the pulse width modulation signal to generate a control signal, and outputs the control signal to the resonance conversion circuit 202, so that the resonance conversion circuit 202 The circuit works and ends the process.
  • the pulse width modulation module in the digital processor blocks the driving circuit 210, and the LLC resonance conversion circuit 202 stops working, and the process ends.
  • the sampling signal is taken as a voltage signal as an example.
  • the present invention is not limited thereto, and the sampling signal may be a current signal.
  • the present invention also provides a preferred embodiment in order to cope with
  • the analog compensation circuit 206 can include a current loop compensation circuit for compensating the sampled current signal to obtain a current analog compensation signal.
  • the LLC resonant conversion circuit generally does not only have the function of constant voltage in practical applications, it is usually necessary to have functions such as current limiting, and the present invention also provides another preferred embodiment, so as to achieve The signal is processed at the same time as the voltage signal and the current signal. As shown in FIG.
  • the analog compensation circuit 206 includes: a voltage loop compensation circuit 304 for compensating the sampled voltage signal to obtain a voltage analog compensation signal; and a current loop compensation circuit 302 for The sampled current signal is compensated to obtain a current analog compensation signal; the voltage loop compensation circuit 304 and the current loop compensation circuit 302 operate in parallel, the voltage loop compensation circuit 304 acts as a voltage regulator, and the current loop compensation circuit 302 acts as a current limiting function during operation.
  • a comparison circuit 310 configured to compare the voltage analog compensation signal with the current analog compensation signal; if the voltage analog compensation signal is smaller than the current analog compensation signal, the voltage analog compensation signal is used as The analog compensation signal is output; otherwise, the current analog compensation signal is output as the analog compensation signal.
  • the voltage loop compensation circuit 304 when the voltage loop compensation circuit 304 is active, the current loop compensation circuit 302 is in a saturated state, and the output voltage is stable; when the current loop compensation circuit 302 acts, the voltage loop compensation circuit 304 is in a saturated state. At this time, the output current is limited to a certain value.
  • the analog compensation signals of the two are compared, and the output of the analog compensation circuit is selected as small, so that the voltage regulation and the current limiting function can be simultaneously realized. , achieves more efficient control of the resonant converter.
  • the voltage signal and the current signal are taken as an example for description.
  • the present invention is not limited thereto, and the corresponding feedback signal can be changed to implement functions such as constant power and current limiting, and there are multiple loops.
  • the output only needs to be compared by the comparator, and the feedback signal with the smallest error signal is selected to compensate for the control signal, and the control signal is sent to the digital processor for processing.
  • the LLC resonant converter operating modes are as follows: fixed frequency phase shifting, phase shifting frequency modulation, and frequency modulation are described as an example, but the present invention is not limited thereto, for example: half of the LLC resonant converter In the bridge topology, the working modes are: fixed frequency adjustment, frequency modulation, and frequency modulation.
  • the control mode of the LLC resonant converter is similar to that of the fixed-frequency phase shifting, phase shifting frequency modulation, and frequency modulation, and will not be described herein.
  • Embodiment 2 Based on the control device of the preferred resonant converter shown in FIG. 2, the present invention also provides a preferred control method of the resonant converter. As shown in FIG. 12, the specific steps of the method include: S1202: Resonance The analog output signal of the conversion circuit is sampled; S1204: The sampled signal is subjected to an analog compensation circuit to obtain an analog compensation signal;
  • S1206 Convert the analog compensation signal into a digital compensation signal, and perform feedback control on the resonance conversion circuit according to the digital compensation signal.
  • the over analog compensation circuit 206 performs compensation for the loop such that the digital processor 208 only needs to convert the output of the analog compensation circuit 206 to a corresponding pulse width modulated signal, thereby shortening the number.
  • the processor 208 interrupts the execution time of the algorithm, and solves the problem that the delay of the feedback control caused by the digital processor being difficult to perform a feedback control operation within one pulse width modulation period when the resonant converter operates at a high frequency.
  • the present invention also provides a preferred signal compensation method for improving the adaptability of the present invention.
  • the sampled voltage signal is passed through a voltage loop compensation circuit to obtain a voltage analog compensation signal;
  • the current signal is subjected to a current loop compensation circuit to obtain a current analog compensation signal.
  • a different loop compensation circuit is established for the voltage signal and the current signal to cope with different circuit compensation scenarios.
  • the present invention also provides another preferred signal compensation method for improving the adaptability of the present invention.
  • the sampled voltage signal is passed through a voltage loop compensation circuit to obtain a voltage analog compensation signal, and the sample is obtained.
  • the current signal is obtained by the current loop compensation circuit to obtain a current analog compensation signal; the voltage analog compensation signal is compared with the current analog compensation signal; if the voltage analog compensation signal is smaller than the current analog compensation signal, the voltage analog compensation signal is output as an analog compensation signal ; Otherwise, the current analog compensation signal is output as an analog compensation signal.
  • a signal having a smaller error is selected for compensation feedback, thereby achieving a more resonant converter. Effectively controlled to cope with different circuit compensation scenarios.
  • the present invention also provides a preferred way of converting an analog compensation signal into a digital compensation signal in order to achieve a different mode of pulse width modulation.
  • the analog compensation signal is analog-to-digital converted to obtain a digital signal. And comparing the value of the digital signal with a predetermined threshold; and generating a pulse width modulated signal as a digital compensation signal according to the result of the comparison by using a corresponding control manner.
  • more reasonable and effective control of the resonant converter is achieved by determining a particular pulse width modulated signal based on different values of the resulting digital signal.
  • the step of generating a pulse width modulated signal as the digital compensation signal by using a corresponding control manner according to the result of the comparison includes: generating a phase shifting manner when the digital signal is less than a first predetermined threshold a pulse width modulation signal as the digital compensation signal; when the digital signal is greater than or equal to the first When the predetermined threshold is less than the second predetermined threshold, the pulse width modulation signal as the digital compensation signal is generated by the phase shift modulation method.
  • the digital signals are judged by setting different thresholds to generate different modulation modes to meet different modulation requirements, thereby improving the applicability of the present invention.
  • the operating modes of the LLC resonant converter are as follows: fixed frequency phase shifting, phase shifting frequency modulation, and frequency modulation are described as an example, but the present invention is not limited thereto, for example: in the LLC resonant converter In the half-bridge topology, the working modes are: fixed-frequency widening, frequency-modulated widening, and frequency-modulated.
  • the control mode of the LLC resonant converter is similar to that of the fixed-frequency phase shifting, phase shifting frequency modulation, and frequency modulation, and will not be described here.
  • modules or steps of the present invention can be implemented by a general-purpose computing device, which can be concentrated on a single computing device or distributed over a network composed of multiple computing devices. Alternatively, they may be implemented by program code executable by the computing device, such that they may be stored in the storage device by the computing device and, in some cases, may be different from the order herein.
  • the steps shown or described are performed, or they are separately fabricated into individual integrated circuit modules, or a plurality of modules or steps are fabricated as a single integrated circuit module.
  • the invention is not limited to any specific combination of hardware and software.
  • the above is only the preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes can be made to the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and scope of the present invention are intended to be included within the scope of the present invention.

Abstract

A method and device for controlling a resonant converter. The method comprises: sampling an analog output signal of a resonant conversion circuit (202); obtaining an analog compensation signal from the sampled signal through an analog compensation circuit (206); converting the analog compensation signal to a digital compensation signal and performing feedback control on the resonant conversion circuit (202) according to the digital compensation signal. The present invention solves the problem that when the resonant converter works under a high frequency, the feedback control is delayed as the digital processor is incapable of completing a feedback control operation within one pulse width modulation period. Therefore, the present invention is capable of controlling the resonance circuit in each pulse width modulation period, thereby improving the reliability and effectiveness of the resonance circuit.

Description

谐振变换器的控制方法和装置 技术领域 本发明涉及通信领域， 具体而言， 涉及一种谐振变换器的控制方法和装置。 背景技术 高效率高功率高密度是电力电子产品的一个重要的发展趋势。 LLC (Lr， Lm， Cr 的缩写， 它们分别代表谐振参数中的谐振电感、 励磁电感和谐振电容） 谐振变换器由 于在变换效率和功率密度方面具有突出的优势， 从而得到很多开关电源行业人员的青 睐， 具体而言， LLC谐振变换器的优点包括以下三点：  TECHNICAL FIELD The present invention relates to the field of communications, and in particular to a control method and apparatus for a resonant converter. BACKGROUND OF THE INVENTION High efficiency, high power and high density are an important development trend of power electronic products. LLC (abbreviation of Lr, Lm, Cr, which represents the resonant inductance, magnetizing inductance and resonant capacitance in the resonance parameters, respectively). The resonant converter has outstanding advantages in terms of conversion efficiency and power density, and thus many switching power supply industry personnel Favor, specifically, the advantages of the LLC resonant converter include the following three points:
1) LLC谐振变换器的谐振元件工作在正弦谐振状态的时候， 开关管上的电压自然 过零， 在变频的范围内都能够实现原边开关管的零电压开通与关断， 所以电源损耗很 小； 1) When the resonant component of the LLC resonant converter operates in a sinusoidal resonant state, the voltage on the switching transistor naturally crosses zero, and the zero-voltage turn-on and turn-off of the primary-side switching transistor can be realized in the range of the frequency conversion, so the power loss is very high. small;
2)由于电源损耗很小， 所以 LLC谐振变换器的工作频率可以做得比较高， 因此可 有效减小变换器的体积降低制造变换器的成本， 同时提高了变换器的功率密度； 2) Since the power loss is small, the operating frequency of the LLC resonant converter can be made relatively high, so that the volume of the converter can be effectively reduced, the cost of manufacturing the converter can be reduced, and the power density of the converter can be improved;
3)由于 LLC谐振变换器的副边二极管可以实现自然的关断， 因此消除了副边电压 尖峰， 降低了关断所造成的电源损耗。 然而， 由于 LLC谐振变换器在采用低压轻载输出时一般采用的是调宽或者移相的 控制方式， 无论是采用调宽的控制方式还是采用移相的控制方式， 都不能在全负载范 围内很好地实现变压器原边开关管的软开关。 目前， 根据数字控制由于具有很强适应性和灵活性的优点， 并具备直接监控、 处 理并适用系统条件的能力， 还可以通过远程诊断以确保持续的系统可靠性， 实现故障 管理、 自动冗余以及在线升级等功能， 因此数字控制在开关电源领域得到了越来越广 泛的应用。 目前， 通过数字处理器对谐振变换器进行控制的步骤如图 1所示包括： 3) Since the secondary side diode of the LLC resonant converter can achieve natural turn-off, the secondary side voltage spike is eliminated, reducing the power loss caused by the turn-off. However, since the LLC resonant converter generally adopts a control method of widening or phase shifting when using a low-voltage light-load output, neither the widened control method nor the phase shift control method can be used within the full load range. The soft switch of the primary switch of the transformer is well realized. Currently, digital control has the advantages of strong adaptability and flexibility, and the ability to directly monitor, process, and apply system conditions. Remote diagnostics can be used to ensure continuous system reliability, fault management, and automatic redundancy. As well as online upgrades and other functions, digital control has become more and more widely used in the field of switching power supplies. At present, the steps of controlling the resonant converter by the digital processor are as shown in FIG. 1 :
S102: 判断 LLC谐振变换器的工作状态， 如果 LLC谐振变换器处于开机且无故 障发生， 则执行步骤 S104, 否则， 转而执行 S112; S102: determining the operating state of the LLC resonant converter, if the LLC resonant converter is turned on and no fault occurs, step S104 is performed, otherwise, S112 is performed instead;
S104: 数字处理器的采样电路对谐振变换电路的输出信号进行采样； S106: 数字处理器根据预设的给定量和采样得到的信号进行比较， 进而得到电压 补偿控制信号； S104: The sampling circuit of the digital processor samples the output signal of the resonant conversion circuit; S106: the digital processor compares according to the preset given amount and the sampled signal, thereby obtaining a voltage compensation control signal;
S108:数字处理器对得到的电压补偿控制信号进行比较判断确定对 LLC谐振变换 器的控制方式， 生成相应的脉宽调制信号； S110: 驱动电路对上述脉宽调制信号进行放大， 驱动 LLC谐振变换电路工作， 结 束本流程； S108: The digital processor compares and obtains the obtained voltage compensation control signal to determine a control mode of the LLC resonant converter, and generates a corresponding pulse width modulation signal. S110: The driving circuit amplifies the pulse width modulation signal to drive the LLC resonant conversion The circuit works, ending the process;
S112: 数字处理器中的脉宽调制模块封锁驱动电路， LLC谐振电路停止工作， 结 束本流程。 由上述方法可以看出在一个中断算法周期内， 数字处理器需要通过实现补偿环路 的电压输出， 并通过此电压输出转换成相应的脉宽调制信号， 完成一个完整的 DC/DC 变换器应该具备恒压、 限流、 恒功率甚至限流回缩等功能。 目前， 补偿环路都在数字 处理器的算法中断过程中执行， 由于成本的限制， 运用在 LLC谐振变换器控制上的数 字处理器的主频一般不会很高， 而 LLC谐振变换器的最高工作频率一般在 200KHz甚 至 300KHz以上。 由此可知， 由于数字处理器在一个中断算法周期内需要处理的步骤太多， 因此在 谐振变换器频率很高的时候， 在一个脉宽调制周期内数字处理器无法完成对整个反馈 控制运算的处理， 也就不可能在每个脉宽调制周期上都对 LLC谐振变换器进行控制， 从而使得对 LLC谐振变换器的控制产生延时， 进而使得整个环路的相位产生衰减， 环 路带宽变窄， 同时， 对输出直接的影响是使输出电压的峰峰值杂音和电话衡重等指标 很难得到优化。 针对上述的问题， 目前尚未提出有效的解决方案。 发明内容 本发明提供了一种谐振变换器的控制方法和装置， 以至少解决在谐振变换器工作 频率很高的情况下由于数字处理器难以在一个脉宽调制周期内执行完一次反馈控制运 算造成的反馈控制产生延时的问题。 根据本发明的一个方面， 提供了一种谐振变换器的控制方法， 包括： 对谐振变换 电路的模拟输出信号进行采样； 将采样得到的信号经过模拟补偿电路得到模拟补偿信 号； 将模拟补偿信号转换成数字补偿信号， 并根据数字补偿信号对谐振变换电路进行 反馈控制。 优选地， 将采样得到的信号经过模拟补偿电路得到模拟补偿信号的步骤包括： 将 采样得到的电压信号经过电压环补偿电路得到电压模拟补偿信号； 或者将采样得到的 电流信号经过电流环补偿电路得到电流模拟补偿信号。 优选地， 将采样得到的信号经过模拟补偿电路得到模拟补偿信号的步骤包括： 将 采样得到的电压信号经过电压环补偿电路得到电压模拟补偿信号， 以及将采样得到的 电流信号经过电流环补偿电路得到电流模拟补偿信号； 将电压模拟补偿信号与电流模 拟补偿信号进行比较； 若电压模拟补偿信号小于电流模拟补偿信号， 则将电压模拟补 偿信号作为模拟补偿信号进行输出； 否则， 将电流模拟补偿信号作为模拟补偿信号进 行输出。 优选地， 将模拟补偿信号转换成数字补偿信号的步骤包括： 将模拟补偿信号进行 模数转换得到数字信号； 将数字信号的值与预定阈值进行比较； 根据比较得到的结果 采用相应的控制方式生成作为数字补偿信号的脉宽调制信号。 优选地， 根据比较得到的结果采用相应的控制方式生成作为数字补偿信号的脉宽 调制信号的步骤包括： 当数字信号小于第一预定阈值时， 采用移相方式生成作为数字 补偿信号的脉宽调制信号； 当数字信号大于等于第一预定阈值小于第二预定阈值时， 采用移相调频方式生成作为数字补偿信号的脉宽调制信号； 当数字信号大于等于第二 预定阈值时， 采用调频方式生成作为数字补偿信号的脉宽调制信号。 根据本发明的另一方面， 提供了一种谐振变换器的控制装置， 包括： 谐振变换电 路， 设置为输出模拟输出信号； 采样电路， 设置为对谐振变换电路的模拟输出信号进 行采样； 模拟补偿电路， 设置为对采样得到的信号进行补偿得到模拟补偿信号； 数字 处理器， 设置为将模拟补偿信号转换成数字补偿信号， 并根据数字补偿信号对谐振变 换电路进行反馈控制。 优选地， 模拟补偿电路包括： 电压环补偿电路， 设置为对采样得到的电压信号补 偿得到电压模拟补偿信号； 或者电流环补偿电路， 设置为对采样得到的电流信号补偿 得到电流模拟补偿信号。 优选地， 模拟补偿电路包括： 电压环补偿电路， 设置为对采样得到的电压信号补 偿得到电压模拟补偿信号； 电流环补偿电路， 设置为对采样得到的电流信号补偿得到 电流模拟补偿信号； 比较电路， 设置为将电压模拟补偿信号与电流模拟补偿信号进行 比较； 若电压模拟补偿信号小于电流模拟补偿信号， 则将电压模拟补偿信号作为模拟 补偿信号进行输出； 否则， 将电流模拟补偿信号作为模拟补偿信号进行输出。 优选地， 数字处理器包括： 模数转换单元， 设置为将模拟补偿信号进行模数转换 得到数字信号； 比较单元， 设置为将数字信号的值与预定阈值进行比较； 生成单元， 设置为根据比较得到的结果采用相应的控制方式生成用于反馈控制的脉宽调制信号。 优选地， 谐振变换器的控制装置还包括： 驱动电路， 设置为根据脉宽调制信号生 成控制信号， 并输出给谐振变换电路。 在本发明中， 采用一种数模混合的谐振变换器控制方法， 通过模拟补偿电路完成 对环路的补偿， 从而使得数字处理器只需要将模拟补偿电路的输出转换为相应的脉宽 调制信号， 从而缩短了数字处理器执行反馈控制运算的时间， 能够做到在每个脉宽调 制周期内都对谐振电路进行控制， 解决了在谐振变换器工作频率很高的情况下由于数 字处理器难以在一个脉宽调制周期内执行完一次反馈控制运算造成的反馈控制产生延 时的问题， 达到了能够做到在每个脉宽调制周期内都对谐振电路进行控制的目的， 从 而保证了对谐振电路进行控制的稳定性和实时性。 附图说明 此处所说明的附图用来提供对本发明的进一步理解， 构成本申请的一部分， 本发 明的示意性实施例及其说明用于解释本发明， 并不构成对本发明的不当限定。 在附图 中： 图 1是根据现有技术的一种谐振变换器的控制方法的流程图； 图 2是根据本发明实施例的谐振变换器的控制装置的一种优选结构框图； 图 3是根据本发明实施例的谐振变换器的控制装置的另一种优选结构框图； 图 4是根据本发明实施例的三种控制方式对应的电压控制信号和开关频率之间的 关系示意图； 图 5是根据本发明实施例的三种控制方式对应的电压控制信号和占空比之间的关 系示意图； 图 6是根据本发明实施例的谐振变换器的控制装置的一种优选流程图； 图 7是根据本发明实施例的谐振变换器的控制方法的一种优选结构框图； 图 8是根据本发明实施例的一种优选的电压环补偿电路示意图； 图 9是根据本发明实施例的一种优选的电流环补偿电路示意图； 图 10是根据本发明实施例的工作在调频区间时的脉宽调制信号示意图； 图 11是根据本发明实施例的工作在移相区间时的脉宽调制信号示意图； 图 12是根据本发明实施例的谐振变换器的控制方法的另一种优选流程图。 具体实施方式 下文中将参考附图并结合实施例来详细说明本发明。 需要说明的是， 在不冲突的 情况下， 本申请中的实施例及实施例中的特征可以相互组合。 实施例 1 如图 2所示， 本发明提供了一种优选的谐振变换器的控制装置， 该装置包括： 谐 振变换电路 202; 采样电路 204， 直接与谐振变换电路 202连接， 或者通过负载与谐振 变换电路 202连接； 模拟补偿电路 206， 与采样电路 204连接； 数字处理器 208， 与模 拟补偿电路 206连接； 以及， 驱动电路 210， 与谐振变换电路 202和数字处理器 208 连接。 其中， 数字处理器 208包括： 模数转换单元 2082， 与模拟补偿电路 206连接； 生成单元 2086， 与驱动电路 210连接； 比较单元 2084， 与模数转换单元 2082以及生 成单元 2086相连； 以及， 给定单元 2088， 与模拟补偿电路 206连接。 在本发明的一个优选实施方式中， 通过模拟补偿电路 206完成对环路的补偿， 从 而使得数字处理器 208只需要将模拟补偿电路 206的输出转换为相应的脉宽调制信号， 从而缩短了数字处理器 208中断算法的执行时间， 解决了在谐振变换器工作频率很高 的情况下由于数字处理器难以在一个脉宽调制周期内执行完一次反馈控制运算造成的 反馈控制产生延时的问题， 达到了能够做到在每个脉宽调制周期内都对谐振电路进行 控制的目的， 从而保证了对谐振电路进行控制的稳定性和实时性。 基于图 2所示的装置， 本发明提供了一个优选的谐振变换器的控制方法， 在本优 选实施例所涉及的控制方法中， 以采样信号为电压信号为例进行说明， 但是本发明不 限于此， 上述采样信号也可以是电流信号。 下面将结合图 2和图 3来描述本实施例中 的谐振变换器的控制方法， 其包括步骤 S1-S8: S112: The pulse width modulation module in the digital processor blocks the driving circuit, and the LLC resonant circuit stops working, and the process ends. It can be seen from the above method that in an interrupt algorithm cycle, the digital processor needs to realize the voltage output of the compensation loop and convert the voltage output into a corresponding pulse width modulation signal to complete a complete DC/DC converter. With constant pressure, current limit, constant power and even current limit retraction. At present, the compensation loop is executed in the algorithm interrupt process of the digital processor. Due to the cost limitation, the frequency of the digital processor used in the control of the LLC resonant converter is generally not very high, and the maximum of the LLC resonant converter is high. The operating frequency is generally above 200KHz or even 300KHz. It can be seen that since the digital processor needs to process too many steps in one interrupt algorithm cycle, when the resonant converter frequency is high, the digital processor cannot complete the entire feedback control operation in one pulse width modulation period. Processing, it is impossible to control the LLC resonant converter in each pulse width modulation period, thereby causing delay in the control of the LLC resonant converter, thereby causing the phase of the entire loop to be attenuated, and the loop bandwidth is changed. Narrow, at the same time, the direct impact on the output is such that the peak-to-peak noise of the output voltage and the telephone weight are difficult to optimize. In response to the above problems, no effective solution has been proposed yet. SUMMARY OF THE INVENTION The present invention provides a control method and apparatus for a resonant converter to at least solve the problem that it is difficult for a digital processor to perform a feedback control operation within a pulse width modulation period when the resonant converter operates at a high frequency. The feedback control produces a delay problem. According to an aspect of the present invention, a control method for a resonant converter is provided, comprising: sampling an analog output signal of a resonant conversion circuit; and obtaining a simulated compensation signal by the sampled signal through an analog compensation circuit; converting the analog compensation signal The digital compensation signal is input, and the resonance conversion circuit is feedback-controlled according to the digital compensation signal. Preferably, the step of obtaining the analog compensation signal by the sampled signal through the analog compensation circuit comprises: obtaining the voltage analog compensation signal by the sampled voltage signal through the voltage loop compensation circuit; or obtaining the sampled current signal through the current loop compensation circuit. Current analog compensation signal. Preferably, the step of obtaining the analog compensation signal by the sampled signal through the analog compensation circuit comprises: obtaining the voltage analog compensation signal by the sampled voltage signal through the voltage loop compensation circuit, and obtaining the sampled current signal through the current loop compensation circuit. The current analog compensation signal is compared with the current analog compensation signal; if the voltage analog compensation signal is smaller than the current analog compensation signal, the voltage analog compensation signal is output as an analog compensation signal; otherwise, the current analog compensation signal is used as The analog compensation signal is output. Preferably, the step of converting the analog compensation signal into the digital compensation signal comprises: performing analog-to-digital conversion of the analog compensation signal to obtain a digital signal; comparing the value of the digital signal with a predetermined threshold; and generating the result according to the comparison by using a corresponding control method A pulse width modulated signal that is a digital compensation signal. Preferably, the step of generating a pulse width modulation signal as a digital compensation signal by using a corresponding control manner according to the result of the comparison comprises: generating a pulse width modulation as a digital compensation signal by using a phase shifting method when the digital signal is smaller than the first predetermined threshold a signal; when the digital signal is greater than or equal to the first predetermined threshold is less than the second predetermined threshold, using a phase shift modulation method to generate a pulse width modulation signal as a digital compensation signal; when the digital signal is greater than or equal to a second predetermined threshold, using a frequency modulation method to generate A pulse width modulated signal of a digitally compensated signal. According to another aspect of the present invention, a control apparatus for a resonant converter is provided, comprising: a resonant conversion circuit configured to output an analog output signal; a sampling circuit configured to sample an analog output signal of the resonant conversion circuit; The circuit is configured to compensate the sampled signal to obtain an analog compensation signal; the digital processor is configured to convert the analog compensation signal into a digital compensation signal, and perform feedback control on the resonance conversion circuit according to the digital compensation signal. Preferably, the analog compensation circuit comprises: a voltage loop compensation circuit configured to compensate the sampled voltage signal to obtain a voltage analog compensation signal; or a current loop compensation circuit configured to compensate the sampled current signal to obtain a current analog compensation signal. Preferably, the analog compensation circuit comprises: a voltage loop compensation circuit, configured to compensate the obtained voltage signal to obtain a voltage analog compensation signal; and a current loop compensation circuit configured to compensate the sampled current signal to obtain a current analog compensation signal; , the voltage analog compensation signal is compared with the current analog compensation signal; if the voltage analog compensation signal is smaller than the current analog compensation signal, the voltage analog compensation signal is output as an analog compensation signal; otherwise, the current analog compensation signal is used as an analog compensation The signal is output. Preferably, the digital processor comprises: an analog to digital conversion unit configured to perform analog to digital conversion of the analog compensation signal to obtain a digital signal; a comparison unit configured to compare the value of the digital signal with a predetermined threshold; generating a unit, configured to compare The result obtained uses a corresponding control method to generate a pulse width modulated signal for feedback control. Preferably, the control device of the resonant converter further includes: a driving circuit configured to generate a control signal according to the pulse width modulation signal and output the signal to the resonance conversion circuit. In the present invention, a digital-analog hybrid resonant converter control method is adopted, and the compensation of the loop is completed by the analog compensation circuit, so that the digital processor only needs to convert the output of the analog compensation circuit into a corresponding pulse width modulation signal. Therefore, the time for the digital processor to perform the feedback control operation is shortened, and the resonant circuit can be controlled in each pulse width modulation period, thereby solving the problem that the digital processor is difficult in the case where the resonant converter operates at a high frequency. The delay of the feedback control caused by performing a feedback control operation in a pulse width modulation period achieves the purpose of controlling the resonant circuit in each pulse width modulation period, thereby ensuring the resonance The stability and real-time control of the circuit. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are set to illustrate,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, In the drawings: FIG. 1 is a flow chart of a control method of a resonant converter according to the prior art; FIG. 2 is a block diagram showing a preferred configuration of a control device for a resonant converter according to an embodiment of the present invention; Another preferred structural block diagram of a control device for a resonant converter according to an embodiment of the present invention; FIG. 4 is a schematic diagram showing a relationship between a voltage control signal and a switching frequency corresponding to three control modes according to an embodiment of the present invention; A schematic diagram of the relationship between the voltage control signal and the duty ratio corresponding to the three control modes according to the embodiment of the present invention; FIG. 6 is a preferred flowchart of the control device of the resonant converter according to the embodiment of the present invention; A preferred block diagram of a control method of a resonant converter according to an embodiment of the present invention; FIG. 8 is a schematic diagram of a preferred voltage loop compensation circuit according to an embodiment of the present invention; 9 is a schematic diagram of a preferred current loop compensation circuit according to an embodiment of the present invention; FIG. 10 is a schematic diagram of a pulse width modulation signal when operating in a frequency modulation interval according to an embodiment of the present invention; FIG. 11 is a diagram of an operation according to an embodiment of the present invention. Schematic diagram of a pulse width modulation signal at the phase shift interval; Fig. 12 is another preferred flow chart of the control method of the resonant converter according to an embodiment of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the embodiments in the present application and the features in the embodiments may be combined with each other without conflict. Embodiment 1 As shown in FIG. 2, the present invention provides a preferred control device for a resonant converter, the device comprising: a resonant converter circuit 202; a sampling circuit 204 directly connected to the resonant converter circuit 202, or through load and resonance The conversion circuit 202 is connected; the analog compensation circuit 206 is connected to the sampling circuit 204; the digital processor 208 is connected to the analog compensation circuit 206; and the drive circuit 210 is connected to the resonance conversion circuit 202 and the digital processor 208. The digital processor 208 includes: an analog-to-digital conversion unit 2082 connected to the analog compensation circuit 206; a generating unit 2086 connected to the driving circuit 210; a comparison unit 2084 connected to the analog-to-digital conversion unit 2082 and the generating unit 2086; The unit 2088 is connected to the analog compensation circuit 206. In a preferred embodiment of the invention, the compensation of the loop is accomplished by the analog compensation circuit 206 such that the digital processor 208 only needs to convert the output of the analog compensation circuit 206 to a corresponding pulse width modulated signal, thereby shortening the number. The processor 208 interrupts the execution time of the algorithm, and solves the problem that the delay of the feedback control caused by the digital processor being difficult to perform a feedback control operation within one pulse width modulation period when the resonant converter operates at a high frequency. It achieves the purpose of controlling the resonant circuit in each pulse width modulation period, thereby ensuring the stability and real-time control of the resonant circuit. Based on the apparatus shown in FIG. 2, the present invention provides a preferred method for controlling a resonant converter. In the control method of the preferred embodiment, the sampling signal is used as a voltage signal as an example, but the present invention is not limited thereto. Therefore, the sampling signal may also be a current signal. A control method of the resonant converter in the present embodiment will be described below with reference to FIGS. 2 and 3, which includes steps S1-S8:
S1 : 在每个脉宽调制周期中断程序开始时， 判断 LLC谐振变换器的工作状态， 如 果 LLC谐振变换器处于开机且无故障发生， 则执行步骤 S2， 否则， 转而执行 S8。 S2: 采样电路 204对谐振变换电路 202输出的电压模拟输出信号进行采样， 得到 电压 ^ 。 S1: At the beginning of each pulse width modulation period interrupt routine, the operating state of the LLC resonant converter is judged. If the LLC resonant converter is turned on and no fault occurs, step S2 is performed, otherwise, S8 is performed instead. S2: The sampling circuit 204 samples the voltage analog output signal output from the resonance conversion circuit 202 to obtain a voltage ^.
S3： 模拟补偿电路 206对给定单元 2088给定的电压给定量 和采样得到的电压 信号 V。进行比较， 根据比较结果对采样得到的电压信号 V。进行补偿得到模拟补偿信号 Vf ， 然后， 将得到的模拟补偿信号 输出给数字处理器 208中的模数转换单元 2082。 S3: The analog compensation circuit 206 gives a given voltage signal V to a given voltage given by the given unit 2088. For comparison, the sampled voltage signal V is obtained based on the comparison result. Compensation is performed to obtain an analog compensation signal Vf , and then the resulting analog compensation signal is output to an analog to digital conversion unit 2082 in the digital processor 208.
S4:模数转换单元 2082对模拟补偿信号^进行模数转换，以便将模拟补偿信号 转换得到数字信号， 并将得到的数字信号传输给比较单元 2084。 S4: The analog-to-digital conversion unit 2082 performs analog-to-digital conversion on the analog compensation signal to convert the analog compensation signal to a digital signal, and transmits the obtained digital signal to the comparison unit 2084.
S5 : 比较单元 2084将转换得到的数字信号和预定的阈值进行比较。 S5: The comparing unit 2084 compares the converted digital signal with a predetermined threshold.
S6:生成单元 2086根据比较得到的结果采用相应的控制方式生成用于所述反馈控 制的脉宽调制信号。 在本发明的优选实施例中， 谐振变换器 202 (例如， LLC谐振变换器） 的工作方 式包括定频移相、 移相调频和调频三种， 基于这三种工作方式， 对于定频移相、 移相 调频和调频三种工作和预先设定的固定电压 （或者是电流， 功率等） 存在如图 4-5所 示的关系。基于图 4-5所示的关系， 比较单元 2084将转换得到的数字信号和预定的阈 值进行比较的步骤可以包括： 当电压控制信号（例如， 上述步骤 S4中转换得到的数字 信号） 小于固定电压 VI (第一预定阈值） 时， 采用定频移相控制， LLC 谐振变换器 工作的开关频率保持最大值 (fmax)不变， 移相占空比随电压控制信号线性变化， 电压 控制信号越小， 移相占空比 D越小； 当电压控制信号（例如， S4中转换得到的数字信 号） 大于等于固定电压 VI但小于固定电压 V2 (第二预定阈值） 时， 采用调频移相控 制， 移相占空比和开关频率均随电压控制信号线性变化， 电压控制信号越小， 移相占 空比 D越小， 开关频率越高； 当电压控制信号大于等于固定电压 V2时， 采用调频控 制方式， 移相占空比为最大值 Dmax不变， 开关频率随电压控制信号线性变化， 电压 控制信号越大， 开关频率越低。 图 6进一步示出了上述步骤 S5和 S6中的生成用于所述反馈控制的脉宽调制信号 的方案， 具体而言， 如图 6所示， 当判断 LLC谐振变换器 202工作状态为开机且无故 障发生时， 采样电路 204采样模拟补偿信号（Vf)， 将采样得到的数字信号和预定的阈 值进行比较， 根据比较得到的结果采用相应的控制方式生成用于所述反馈控制的脉宽 调制信号。 具体判断步骤包括： 当所述数字信号 （VO 小于第一预定阈值 （VI ) 时， 采用移相方式生成作为所述数字补偿信号的脉宽调制信号； 当所述数字信号大于等于 所述第一预定阈值小于第二预定阈值 (V2)时， 采用移相调频方式生成作为所述数字补 偿信号的脉宽调制信号； 当所述数字信号大于等于所述第二预定阈值时， 采用调频方 式生成作为所述数字补偿信号的脉宽调制信号。 优选的， 电压环补偿电路如图 8所示， 将给定单元 2088给定的电压给定量 和 采样得到的电压信号 。进行比较， 求取误差； 然后经过一个双零点、 三极点的 III型补 偿放大器， 得到一个经过放大补偿过的电压信号 。 优选的， III型补偿放大器的传递 函数如下式所示： S6: The generating unit 2086 generates a pulse width modulation signal for the feedback control according to the result of the comparison by using a corresponding control manner. In a preferred embodiment of the present invention, the resonant converter 202 (e.g., LLC resonant converter) operates in three modes: fixed frequency phase shifting, phase shifting frequency modulation, and frequency modulation. Based on these three modes of operation, for fixed frequency phase shifting The three phases of phase shifting and frequency modulation and the preset fixed voltage (or current, power, etc.) exist as shown in Figure 4-5. Based on the relationship shown in FIG. 4-5, the comparing unit 2084 may compare the converted digital signal with a predetermined threshold value, and may include: when the voltage control signal (for example, the digital signal converted in the above step S4) is smaller than the fixed voltage. VI (first predetermined threshold), using constant frequency phase shift control, the switching frequency of the LLC resonant converter works to keep the maximum value (fmax) unchanged, the phase shift duty ratio changes linearly with the voltage control signal, and the voltage control signal is smaller. The smaller the phase shift duty ratio D is; when the voltage control signal (for example, the digital signal converted in S4) is greater than or equal to the fixed voltage VI but less than the fixed voltage V2 (second predetermined threshold), the frequency shifting phase shift control is used. The phase duty ratio and the switching frequency both vary linearly with the voltage control signal. The smaller the voltage control signal is, the smaller the phase shift duty ratio D is, the higher the switching frequency is. When the voltage control signal is greater than or equal to the fixed voltage V2, the frequency modulation control mode is adopted. The phase shift duty ratio is the maximum value Dmax, the switching frequency varies linearly with the voltage control signal, and the voltage control signal is larger, the switch The lower the frequency. FIG. 6 further shows a scheme for generating a pulse width modulation signal for the feedback control in the above steps S5 and S6. Specifically, as shown in FIG. 6, when it is determined that the LLC resonant converter 202 is in the ON state and When no fault occurs, the sampling circuit 204 samples the analog compensation signal (Vf), compares the sampled digital signal with a predetermined threshold, and generates a pulse width modulation for the feedback control according to the comparison result using a corresponding control manner. signal. The specific determining step includes: when the digital signal (VO is less than the first predetermined threshold (VI), generating a pulse width modulation signal as the digital compensation signal by using a phase shifting method; when the digital signal is greater than or equal to the first When the predetermined threshold is less than the second predetermined threshold (V2), the phase shift modulation method is used to generate the digital complement Compensating for a pulse width modulation signal of the signal; when the digital signal is greater than or equal to the second predetermined threshold, generating a pulse width modulation signal as the digital compensation signal by using a frequency modulation method. Preferably, the voltage loop compensation circuit, as shown in FIG. 8, gives a voltage signal given by the given unit 2088 to the quantized and sampled voltage signal. Compare and obtain the error; then pass through a double-zero, three-pole type III compensation amplifier to obtain an amplified and compensated voltage signal. Preferably, the transfer function of the type III compensation amplifier is as follows:
GG
Figure imgf000009_0001
其中 k为放大比例增益， ωζ1和 ωζ2对应为两零点位置， ωρ1和 ωρ2对应为两极点位 置， 另一极点为原点处的积分。 值得注意的是， 在本发明各优选实施例中， 数字信号以电压信号为例进行说明， 但是并不构成对本发明的限定， 数字信号还可以为电流信号等； 进一步， 上述实施例 中的模拟补偿电路以电压环补偿电路为例进行说明， 本发明不限于此， 模拟补偿电路 还可以包括电流环补偿电路、 恒功率环补偿电路以及回缩环补偿电路等。 例如， 对于电流环补偿电路而言， 上述传递函数同样适用于电流环补偿电流。 具 体地， 电流环补偿电路如图 9所示，将给定单元 2088给定的电流给定量 /g和采样得到 的电流信号 /。进行比较， 求取误差； 然后经过一个双零点、三极点的 III型补偿放大器， 得到一个经过放大补偿过的电流信号 /。 优选的， III型补偿放大器的传递函数如下式 所示：
Figure imgf000009_0001
Where k is the amplification proportional gain, ω ζ1 and ω ζ2 correspond to the two zero position, ω ρ1 and ω ρ2 correspond to the two pole position, and the other pole is the integral at the origin. It should be noted that, in various preferred embodiments of the present invention, the digital signal is exemplified by a voltage signal, but does not constitute a limitation of the present invention, and the digital signal may also be a current signal or the like; further, the simulation in the above embodiment The compensation circuit is described by taking a voltage loop compensation circuit as an example. The present invention is not limited thereto, and the analog compensation circuit may further include a current loop compensation circuit, a constant power loop compensation circuit, and a retraction loop compensation circuit. For example, for a current loop compensation circuit, the above transfer function is equally applicable to current loop compensation current. Specifically, the current loop compensation circuit, as shown in FIG. 9, gives a given current to the given unit 2088 a given amount / g and the sampled current signal /. Compare and obtain the error; then pass through a double-zero, three-pole type III compensation amplifier to obtain an amplified and compensated current signal / . Preferably, the transfer function of the type III compensation amplifier is as follows:
G =G =
Figure imgf000009_0002
其中 k为放大比例增益， ωζ1和 ωζ2对应为两零点位置， ωρ1和 ωρ2对应为两极点位 另一极点为原点处的积分。 值得注意的是， 在本发明各个优选实施例中补偿电路是采用双零点、 三极点的 III 型补偿放大器进行信号的放大， 但本发明不限于此， 还可以采用其他的补偿网络来实 现。 图 10为工作在调频区间 （采用调频控制方式） 时的脉宽调制信号示意图。 其中， Q1和 Q4分别为超前臂上管驱动和滞后臂下管驱动 （如图 10中实线所示）， Q2和 Q3 分别为超前臂下管驱动和滞后臂上管驱动 （如图 10中虚线所示）。 当采用调频控制方 式工作时， Q1禾 P Q4的有效驱动 （如图 10中对应的实线高电平） 完全相同； Q2和 Q3的有效驱动（如图 10中对应的虚线高电平）也完全相同。而同一桥臂的上下管（Q1 和 Q2、 Q3和 Q4)有效驱动相差 180度， 并且中间有一死区区间， 这个死区时间为一 固定值， 其目的是为了防止同一桥臂的上下管之间发生直通。 图 11为工作在移相区间（包括采用定频移相控制方式和移相调频控制方式）时的 脉宽调制信号示意图。 其中， Q1和 Q4分别为超前臂上管驱动和滞后臂下管驱动， Q2 和 Q3分别为超前臂下管驱动和滞后臂上管驱动。 当工作在移相区间时， Q1和 Q4的 有效驱动错开一定的角度， Q2和 Q3的有效驱动也错开一定的角度， 这个角度就称为 移相角。 而同一桥臂的上下管（例如， Q1和 Q2、 Q3和 Q4)之间的有效驱动相差 180 度， 并且同一桥臂的上下管中间有一死区区间， 这个死区区间除了能防止同一桥臂的 上下管之间发生直通，还能实现软开关。死区时间不是固定的，而是随着负载特性（包 括输出电压和负载大小） 而发生改变， 其对应关系由 LLC谐振变换器的特性来决定。 死区大小一般是根据移相角的大小来确定， 它们之间的关系通常为非线性的单调递归 关系， 即移相角越大， 死区越大。 数字处理器中， 可以通过直线拟合的方法将移相角 和死区的关系转化为分段的线性关系； 也可以制作一个移相角和死区的表格， 通过查 表的方式来得到死区的大小。 总之， 利用数字控制灵活多变的特性， 在移相或者调宽 控制时变压器原边开关管也能够较好地实现软开关。
Figure imgf000009_0002
Where k is the amplification proportional gain, ω ζ1 and ω ζ2 correspond to the two zero position, and ω ρ1 and ω ρ2 correspond to the integration of the other pole of the two poles at the origin. It should be noted that in various preferred embodiments of the present invention, the compensation circuit uses a two-zero, three-pole type III compensation amplifier for signal amplification, but the present invention is not limited thereto, and other compensation networks may be used. FIG. 10 is a schematic diagram of a pulse width modulation signal when operating in a frequency modulation interval (using a frequency modulation control method). Among them, Q1 and Q4 are the super forearm upper tube drive and the lag arm lower tube drive respectively (as shown by the solid line in Figure 10), Q2 and Q3 are the super forearm lower tube drive and the lag arm upper tube drive respectively (as in Figure 10). Shown in dotted line). When working in the FM control mode, the effective driving of Q1 and P Q4 (such as the corresponding solid line high level in Figure 10) is exactly the same; the effective driving of Q2 and Q3 (as shown by the corresponding dotted line in Figure 10) It's exactly the same. The upper and lower tubes (Q1 and Q2, Q3 and Q4) of the same bridge arm are effectively driven by 180 degrees, and there is a dead zone in the middle. The dead time is a fixed value. The purpose is to prevent the upper and lower tubes of the same bridge arm. There is a straight through. FIG. 11 is a schematic diagram of a pulse width modulation signal when operating in a phase shift interval (including a fixed frequency phase shift control method and a phase shift frequency modulation control method). Among them, Q1 and Q4 are the super forearm upper tube drive and the lag arm lower tube drive respectively, and Q2 and Q3 are the super forearm lower tube drive and the lag arm upper tube drive respectively. When working in the phase shift interval, the effective driving of Q1 and Q4 is shifted by a certain angle, and the effective driving of Q2 and Q3 is also shifted by a certain angle. This angle is called the phase shifting angle. The effective drive between the upper and lower tubes of the same bridge arm (for example, Q1 and Q2, Q3 and Q4) is 180 degrees apart, and there is a dead zone between the upper and lower tubes of the same bridge arm. This dead zone can prevent the same bridge arm. A straight-through occurs between the upper and lower tubes, and a soft switch can also be realized. The dead time is not fixed, but changes with load characteristics (including output voltage and load size), and the corresponding relationship is determined by the characteristics of the LLC resonant converter. The size of the dead zone is generally determined according to the size of the phase shift angle. The relationship between them is usually a nonlinear monotonous recursive relationship, that is, the larger the phase shift angle, the larger the dead zone. In the digital processor, the relationship between the phase shift angle and the dead zone can be converted into a linear relationship of segments by a straight line fitting method; a table of phase shift angles and dead zones can also be created, and the table can be used to obtain the dead. The size of the area. In short, with the flexible and variable characteristics of digital control, the primary switching tube of the transformer can also achieve soft switching when phase shifting or widening control.
S7:驱动电路 210接收生成单元 2086生成的用于反馈控制的脉宽调制信号，并对 该脉宽调制信号进行放大生成控制信号， 并将控制信号输出给谐振变换电路 202， 使 得谐振变换电路 202电路工作， 结束本流程。 S7: The driving circuit 210 receives the pulse width modulation signal generated by the generating unit 2086 for feedback control, and amplifies the pulse width modulation signal to generate a control signal, and outputs the control signal to the resonance conversion circuit 202, so that the resonance conversion circuit 202 The circuit works and ends the process.
S8: 数字处理器中的脉宽调制模块封锁驱动电路 210， LLC谐振变换电路 202停 止工作， 结束本流程。 上述实施例以采样信号为电压信号为例进行说明， 但是本发明不限于此， 上述采 样信号也可以是电流信号。 例如， 本发明还提供了一种优选的实施方式， 以便应对不 同的电路补偿的场景， 在本优选的实施例中， 所示模拟补偿电路 206可以包括电流环 补偿电路， 用于对采样得到的电流信号补偿得到电流模拟补偿信号。 作为另一种实施例， 由于实际应用中 LLC谐振变换电路一般不会只具备恒压的功 能， 通常还必须具备限流等功能， 本发明还提供了另一种优选的实施方式， 以便实现 在同时存在电压信号和电流信号时候对信号的处理。 如图 7所示， 在本优选的实施例 中， 模拟补偿电路 206包括： 电压环补偿电路 304， 用于对采样得到的电压信号补偿 得到电压模拟补偿信号； 电流环补偿电路 302， 用于对采样得到的电流信号补偿得到 电流模拟补偿信号； 电压环补偿电路 304和电流环补偿电路 302是并行工作， 电压环 补偿电路 304起稳压作用，电流环补偿电路 302起限流作用，在工作时，比较电路 310， 用于将所述电压模拟补偿信号与所述电流模拟补偿信号进行比较； 若所述电压模拟补 偿信号小于所述电流模拟补偿信号， 则将所述电压模拟补偿信号作为所述模拟补偿信 号进行输出； 否则， 将所述电流模拟补偿信号作为所述模拟补偿信号进行输出。 在本 实施例中， 当电压环补偿电路 304起作用的时候， 电流环补偿电路 302处于饱和状态， 此时输出电压稳定； 当电流环补偿电路 302作用时， 电压环补偿电路 304处于饱和状 态， 此时输出电流被限制在一定的值。 在上述优选的实施方式中， 在同时有电压信号和电流信号的时候， 对两者的模拟 补偿信号进行比较， 选择小的作为模拟补偿电路的输出， 从而可以同时实现稳压和限 流的作用， 实现了对谐振变换器更有效地控制。 当然， 在本优选实施例中以电压信号和电流信号为例进行说明， 但是本发明不限 于此， 改变相应的反馈信号还可以实现恒功率、 限流回缩等功能， 对于有多个环路的 输出只需要通过比较器进行比较， 选择误差信号最小的那个反馈信号进行补偿得到控 制信号， 将此控制信号送到数字处理器进行处理。 在上述各优选实施方式中， 以 LLC谐振变换器工作模式为： 定频移相、 移相调频 和调频三种为例进行说明， 但是本发明不限于此， 例如： 在 LLC谐振变换器为半桥拓 扑结构时， 工作模式为： 定频调宽、 调频调宽、 调频三种。 在这种情况下， 以 LLC谐 振变换器的控制方式和工作在定频移相、 移相调频和调频方式类似， 在此不再赘述。 实施例 2 基于图 2所示的优选的谐振变换器的控制装置， 本发明还提供了一种优选的谐振 变换器的控制方法， 如图 12所示， 该方法具体步骤包括： S1202: 对谐振变换电路的模拟输出信号进行采样； S1204: 将采样得到的信号经过模拟补偿电路得到模拟补偿信号； S8: The pulse width modulation module in the digital processor blocks the driving circuit 210, and the LLC resonance conversion circuit 202 stops working, and the process ends. In the above embodiment, the sampling signal is taken as a voltage signal as an example. However, the present invention is not limited thereto, and the sampling signal may be a current signal. For example, the present invention also provides a preferred embodiment in order to cope with In the preferred embodiment of the circuit compensation, in the preferred embodiment, the analog compensation circuit 206 can include a current loop compensation circuit for compensating the sampled current signal to obtain a current analog compensation signal. As another embodiment, since the LLC resonant conversion circuit generally does not only have the function of constant voltage in practical applications, it is usually necessary to have functions such as current limiting, and the present invention also provides another preferred embodiment, so as to achieve The signal is processed at the same time as the voltage signal and the current signal. As shown in FIG. 7, in the preferred embodiment, the analog compensation circuit 206 includes: a voltage loop compensation circuit 304 for compensating the sampled voltage signal to obtain a voltage analog compensation signal; and a current loop compensation circuit 302 for The sampled current signal is compensated to obtain a current analog compensation signal; the voltage loop compensation circuit 304 and the current loop compensation circuit 302 operate in parallel, the voltage loop compensation circuit 304 acts as a voltage regulator, and the current loop compensation circuit 302 acts as a current limiting function during operation. a comparison circuit 310, configured to compare the voltage analog compensation signal with the current analog compensation signal; if the voltage analog compensation signal is smaller than the current analog compensation signal, the voltage analog compensation signal is used as The analog compensation signal is output; otherwise, the current analog compensation signal is output as the analog compensation signal. In this embodiment, when the voltage loop compensation circuit 304 is active, the current loop compensation circuit 302 is in a saturated state, and the output voltage is stable; when the current loop compensation circuit 302 acts, the voltage loop compensation circuit 304 is in a saturated state. At this time, the output current is limited to a certain value. In the above preferred embodiment, when the voltage signal and the current signal are simultaneously, the analog compensation signals of the two are compared, and the output of the analog compensation circuit is selected as small, so that the voltage regulation and the current limiting function can be simultaneously realized. , achieves more efficient control of the resonant converter. Certainly, in the preferred embodiment, the voltage signal and the current signal are taken as an example for description. However, the present invention is not limited thereto, and the corresponding feedback signal can be changed to implement functions such as constant power and current limiting, and there are multiple loops. The output only needs to be compared by the comparator, and the feedback signal with the smallest error signal is selected to compensate for the control signal, and the control signal is sent to the digital processor for processing. In the above preferred embodiments, the LLC resonant converter operating modes are as follows: fixed frequency phase shifting, phase shifting frequency modulation, and frequency modulation are described as an example, but the present invention is not limited thereto, for example: half of the LLC resonant converter In the bridge topology, the working modes are: fixed frequency adjustment, frequency modulation, and frequency modulation. In this case, the control mode of the LLC resonant converter is similar to that of the fixed-frequency phase shifting, phase shifting frequency modulation, and frequency modulation, and will not be described herein. Embodiment 2 Based on the control device of the preferred resonant converter shown in FIG. 2, the present invention also provides a preferred control method of the resonant converter. As shown in FIG. 12, the specific steps of the method include: S1202: Resonance The analog output signal of the conversion circuit is sampled; S1204: The sampled signal is subjected to an analog compensation circuit to obtain an analog compensation signal;
S1206:将模拟补偿信号转换成数字补偿信号，并根据数字补偿信号对谐振变换电 路进行反馈控制。 在本发明的一个优选实施方式中， 过模拟补偿电路 206完成对环路的补偿， 从而 使得数字处理器 208只需要将模拟补偿电路 206的输出转换为相应的脉宽调制信号， 从而缩短了数字处理器 208中断算法的执行时间， 解决了在谐振变换器工作频率很高 的情况下由于数字处理器难以在一个脉宽调制周期内执行完一次反馈控制运算造成的 反馈控制产生延时的问题， 达到了能够做到在每个脉宽调制周期内都对谐振电路进行 控制的目的， 从而保证了对谐振电路进行控制的稳定性和实时性。 本发明还提供了一种优选的信号补偿方式， 以便提高本发明的适应性， 在本优选 的实施例中， 将采样得到的电压信号经过电压环补偿电路得到电压模拟补偿信号； 或 者将采样得到的电流信号经过电流环补偿电路得到电流模拟补偿信号。 在本优选的实 施例中， 通过对电压信号和电流信号的建立不同的环路补偿电路， 以便应对不同的电 路补偿的场景。 本发明还提供了另一种优选的信号补偿方式， 以便提高本发明的适应性， 在本优 选实施例中， 将采样得到的电压信号经过电压环补偿电路得到电压模拟补偿信号， 以 及将采样得到的电流信号经过电流环补偿电路得到电流模拟补偿信号； 将电压模拟补 偿信号与电流模拟补偿信号进行比较； 若电压模拟补偿信号小于电流模拟补偿信号， 则将电压模拟补偿信号作为模拟补偿信号进行输出； 否则， 将电流模拟补偿信号作为 模拟补偿信号进行输出。 在本优选的实施例中， 通过同时建立电压环补偿电路和电流 环补偿回路， 并在同时存在电压和电流补偿的时候， 选择误差较小的一个信号进行补 偿反馈， 从而实现对谐振变换器更有效地控制， 以便应对不同的电路补偿的场景。 本发明还提供了一种优选的将模拟补偿信号转换成数字补偿信号的方式， 以便达 到对脉宽调制不同方式的选择， 在本优选实施例中， 将模拟补偿信号进行模数转换得 到数字信号； 将数字信号的值与预定阈值进行比较； 根据比较得到的结果采用相应的 控制方式生成作为数字补偿信号的脉宽调制信号。 在本优选实施例中， 通过根据得到 数字信号的不同取值判断具体的脉宽调制信号， 达到了对谐振变换器更合理有效地控 制。 在本优选实施例中， 根据比较得到的结果采用相应的控制方式生成作为所述数字 补偿信号的脉宽调制信号的步骤包括： 当所述数字信号小于第一预定阈值时， 采用移 相方式生成作为所述数字补偿信号的脉宽调制信号； 当所述数字信号大于等于所述第 一预定阈值小于第二预定阈值时， 采用移相调频方式生成作为所述数字补偿信号的脉 宽调制信号。 在本优选实施例中， 通过设置不同的阈值对数字信号进行判断， 从而生 成不同的调制方式， 以满足不同的调制需求， 提高了本发明的适用性。 在本发明各优选实施方式中， 以 LLC谐振变换器工作模式为： 定频移相、 移相调 频和调频三种为例进行说明， 但是本发明不限于此， 例如： 在 LLC谐振变换器为半桥 拓扑结构时， 工作模式为： 定频调宽、 调频调宽、 调频三种。 在这种情况下， 以 LLC 谐振变换器的控制方式和工作在定频移相、移相调频和调频方式类似，在此不再赘述。 显然， 本领域的技术人员应该明白， 上述的本发明的各模块或各步骤可以用通用 的计算装置来实现， 它们可以集中在单个的计算装置上， 或者分布在多个计算装置所 组成的网络上， 可选地， 它们可以用计算装置可执行的程序代码来实现， 从而， 可以 将它们存储在存储装置中由计算装置来执行， 并且在某些情况下， 可以以不同于此处 的顺序执行所示出或描述的步骤， 或者将它们分别制作成各个集成电路模块， 或者将 它们中的多个模块或步骤制作成单个集成电路模块来实现。 这样， 本发明不限制于任 何特定的硬件和软件结合。 以上所述仅为本发明的优选实施例而已， 并不用于限制本发明， 对于本领域的技 术人员来说， 本发明可以有各种更改和变化。 凡在本发明的精神和原则之内， 所作的 任何修改、 等同替换、 改进等， 均应包含在本发明的保护范围之内。 S1206: Convert the analog compensation signal into a digital compensation signal, and perform feedback control on the resonance conversion circuit according to the digital compensation signal. In a preferred embodiment of the present invention, the over analog compensation circuit 206 performs compensation for the loop such that the digital processor 208 only needs to convert the output of the analog compensation circuit 206 to a corresponding pulse width modulated signal, thereby shortening the number. The processor 208 interrupts the execution time of the algorithm, and solves the problem that the delay of the feedback control caused by the digital processor being difficult to perform a feedback control operation within one pulse width modulation period when the resonant converter operates at a high frequency. It achieves the purpose of controlling the resonant circuit in each pulse width modulation period, thereby ensuring the stability and real-time control of the resonant circuit. The present invention also provides a preferred signal compensation method for improving the adaptability of the present invention. In the preferred embodiment, the sampled voltage signal is passed through a voltage loop compensation circuit to obtain a voltage analog compensation signal; The current signal is subjected to a current loop compensation circuit to obtain a current analog compensation signal. In the preferred embodiment, a different loop compensation circuit is established for the voltage signal and the current signal to cope with different circuit compensation scenarios. The present invention also provides another preferred signal compensation method for improving the adaptability of the present invention. In the preferred embodiment, the sampled voltage signal is passed through a voltage loop compensation circuit to obtain a voltage analog compensation signal, and the sample is obtained. The current signal is obtained by the current loop compensation circuit to obtain a current analog compensation signal; the voltage analog compensation signal is compared with the current analog compensation signal; if the voltage analog compensation signal is smaller than the current analog compensation signal, the voltage analog compensation signal is output as an analog compensation signal ; Otherwise, the current analog compensation signal is output as an analog compensation signal. In the preferred embodiment, by simultaneously establishing a voltage loop compensation circuit and a current loop compensation loop, and simultaneously having voltage and current compensation, a signal having a smaller error is selected for compensation feedback, thereby achieving a more resonant converter. Effectively controlled to cope with different circuit compensation scenarios. The present invention also provides a preferred way of converting an analog compensation signal into a digital compensation signal in order to achieve a different mode of pulse width modulation. In the preferred embodiment, the analog compensation signal is analog-to-digital converted to obtain a digital signal. And comparing the value of the digital signal with a predetermined threshold; and generating a pulse width modulated signal as a digital compensation signal according to the result of the comparison by using a corresponding control manner. In the preferred embodiment, more reasonable and effective control of the resonant converter is achieved by determining a particular pulse width modulated signal based on different values of the resulting digital signal. In the preferred embodiment, the step of generating a pulse width modulated signal as the digital compensation signal by using a corresponding control manner according to the result of the comparison includes: generating a phase shifting manner when the digital signal is less than a first predetermined threshold a pulse width modulation signal as the digital compensation signal; when the digital signal is greater than or equal to the first When the predetermined threshold is less than the second predetermined threshold, the pulse width modulation signal as the digital compensation signal is generated by the phase shift modulation method. In the preferred embodiment, the digital signals are judged by setting different thresholds to generate different modulation modes to meet different modulation requirements, thereby improving the applicability of the present invention. In the preferred embodiments of the present invention, the operating modes of the LLC resonant converter are as follows: fixed frequency phase shifting, phase shifting frequency modulation, and frequency modulation are described as an example, but the present invention is not limited thereto, for example: in the LLC resonant converter In the half-bridge topology, the working modes are: fixed-frequency widening, frequency-modulated widening, and frequency-modulated. In this case, the control mode of the LLC resonant converter is similar to that of the fixed-frequency phase shifting, phase shifting frequency modulation, and frequency modulation, and will not be described here. Obviously, those skilled in the art should understand that the above modules or steps of the present invention can be implemented by a general-purpose computing device, which can be concentrated on a single computing device or distributed over a network composed of multiple computing devices. Alternatively, they may be implemented by program code executable by the computing device, such that they may be stored in the storage device by the computing device and, in some cases, may be different from the order herein. The steps shown or described are performed, or they are separately fabricated into individual integrated circuit modules, or a plurality of modules or steps are fabricated as a single integrated circuit module. Thus, the invention is not limited to any specific combination of hardware and software. The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes can be made to the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and scope of the present invention are intended to be included within the scope of the present invention.

Claims

权 利 要 求 书 Claim
1. 一种谐振变换器的控制方法， 包括： A control method for a resonant converter, comprising:
对谐振变换电路的模拟输出信号进行采样；  Sampling the analog output signal of the resonant converter circuit;
将采样得到的信号经过模拟补偿电路得到模拟补偿信号；  The sampled signal is subjected to an analog compensation circuit to obtain an analog compensation signal;
将所述模拟补偿信号转换成数字补偿信号， 并根据所述数字补偿信号对所 述谐振变换电路进行反馈控制。  And converting the analog compensation signal into a digital compensation signal, and performing feedback control on the resonance conversion circuit according to the digital compensation signal.
2. 根据权利要求 1所述的方法， 其中， 将采样得到的信号经过模拟补偿电路得到 模拟补偿信号的步骤包括： 2. The method according to claim 1, wherein the step of obtaining the analog compensation signal by the sampled signal through the analog compensation circuit comprises:
将采样得到的电压信号经过电压环补偿电路得到电压模拟补偿信号； 或者 将采样得到的电流信号经过电流环补偿电路得到电流模拟补偿信号。  The sampled voltage signal is subjected to a voltage analog compensation signal through a voltage loop compensation circuit; or the sampled current signal is subjected to a current loop compensation circuit to obtain a current analog compensation signal.
3. 根据权利要求 1所述的方法， 其中， 将采样得到的信号经过模拟补偿电路得到 模拟补偿信号的步骤包括： 3. The method according to claim 1, wherein the step of obtaining the simulated compensation signal by passing the sampled signal through an analog compensation circuit comprises:
将采样得到的电压信号经过电压环补偿电路得到电压模拟补偿信号， 以及 将采样得到的电流信号经过电流环补偿电路得到电流模拟补偿信号；  The sampled voltage signal is passed through a voltage loop compensation circuit to obtain a voltage analog compensation signal, and the sampled current signal is passed through a current loop compensation circuit to obtain a current analog compensation signal;
将所述电压模拟补偿信号与所述电流模拟补偿信号进行比较； 若所述电压模拟补偿信号小于所述电流模拟补偿信号， 则将所述电压模拟 补偿信号作为所述模拟补偿信号进行输出； 否则， 将所述电流模拟补偿信号作 为所述模拟补偿信号进行输出。  Comparing the voltage analog compensation signal with the current analog compensation signal; if the voltage analog compensation signal is smaller than the current analog compensation signal, outputting the voltage analog compensation signal as the analog compensation signal; And outputting the current analog compensation signal as the analog compensation signal.
4. 根据权利要求 1所述的方法， 其中， 将所述模拟补偿信号转换成数字补偿信号 的步骤包括： 4. The method according to claim 1, wherein the step of converting the analog compensation signal into a digital compensation signal comprises:
将所述模拟补偿信号进行模数转换得到数字信号；  Performing analog-to-digital conversion on the analog compensation signal to obtain a digital signal;
将所述数字信号的值与预定阈值进行比较；  Comparing the value of the digital signal to a predetermined threshold;
根据比较得到的结果采用相应的控制方式生成作为所述数字补偿信号的脉 宽调制信号。  According to the result of the comparison, a pulse width modulation signal as the digital compensation signal is generated by a corresponding control method.
5. 根据权利要求 4所述的方法， 其中， 根据比较得到的结果采用相应的控制方式 生成作为所述数字补偿信号的脉宽调制信号的步骤包括： 当所述数字信号小于第一预定阈值时， 采用移相方式生成作为所述数字补 偿信号的脉宽调制信号； The method according to claim 4, wherein the step of generating a pulse width modulation signal as the digital compensation signal by using a corresponding control manner according to the result of the comparison comprises: Generating a pulse width modulation signal as the digital compensation signal by a phase shifting method when the digital signal is less than a first predetermined threshold;
当所述数字信号大于等于所述第一预定阈值小于第二预定阈值时， 采用移 相调频方式生成作为所述数字补偿信号的脉宽调制信号；  Generating a pulse width modulation signal as the digital compensation signal by using a phase shift modulation method when the digital signal is greater than or equal to the first predetermined threshold being less than a second predetermined threshold;
当所述数字信号大于等于所述第二预定阈值时， 采用调频方式生成作为所 述数字补偿信号的脉宽调制信号。  When the digital signal is greater than or equal to the second predetermined threshold, a pulse width modulation signal as the digital compensation signal is generated by a frequency modulation method.
6. 一种谐振变换器的控制装置， 包括： 6. A control device for a resonant converter, comprising:
谐振变换电路， 设置为输出模拟输出信号；  a resonant conversion circuit configured to output an analog output signal;
采样电路， 设置为对所述谐振变换电路的模拟输出信号进行采样； 模拟补偿电路， 设置为对采样得到的信号进行补偿得到模拟补偿信号； 数字处理器， 设置为将所述模拟补偿信号转换成数字补偿信号， 并根据所 述数字补偿信号对所述谐振变换电路进行反馈控制。  a sampling circuit configured to sample an analog output signal of the resonant converter circuit; an analog compensation circuit configured to compensate the sampled signal to obtain an analog compensation signal; and a digital processor configured to convert the analog compensation signal into Digitally compensating the signal and performing feedback control on the resonant converter circuit according to the digital compensation signal.
7. 根据权利要求 6所述的装置， 其中， 所述模拟补偿电路包括： 7. The apparatus according to claim 6, wherein the analog compensation circuit comprises:
电压环补偿电路， 设置为对采样得到的电压信号补偿得到电压模拟补偿信 号； 或者  a voltage loop compensation circuit configured to compensate a sampled voltage signal to obtain a voltage analog compensation signal; or
电流环补偿电路， 设置为对采样得到的电流信号补偿得到电流模拟补偿信 号。  The current loop compensation circuit is configured to compensate the sampled current signal to obtain a current analog compensation signal.
8. 根据权利要求 6所述的装置， 其中， 所述模拟补偿电路包括： 8. The apparatus according to claim 6, wherein the analog compensation circuit comprises:
电压环补偿电路， 设置为对采样得到的电压信号补偿得到电压模拟补偿信 号；  The voltage loop compensation circuit is configured to compensate the sampled voltage signal to obtain a voltage analog compensation signal;
电流环补偿电路， 设置为对采样得到的电流信号补偿得到电流模拟补偿信 号；  The current loop compensation circuit is configured to compensate the current signal obtained by the sampling to obtain a current analog compensation signal;
比较电路， 设置为将所述电压模拟补偿信号与所述电流模拟补偿信号进行 比较； 若所述电压模拟补偿信号小于所述电流模拟补偿信号， 则将所述电压模 拟补偿信号作为所述模拟补偿信号进行输出； 否则， 将所述电流模拟补偿信号 作为所述模拟补偿信号进行输出。  Comparing a circuit, configured to compare the voltage analog compensation signal with the current analog compensation signal; if the voltage analog compensation signal is less than the current analog compensation signal, using the voltage analog compensation signal as the analog compensation The signal is output; otherwise, the current analog compensation signal is output as the analog compensation signal.
9. 根据权利要求 6所述的装置， 其中， 所述数字处理器包括： 9. The apparatus according to claim 6, wherein the digital processor comprises:
模数转换单元， 设置为将所述模拟补偿信号进行模数转换得到数字信号； 比较单元， 设置为将所述数字信号的值与预定阈值进行比较； An analog-to-digital conversion unit configured to perform analog-to-digital conversion on the analog compensation signal to obtain a digital signal; a comparing unit, configured to compare a value of the digital signal with a predetermined threshold;
生成单元， 设置为根据比较得到的结果采用相应的控制方式生成用于所述 反馈控制的脉宽调制信号。  The generating unit is configured to generate a pulse width modulation signal for the feedback control by using a corresponding control manner according to the result of the comparison.
10. 根据权利要求 9所述的装置， 其中， 还包括： 驱动电路， 设置为根据所述脉宽 调制信号生成控制信号， 并输出给所述谐振变换电路。 10. The apparatus according to claim 9, further comprising: a driving circuit configured to generate a control signal according to the pulse width modulation signal and output the signal to the resonance conversion circuit.
PCT/CN2012/077951 2011-10-26 2012-06-29 Method and device for controlling resonant converter WO2013060162A1 (en)

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