CN117477966A - Resonant conversion circuit - Google Patents

Resonant conversion circuit Download PDF

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Publication number
CN117477966A
CN117477966A CN202311778087.0A CN202311778087A CN117477966A CN 117477966 A CN117477966 A CN 117477966A CN 202311778087 A CN202311778087 A CN 202311778087A CN 117477966 A CN117477966 A CN 117477966A
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CN
China
Prior art keywords
resistor
capacitor
resonant
winding
operational amplifier
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Withdrawn
Application number
CN202311778087.0A
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Chinese (zh)
Inventor
柯光洁
张斌
陈圣伦
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Jiangsu Qiaosi Technology Co ltd
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Jiangsu Qiaosi Technology Co ltd
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Priority to CN202311778087.0A priority Critical patent/CN117477966A/en
Publication of CN117477966A publication Critical patent/CN117477966A/en
Withdrawn legal-status Critical Current

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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
    • H02M3/01—Resonant DC/DC converters
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
    • G01R19/175—Indicating the instants of passage of current or voltage through a given value, e.g. passage through zero
    • 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
    • H02M1/0003—Details of control, feedback or regulation circuits
    • H02M1/0009—Devices or circuits for detecting current in a converter
    • 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
    • H02M3/33569—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 having several active switching elements
    • 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

Abstract

The invention discloses a resonance conversion circuit, which comprises a resonance branch, a switching unit and a rectifying unit, wherein an input power supply is connected to an input port of the switching unit to supply power to the resonance conversion circuit, the switching unit, the resonance branch and the rectifying unit are connected in parallel, an output end of the rectifying unit is connected with a load, the resonance conversion circuit also comprises a resonance current detection module, an input end of the resonance current detection module is connected with the resonance branch and is used for detecting resonance current in the resonance branch, and the resonance current detection module outputs first voltage; and the exciting current detection module is used for detecting exciting current in the resonant branch, and outputs a second voltage, and the output end of the exciting current detection module is connected with the output end of the resonant current detection circuit in parallel and outputs a third voltage. The invention does not bring extra loss, needs fewer peripheral devices, and is beneficial to improving the efficiency and the power density of the system; the post-stage rectifying circuit can be used for current reporting and zero crossing detection.

Description

Resonant conversion circuit
Technical Field
The present invention relates to the field of power conversion technology, and in particular, to a resonant conversion circuit.
Background
Along with the continuous improvement of functions and performances of electronic devices, requirements on power supply devices for supplying power to the electronic devices are also higher and higher, and in particular, requirements on high power density, high efficiency, high dynamic performance, high reliability and the like are met. To meet these requirements, a control mode with high dynamic characteristics is required for power supply design. Therefore, a current signal is needed to be added into the power supply module as input signals of the control circuit and the protection circuit to control the power supply, so that the circuit works more stably and reliably. In order to control using the current signal in the circuit, the current needs to be sampled.
For a resonant circuit, the resonant current in the sampling circuit is controlled and is important for the operation of the whole circuit. In some application occasions, the current sampling signal is also required to be used for load current reporting and zero crossing detection, so that the exciting current is required to be sampled while the resonant current is sampled, and the two are weighted to obtain a secondary side winding current signal, namely a load signal.
Disclosure of Invention
In order to achieve the above purpose, the technical scheme of the invention is as follows:
the utility model provides a resonance converting circuit, includes resonance branch road, switch unit and rectification unit, and input power supply connects the input port of switch unit is for resonance converting circuit supplies power, switch unit, resonance branch road and rectification unit parallel connection, the load is connected to the output of rectification unit, resonance converting circuit still includes: the input end of the resonance current detection module is connected with the resonance branch and is used for detecting resonance current in the resonance branch, and the resonance current detection module outputs a first voltage;
the exciting current detection module is used for detecting exciting current in the resonant branch, the exciting current detection module outputs second voltage, and the output end of the exciting current detection circuit is connected with the output end of the resonant current detection circuit in parallel and outputs third voltage.
In a specific embodiment of the present invention, the resonant branch includes a resonant capacitor, a first end of the resonant capacitor is connected to the first output end of the switching unit, an input end of the resonant current detection module is connected to the second end of the resonant capacitor,
a resonant inductor, a first end of the resonant inductor is connected with a second end of the resonant capacitor,
the first end of the primary side winding of the main transformer is connected with the second end of the resonant inductor, the second end of the primary side winding of the main transformer is connected with the second output end of the switch unit, the first end of the first secondary side winding of the main transformer is connected with the first input end of the rectifying unit, the second end of the first secondary side winding of the main transformer is connected with the first end of the second secondary side winding of the main transformer, and the second end of the second secondary side winding of the main transformer is connected with the second input end of the rectifying unit.
Further, the resonant current detection module comprises a first operational amplifier, a first capacitor, a second capacitor, a first resistor and a second resistor, wherein a first end of the resonant capacitor is connected with an input positive end of the first operational amplifier through the second capacitor, a second end of the resonant capacitor is connected with an input negative end of the first operational amplifier through the first capacitor, the input positive end of the first operational amplifier is grounded through the second resistor, an input negative end of the first operational amplifier is connected with an output end of the first operational amplifier through the first resistor, and an output end of the first operational amplifier outputs the first voltage.
In a specific embodiment of the present invention, the exciting current detection module includes a third winding, a third resistor and a third capacitor, where the third winding is coupled to the primary side of the main transformer, a first end of the third winding is connected to a second end of the primary side winding of the main transformer, a first end of the third resistor is connected to the second end of the third winding, a first end of the third capacitor is connected to the second end of the third resistor, a second end of the third capacitor is grounded, and a connection point of the third capacitor and the third resistor outputs the second voltage.
Further, the resonant conversion circuit further comprises a fourth resistor and a fifth resistor, wherein the second end of the third resistor is connected with the output end of the first operational amplifier through the fourth resistor and the fifth resistor.
Further, the resonant conversion circuit further comprises a second operational amplifier, a sixth resistor and a seventh resistor, wherein an input positive end of the second operational amplifier is connected to a connection point of the fourth resistor and the fifth resistor, an input negative end of the second operational amplifier is grounded through the sixth resistor, and an input negative end of the second operational amplifier is connected to an output end of the second operational amplifier through the seventh resistor.
In a specific embodiment of the present invention, the exciting current detection module includes a third winding, a third resistor and a third capacitor, where the third winding is coupled to the primary side of the main transformer, a first end of the third winding is connected to the first end of the third resistor, a second end of the third resistor is connected to the first end of the third capacitor, a second end of the third capacitor is connected to the second end of the third winding, a second end of the third capacitor is connected to the output end of the first operational amplifier, a voltage at two ends of the third capacitor is the second voltage, and a connection point of the third capacitor and the third resistor outputs the third voltage.
Further, the exciting current detection module further comprises a secondary transformer, the third winding is a secondary side winding of the secondary transformer, and driving signals of the switch module are input to two ends of a primary side winding of the secondary transformer.
In a specific embodiment of the present invention, the resonant current detection module includes a ninth resistor and a tenth resistor, an input positive terminal of the third operational amplifier is grounded through the ninth resistor, the input positive terminal of the third operational amplifier is connected to the second terminal of the resonant capacitor through the tenth resistor, and a connection point between the tenth resistor and the ninth resistor outputs the first voltage.
Further, the exciting current detection module comprises a sixth winding and a fifth capacitor, the sixth winding is coupled to the primary side of the main transformer, a first end of the sixth winding is connected with a second end of the primary side winding of the main transformer, a second end of the sixth winding is connected with an input negative end of the third operational amplifier, a first end of the fifth capacitor is connected with a second end of the sixth winding, a second end of the fifth capacitor is connected with an input positive end of the third operational amplifier, and an output end of the third operational amplifier outputs the third voltage.
In a specific embodiment of the present invention, the exciting current detection module includes a plurality of current sources and a sixth capacitor, wherein one end of the sixth capacitor is connected to a common end of the plurality of current sources, and the sixth capacitor is connected to an output end of the resonant current detection module.
Further, a driving signal of the switching module controls the current source and is proportional to an output current of the current source.
The resonant conversion circuit has the beneficial effects that the resonant conversion circuit obtains resonant current through sampling the voltage on the resonant capacitor, obtains exciting current through an integration module consisting of an additional winding, the capacitor and the resistor, does not bring extra loss, requires fewer peripheral devices, and is beneficial to improving the efficiency and the power density of the system; the differential sampling mode is adopted, so that the influence of switching noise on sampling signals is reduced, and current control and rapid protection are facilitated; the resonance current and the exciting current are weighted to obtain a secondary side winding current signal, namely a load current signal, and a signal post-stage rectifier circuit can be used for current reporting and zero crossing point detection; the current detection method for subtracting the exciting current can obtain more accurate resonance current and can be used for more accurate current control and protection.
In order to make the above features and advantages of the present invention more comprehensible, embodiments accompanied with figures are described in detail below.
Drawings
Fig. 1 is a block diagram of a resonant conversion circuit according to the present invention.
Fig. 2 is a schematic diagram of a first embodiment of a resonant conversion circuit according to the present invention.
Fig. 3 is a second embodiment of a resonant conversion circuit according to the present invention.
Fig. 4 is a third embodiment of a resonant conversion circuit according to the present invention.
Fig. 5 is a fourth embodiment of a resonant conversion circuit according to the present invention.
Fig. 6 is a fifth embodiment of a resonant conversion circuit according to the present invention.
Fig. 7 is a sixth embodiment of a resonant conversion circuit according to the present invention.
Fig. 8 is a seventh embodiment of a resonant conversion circuit according to the present invention.
Fig. 9 is a schematic diagram of an eighth embodiment of a resonant conversion circuit according to the present invention.
Fig. 10 is a ninth embodiment of a resonant conversion circuit according to the present invention.
Fig. 11 is a tenth embodiment of a resonant conversion circuit according to the present invention.
Fig. 12 is a waveform diagram illustrating the operation of the resonance module of fig. 2.
Fig. 13 is a waveform diagram illustrating the operation of the resonance module of fig. 11.
The attached drawings are used for identifying and describing:
101. 201, 301, 401, 501, 601, 701, 801, 901, 1001, 1101-resonance module; 1011. 2011, 3011, 4011, 5011, 6011, 7011, 8011, 9011, 10011, 11011-resonant branch; 1012. 2012, 3012, 4012, 5012, 6012, 7012, 8012, 9012, 10012, 11012-switching units; 1013. 2013, 3013, 4013, 5013, 6013, 7013, 8013, 9013, 10013, 11013-rectifying unit; 102. 202, 302, 402, 502, 602, 702, 802, 902, 1002, 1102-a resonant current detection module; 103. 203, 303, 403, 503, 603, 703, 803, 903, 1003, 1103—excitation current detection module.
Detailed Description
In order to make the purpose and technical solutions of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. It will be apparent that the described embodiments are some, but not all, embodiments of the invention. All other embodiments, which can be made by a person skilled in the art without creative efforts, based on the described embodiments of the present invention fall within the protection scope of the present invention.
Referring to FIG. 1, a resonant conversion circuit of the present invention comprises a resonant module 101, a resonant current detection module 102, and an exciting current detection module 103, and is input with a power supply V in The power supply is performed to the resonance module 101, the output end of the resonance module 101 is connected with a load, the input end of the resonance current detection module 102 is connected in the resonance module 101, and the resonance current i in the resonance module 101 is detected Lr The resonant current detection module 102 outputs a voltage v cs1 The exciting current detection module 103 is configured to detect an exciting current i in the resonance module 101 Lm The exciting current detection module 103 outputs a voltage v cs2 The output end of the exciting current detection module 103 is connected in parallel with the output end of the resonant current detection module 102 and outputs a voltage v sy . The resonant current i Lr And the exciting current i Lm The weighting obtains a secondary winding current signal, i.e. a load current signal, which can be used for current reporting and zero crossing detection.
Further, the input power V in Is a direct current voltage source.
Further, the resonant module 101 includes a resonant branch 1011, a switching unit 1012 and a rectifying unit 1013, the resonant branch 1011, the switching unit 1012 and the rectifying unit 1013 are connected in parallel, and an input terminal of the resonant current detection module 102 is connected to the resonant branch 1011. The switching unit 1012 is, for example, a full-bridge or half-bridge module, and the rectifying unit 1013 is, for example, a full-wave rectifying unit or a half-wave rectifying unit, and is not limited to synchronous rectification or asynchronous rectification.
More specifically, resonant branch 1011 includes a capacitance C r Inductance L r And a transformer T r The capacitor C r Is connected to the first output of the switching unit 1012An input end of the resonant current detection module 102 and the capacitor C r Is connected with the second end of the inductor L r One end of (a) is connected with the capacitor C r Is the second end of the inductor L r Is connected with the other end of the transformer T r Primary side winding N of (a) p Is provided with a primary side winding N p Is connected to a second output terminal of the switching unit 1012, the transformer T r Exciting inductance L of (1) m Equivalent parallel connection with the primary side winding N p Two ends of the transformer T r Is arranged on the secondary side of winding N s Is connected to the first input of the rectifying unit 1013, the secondary side winding N s Is connected to a second input of the rectifying unit 1013.
Fig. 2 shows a first embodiment of a resonant conversion circuit according to the present invention, and a specific structure of the switching unit 2012, the rectifying unit 2013, the resonant current detecting module 202 and the exciting current detecting module 203 is provided on the basis of the circuit in fig. 1.
The switch unit 2012 includes a switch Q 1 And switch Q 2 The switch Q 1 Is connected with the source of the switch Q 2 Is connected with the drain electrode of the switch Q 1 Is connected with the input power V in The switch Q 2 Is connected with the input power V in The negative electrode of the input power V in The negative pole of the switch Q is grounded 1 Is connected with the capacitor C r Is provided.
The rectifying unit 2013 includes a diode D 1 And diode D 2 The diode D 1 Is connected to the transformer T r Is arranged on the secondary side of winding N s1 Is connected with the first end of the secondary side winding N s1 Is connected to the transformer T at its second end r Is arranged on the secondary side of winding N s2 Is connected with the first end of the secondary side winding N s2 Is connected to the diode D 2 The anode of the diode D 2 Is connected to the diode D 1 Is a cathode of the diode D 1 Cathode and (B) of (C)The secondary side winding N s1 A capacitor C connected in parallel between the second ends of (2) o The capacitor C o Two ends of parallel resistor R o The resistance R o The voltage at two ends is the output voltage V o 。
Further, the transformer T r Is N.
More specifically, the primary side winding N p Has a number of turns of N 1 The secondary side winding N s1 And the secondary side winding N s2 The number of turns of (a) is N 2 。
The resonant current detection module 202 includes an operational amplifier a 1 Capacitance C 1 Capacitance C 2 Resistance R 1 And resistance R 2 The capacitor C r Through the capacitor C 2 Is connected with the operational amplifier A 1 The capacitor C r Through the capacitor C 1 Is connected with the operational amplifier A 1 Is the negative input terminal of the resistor R 2 Is grounded, the resistor R 2 Is connected to the second end of the operational amplifier A 1 The resistor R is at the input positive end of 1 Is connected with the operational amplifier A 1 Is the negative input terminal of the resistor R 1 Is connected to the second end of the operational amplifier A 1 The output end of the operational amplifier A 1 The output end of (2) outputs the voltage v cs1 。
Further, diode D 1 Diode D 2 Capacitance C o And forming a rectifying and filtering network.
Further, the resistor R 1 And the resistance R 2 Is equal to R s The capacitor C 1 And the capacitor C 2 Is equal to C s 。
The capacitor C r Not grounded at either end, for the capacitor C r Differential sampling of the voltage at two ends and taking differential form as the operational amplifier A 1 According to the input of the operational amplifier A 1 The voltage can be obtained by the virtual short and the virtual break of (1)v cs1 ：
，
The above-mentioned formulas are available in parallel,
，
that is to say,
，
wherein v is cr+ For the capacitor C r Voltage at positive terminal v cr- For the capacitor C r Voltage of negative terminal v + For the operational amplifier A 1 V of the input positive terminal - For the operational amplifier A 1 V of the negative input terminal cr For the capacitor C r The voltage across the two terminals, as can be seen from the above formula, the voltage v cs1 With the resonant current i Lr In proportion R s C s /C r 。
The exciting current detection module 203 includes a winding N s3 Resistance R 3 And capacitor C 3 The winding N s3 Coupled to the transformer T r Is arranged on the primary side of the winding N s3 Is connected to the primary side winding N p The resistor R is at the second end of 3 Is connected to the winding N at a first end thereof s3 The capacitor C 3 Is connected to the resistor R 3 The capacitor C 3 Is grounded at the second end of the resistor R 3 Is passed through resistor R 4 And resistance R 5 Is connected with the operational amplifier A 1 The output end of the capacitor C 3 And the resistance R 3 Outputs the voltage v at the connection point of (2) cs2 The resistance R 4 And the resistance R 5 Output voltage v of the junction point of (2) sy1 。
Further, the winding N s3 Turns of (2)Is N 3 。
In this embodiment, the working principle of the resonant conversion circuit is as follows: a complete switching period T s The switch Q is internally provided with 1 And the switch Q 2 Is switched on alternately when only switch Q 1 On, half of the switching period T is passed s The positive half cycle of the resonant module 201 operates, the diode D 1 Forward conduction, the output voltage V o Through the transformer T r Added to the exciting inductance L m Two ends of the exciting inductance L m Is clamped to N x V o The method comprises the steps of carrying out a first treatment on the surface of the When the switch Q 2 Conduction, the negative half cycle of the resonant module 201 is operated, the diode D 2 Forward conduction, the output voltage V o Through the transformer T r Added to the exciting inductance L m Two ends of the exciting inductance L m Is clamped to-N x V o From this, it can be seen that the exciting current i Lm And the transformer T r The relation of the voltages of (a) is:
。
in the exciting current detection module 203, the resistor R 3 And the capacitor C 3 An integrating module is formed by connecting the windings N in series 3 The voltage at two ends is the input voltage of the integration module, the voltage v cs2 For the output voltage of the integrating module, the correlation formula is as follows:
。
as can be seen from the above two formulas, the voltage v cs2 With the exciting current i Lm The relation of (2) is as follows:
。
due to the voltage v sy1 For the voltage v cs1 And saidVoltage v cs2 And, then, the voltage v sy1 With the exciting current i Lm The resonant current i Lr The relation of (2) is as follows:
，
when the proper parameters are selected so thatAnd when the method is used, the following steps are carried out:
，
wherein i is o Is the load current. As can be seen from the above, the voltage v sy1 With the load current i o In proportion R s C s /C r 。
FIG. 12 is a waveform diagram illustrating the operation of the resonant module 201 of FIG. 2, wherein V gs1 For the switch Q 1 Drive signal of V gs2 For the switch Q 2 I Lr For resonant current, i Lm For exciting current, i o For load current, v ys1 For the load current i o A corresponding sampled signal. As can be seen from the figure, the load current i o Corresponding sampled signal v ys1 Can follow the load current i o The same ratio is changed.
In summary, the resonant conversion circuit in fig. 2 samples the capacitance C through the differentiating circuit r The voltage on the capacitor obtains the resonant current i Lr By externally adding the winding N s3 The integrating module obtains the exciting current i Lm No extra loss is brought, fewer peripheral devices are needed, and the efficiency and the power density of the system are improved; the differential sampling mode is adopted, so that the influence of switching noise on sampling signals is reduced, and current control and rapid protection are facilitated; the resonant current i Lr And the exciting current i Lm Weighting to obtain secondary side winding current signal, i.e. the load current i o The signal post-stage rectifier circuit can be used for current reporting and zero crossing point detection; the current sampling method for subtracting the exciting current can obtain a more accurate resonance current signal and can be used for more accurate current control and protection.
As shown in FIG. 3, a second embodiment of a resonant conversion circuit according to the present invention is shown, wherein an operational amplifier A is added on the basis of the circuit in FIG. 2 2 Resistance R 6 And resistance R 7 An in-phase proportional amplifying circuit formed by the operational amplifier A 2 Is connected to the input positive terminal of the resistor R 4 And the resistance R 5 Is connected with the operational amplifier A 2 Is passed through the resistor R 6 Is connected with the resistor R 2 The resistor R 7 Is connected with the operational amplifier A 2 Is the negative input terminal of the resistor R 7 Is connected to the second end of the operational amplifier A 2 The output end of the operational amplifier A 2 Output terminal of (2) outputs voltage v sy2 . In the present embodiment, the resistor R 4 And the resistance R 5 The resistance values of (2) are equal.
According to the property of the homodromous proportional amplifying circuit, the following steps are obtained:
，
as can be seen from the above, the voltage v sy2 With the load current i o Proportional (1+R) 7 /R 6 )R s C s /C r 。
Referring to FIG. 4, a third embodiment of a resonant conversion circuit according to the present invention is shown, and another embodiment of an exciting current detection module 403 is provided based on the circuit in FIG. 2, which includes a winding N s3 Resistance R 3 And capacitor C 3 The winding N s3 Coupled to the transformer T r Is arranged on the primary side of the winding N s3 Is connected to the resistor R 3 The resistor R 3 Is connected to the capacitor C 3 Is arranged at the first end ofThe capacitor C 3 Is connected to the winding N at a second end thereof s3 The capacitor C 3 Is connected to the second end of the operational amplifier A 1 The output end of the capacitor C 3 Is the voltage v cs2 The capacitor C 3 And the resistance R 3 Output voltage v of the junction point of (2) sy3 。
In this embodiment, the working principle of the resonant conversion circuit is the same as that of fig. 2, and it can be obtained that:
，
as can be seen from the above, the voltage v sy3 With the load current i o In proportion R s C s /C r 。
Figures 2 to 4 are all obtained by the use of a main transformer, namely the transformer T r With the addition of the windings N s3 And the integrating module obtains the exciting current i Lm The winding N s3 And the transformer T in the resonant circuit r Is coupled together, the transformer T is additionally increased r Is provided. Referring to fig. 5, a fourth embodiment of a resonant conversion circuit according to the present invention is provided, based on the circuit in fig. 2, with another embodiment of an exciting current detection module 503, including a transformer T r1 Resistance R 8 And capacitor C 4 The transformer T r1 Is arranged on the secondary side of winding N f4 Is connected to the primary side winding N p The resistor R is at the second end of 8 Is connected to the secondary side winding N f4 The capacitor C 4 Is connected to the resistor R 8 The capacitor C 4 Is grounded at the second end of the resistor R 8 Through the resistor R 4 And the resistance R 5 Is connected with the operational amplifier A 1 The output end of the capacitor C 4 And the resistance R 8 Outputs the voltage v at the connection point of (2) cs2 The resistance R 4 And the resistance R 5 Output voltage v of the junction point of (2) sy4 The transformer T r1 Primary side winding N of (a) f5 Is input to the switch Q 2 Is set to drive signal V of gs2 The transformer T r1 Primary side winding N of (a) f5 Is input to the switch Q 1 Is set to drive signal V of gs1 。
Further, the secondary side winding N f4 Has a number of turns of N 4 The primary side winding N f5 Has a number of turns of N 5 。
In the exciting current detection module 503, the resistor R 8 And the capacitor C 4 An integrating module is formed by connecting the windings N in series f4 The voltage at two ends is the input voltage of the integration module, the voltage v cs2 For the output voltage of the integrating module, the correlation formula is as follows:
，
wherein due to the switch Q 1 And the switch Q 2 Complementary conduction, record V gs For the switch Q 1 Is set to drive signal V of gs1 then-V gs The switch Q 2 Is set to drive signal V of gs2 。
As is known from fig. 2, the excitation current i Lm And the transformer T r The relation of the voltages of (a) is:
。
as can be seen from the above two formulas, the voltage v cs2 With the exciting current i Lm The relation of (2) is as follows:
。
due to the voltage v sy4 For the voltage v cs1 And the voltage v cs2 And, then, the voltage v sy4 With the exciting current i Lm The resonant current i Lr The relation of (2) is as follows:
，
when the proper parameters are selected so thatAnd when the method is used, the following steps are carried out:
，
as can be seen from the above, the voltage v sy4 With the load current i o In proportion R s C s /C r 。
As shown in FIG. 6, a fifth embodiment of a resonant conversion circuit according to the present invention is shown, wherein an operational amplifier A is added on the basis of the circuit in FIG. 5 2 Resistance R 6 And resistance R 7 An in-phase proportional amplifying circuit formed by the operational amplifier A 2 Is connected to the input positive terminal of the resistor R 4 And the resistance R 5 Is connected with the operational amplifier A 2 Is passed through the resistor R 6 Is connected with the resistor R 2 The resistor R 7 Is connected with the operational amplifier A 2 Is the negative input terminal of the resistor R 7 Is connected to the second end of the operational amplifier A 2 The output end of the operational amplifier A 2 Output terminal of (2) outputs voltage v sy5 . In the present embodiment, the resistor R 4 And the resistance R 5 The resistance values of (2) are equal.
According to the property of the homodromous proportional amplifying circuit, the following steps are obtained:
，
as can be seen from the above, the voltage v sy5 With the load current i o Proportional (1+R) 7 /R 6 )R s C s /C r 。
As shown in fig. 7, which shows a sixth embodiment of a resonant conversion circuit according to the present invention, another embodiment of the exciting current detection module 703 is provided based on the circuit in fig. 4, which includes a transformer T r1 Resistance R 8 And capacitor C 4 The transformer T r1 Is arranged on the secondary side of winding N f4 Is connected to the resistor R 8 The resistor R 8 Is connected to the capacitor C 4 Is the first end of the capacitor C 4 Is connected to the secondary side winding N f4 The capacitor C 4 Is connected to the second end of the operational amplifier A 1 The output end of the capacitor C 4 Is the voltage v cs2 The capacitor C 4 And the resistance R 8 Output voltage v of the junction point of (2) sy6 The transformer T r1 Primary side winding N of (a) f5 Is input to the switch Q 1 Is set to drive signal V of gs1 The transformer T r1 Primary side winding N of (a) f5 Is input to the switch Q 2 Is set to drive signal V of gs2 。
In this embodiment, the working principle of the resonant conversion circuit is the same as that of fig. 5, and it can be obtained that:
，
as can be seen from the above, the voltage v sy6 With the load current i o In proportion R s C s /C r 。
Compared with fig. 2 to 4, the exciting current sampling winding in fig. 5 to 7 is a transformer T r1 Is arranged on the secondary side of winding N f4 With main transformer, i.e. transformer T r Is not occupied by transformer T r Is beneficial to miniaturization design of the magnetic element and improves the power density. And it can be seen from the embodiments of fig. 5 to 7 that the exciting current sampling winding exciting voltage only needs to be equal to the output voltage V o The same phase is needed, constant current is generated to detect exciting current in a complete periodThe capacitor in the measuring module is charged and discharged, and then the exciting current i is obtained Lm Capacitive voltage signal of the same proportion, i.e. the voltage v cs2 For sampling the signal, a specific circuit structure is shown in fig. 8 to 10, and another specific structure of the exciting current detection module is provided on the basis of the circuits in fig. 2 to 4.
The exciting current detection module in fig. 8 to 10 includes a current source CS 1 Current source CS 2 And capacitor C 6 The current source CS 1 Output current I 1 The current source CS 2 Output current I 2 The capacitor C 6 One end of which is connected to the current source CS 1 And the current source CS 2 Is the mid-point of the series connection of the capacitor C 6 Is connected with the output end of the resonant current detection module, and a switch Q 1 Is set to drive signal V of gs1 Switch Q 2 Is set to drive signal V of gs2 Separately controlling current sources CS 1 And a current source CS 2 The following conditions are satisfied:
，
，
the voltage v in the exciting current detection module cs2 The relationship with the switch drive signal is as follows:
，
referring to the derivation process in fig. 5, it can be seen that:
，
when the proper parameters are selected so thatWhen the load current i is equal to the sampling voltage o In proportion R s C s /C r . Where K is a coefficient.
The embodiments of fig. 2-10, while having lossless characteristics and accurate sampling, introduce many peripheral devices that are detrimental to power density improvement. For further improvement, the resonant conversion circuit obtains the resonant current i Lr And the exciting current i Lm The method of (1) shares a shunt capacitor, and the load current i is obtained by adopting a two-current weighting method o The specific circuit configuration is shown in fig. 11.
Fig. 11 is a tenth embodiment of a resonant conversion circuit according to the present invention, and another specific structure of the resonant current detection module 1102 and the exciting current detection module 1103 is provided based on the circuit in fig. 2. In this embodiment, the resonant current detection module 1102 outputs a voltage v cs1 Input operational amplifier A 3 The voltage v output by the exciting current detection module 1103 cs2 Input the operational amplifier A 3 Is the negative input terminal of the operational amplifier A 3 Output voltage v sy10 。
The resonant current detection module 1102 includes a resistor R 9 And resistance R 10 The resistance R 9 Is grounded, the resistor R 9 Is connected to the second end of the operational amplifier A 3 The resistor R is at the input positive end of 10 Is connected to the resistor R 9 The resistor R is at the second end of 10 Is connected to the inductor L r The resistor R 10 And the resistance R 9 Outputs the voltage v at the connection point of (2) cs1 。
The exciting current detection module 1103 includes a winding N s6 And capacitor C 5 The winding N s6 Coupled to the transformer T r Is arranged on the primary side of the winding N s6 Is connected to the primary side winding N p Is connected with the second end of the winding N s6 Is connected to the second end of the operational amplifier A 3 Is the negative input terminal of the capacitor C 5 Is connected to the winding N at a first end thereof s6 The capacitor C 5 Is connected with the second end of (a)Connected to the resistor R 9 The capacitor C 5 And the winding N s6 Outputs the voltage v at the connection point of (2) cs2 。
Further, the winding N s6 Has a number of turns of N 6 。
In the present embodiment, the resistor R 9 And the capacitor C 5 An integrating module is formed by connecting the windings N in series s6 The voltage at two ends is the input voltage of the integration module, the voltage v cs2 For the output voltage of the integrating module, the correlation formula is as follows:
。
the exciting current i Lm And the transformer T r The relation of the voltages of (a) is:
。
as can be seen from the above two formulas, the voltage v cs2 With the exciting current i Lm The relation of (2) is as follows:
。
from FIG. 11, the voltage v cs1 For the parasitic resistance R Lr And (3) applying voltage to obtain:
，
when the proper parameters are selected so thatThe method can obtain:
。
when the proper parameters are selected so thatThe method can obtain:
，
that is to say,
，
as can be seen from the above, the voltage v sy10 With the load current i o In proportion R Lr 。
FIG. 13 is a waveform diagram illustrating the operation of the resonant module 1101 of FIG. 11, wherein V gs1 For the switch Q 1 Drive signal of V gs2 For the switch Q 2 I Lr For resonant current, i Lm For exciting current, i o For load current, v sy10 For the operational amplifier A 3 Is set, the output voltage of which is set. As can be seen from the figure, the operational amplifier a 3 Output voltage v of (2) sy10 Can follow the load current i o The same ratio is changed.
To sum up, the resonant conversion circuit in fig. 11 only needs to add one additional winding, namely the winding N s6 The load current i can be obtained by matching with simple units such as capacitance, resistance and the like o No extra loss is brought, fewer peripheral devices are needed, and the efficiency and the power density of the system are improved; and is suitable for any resonant circuit in which a resonant inductor and a transformer are connected in series, and the resonant circuit is free from an external resonant inductor and replaces the resonant inductor with a transformer leakage inductance.
It should be noted that the resonant conversion circuit of the present invention is applicable not only to LLC half-bridge resonant circuits, but also to various resonant circuits, such as LCC resonant conversion circuits, series resonant conversion circuits, parallel resonant conversion circuits, and the like, and various quasi-resonant conversion circuits.
Although the present invention has been described with reference to the above embodiments, it should be understood that the invention is not limited thereto, but rather is capable of modification and variation without departing from the spirit and scope of the present invention.

Claims (12)

1. The utility model provides a resonance converting circuit, includes resonance branch road, switch unit and rectification unit, and input power supply connects the input port of switch unit is for resonance converting circuit supplies power, switch unit, resonance branch road and rectification unit parallel connection, the load is connected to rectification unit's output, its characterized in that, resonance converting circuit still includes: the input end of the resonance current detection module is connected with the resonance branch and is used for detecting resonance current in the resonance branch, and the resonance current detection module outputs a first voltage;
the exciting current detection module is used for detecting exciting current in the resonant branch, the exciting current detection module outputs second voltage, and the output end of the exciting current detection circuit is connected with the output end of the resonant current detection circuit in parallel and outputs third voltage.
2. A resonant conversion circuit according to claim 1, wherein the resonant branch comprises a resonant capacitor, a first terminal of the resonant capacitor being connected to the first output terminal of the switching unit, an input terminal of the resonant current detection module being connected to the second terminal of the resonant capacitor,
a resonant inductor, a first end of the resonant inductor is connected with a second end of the resonant capacitor,
the first end of the primary side winding of the main transformer is connected with the second end of the resonant inductor, the second end of the primary side winding of the main transformer is connected with the second output end of the switch unit, the first end of the first secondary side winding of the main transformer is connected with the first input end of the rectifying unit, the second end of the first secondary side winding of the main transformer is connected with the first end of the second secondary side winding of the main transformer, and the second end of the second secondary side winding of the main transformer is connected with the second input end of the rectifying unit.
3. The resonant conversion circuit of claim 2, wherein the resonant current detection module comprises a first operational amplifier, a first capacitor, a second capacitor, a first resistor and a second resistor, wherein a first end of the resonant capacitor is connected to an input positive end of the first operational amplifier through the second capacitor, a second end of the resonant capacitor is connected to an input negative end of the first operational amplifier through the first capacitor, an input positive end of the first operational amplifier is grounded through the second resistor, an input negative end of the first operational amplifier is connected to an output end of the first operational amplifier through the first resistor, and the output end of the first operational amplifier outputs the first voltage.
4. A resonant conversion circuit according to claim 3, wherein the exciting current detection module comprises a third winding, a third resistor and a third capacitor, the third winding is coupled to the primary side of the main transformer, a first end of the third winding is connected to a second end of the primary side winding of the main transformer, a first end of the third resistor is connected to a second end of the third winding, a first end of the third capacitor is connected to a second end of the third resistor, a second end of the third capacitor is grounded, and a junction of the third capacitor and the third resistor outputs the second voltage.
5. The resonant conversion circuit of claim 4, further comprising a fourth resistor and a fifth resistor, wherein a second terminal of the third resistor is connected to the output terminal of the first operational amplifier through the fourth resistor and the fifth resistor.
6. The resonant conversion circuit of claim 5, further comprising a second operational amplifier, a sixth resistor, and a seventh resistor, wherein an input positive terminal of the second operational amplifier is connected to a connection point between the fourth resistor and the fifth resistor, an input negative terminal of the second operational amplifier is grounded through the sixth resistor, and an input negative terminal of the second operational amplifier is connected to an output terminal of the second operational amplifier through the seventh resistor.
7. A resonant conversion circuit according to claim 3, wherein the exciting current detection module comprises a third winding, a third resistor and a third capacitor, the third winding is coupled to the primary side of the main transformer, a first end of the third winding is connected to the first end of the third resistor, a second end of the third resistor is connected to the first end of the third capacitor, a second end of the third capacitor is connected to the second end of the third winding, a second end of the third capacitor is connected to the output end of the first operational amplifier, a voltage across the third capacitor is the second voltage, and a junction point of the third capacitor and the third resistor outputs the third voltage.
8. A resonant conversion circuit according to any one of claims 4-7, wherein the excitation current detection module further comprises a secondary transformer, the third winding being a secondary side winding of the secondary transformer, the primary side winding of the secondary transformer being provided with a drive signal for the switching module.
9. The resonant conversion circuit of claim 2, wherein the resonant current detection module comprises a ninth resistor and a tenth resistor, an input positive terminal of a third operational amplifier is grounded through the ninth resistor, the input positive terminal of the third operational amplifier is connected to the second terminal of the resonant capacitor through the tenth resistor, and a connection point of the tenth resistor and the ninth resistor outputs the first voltage.
10. The resonant conversion circuit of claim 9, wherein the excitation current detection module comprises a sixth winding and a fifth capacitor, the sixth winding is coupled to the primary side of the main transformer, a first end of the sixth winding is connected to a second end of the primary side winding of the main transformer, a second end of the sixth winding is connected to an input negative terminal of the third operational amplifier, a first end of the fifth capacitor is connected to a second end of the sixth winding, a second end of the fifth capacitor is connected to an input positive terminal of the third operational amplifier, and an output terminal of the third operational amplifier outputs the third voltage.
11. A resonant conversion circuit according to claim 3, wherein the exciting current detection module comprises a plurality of current sources and a sixth capacitor, one end of the sixth capacitor is connected to a common end of the plurality of current sources, and the sixth capacitor is connected to an output end of the resonant current detection module.
12. The resonant conversion circuit of claim 11, wherein the drive signal of the switching module controls the current source and is proportional to the output current of the current source.
CN202311778087.0A 2023-12-22 2023-12-22 Resonant conversion circuit Withdrawn CN117477966A (en)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100020578A1 (en) * 2008-07-25 2010-01-28 Samsung Electro-Mechanics Co., Ltd. Adapter power supply
CN112019002A (en) * 2020-08-06 2020-12-01 杭州电子科技大学 LLC resonant converter primary side constant current control device
CN115811219A (en) * 2022-12-07 2023-03-17 中国船舶集团有限公司第七二三研究所 Self-adaptive soft start control circuit and method for resonant bus converter

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100020578A1 (en) * 2008-07-25 2010-01-28 Samsung Electro-Mechanics Co., Ltd. Adapter power supply
CN112019002A (en) * 2020-08-06 2020-12-01 杭州电子科技大学 LLC resonant converter primary side constant current control device
CN115811219A (en) * 2022-12-07 2023-03-17 中国船舶集团有限公司第七二三研究所 Self-adaptive soft start control circuit and method for resonant bus converter

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Application publication date: 20240130