CN115242096A - Power supply conversion circuit with magnetic balance and control method thereof - Google Patents
Power supply conversion circuit with magnetic balance and control method thereof Download PDFInfo
- Publication number
- CN115242096A CN115242096A CN202210815482.0A CN202210815482A CN115242096A CN 115242096 A CN115242096 A CN 115242096A CN 202210815482 A CN202210815482 A CN 202210815482A CN 115242096 A CN115242096 A CN 115242096A
- Authority
- CN
- China
- Prior art keywords
- peak value
- diode
- current
- resistor
- magnetic balance
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- 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
- H02M3/33576—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 having at least one active switching element at the secondary side of an isolation transformer
- H02M3/33584—Bidirectional converters
-
- 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
- H02M1/32—Means for protecting converters other than automatic disconnection
-
- 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
- H02M3/33576—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 having at least one active switching element at the secondary side of an isolation transformer
-
- 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
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/50—Photovoltaic [PV] energy
- Y02E10/56—Power conversion systems, e.g. maximum power point trackers
Abstract
The invention discloses a power conversion circuit with magnetic balance and a control method thereof, wherein the power conversion circuit comprises a primary side conversion module, a transformer, a secondary side conversion module, a processor and a magnetic balance sampling module which are sequentially connected, the magnetic balance sampling module comprises a current transformer, a first sampling branch and a second sampling branch, the first sampling branch or the second sampling branch respectively collects a positive component and a negative component in output current I0, and the processor adjusts a power switch in the secondary side conversion module according to the difference value of the positive component and the negative component to realize the magnetic balance; according to the invention, the maximum value of a high-frequency signal is acquired by using a lower sampling frequency, the magnetic deflection phenomenon on two sides of the bidirectional resonant converter is effectively eliminated, and the balance control of a magnetic circuit is realized, so that the saturation is avoided, the blocking capacitor on the secondary side is cancelled, and the volume and the cost of equipment are reduced; meanwhile, the circuit and the control method are simple, and the cost is reduced.
Description
Technical Field
The present invention relates to power conversion circuits, and particularly to a power conversion circuit with magnetic balance and a control method thereof.
Background
With the increase of the bidirectional power transmission requirement in a power conversion circuit, at present, in the application of vehicle-mounted OBC, super charging pile, photovoltaic system, energy storage and the like, a bidirectional excitation isolation topological structure is generally adopted, but in the structure, if magnetic bias occurs, the soft switching characteristic of a switching tube is changed, the excitation current of a transformer is superposed with direct current quantity, the magnetic core loss is increased, the transformer can be saturated, and circuit components are burnt. Fig. 1 shows that when magnetic imbalance occurs, resonant cavity current is over-current, peak current is large, and the sampling frequency of the current sampling circuit cannot track the peak current generated in a short time, so that the existing solution cannot realize loop control to adjust the magnetic imbalance.
Therefore, it is an urgent technical problem in the art to design a magnetic balance sampling circuit capable of collecting a short-time peak current, realizing balance control of a magnetic circuit, and avoiding saturation.
Disclosure of Invention
In order to solve the above-mentioned defects in the prior art, the present invention provides a power conversion circuit with magnetic balance and a control method thereof.
The invention adopts the technical scheme that a power conversion circuit with magnetic balance is designed, which comprises a primary side conversion module, a transformer, a secondary side conversion module, a processor and a magnetic balance sampling module, wherein the primary side conversion module, the transformer, the secondary side conversion module and the processor are sequentially connected; the first sampling branch circuit collects a forward component in the output current I0; the second sampling branch circuit collects a negative component in the output current I0; and the processor adjusts a power switch in the secondary side conversion module according to the difference value of the positive component and the negative component to realize magnetic balance.
The first sampling branch comprises a first signal separation unit and a first quasi-peak value sampling unit which are connected in series, the first signal separation unit is used for separating a forward component in the output current I0 and converting the forward component into a forward component voltage signal, and the first quasi-peak value sampling unit is used for collecting a peak value of the forward component voltage signal and defining the peak value as a forward current peak value I1; the second sampling branch comprises a second signal separation unit and a second quasi-peak value sampling unit which are connected in series, the second signal separation unit is used for separating a negative component in the output current I0 and converting the negative component into a negative component voltage signal, and the second quasi-peak value sampling unit is used for collecting a peak value of the negative component voltage signal and defining the peak value as a negative current peak value I2; and the processor adjusts a power switch in the secondary side conversion module according to the peak value difference Is of the output positive current peak value I1 and the output negative current peak value I2 so as to realize magnetic balance.
The first signal separation unit comprises a first diode D1, a second diode D2 and a first resistor R1, the first quasi-peak value sampling unit comprises a first operational amplifier U1, a third diode D3, a second resistor R2, a first capacitor C1 and a third resistor R3, wherein the anode of the first diode D1 is connected with the head end of the secondary winding of the current transformer, the cathode of the first diode D1 is connected with one end of the first resistor R1 and is connected with the first quasi-peak value sampling unit, the cathode of the second diode D2 is connected with the tail end of the secondary winding of the current transformer, and the anode of the second diode D2 is connected with the other end of the first resistor R1 and is grounded; the non-inverting input end of the first operational amplifier U1 is connected with the cathode of the first diode D1, the output end of the first operational amplifier U1 is connected with the anode of the third diode D3, the inverting input end of the first operational amplifier U1 is connected with the cathode of the third diode D3 and one end of the second resistor R2, the other end of the second resistor R2 is connected with one ends of the first capacitor C1 and the third resistor R3 and is connected with the processor, and the other ends of the first capacitor C1 and the third resistor R3 are grounded.
The second signal separation unit comprises a fourth diode D4, a fifth diode D5 and a fourth resistor R4, the second quasi-peak value sampling unit comprises a second operational amplifier U2, a sixth diode D6, a fifth resistor R5, a second capacitor C2 and a sixth resistor R6, wherein the anode of the fourth diode D4 is connected with the tail end of the secondary winding of the current transformer, the cathode of the fourth diode D4 is connected with one end of the fourth resistor R4 and is connected with the second quasi-peak value sampling unit, the cathode of the fifth diode D5 is connected with the head end of the secondary winding of the current transformer, and the anode of the fifth diode D5 is connected with the other end of the fourth resistor R4 and is grounded; the non-inverting input end of the second operational amplifier U2 is connected with the cathode of the fourth diode D4, the output end of the second operational amplifier U2 is connected with the anode of the sixth diode D6, the inverting input end of the second operational amplifier U2 is connected with the cathode of the sixth diode D6 and one end of a fifth resistor R5, the other end of the fifth resistor R5 is connected with one ends of the second capacitor C2 and the sixth resistor R6 and is connected with the processor, and the other ends of the second capacitor C2 and the sixth resistor R6 are grounded.
The secondary winding of the current transformer is further connected with a rectifying module 102, the rectifying module is used for collecting the output current I0 and transmitting the output current I0 to a processor, and when the output current I0 is larger than the maximum output current peak value Imax, the processor controls the primary side conversion module and the secondary side conversion module to stop working.
The transformer includes second secondary winding W2 and fifth secondary winding W5, vice limit conversion module is including the vice limit high voltage conversion module of connecting second secondary winding W2, the vice limit low voltage conversion module of connecting fifth secondary winding W5, magnetic balance sampling module connects second secondary winding W2.
The transformer includes second secondary winding W2 and fourth secondary winding W4, vice limit conversion module is including the first conversion module in vice limit of connecting second secondary winding W2, the vice limit second conversion module of connecting fourth secondary winding W4, and the output of vice limit first conversion module and vice limit second conversion module is parallelly connected, the magnetic balance sampling module is connected the second secondary winding W2.
The invention also discloses a control method of the power supply conversion circuit with magnetic balance, the power supply conversion circuit adopts the power supply conversion circuit with magnetic balance, the control method comprises the steps of collecting the positive component and the negative component in the output current I0, and calculating the peak value difference Is of the positive component and the negative component; and when the peak difference Is larger than the threshold N, controlling a power switch in the secondary side conversion module to enable the peak difference Is to be smaller than or equal to the threshold N.
In one embodiment, the control method specifically includes the following steps:
step 1, collecting a positive current peak value I1 and a negative current peak value I2;
step 13, reducing the positive current peak value I1 or increasing the negative current peak value I2, and turning to the step 1;
and 14, reducing the negative current peak value I2 or increasing the positive current peak value I1, and turning to the step 1.
In another embodiment, the control method specifically includes the following steps:
step 1, collecting a positive current peak value I1 and a negative current peak value I2;
step 2, collecting output current I0;
step 3, judging that I0 is larger than or equal to Imax, if so, turning to step 20, otherwise, turning to step 10;
step 13, reducing the positive current peak value I1 or increasing the negative current peak value I2, and turning to the step 1;
step 14, reducing the negative current peak value I2 or increasing the positive current peak value I1, and turning to the step 1;
and 20, stopping working of the primary side conversion module and the secondary side conversion module.
The technical scheme provided by the invention has the beneficial effects that:
the invention can acquire the maximum value of the high-frequency signal by using a lower sampling frequency, can be suitable for the current conditions of the bidirectional resonant converter in different modes, and has universality; the magnetic deflection phenomenon on two sides of the bidirectional resonant converter is effectively eliminated, and the balance control of a magnetic circuit is realized, so that the saturation is avoided, the blocking capacitor on the secondary side is cancelled, and the equipment volume and the cost are reduced; meanwhile, the circuit and the control method are simple, and the cost is reduced.
Drawings
The invention is described in detail below with reference to examples and figures, in which:
FIG. 1 is a schematic view of secondary side conversion module cavity current imbalance;
FIG. 2 is a functional block diagram of the present invention;
FIG. 3 is a circuit diagram of first and second sampling branches;
FIG. 4 is a functional block diagram of a preferred embodiment of the present invention;
FIG. 5 is a circuit diagram of a rectification block, first and second sampling branches;
FIG. 6 is a plot of actual current versus sampled peak voltage waveform;
FIG. 7 is an application of the present invention to a circuit having only one secondary side conversion module;
FIG. 8 is an application of the present invention to a circuit having a high voltage conversion module and a low voltage conversion module on the secondary side;
FIG. 9 is an application of the present invention to a circuit having a first conversion module and a second conversion module on the secondary side;
FIG. 10 is a control flow diagram of the present invention without a rectifier module;
fig. 11 is a control flow chart when the present invention has a rectifier module.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
The invention provides a power supply conversion circuit with magnetic balance and a magnetic balance control method thereof.
The invention discloses a power conversion circuit with magnetic balance, which comprises a primary side conversion module, a transformer, a secondary side conversion module, a processor and a magnetic balance sampling module, wherein the primary side conversion module, the transformer, the secondary side conversion module and the processor are sequentially connected; the first sampling branch circuit collects a forward component in the output current I0; the second sampling branch circuit collects a negative component in the output current I0; and the processor adjusts a power switch in the secondary side conversion module according to the difference value of the positive component and the negative component to realize magnetic balance.
It should be noted that the current transformer is connected in series in the output line of the secondary winding of the transformer, and can measure the current in the cavity of the secondary conversion module, and when the sampling branch separates the positive component and the negative component, the current has been converted into a voltage signal, and the difference is substantially the difference between the two voltages.
Referring to the schematic block diagram shown in fig. 2, the first sampling branch includes a first signal separation unit 103 and a first quasi-peak sampling unit 104 connected in series, the first signal separation unit is configured to separate a forward component in the output current I0 and convert the forward component into a forward component voltage signal, and the first quasi-peak sampling unit is configured to collect a peak of the forward component voltage signal and define the peak as a forward current peak I1; the second sampling branch comprises a second signal separation unit 105 and a second quasi-peak value sampling unit 106 which are connected in series, the second signal separation unit is used for separating a negative component in the output current I0 and converting the negative component into a negative component voltage signal, and the second quasi-peak value sampling unit is used for collecting a peak value of the negative component voltage signal and defining the peak value as a negative current peak value I2; and the processor adjusts a power switch in the secondary side conversion module according to the peak value difference Is of the output positive current peak value I1 and the output negative current peak value I2 so as to realize magnetic balance.
Referring to the circuit diagram shown in fig. 3, the first signal separation unit includes a first diode D1, a second diode D2, and a first resistor R1, the first quasi-peak sampling unit includes a first operational amplifier U1, a third diode D3, a second resistor R2, a first capacitor C1, and a third resistor R3, wherein an anode of the first diode D1 is connected to a head end of the secondary winding of the current transformer, a cathode of the first diode D1 is connected to one end of the first resistor R1 and connected to the first quasi-peak sampling unit, a cathode of the second diode D2 is connected to a tail end of the secondary winding of the current transformer, and an anode of the second diode D2 is connected to the other end of the first resistor R1 and grounded; the non-inverting input end of the first operational amplifier U1 is connected with the cathode of the first diode D1, the output end of the first operational amplifier U1 is connected with the anode of the third diode D3, the inverting input end of the first operational amplifier U1 is connected with the cathode of the third diode D3 and one end of the second resistor R2, the other end of the second resistor R2 is connected with one ends of the first capacitor C1 and the third resistor R3 and is connected with the processor, and the other ends of the first capacitor C1 and the third resistor R3 are grounded.
The principle of the first signal separation unit is that D1 and D2 form half-wave rectification, the primary measured forward current generates voltage on a resistor R1, the voltage passes through a quasi-peak value sampling unit, and the output end collects the peak value of the forward current of the current. Because the detected signal is a sine signal and is half of the steamed bread wave after being separated by half-wave sampling, the maximum value of the steamed bread wave needs to be known; the output end is a charging and discharging loop composed of R2, C1 and R3, because of the existence of the capacitor C1, the voltage behind the diode D3 is the peak value of sampling, when the value of the input signal is smaller than the maximum value of the last steamed bread wave, the voltage of the in-phase input end of the operational amplifier is smaller than the reverse input end, the output of the operational amplifier is negative infinite at the moment, the output is the minimum value of power supply, and because of the existence of the diode D3, the diode D3 is cut off at the moment, and the output is still the maximum value of the last wave; conversely, when the value of the next wave is larger than the maximum value of the previous value, that is, the in-phase input end of the operational amplifier is larger than the reverse-phase input end, the operational amplifier output is infinite at this time, and is also limited by power supply, the output is the upper limit of the power supply, the anode of the diode D3, that is, the voltage of the operational amplifier output end is larger than the cathode of the diode D3 at this time, the diode D3 is in a conducting state, the output is a new maximum value, the resistors R2 and C1 perform filtering and holding on the peak value, so that the output signal is as smooth as possible, and at this time, the processor can acquire the maximum value of the high-frequency signal under the condition of low sampling frequency. The resistor R3 plays a discharging role, the resistance of the resistor R3 is ten to one hundred times larger than that of the resistor R2, and when the input signal is smaller than the currently maintained maximum value, the output signal slowly drops through the discharging of the resistor R3 so as to acquire the next maximum value. As shown in fig. 3, the sampling circuit is used in combination with a negative phase current maximum sampling circuit, the difference value of two sampling signals is used as the input of control to control the magnetic balance of the transformer, the circuit has no high requirement on the sampling accuracy, the final requirement is not affected as long as the positive and negative sampling circuits deviate to one side, and the difference value of the two signals is the key point. The advantage of this circuit is that the maximum value of the high frequency signal can be acquired with a lower sampling frequency. And because the input impedance of the operational amplifier is infinite, the filter circuit at the rear end cannot influence the normal work of the main power loop.
Referring to the circuit diagram shown in fig. 3, the second signal splitting unit includes a fourth diode D4, a fifth diode D5, and a fourth resistor R4, the second quasi-peak value sampling unit includes a second operational amplifier U2, a sixth diode D6, a fifth resistor R5, a second capacitor C2, and a sixth resistor R6, wherein an anode of the fourth diode D4 is connected to a tail end of the secondary winding of the current transformer, a cathode of the fourth diode D4 is connected to one end of the fourth resistor R4 and is connected to the second quasi-peak value sampling unit, a cathode of the fifth diode D5 is connected to a head end of the secondary winding of the current transformer, and an anode of the fifth diode D5 is connected to the other end of the fourth resistor R4 and is grounded; the non-inverting input end of the second operational amplifier U2 is connected with the cathode of the fourth diode D4, the output end of the second operational amplifier U2 is connected with the anode of the sixth diode D6, the inverting input end of the second operational amplifier U2 is connected with the cathode of the sixth diode D6 and one end of a fifth resistor R5, the other end of the fifth resistor R5 is connected with one ends of the second capacitor C2 and the sixth resistor R6 and is connected with the processor, and the other ends of the second capacitor C2 and the sixth resistor R6 are grounded.
The working principle of the second signal separation unit is the same as that of the first signal separation unit, and is not described in detail. Compare in traditional peak value sampling, this application puts the diode in the follower the inside, both can solve the problem of diode pressure drop, can avoid the sampling error problem of temperature influence again.
Referring to the schematic block diagram of the preferred embodiment shown in fig. 4, the secondary winding of the current transformer is further connected to a rectifying module 102, the rectifying module is configured to collect the output current I0 and transmit the output current I0 to the processor, and when the output current I0 is greater than the maximum output current peak value Imax, the processor controls the primary side converting module and the secondary side converting module to stop working. Fig. 5 shows a circuit diagram of a rectifying module, which includes a rectifying unit composed of D7, D8, D9, D10, and a filtering unit composed of R7, R8, C6, and a first and second sampling branch circuits. The rectifier module 102 is present as a protection circuit, where the transformer 101 is multiplexed; the circuit is used for controlling the normal work of the circuit, but a part of the quick performance is sacrificed, and the quick protection is not facilitated. When the control is out of control, the current can rise rapidly, and the quasi-peak sampling circuit is not beneficial to rapid protection in protection time.
Fig. 6 is a comparison of the actual current with the sampled peak voltage waveform, wherein the box indicates that some current spikes may occur in the actual current waveform, and the maximum value of the high frequency signal may be acquired by the above-mentioned sampling circuit with a lower sampling frequency.
Fig. 7 shows the application of the present invention to a circuit with only one secondary side conversion module, where the magnetic balance sampling module collects peak current at a point a at the rear end of W2 (i.e., current in the cavity of the secondary side conversion module), the processor determines the magnetic bias condition of the bidirectional resonant converter according to the collected peak current, and the bidirectional resonant converter is controlled to reach a magnetic balance state by duty ratio adjustment.
Fig. 8 shows an application of the present invention to a secondary side circuit having a high voltage conversion module and a low voltage conversion module, the transformer includes a second secondary winding W2 and a fifth secondary winding W5, the secondary side conversion module includes a secondary side high voltage conversion module connected to the second secondary winding W2 and a secondary side low voltage conversion module connected to the fifth secondary winding W5, and the magnetic balance sampling module is connected to the second secondary winding W2.
Fig. 9 shows an application of the present invention to a circuit having a first switching module and a second switching module on the secondary side, the transformer includes a second secondary winding W2 and a fourth secondary winding W4, the secondary switching module includes a secondary first switching module connected to the second secondary winding W2 and a secondary second switching module connected to the fourth secondary winding W4, outputs of the secondary first switching module and the secondary second switching module are connected in parallel, and the magnetic balance sampling module is connected to the second secondary winding W2.
The conversion circuit can adopt a bidirectional conversion circuit, and when the conversion circuit works in a reverse direction, the adjustment principle of the conversion circuit working in a forward direction is referred to.
A resonant capacitor, namely DAB (double active bridge), is cancelled in the primary side conversion module, and the magnetic balance sampling circuit can also be adopted to solve the problem of primary side magnetic bias. Diodes D1, D2, D3, D4 in FIG. 9 can be replaced by MOS transistors for control, and the problem of magnetic balance is also considered after control; similarly, the Cr in fig. 7, 8, and 9 can be eliminated and will become the DAB circuit, with magnetic balance control on both the primary and secondary sides.
The invention also discloses a control method of the power supply conversion circuit with magnetic balance, the power supply conversion circuit adopts the power supply conversion circuit with magnetic balance, the control method comprises the steps of collecting the positive component and the negative component in the output current I0, and calculating the peak value difference Is of the positive component and the negative component; and when the peak difference Is larger than the threshold N, controlling a power switch in the secondary side conversion module to enable the peak difference Is to be smaller than or equal to the threshold N. The threshold N is a preset value according to the model.
The invention can be applied to a full-bridge series resonance topology two-port circuit, and can be expanded into a control strategy of bidirectional excitation, a phase-shift control DAB, a three-port magnetic integration topology scheme, an extension scheme of a magnetic integration topology and the like. In fig. 7, 8 and 9, the dc blocking capacitor in the secondary side conversion module is eliminated, and the magnetic bias phenomenon is suppressed by the magnetic balance sampling circuit and the control method.
Referring to fig. 10, a control flow chart of the present invention without a rectifier module is shown, and the control method specifically includes the following steps:
step 1, collecting a positive current peak value I1 and a negative current peak value I2 (obtained by a hardware circuit magnetic balance sampling module);
step 13, reducing the positive current peak value I1 or increasing the negative current peak value I2, and turning to the step 1;
and 14, reducing the negative current peak value I2 or increasing the positive current peak value I1, and turning to the step 1.
It should be noted that, in steps 13 and 14, when magnetic bias occurs and needs to be adjusted, the duty ratio of one or two of Q5, Q6, Q7 and Q8 can be controlled to realize fine adjustment of the forward or reverse part of the current in the cavity of the secondary side conversion module, so as to obtain magnetic balance. If I1 is greater than I2, the positive component current of the current in the cavity of the secondary side conversion module is greater than the negative component current, and the path for constructing the positive component current is as follows: q6 and Q7 are turned off, and Q5 and Q8 are turned on, so that the forward component current is required to be reduced or the reverse component current is required to be improved, and in actual operation, if the duty ratio is 50%, the dead time is very small, the turn-on time of Q5 and Q8 can be shortened, so that I1 is reduced, and further magnetic balance is obtained, and in this case, in order to avoid direct connection of a bridge arm, the adjustment cannot be realized by increasing the duty ratio; if the dead time is large, I2 can be improved by increasing the conduction time of Q6 and Q7, so that the magnetic balance is achieved. If I1 is greater than I2, the positive component current of the current in the cavity of the secondary side conversion module is smaller than the negative component current, and the path for constructing the positive component current is as follows: q6 and Q7 are conducted, Q5 and Q8 are turned off, the aim is to increase the forward component current or decrease the reverse component current, and in actual operation, if the duty ratio is 50%, the dead time is very small, the conduction time of Q6 and Q7 can be reduced, so that I2 is reduced, and magnetic balance is obtained; if the dead time is large, I1 can be improved by increasing the conduction time of Q5 and Q8, so that the magnetic balance is achieved. Or when the preset dead zone of the bridge arm Is set to be larger, the fine tuning of the forward or reverse part of the current in the cavity of the secondary side conversion circuit can be realized by increasing the duty ratio of one or two of Q5, Q6, Q7 and Q8, so that | Is | < N Is achieved, and further magnetic balance Is obtained.
Referring to fig. 11, a control flow chart of the invention with a rectifier module is shown, and the control method specifically includes the following steps:
step 1, collecting a positive current peak value I1 and a negative current peak value I2 (obtained by a hardware circuit magnetic balance sampling module);
step 2, collecting output current I0;
step 3, judging that I0 is larger than or equal to Imax (maximum output current), if so, turning to step 20, otherwise, turning to step 10;
step 13, reducing the positive current peak value I1 or increasing the negative current peak value I2, and turning to the step 1;
step 14, reducing the negative current peak value I2 or increasing the positive current peak value I1, and turning to the step 1;
and 20, stopping working of the primary side conversion module and the secondary side conversion module.
This control method has more than the previous control method: step 2 (collecting output current I0 (namely cavity current of a secondary converter) of a secondary winding of the transformer), step 3 (judging that I0 is larger than or equal to Imax), and step 20 (emergency stop work), when the converter is out of control, the output current I0 can rapidly rise, a quasi-peak value sampling circuit is used for protection, precious time can be delayed, and by adopting the rectifier module and the method, the protection can be rapidly implemented.
The foregoing examples are illustrative only and not intended to be limiting. Any equivalent modifications or variations without departing from the spirit and scope of the present application should be included in the scope of the claims of the present application.
Claims (10)
1. A power conversion circuit with magnetic balance comprises a primary side conversion module, a transformer, a secondary side conversion module and a processor which are sequentially connected, and is characterized by further comprising a magnetic balance sampling module, wherein the magnetic balance sampling module comprises a current transformer (101), a first sampling branch and a second sampling branch, and the magnetic balance sampling module comprises a current transformer (101), a first sampling branch and a second sampling branch
The current transformer (101) is connected with the secondary winding of the transformer and is used for collecting the output current I0 of the secondary winding of the transformer;
the first sampling branch circuit collects a forward component in the output current I0;
the second sampling branch circuit collects a negative component in the output current I0;
and the processor adjusts a power switch in the secondary side conversion module according to the difference value of the positive component and the negative component to realize magnetic balance.
2. The power conversion circuit with magnetic balance according to claim 1, wherein the first sampling branch comprises a first signal separation unit (103) and a first quasi-peak value sampling unit (104) connected in series, the first signal separation unit is configured to separate a forward component in the output current I0 and convert the forward component into a forward component voltage signal, and the first quasi-peak value sampling unit is configured to collect a peak value of the forward component voltage signal and define the peak value as a forward current peak value I1;
the second sampling branch comprises a second signal separation unit (105) and a second quasi-peak value sampling unit (106) which are connected in series, the second signal separation unit is used for separating a negative component in the output current I0 and converting the negative component into a negative component voltage signal, and the second quasi-peak value sampling unit is used for collecting a peak value of the negative component voltage signal and defining the peak value as a negative current peak value I2;
and the processor adjusts a power switch in the secondary side conversion module according to the peak value difference Is of the output positive current peak value I1 and the output negative current peak value I2 so as to realize magnetic balance.
3. The power conversion circuit with magnetic balance of claim 2, wherein the first signal separation unit comprises a first diode D1, a second diode D2, and a first resistor R1, and the first quasi-peak sampling unit comprises a first operational amplifier U1, a third diode D3, a second resistor R2, a first capacitor C1, and a third resistor R3, wherein
The anode of the first diode D1 is connected with the head end of the secondary winding of the current transformer, the cathode of the first diode D1 is connected with one end of the first resistor R1 and is connected with the first quasi-peak sampling unit, the cathode of the second diode D2 is connected with the tail end of the secondary winding of the current transformer, and the anode of the second diode D2 is connected with the other end of the first resistor R1 and is grounded;
the non-inverting input end of the first operational amplifier U1 is connected with the cathode of the first diode D1, the output end of the first operational amplifier U1 is connected with the anode of the third diode D3, the inverting input end of the first operational amplifier U1 is connected with the cathode of the third diode D3 and one end of the second resistor R2, the other end of the second resistor R2 is connected with one ends of the first capacitor C1 and the third resistor R3 and is connected with the processor, and the other ends of the first capacitor C1 and the third resistor R3 are grounded.
4. The power conversion circuit with magnetic balance according to claim 3, wherein the second signal separation unit comprises a fourth diode D4, a fifth diode D5, and a fourth resistor R4, and the second quasi-peak value sampling unit comprises a second operational amplifier U2, a sixth diode D6, a fifth resistor R5, a second capacitor C2, and a sixth resistor R6, wherein
The anode of the fourth diode D4 is connected with the tail end of the secondary winding of the current transformer, the cathode of the fourth diode D4 is connected with one end of a fourth resistor R4 and is connected with the second quasi-peak sampling unit, the cathode of the fifth diode D5 is connected with the head end of the secondary winding of the current transformer, and the anode of the fifth diode D5 is connected with the other end of the fourth resistor R4 and is grounded;
the non-inverting input end of the second operational amplifier U2 is connected with the cathode of the fourth diode D4, the output end of the second operational amplifier U2 is connected with the anode of the sixth diode D6, the inverting input end of the second operational amplifier U2 is connected with the cathode of the sixth diode D6 and one end of a fifth resistor R5, the other end of the fifth resistor R5 is connected with one ends of the second capacitor C2 and the sixth resistor R6 and is connected with the processor, and the other ends of the second capacitor C2 and the sixth resistor R6 are grounded.
5. The power conversion circuit with magnetic balance according to claim 4, wherein the secondary winding of the current transformer is further connected to a rectifying module (102), the rectifying module is configured to collect the output current I0 and transmit the output current I0 to the processor, and when the output current I0 is greater than the maximum output current peak value Imax, the processor controls the primary side conversion module and the secondary side conversion module to stop working.
6. The power conversion circuit with magnetic balance according to claim 1, wherein the transformer includes a second secondary winding W2 and a fifth secondary winding W5, the secondary side conversion module includes a secondary side high voltage conversion module connected to the second secondary winding W2 and a secondary side low voltage conversion module connected to the fifth secondary winding W5, and the magnetic balance sampling module is connected to the second secondary winding W2.
7. The power conversion circuit with magnetic balance according to claim 1, wherein the transformer includes a second secondary winding W2 and a fourth secondary winding W4, the secondary switching module includes a secondary first switching module connected to the second secondary winding W2 and a secondary second switching module connected to the fourth secondary winding W4, outputs of the secondary first switching module and the secondary second switching module are connected in parallel, and the magnetic balance sampling module is connected to the second secondary winding W2.
8. A control method of a power conversion circuit with magnetic balance Is characterized in that the power conversion circuit with magnetic balance adopts the power conversion circuit with magnetic balance of any one of claims 1 to 6, and the control method comprises the steps of collecting a positive component and a negative component in the output current I0, and calculating the peak value difference Is of the positive component and the negative component; and when the peak difference Is larger than the threshold N, controlling a power switch in the secondary side conversion module to enable the peak difference Is to be smaller than or equal to the threshold N.
9. The method for controlling a power conversion circuit with magnetic balance according to claim 8, wherein the method specifically comprises the steps of:
step 1, collecting a positive current peak value I1 and a negative current peak value I2;
step 10, calculating a peak value difference Is, wherein Is = I1-I2;
step 11, judging whether the absolute value of the peak value difference Is smaller than a threshold value N, if so, turning to step 1, otherwise, turning to step 12;
step 12, judging whether Is greater than 0, if so, turning to step 13, otherwise, turning to step 14;
step 13, reducing the positive current peak value I1 or increasing the negative current peak value I2, and turning to the step 1;
and 14, reducing the negative current peak value I2 or increasing the positive current peak value I1, and turning to the step 1.
10. The method for controlling a power conversion circuit with magnetic balance according to claim 8, wherein the method specifically comprises the steps of:
step 1, collecting a positive current peak value I1 and a negative current peak value I2;
step 2, collecting output current I0;
step 3, judging that I0 is larger than or equal to Imax, if so, turning to step 20, otherwise, turning to step 10;
step 10, calculating a peak value difference Is, wherein Is = I1-I2;
step 11, judging whether the absolute value of the peak value difference Is smaller than a threshold value N, if so, turning to step 1, otherwise, turning to step 12;
step 12, judging whether Is greater than 0, if so, turning to step 13, otherwise, turning to step 14;
step 13, reducing the positive current peak value I1 or increasing the negative current peak value I2, and turning to the step 1;
step 14, reducing the negative current peak value I2 or increasing the positive current peak value I1, and turning to the step 1;
and 20, stopping working of the primary side conversion module and the secondary side conversion module.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210815482.0A CN115242096A (en) | 2022-07-08 | 2022-07-08 | Power supply conversion circuit with magnetic balance and control method thereof |
| PCT/CN2023/095607 WO2024007754A1 (en) | 2022-07-08 | 2023-05-22 | Power supply conversion circuit with magnetic balance and control method therefor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210815482.0A CN115242096A (en) | 2022-07-08 | 2022-07-08 | Power supply conversion circuit with magnetic balance and control method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115242096A true CN115242096A (en) | 2022-10-25 |
Family
ID=83673557
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210815482.0A Pending CN115242096A (en) | 2022-07-08 | 2022-07-08 | Power supply conversion circuit with magnetic balance and control method thereof |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN115242096A (en) |
| WO (1) | WO2024007754A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2024007754A1 (en) * | 2022-07-08 | 2024-01-11 | 深圳威迈斯新能源股份有限公司 | Power supply conversion circuit with magnetic balance and control method therefor |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5347419A (en) * | 1992-12-22 | 1994-09-13 | Eaton Corporation | Current limiting solenoid driver |
| JP5351944B2 (en) * | 2011-09-12 | 2013-11-27 | 株式会社日本自動車部品総合研究所 | Power converter |
| CN106998155B (en) * | 2017-05-17 | 2019-07-26 | 中车永济电机有限公司 | Inhibit the method with the transformer bias of full-bridge inverter cooperation |
| CN112202342B (en) * | 2020-11-03 | 2021-06-25 | 深圳威迈斯新能源股份有限公司 | Magnetic balance circuit of bidirectional resonant converter and control method thereof |
| CN218041215U (en) * | 2022-07-08 | 2022-12-13 | 深圳威迈斯新能源股份有限公司 | Power supply conversion circuit with magnetic balance sampling |
| CN115242096A (en) * | 2022-07-08 | 2022-10-25 | 深圳威迈斯新能源股份有限公司 | Power supply conversion circuit with magnetic balance and control method thereof |
-
2022
- 2022-07-08 CN CN202210815482.0A patent/CN115242096A/en active Pending
-
2023
- 2023-05-22 WO PCT/CN2023/095607 patent/WO2024007754A1/en unknown
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2024007754A1 (en) * | 2022-07-08 | 2024-01-11 | 深圳威迈斯新能源股份有限公司 | Power supply conversion circuit with magnetic balance and control method therefor |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2024007754A1 (en) | 2024-01-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108237943B (en) | A kind of dual output port charging circuit and its control method | |
| CN101304217B (en) | Switch power supply for chain type convertor power unit controller | |
| KR102600699B1 (en) | Bidirectional resonant transducer magnetic field flattening circuit and its control method | |
| CN201234208Y (en) | Switch power supply for chain type convertor power unit controller | |
| CN101471606A (en) | LLC resonant transformation device | |
| CN106505866B (en) | A kind of three Level Full Bridge DC converters | |
| CN106981994A (en) | A kind of single tube both-end inversion isolated form DC DC booster converters | |
| WO2022033239A1 (en) | Current detection circuit, converter, and current detection method for converter | |
| CN106059314A (en) | LLC resonance power converter with double resonance frequencies | |
| CN109245539B (en) | Voltage superposition type boost circuit | |
| CN103840670A (en) | Energy-saving type high-frequency switching power source | |
| CN115242096A (en) | Power supply conversion circuit with magnetic balance and control method thereof | |
| CN111157781A (en) | Dynamic knee point detection circuit | |
| CN114448274A (en) | Three-phase single-stage resonant type electric energy conversion device and control method | |
| TW202213919A (en) | Power-factor-correction rectifier | |
| CN218041215U (en) | Power supply conversion circuit with magnetic balance sampling | |
| CN208461691U (en) | A kind of Capacitor apart resonance type power factor correction converter | |
| CN112234833B (en) | Direct-current magnetic bias suppression method and device for double-active-bridge direct-current converter | |
| CN113872448A (en) | Fixed-frequency LLC circuit and resonant frequency tracking method thereof | |
| CN214590788U (en) | Hysteresis adjusting device of wireless power transmission system based on output state feedback | |
| TWI742852B (en) | Resonant switching power converter | |
| Wu et al. | Robust Parity-Time-Symmetric WPT System With Reduced Switching-Frequency and Improved Step-Down Conversion Ratio | |
| CN208571590U (en) | A kind of high-voltage large current pulse power with adjustable over-current detection | |
| CN112039344A (en) | High-power high-density module power supply | |
| CN111987914A (en) | Isolated full-bridge converter |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |