Driving control method of interleaved parallel flyback micro inverter

Abstract

The invention discloses a driving control method of an interleaving parallel flyback micro inverter. The driving control method comprises the following steps: comparing the total output power of the interleaved parallel flyback micro inverter with the maximum output power of a single branch; when the total output power of the interleaved parallel flyback micro inverter is smaller than the maximum output power of a single branch, determining a time point corresponding to the maximum value according to the peak current reference value, and controlling the first transformer and the second transformer to work alternately based on the time point; and when the total output power of the interleaving flyback micro inverter is greater than or equal to the maximum output power of the single branch, determining a time interval corresponding to the condition that the total output power is greater than or equal to the maximum output power of the single branch, and controlling the first transformer and the second transformer to work at the same time in the time interval, and alternately working outside the time interval. According to the technical scheme, the aging difference of branch devices can be effectively reduced, and the situation that branch heat accumulation is serious is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of inverter drive control, and particularly to a drive control method for an interleaved parallel flyback micro-inverter. Background Art

[0002] An inverter is a converter that converts direct current into alternating current with a fixed frequency and voltage or a variable frequency and voltage. The inverter can be applied in a photovoltaic power generation system and used as the core grid-connected device of the photovoltaic power generation system. In the traditional scheme, usually one branch of the interleaved parallel flyback circuit continuously operates within the full power range, and other parallel branches are enabled when the grid-connected current is large, so that multiple branches share the large current together. This control method can reduce the current stress of the continuously operating branch during grid connection.

[0003] However, this causes the uneven working loads of the two interleaved paths of the inverter, resulting in a large difference in the aging speed of the components of the two paths. The aging speed of the components of the continuously operating branch is fast, which brings potential risks to the system stability and affects the working life of the inverter; moreover, the switching control of the inverter is mainly concentrated on the continuously operating branch, resulting in the heat generated by the switching loss mainly accumulating in this branch, which deteriorates the working temperature of the switching tube of this path, keeps the switching loss of the continuously operating branch at a high level, increases the heat generation of the inverter, and increases the heat dissipation burden. Summary of the Invention

[0004] Aiming at the defects in the prior art, the present invention provides a drive control method for an interleaved parallel flyback micro-inverter, which can effectively reduce the aging difference of the branch components and avoid the serious heat accumulation in one of the branches.

[0005] A drive control method for an interleaved parallel flyback micro-inverter provided by this application, the interleaved parallel flyback micro-inverter includes a primary circuit, a first transformer, a second transformer and a secondary circuit. The primary circuit is respectively connected to one end of the first transformer and one end of the second transformer, and the secondary circuit is respectively connected to the other end of the first transformer and the other end of the second transformer. The drive control method includes:

[0006] Obtain the peak current reference value of the interleaved parallel flyback micro-inverter;

[0007] Compare the total output power of the interleaved parallel flyback micro-inverter with the maximum output power of a single branch;

[0008] When the total output power of the interleaved parallel flyback micro-inverter is less than the maximum output power of a single branch, based on the time point corresponding to the maximum value of the peak current reference value, control the first transformer and the second transformer to alternately operate based on this time point;

[0009] When the total output power of the interleaved flyback micro-inverter is greater than or equal to the maximum output power of a single branch, determine the time interval corresponding to the total output power being greater than or equal to the maximum output power of the single branch, control the first transformer and the second transformer to work simultaneously within the time interval, and control the first transformer and the second transformer to work alternately outside the time interval.

[0010] In one aspect, define the starting time of the peak current reference value as T0, the time point of the maximum value of the peak current reference value as T1, and the ending time of the peak current reference value as T2. The time period from T0 to T1 is the first time period, and the time period from T1 to T2 is the second time period. The time lengths of the first time period and the second time period are equal;

[0011] During the first time period, control the first transformer to work and the second transformer to pause;

[0012] During the second time period, control the second transformer to work and the first transformer to pause.

[0013] In one aspect, the interleaved flyback micro-inverter further includes a first response switch and a second response switch;

[0014] The first end of the first response switch is connected to the primary circuit, the second end of the first response switch is connected to the first transformer, generate a first response signal during the first time period, and the control end of the first response switch responds to the first response signal to make the first end and the second end of the first response switch conduct;

[0015] The first end of the second response switch is connected to the primary circuit, the second end of the second response switch is connected to the second transformer, generate a second response signal during the second time period, and the control end of the second response switch responds to the second response signal to make the first end and the second end of the second response switch conduct.

[0016] In one aspect, define the starting point of the time interval as t1 and the ending point of the time interval as t2. The time period from T0 to t1 is the third time period, and the time period from t2 to T2 is the fourth time period;

[0017] During the third time period, control the first transformer to work and the second transformer to pause;

[0018] During the time interval, control both the first transformer and the second transformer to work;

[0019] During the fourth time period, control the second transformer to work and the first transformer to pause.

[0020] In one aspect, the first response signal is generated within a time range where the third time period overlaps the time interval;

[0021] The second response signal is generated within a time range where the time interval overlaps the fourth time period.

[0022] In one aspect, the primary circuit also includes an electrolytic capacitor and a photovoltaic component, the electrolytic capacitor is connected in parallel with the photovoltaic component, the positive electrode of the electrolytic capacitor is connected to the positive electrode of the photovoltaic component, the positive electrode of the electrolytic capacitor is connected to one end of the primary windings of the first transformer and the second transformer, the other end of the primary winding of the first transformer is connected to the first end of the first response switch, the other end of the primary winding of the second transformer is connected to the first end of the second response switch, the second end of the first response switch is connected to the negative electrode of the electrolytic capacitor, and the second end of the second response switch is connected to the negative electrode of the electrolytic capacitor.

[0023] In one aspect, the secondary circuit includes a first rectifier diode, a second rectifier diode, a decoupling capacitor, a first control switch, a second control switch, a third control switch and a fourth control switch, the opposite-name end of the first transformer is connected to the positive electrode of the first rectifier diode, the opposite-name end of the second transformer is connected to the positive electrode of the second rectifier diode, the decoupling capacitor is connected in parallel with the first transformer and the second transformer, the drain of the first control switch is connected to the drain of the fourth control switch, the source of the first control switch is connected to the drain of the second control switch, the source of the second control switch is connected to the source of the third control switch, the source of the fourth control switch is connected to the drain of the third control switch, and the source of the second control switch and the source of the third control switch are connected to the secondary same-name end of the second transformer;

[0024] The secondary circuit also includes a filter circuit, which includes a filter capacitor and a filter inductor. The filter capacitor is connected in parallel between the source of the first control switch and the drain of the third control switch, one end of the filter capacitor is connected to the drain of the third control switch, the other end of the filter capacitor is connected to one end of the power grid, one end of the filter inductor is connected to one end of the filter capacitor, and the other end of the filter inductor is connected to the other end of the power grid.

[0025] The beneficial effects of the present invention are reflected in: by comparing the total output power of the interleaved flyback micro-inverter with the maximum output power of a single branch, two cases are thus divided. In the first case, when the total output power of the interleaved flyback micro-inverter is less than the maximum output power of a single branch, based on the time point corresponding to the maximum value of the peak current reference value, the first transformer and the second transformer are controlled to work alternately based on the time point. In the second case, when the total output power of the interleaved flyback micro-inverter is greater than or equal to the maximum output power of a single branch, the time interval corresponding to the total output power being greater than or equal to the maximum output power of a single branch is determined, and the first transformer and the second transformer are controlled to work simultaneously within the time interval and alternately outside the time interval. It can be seen that in both the first case and the second case, the first transformer and the second transformer can work alternately, thereby reducing the aging difference of the branch devices and avoiding the situation where the heat accumulation in one of the branches is serious. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. In all the drawings, similar elements or parts are generally denoted by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0027] Figure 1 It is a schematic flow chart of the driving control method of the interleaved flyback micro-inverter of the present application;

[0028] Figure 2 It is a circuit schematic diagram of the interleaved flyback micro-inverter of the present application;

[0029] Figure 3 It is a curve diagram of the first embodiment of the currents of the first transformer branch and the second transformer branch changing with time in a half power frequency period in the driving control method of the interleaved flyback micro-inverter of the present application;

[0030] Figure 4 It is a curve diagram of the second embodiment of the currents of the first transformer branch and the second transformer branch changing with time in a half power frequency period in the driving control method of the interleaved flyback micro-inverter of the present application.

[0031] Description of the Drawings: 10, primary circuit; 20, secondary circuit; TM, first transformer; TS, second transformer; Cin, electrolytic capacitor; PV, photovoltaic module; QM, first response switch; QS, second response switch; DM, first rectifier diode; DS, second rectifier diode; Co, decoupling capacitor; Q1, first control switch; Q2, second control switch; Q3, third control switch; Q4, fourth control switch; Cf, filter capacitor; Lf, filter inductor; Grid, power grid. Detailed Embodiment

[0032] The embodiments of the technical solution of the present invention will be described in detail below with reference to the drawings. The following embodiments are only used to illustrate the technical solution of the present invention more clearly, so they are only examples and cannot be used to limit the protection scope of the present invention.

[0033] It should be noted that unless otherwise specified, the technical terms or scientific terms used in this application should have the ordinary meanings understood by those skilled in the art to which the present invention belongs.

[0034] The inverter of this application mainly refers to a flyback micro-inverter. The flyback micro-inverter has three different operating modes. When the flyback micro-inverter operates in the discontinuous current mode (DCM), the control method is simple, and it has a high energy conversion efficiency in the low-power output state. However, the drain-source voltage value of the switching transistor is random when it is turned on, and the conduction loss cannot be guaranteed to be always the lowest. When the flyback micro-inverter operates in the continuous conduction mode (CCM), the drain-source voltage and the equivalent current flowing through the switching transistor are not zero when the switching transistor is turned on and off. The switching loss in the hard-switching state is large, and the energy conversion efficiency is low. When the flyback micro-inverter operates in the boundary conduction mode (BCM), the equivalent current flowing through the switching transistor is zero when it is turned on. When the output power is large, the conversion efficiency is high. However, when the output power is small, the switching frequency is extremely high, the switching loss is very large, and the energy conversion efficiency is extremely low.

[0035] Refer to Figure 1 And Figure 2 As shown, this application provides a drive control method for an interleaved flyback micro-inverter. The interleaved flyback micro-inverter includes a primary circuit 10, a first transformer TM, a second transformer TS, and a secondary circuit 20. The primary circuit 10 is respectively connected to one end of the first transformer TM and one end of the second transformer TS. The secondary circuit 20 is respectively connected to the other end of the first transformer TM and the other end of the second transformer TS. The drive control method includes:

[0036] Step S10, obtain the peak current reference value of the interleaved flyback micro-inverter. The peak current reference value can be calculated by the following formula.

[0037]

[0038] Among them, θ g is the phase angle, and i ref (θ g ) is the peak current reference value, f DCM (θ g ) is the switching frequency of the traditional DCM mode, f BCM (θ g ) is the switching frequency of the traditional BCM mode, P o is the grid-connected power of the inverter, L m is the primary inductance value of the flyback transformer. It can be seen that the peak current reference value is directly related to the grid-connected power P o of the inverter.

[0039] Step S20, compare the total output power of the interleaved flyback micro-inverter with the maximum output power of a single branch. A single branch refers to the circuit conducting when the first transformer TM works, or the circuit conducting when the second transformer TS works. The first transformer TM and the second transformer TS have the same model. The maximum output power of a single branch can be understood as a fixed value, and different interleaved flyback micro-inverters have different maximum output powers of a single branch, which can be set as needed.

[0040] Step S30, when the total output power of the interleaved flyback micro-inverter is less than the maximum output power of a single branch, determine the time point corresponding to its maximum value based on the peak current reference value, and control the first transformer TM and the second transformer TS to work alternately based on the time point. The time point corresponding to the maximum value of the peak current reference value is generally the time midpoint of the peak current reference value waveform. Taking the time point as the boundary, control the first transformer TM and the second transformer TS to work separately. For example, control the first transformer TM to work in the time period before the time point, and control the second transformer TS to work in the time period after the time point; or control the second transformer TS to work in the time period before the time point, and control the first transformer TM to work in the time period after the time point.

[0041] Step S40: When the total output power of the interleaved flyback micro-inverter is greater than or equal to the maximum output power of a single branch, determine the time interval corresponding to the total output power being greater than or equal to the maximum output power of a single branch, control the first transformer TM and the second transformer TS to work simultaneously within the time interval, and control the first transformer TM and the second transformer TS to work alternately outside the time interval. It can be understood that controlling the first transformer TM and the second transformer TS simultaneously within the time interval can reduce the power peak when a single branch is working and reduce the burden on the first transformer TM. A time point is a specific time value, and a time interval is a time range value.

[0042] In this embodiment, by comparing the total output power of the interleaved flyback micro-inverter with the maximum output power of a single branch, it can be divided into two cases. The first case is when the total output power of the interleaved flyback micro-inverter is less than the maximum output power of a single branch. Determine the time point corresponding to its maximum value based on the peak current reference value, and control the first transformer TM and the second transformer TS to work alternately based on the time point. The second case is when the total output power of the interleaved flyback micro-inverter is greater than or equal to the maximum output power of a single branch. Determine the time interval corresponding to the total output power being greater than or equal to the maximum output power of a single branch, control the first transformer TM and the second transformer TS to work simultaneously within the time interval, and control the first transformer TM and the second transformer TS to work alternately outside the time interval. It can be seen that both the first case and the second case can make the first transformer TM and the second transformer TS work alternately, thereby reducing the aging difference of the branch devices and avoiding the situation where heat accumulates severely in one of the branches.

[0043] Refer to Figure 3 As shown, in an embodiment of the present application, define the starting time of the peak current reference value as T0, the time point of the maximum value of the peak current reference value as T1, and the ending time of the peak current reference value as T2. The time period from T0 to T1 is the first time period, and the time period from T1 to T2 is the second time period. The time lengths of the first time period and the second time period are equal. For example, if half of the power frequency period is 10 ms and the starting time T0 is 0, then the time point T1 is 5 ms.

[0044] In the first time period, control the first transformer TM to work and the second transformer TS to pause; when the first transformer TM is working, the switching between the BCM mode and the DCM mode can also be carried out normally.

[0045] In the second time period, control the second transformer TS to work and the first transformer TM to pause. It can be seen that the shapes of the currents when the first transformer TM and the second transformer TS are working are mirror-symmetrical with respect to the time point T1. When the second transformer TS is working, the switching between the BCM mode and the DCM mode can also be carried out normally.

[0046] From Figure 3 As can be seen, the black solid line is the actual current change curve on the first transformer branch and the second transformer branch. It can also be seen that the current change of i ref (DCM) and the current change of i ref (BCM) in the BCM mode, as well as the change curve of the peak current reference value i ref (θ g ). When the output power of the inverter increases by a certain value, the change curve of the peak current reference value i ref (θ g ) and the current change curve of i ref (BCM) in the BCM mode generate two intersection points A and B. The flyback inverter operates in the BCM mode between points A and B and in the DCM mode outside points A and B, improving the power density of the inverter and reducing the peak current and switching losses on the primary side of the transformer.

[0047] In an embodiment of the present application, the interleaved flyback micro-inverter further includes a first response switch QM and a second response switch QS; the operation switching of the first transformer TM and the second transformer TS is realized by respectively controlling the first response switch QM and the second response switch QS.

[0048] The first end of the first response switch QM is connected to the primary circuit 10, the second end of the first response switch QM is connected to the first transformer TM, a first response signal is generated in the first time period, and the control end of the first response switch QM responds to the first response signal to make the first end and the second end of the first response switch QM conduct; when the first response switch QM conducts, the second response switch QS is in the off state, the first transformer TM is connected to the primary circuit 10, and the second transformer TS is disconnected from the primary circuit 10.

[0049] The first end of the second response switch QS is connected to the primary circuit 10, the second end of the second response switch QS is connected to the second transformer TS, a second response signal is generated in the second time period, and the control end of the second response switch QS responds to the second response signal to make the first end and the second end of the second response switch QS conduct. When the second response switch QS conducts, the first response switch QM is in the off state, the second transformer TS is connected to the primary circuit 10, and the first transformer TM is disconnected from the primary circuit 10. Generally, the first response switches QM have the same model, which can reduce the complexity of drive control. Of course, different models can also be used and specific adjustment and control can be carried out for different models.

[0050] Refer to Figure 4As shown, in an embodiment of the present application, the starting point of the time interval is defined as t1, the ending point of the time interval is defined as t2, the time period from T0 to t1 is the third time period, and the time period from t2 to T2 is the fourth time period.

[0051] In the third time period, control the first transformer TM to operate and the second transformer TS to pause; when the first transformer TM is operating, also maintain the normal switching between the DCM mode and the BCM mode.

[0052] In the time interval, control both the first transformer TM and the second transformer TS to operate; when the first transformer TM and the second transformer TS are operating simultaneously, the inverter is in the interleaved BCM mode at this time.

[0053] In the fourth time period, control the second transformer TS to operate and the first transformer TM to pause. When the second transformer TS is operating, also maintain the normal switching between the DCM mode and the BCM mode.

[0054] From Figure 4 it can be seen that the solid black line is the actual current change curve on the first transformer branch and the second transformer branch. It can also be seen that the current change curve of i ref (DCM) and the current change curve of i ref (BCM) in the BCM mode, as well as the change curve of the peak current reference value i ref (θ g ). When the output power of the inverter increases by a certain value, the change curve of the peak current reference value i ref (θ g ) and the current change curve of i ref (BCM) in the BCM mode generate two intersection points A and B. The flyback inverter operates in the BCM mode between points A and B and in the DCM mode outside points A and B. Among them, point A is between T0 and t1, point B is between t2 and T2. The first transformer branch is in the BCM mode between A and t1, the second transformer branch is in the BCM mode between t2 and point B, and both the first transformer branch and the second transformer branch are in the BCM mode, that is, in the interleaved BCM mode, between t1 and t2. Thereby, the power density of the inverter is improved, and the peak current and switching losses on the primary side of the transformer are reduced.

[0055] In an embodiment of the present application, a first response signal is generated within the time range of the third time period superimposed on the time interval; that is to say, the first response signal is continuously provided within the time range of the third time period and the time interval, ensuring that the first response switch QM remains conductive during the third time period and the time interval.

[0056] The second response signal is generated within the time range of the time interval superimposed on the fourth time period. It can also be seen that the second response signal is continuously provided within the time range of the fourth time period and the time interval, ensuring that the second response switch QS remains turned on within the fourth time period and the time interval. It can be seen that the first response signal and the second response signal are provided simultaneously in the time interval, so that the first response switch QM and the second response switch QS are turned on at the same time.

[0057] See again Figure 2 As shown, in one embodiment of the present application, the primary circuit 10 also includes an electrolytic capacitor Cin and a photovoltaic component PV. The electrolytic capacitor Cin is connected in parallel with the photovoltaic component PV. The positive electrode of the electrolytic capacitor Cin is connected to the positive electrode of the photovoltaic component PV. The positive electrode of the electrolytic capacitor Cin is connected to one end of the primary winding of the first transformer TM and the second transformer TS. The other end of the primary winding of the first transformer TM is connected to the first end of the first response switch QM, the other end of the primary winding of the second transformer TS is connected to the first end of the second response switch QS, the second end of the first response switch QM is connected to the negative electrode of the electrolytic capacitor Cin, and the second end of the second response switch QS is connected to the negative electrode of the electrolytic capacitor Cin.

[0058] In an embodiment of the present application, the secondary circuit 20 includes a first rectifier diode DM, a second rectifier diode DS, a decoupling capacitor Co, a first control switch Q1, a second control switch Q2, a third control switch Q3 and a fourth control switch Q4. The opposite-name end of the first transformer TM is connected to the positive electrode of the first rectifier diode DM, the opposite-name end of the second transformer TS is connected to the positive electrode of the second rectifier diode DS, the decoupling capacitor Co is connected in parallel with the first transformer TM and the second transformer TS, the drain of the first control switch Q1 is connected to the drain of the fourth control switch Q4, the source of the first control switch Q1 is connected to the drain of the second control switch Q2, the source of the second control switch Q2 is connected to the source of the third control switch Q3, the source of the fourth control switch Q4 is connected to the drain of the third control switch Q3, and the source of the second control switch Q2 and the source of the third control switch Q3 are connected to the secondary same-name end of the second transformer TS.

[0059] The secondary circuit 20 further includes a filtering circuit, which includes a filtering capacitor Cf and a filtering inductor Lf. The filtering capacitor Cf is connected in parallel between the source of the first control switch Q1 and the drain of the third control switch Q3. One end of the filtering capacitor Cf is connected to the drain of the third control switch Q3, and the other end of the filtering capacitor Cf is connected to one end of the power grid Grid. One end of the filtering inductor Lf is connected to one end of the filtering capacitor Cf, and the other end of the filtering inductor Lf is connected to the other end of the power grid Grid. Under the alternating operation of the first transformer TM and the second transformer TS, the aging difference of the branch devices is reduced, and the situation where heat accumulates severely in one of the branches is avoided. At the same time, when the total output power of the interleaved parallel flyback micro-inverter is greater than or equal to the maximum output power of a single branch, the first transformer TM and the second transformer TS can be controlled to work simultaneously, reducing the peak current passing through the first transformer TM and the second transformer TS.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered by the scope of the claims and the description of the present invention.

Claims

1. A drive control method for interleaved parallel flyback micro-inverters, characterized in that: The interleaved parallel flyback micro-inverter comprises a primary circuit, a first transformer, a second transformer and a secondary circuit, wherein the primary circuit is respectively connected to one end of the first transformer and one end of the second transformer, and the secondary circuit is respectively connected to the other end of the first transformer and the other end of the second transformer, and the drive control method comprises: Obtaining a peak current reference value of the interleaved parallel flyback micro-inverter; Comparing the total output power of the interleaved parallel flyback micro-inverter with the maximum output power of a single branch; When the total output power of the interleaved parallel flyback micro-inverter is less than the maximum output power of the single branch, determining the time point corresponding to the maximum value of the peak current reference value according to the peak current reference value, and controlling the first transformer and the second transformer to work alternately based on the time point; When the total output power of the interleaved parallel flyback micro-inverter is greater than or equal to the maximum output power of the single branch, determine the time interval corresponding to the total output power being greater than or equal to the maximum output power of the single branch, control the first transformer and the second transformer to operate simultaneously within the time interval, and control the first transformer and the second transformer to operate alternately outside the time interval.

2. The driving control method according to claim 1, characterized in that: Define the starting time of the peak current reference value as T0, the time point of the maximum value of the peak current reference value as T1, the ending time of the peak current reference value as T2, the time period from T0 to T1 as the first time period, and the time period from T1 to T2 as the second time period, and the time lengths of the first time period and the second time period are equal; In the first time period, the first transformer is controlled to operate, and the second transformer is controlled to be suspended; During the second time period, the second transformer is controlled to operate, and the first transformer is suspended.

3. The driving control method according to claim 2, characterized in that: The interleaved parallel flyback micro-inverter further includes a first response switch and a second response switch; The first end of the first response switch is connected to the primary circuit, the second end of the first response switch is connected to the first transformer, a first response signal is generated in the first time period, and the control end of the first response switch responds to the first response signal to make the first end and the second end of the first response switch conductive; The first end of the second response switch is connected to the primary circuit, the second end of the second response switch is connected to the second transformer, a second response signal is generated in the second time period, and the control end of the second response switch responds to the second response signal to make the first end and the second end of the second response switch conductive.

4. The driving control method according to claim 3, characterized in that: Define the starting point of the time interval as t1, the end point of the time interval as t2, the time period from T0 to t1 as the third time period, and the time period from t2 to T2 as the fourth time period; In the third time period, the first transformer is controlled to operate, and the second transformer is controlled to be suspended; During the time interval, controlling both the first transformer and the second transformer to operate; In the fourth time period, the second transformer is controlled to operate, and the first transformer is suspended.

5. The driving control method according to claim 4, characterized in that: generating the first response signal within a time range in which the third time period overlaps the time interval; The second response signal is generated within a time range where the time interval overlaps the fourth time period.

6. The driving control method according to any one of claims 1 to 5, characterized in that: The primary circuit also includes an electrolytic capacitor and a photovoltaic component. The electrolytic capacitor is connected in parallel with the photovoltaic component. The positive electrode of the electrolytic capacitor is connected to the positive electrode of the photovoltaic component. The positive electrode of the electrolytic capacitor is connected to one end of the primary windings of the first transformer and the second transformer. The other end of the primary winding of the first transformer is connected to the first end of the first response switch. The other end of the primary winding of the second transformer is connected to the first end of the second response switch. The second end of the first response switch is connected to the negative electrode of the electrolytic capacitor. The second end of the second response switch is connected to the negative electrode of the electrolytic capacitor.

7. The driving control method according to claim 6, characterized in that: The secondary circuit includes a first rectifier diode, a second rectifier diode, a decoupling capacitor, a first control switch, a second control switch, a third control switch and a fourth control switch, the opposite-name end of the first transformer is connected to the positive electrode of the first rectifier diode, the opposite-name end of the second transformer is connected to the positive electrode of the second rectifier diode, the decoupling capacitor is connected in parallel with the first transformer and the second transformer, the drain of the first control switch is connected to the drain of the fourth control switch, the source of the first control switch is connected to the drain of the second control switch, the source of the second control switch is connected to the source of the third control switch, the source of the fourth control switch is connected to the drain of the third control switch, and the source of the second control switch and the source of the third control switch are connected to the secondary like-name end of the second transformer; The secondary circuit also includes a filter circuit, which includes a filter capacitor and a filter inductor. The filter capacitor is connected in parallel between the source of the first control switch and the drain of the third control switch, one end of the filter capacitor is connected to the drain of the third control switch, the other end of the filter capacitor is connected to one end of the power grid, one end of the filter inductor is connected to one end of the filter capacitor, and the other end of the filter inductor is connected to the other end of the power grid.

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