Topology circuit, control system and control method of single-phase dual-active half-bridge inverter

Abstract

The invention discloses a topology circuit, a control system and a control method of a single-phase dual-active half-bridge inverter. The topology circuit comprises a primary side half-bridge circuit, a transformer and a secondary side half-bridge circuit, the primary side half-bridge circuit comprises a first capacitor, a second capacitor, a first switch tube and a second switch tube; and the secondary side half-bridge circuit comprises a third capacitor, a fourth capacitor, a third switching tube, a fourth switching tube, a fifth switching tube and a sixth switching tube. The topological circuit adopts a single-pole structure, so that the loss of power transmission in the use process of the inverter is reduced; the number of used switching tubes is reduced, and switching loss caused by device operation is reduced, so that the operation efficiency and the power density of the inverter are improved; and a nonlinear function of closed-loop control is linearized, so that the control method for regulating and controlling the inverter is optimized, and the control difficulty of the inverter is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of power electronics, and in particular to a topological circuit, a control system and a control method of a single-phase dual-active half-bridge inverter. Background Art

[0002] With the increasing attention paid to environmental issues and the rise in global energy prices, various countries have begun to pay attention to the development of renewable energy; and among renewable energy technologies, photovoltaic power generation occupies an important position. Photovoltaic power generation needs to be connected to the grid or output energy storage through an inverter; most of the existing inverters are two-stage structures, with the front stage being a DC-DC (direct current-direct current) stage, which is used to track the maximum power point of the photovoltaic module, and the rear stage being a DC-AC (direct current-alternating current) stage, which is used to inject alternating current into the grid. However, this type of inverter uses more switching tubes due to its two-stage structure, resulting in greater power loss; at the same time, this type of inverter is larger in size and more expensive. Therefore, the inverter in the prior art has the problem of large power loss. Summary of the invention

[0003] The embodiments of the present invention provide a topology circuit, a control system and a control method of a single-phase dual-active half-bridge inverter, aiming to solve the problem of high power loss in the inverter in the prior art.

[0004] In a first aspect, an embodiment of the present invention discloses a topology circuit of a single-phase dual-active half-bridge inverter, wherein the topology circuit includes a primary half-bridge circuit, a transformer, and a secondary half-bridge circuit; The primary half-bridge circuit includes a first capacitor, a second capacitor, a first switch tube and a second switch tube; the secondary half-bridge circuit includes a third capacitor, a fourth capacitor, a third switch tube, a fourth switch tube, a fifth switch tube and a sixth switch tube; One end of the first capacitor is connected to the drain of the first switch tube, and the connection point is used as the positive electrode of the DC power supply; one end of the second capacitor is connected to the source of the second switch tube, and the connection point is used as the negative electrode of the DC power supply; the other end of the first capacitor is connected to the other end of the second capacitor and the primary opposite-name terminal of the transformer, and the source of the first switch tube is connected to the drain of the second switch tube and the primary same-name terminal of the transformer; One end of the third capacitor is connected to the drain of the third switch tube, and the connection point serves as an AC input terminal; one end of the fourth capacitor is connected to the drain of the sixth switch tube, and the connection point serves as another AC input terminal; the source of the third switch tube is connected to the source of the fourth switch tube, and the drain of the fourth switch tube is connected to the drain of the fifth switch tube and the secondary same-name terminal of the transformer; the source of the sixth switch tube is connected to the source of the fifth switch tube; the other end of the third capacitor is connected to the other end of the fourth capacitor and the secondary opposite-name terminal of the transformer, and the equivalent leakage inductance of the transformer is connected in series between the secondary same-name terminal and the drain of the fourth switch tube; The load is arranged in parallel between the two AC input terminals.

[0005] In a second aspect, an embodiment of the present invention further discloses a control system for a topology circuit of a single-phase dual-active half-bridge inverter, wherein the control system includes a controller, a voltage sensor, a current sensor, a pulse modulation unit, and the topology circuit of the single-phase dual-active half-bridge inverter as described in the first aspect above; The two voltage detection terminals of the voltage sensor are electrically connected to the two AC input terminals respectively to measure the grid-side input voltage; The controller is respectively connected to the detection output end of the voltage sensor, the detection output end of the current sensor and the control receiving end of the pulse modulation unit, and the pulse signal output end of the pulse modulation unit is respectively connected to the control end of each switch tube in the topology circuit of the single-phase dual active half-bridge inverter; The detection end of the current sensor is connected in series to one of the AC input ends.

[0006] In a third aspect, an embodiment of the present invention further discloses a control method for a topology circuit of a single-phase dual-active half-bridge inverter, wherein the control method is applied to a controller of a control system of a topology circuit of a single-phase dual-active half-bridge inverter as described in the second aspect above, and the control method includes: The voltage sensor collects the amplitude and angular frequency of the grid-side input voltage connected to the two AC input terminals in real time; The angular frequency is analyzed according to a preset phase shift angle expression to calculate the phase angle corresponding to the angular frequency at the current moment; Adding the phase angle to the compensation value of the angular frequency at the current moment to obtain a phase compensation angle; The phase compensation angle is calculated according to a preset switching frequency expression to obtain the switching frequency corresponding to the switch tube at the current moment; Inputting the phase compensation angle and the switching frequency into the pulse modulation unit, so that the pulse modulation unit inputs a corresponding driving signal to each switch tube; The output current value is collected in real time through the current sensor; Subtracting the output current value from the corresponding calculated value to obtain a current error value; The compensation value is updated according to the current error value.

[0007] The embodiment of the present application discloses a topological circuit, control system and control method of a single-phase dual-active half-bridge inverter, wherein the topological circuit includes a primary half-bridge circuit, a transformer and a secondary half-bridge circuit; the primary half-bridge circuit includes a first capacitor, a second capacitor, a first switch tube and a second switch tube; the secondary half-bridge circuit includes a third capacitor, a fourth capacitor, a third switch tube, a fourth switch tube, a fifth switch tube and a sixth switch tube. The above topological circuit adopts a unipolar structure, which reduces the loss of power transmission during the use of the inverter; reduces the number of switch tubes used, reduces the switching loss caused by the operation of the device, thereby improving the operating efficiency and power density of the inverter; and linearizes the nonlinear function of the closed-loop control, optimizes the control method for regulating the inverter, and reduces the control difficulty of the inverter. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0009] Figure 1 A circuit structure diagram of a topological circuit provided in an embodiment of the present invention; Figure 2 An application effect diagram of a topological circuit provided by an embodiment of the present invention; Figure 3 Another application effect diagram of the topological circuit provided by the embodiment of the present invention; Figure 4 Another application effect diagram of the topological circuit provided by the embodiment of the present invention; Figure 5 A schematic diagram of the structure of a control system of a topology circuit provided by an embodiment of the present invention; Figure 6 A method flow chart of a method for controlling a topology circuit provided by an embodiment of the present invention; Reference numerals: C1, first capacitor; C2, second capacitor; C3, third capacitor; C4, fourth capacitor; Q1, first switch tube; Q2, second switch tube; Q3, third switch tube; Q4, fourth switch tube; Q5, fifth switch tube; Q6, sixth switch tube; T r1 , transformer; L lk, equivalent leakage inductance; 11, controller; 12, voltage sensor; 13, current sensor; 14, pulse modulation unit; R1, load; L1, first inductor; L2, second inductor; C5, fifth capacitor. DETAILED DESCRIPTION

[0010] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0011] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0012] It should also be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0013] It should be further understood that the term "and / or" used in the present description and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0014] The embodiment of the present invention discloses a topology circuit of a single-phase dual-active half-bridge inverter, such as Figure 1 As shown, the topology circuit includes a primary half-bridge circuit, a transformer T r1 and a secondary half-bridge circuit; the primary half-bridge circuit includes a first capacitor C1, a second capacitor C2, a first switch tube Q1 and a second switch tube Q2; the secondary half-bridge circuit includes a third capacitor C3, a fourth capacitor C4, a third switch tube Q3, a fourth switch tube Q4, a fifth switch tube Q5 and a sixth switch tube Q6; one end of the first capacitor C1 is connected to the drain of the first switch tube Q1, and the connection point is used as the positive electrode of the DC power supply; one end of the second capacitor C2 is connected to the source of the second switch tube Q2, and the connection point is used as the negative electrode of the DC power supply; the other end of the first capacitor C1 is connected to the other end of the second capacitor C2 and the transformer T r1 The source of the first switch tube Q1 is connected to the drain of the second switch tube Q2 and the transformer T r1The primary side of the same name end; one end of the third capacitor C3 is connected to the drain of the third switch tube Q3, and the connection point serves as an AC input end; one end of the fourth capacitor C4 is connected to the drain of the sixth switch tube Q6, and the connection point serves as another AC input end; the source of the third switch tube Q3 is connected to the source of the fourth switch tube Q4, and the drain of the fourth switch tube Q4 is connected to the drain of the fifth switch tube Q5 and the transformer T r1 The source of the sixth switch tube Q6 is connected to the source of the fifth switch tube Q5; the other end of the third capacitor C3 is connected to the other end of the fourth capacitor C4 and the transformer T r1 The secondary side of the transformer T r1 The equivalent leakage inductance L lk It is connected in series between the secondary side same-name terminal and the drain of the fourth switch tube Q4; the load R1 is arranged in parallel between the two AC input terminals.

[0015] The positive and negative electrodes of the DC power supply in the primary half-bridge circuit are used as DC source inputs. The voltage value of the DC source input is V dc ; The positive and negative electrodes of the DC source input are connected to the first capacitor C1 and the second capacitor C2 respectively, wherein the positive electrode of the DC power supply is connected to one end of the first capacitor C1 and the drain of the first switch tube Q1, and the negative electrode of the DC power supply is connected to one end of the second capacitor C2 and the source of the second switch tube Q2. The other end of the first capacitor C1 is connected to the other end of the second capacitor C2, and the node is connected to the transformer T r1 The source of the first switch tube Q1 and the drain of the second switch tube Q2 are connected, and the node is connected to the transformer T r1 The original side with the same name as the end.

[0016] In the embodiment of the present invention, the transformer T r1 The transformer leakage inductance is completely equivalent to the transformer T r1 The secondary side of the transformer leakage inductance can be expressed as the equivalent leakage inductance L lk , equivalent leakage inductance L lk It is not an actual inductor, the transformer T r1 The secondary side of the same name terminal and the equivalent leakage inductance L lk One end is connected.

[0017] In the embodiment of the present invention, the two AC input terminals in the secondary half-bridge circuit are used to connect to the power grid, so as to output the converted AC power to the power grid, and the two AC input terminals are respectively connected to the third capacitor C3 and the fourth capacitor C4, one of the AC input terminals is connected to one end of the third capacitor C3 and the drain of the third switch tube Q3, and the other AC input terminal is connected to the negative electrode of the fourth capacitor C4 and the source of the sixth switch tube Q6, the source of the third switch tube Q3 is connected to the drain of the fourth switch tube Q4, the source of the fifth switch tube Q5 is connected to the drain of the sixth switch tube Q6, the other end of the third capacitor C3 is connected to the other end of the fourth capacitor C4, and the node is connected to the transformer T r1 The source of the fourth switch tube Q4 is connected to the drain of the fifth switch tube Q5, and the node is connected to the equivalent leakage inductance L lk the other end.

[0018] In a more specific embodiment, the capacitance values ​​of the first capacitor C1 and the second capacitor C2 are equal. The capacitance values ​​of the third capacitor C3 and the fourth capacitor C4 are equal.

[0019] In a more specific embodiment, the first switch tube Q1, the second switch tube Q2, the third switch tube Q3, the fourth switch tube Q4, the fifth switch tube Q5 and the sixth switch tube Q6 are all insulated-gate bipolar transistors (IGBT) or metal-oxide semiconductor field effect transistors (MOSFET).

[0020] In a more specific embodiment, the topology circuit further includes a filter circuit, which is arranged in parallel between the two AC input terminals of the secondary half-bridge circuit. The filter circuit includes a first inductor L1, a second inductor L2 and a fifth capacitor C5; one end of the first inductor L1 is connected to one end of the third capacitor C3, the other end of the first inductor L1 is connected to one end of the fifth capacitor C5 and one end of the second inductor L2, the other end of the second inductor L2 is connected to one end of the load R1; the other end of the fifth capacitor C5 is connected to the other end of the load R1. The first inductor, the second inductor and the fifth capacitor form an LCL filter, thereby filtering the AC output from the AC input terminal of the secondary half-bridge circuit to improve the stability of the waveform of the output AC.

[0021] The present application also discloses a control system for a topology circuit of a single-phase dual-active half-bridge inverter, such as Figure 5As shown, the control system includes a controller 11, a voltage sensor 12, a current sensor 13, a pulse modulation unit 14 and the topology circuit of the single-phase dual-active half-bridge inverter described in the above embodiment. Among them, the two voltage detection terminals of the voltage sensor 12 are electrically connected to the two AC input terminals respectively to measure the grid-side input voltage; the controller 11 is respectively connected to the detection output terminal of the voltage sensor 12, the detection output terminal of the current sensor 13 and the control receiving terminal of the pulse modulation unit 14, and the pulse signal output terminal of the pulse modulation unit 14 is respectively connected to the control terminal of each switch tube in the topology circuit of the single-phase dual-active half-bridge inverter; the detection terminal of the current sensor 13 is connected in series to one of the AC input terminals.

[0022] The present application also discloses a control method for a topology circuit of a single-phase dual-active half-bridge inverter, wherein the control method is applied to a controller, which may be a SoC control chip, a PLC (Programmable Logic Controller) circuit board, or a terminal device such as a laptop computer, a desktop computer, a tablet computer, or a mobile phone. Figure 6 As shown, the control method includes steps S110 to S180.

[0023] S110 , collecting the amplitude and angular frequency of the grid-side input voltage connected to the two AC input terminals in real time through a voltage sensor.

[0024] That is to obtain the grid side voltage The amplitude and angular frequency at the current moment. The angular frequency can be expressed as .

[0025] Figure 2 Figure (a) shows the first period when the input voltage of the inverter on the grid side is greater than or equal to zero ( ) within the working state, Figure 2 Figure (b) shows the second period when the input voltage of the inverter on the grid side is greater than or equal to zero ( ) within the working state, Figure 2 Figure (c) shows the first period when the input voltage of the inverter is less than zero on the grid side ( ) within the working state, Figure 2 (d) The figure shows the second period when the input voltage of the inverter is less than zero on the grid side. ) within the working status.

[0026] When the grid input voltage is greater than or equal to zero, Figure 2As shown in Figure (a), in the first time period, the first switch tube Q1, the fourth switch tube Q4, the fifth switch tube Q5 and the sixth switch tube Q6 are turned on, and the second switch tube Q2 and the third switch tube Q3 are turned off; Figure 2 As shown in Figure (b), in the second period, the first switch tube Q1, the third switch tube Q3, the fourth switch tube Q4 and the sixth switch tube Q6 are turned on, and the second switch tube Q2 and the fifth switch tube Q5 are turned off. The conduction control of the second half of the switching cycle is symmetrical with that of the first half of the switching cycle.

[0027] When the grid input voltage is less than zero, Figure 2 As shown in Figure (c), in the first time period, the first switch tube Q1, the third switch tube Q3, the fourth switch tube Q4 and the fifth switch tube Q5 are turned on, and the second switch tube Q2 and the sixth switch tube Q6 are turned off; Figure 2 As shown in the middle (d), in the second period, the first switch tube Q1, the third switch tube Q3, the fifth switch tube Q5 and the sixth switch tube Q6 are turned on, and the second switch tube Q2 and the fourth switch tube Q4 are turned off. The conduction control of the second half of the switching cycle is symmetrical with that of the first half of the switching cycle.

[0028] See also Figure 3 , Figure 3 The single-phase dual active half-bridge inverter provided by the embodiment of the present invention works at the grid side input voltage V ac Waveform diagram when it is greater than or equal to zero, where the upper light-colored line is the curve of the product of the DC input voltage and the ratio of the number of coil turns N, and the lighter line in the middle is the grid-side input voltage V ac Curve, the darker line below is the leakage current When the grid input V ac When the phase shift angle is greater than or equal to zero, the first switch tube Q1 and the second switch tube Q2 are alternately turned on in the first half of the switching cycle and the second half of the switching cycle, and the third switch tube Q3 and the fifth switch tube Q5 are alternately turned on at a phase shift angle φ relative to the first switch tube Q1 and the second switch tube Q2. Therefore, by determining the phase shift angle, the conduction of the third switch tube Q3, the fourth switch tube Q4, the fifth switch tube Q5 and the sixth switch tube Q6 can be accurately controlled.

[0029] Specifically, in the first period when the input voltage on the grid side is greater than or equal to zero, the first switch tube Q1, the fourth switch tube Q4, the fifth switch tube Q5 and the sixth switch tube Q6 are controlled to be turned on, and the second switch tube Q2 and the third switch tube Q3 are controlled to be turned off. lk The voltage across both ends for: ;in, For transformer T r1The ratio of the number of turns of the primary winding to the number of turns of the secondary winding. is the DC input voltage, is the grid-side input voltage; equivalent leakage inductance L lk The leakage current The instantaneous expression of is: ;in, is the leakage current exist The current value at the moment, is the equivalent leakage inductance L lk The size of the inductor.

[0030] Furthermore, during the second period when the grid-side input voltage is greater than or equal to zero, the first switch tube Q1, the third switch tube Q3, the fourth switch tube Q4 and the sixth switch tube Q6 are controlled to be turned on, and the second switch tube Q2 and the fifth switch tube Q5 are controlled to be turned off, and the equivalent leakage inductance L lk The voltage across both ends for: ; Equivalent leakage inductance L lk The leakage current The instantaneous expression of is: ;in, is the leakage current exist Current value at the moment.

[0031] According to the volt-second balance principle of the inductor and the symmetry between the first half of the switching cycle and the second half of the switching cycle, the leakage current can be obtained exist The current value at the moment is equal to the leakage inductance current exist The current value at the moment is negative, that is: ; Substituting into the above formula, the leakage inductance current can be solved exist , and The current values ​​at each moment are: ; ; .

[0032] Therefore, the inverter output current can be calculated The expression is: .

[0033] In the embodiment of the present invention, in order to make the output current Phase Shift Angle The relationship between the switching frequency and the The relationship is set as: (1).

[0034] Therefore, the inverter output current The expression can be simplified to: ; It is understandable that the inverter output current The voltage on the grid side needs to be Same phase, f s,max is the upper limit of the maximum switching frequency of the switch tube. Therefore, in the embodiment of the present invention, it is assumed that the current output by the inverter is The expression is: ;in, To request the inverter output current amplitude, The grid side voltage angular frequency.

[0035] Let the inverter output current The inverter output current is required If the phase shift angle is equal, The expression is: (2).

[0036] S120, analyzing the angular frequency according to a preset phase shift angle expression to calculate the phase angle corresponding to the angular frequency at the current moment.

[0037] Then the angular frequency is known to be According to the above formula (2), the calculated value of the phase angle at the current moment can be obtained , then the calculated value That is, the phase angle corresponding to the angular frequency at the current moment.

[0038] S130: Add the phase angle to the compensation value of the angular frequency at the current moment to obtain a phase compensation angle.

[0039] The compensation value of the angular frequency at the current moment is ,Will and Adding them together gives the actual value of the phase angle , then the actual value of the phase angle That is the phase compensation angle.

[0040] S140, calculating the phase compensation angle according to a preset switching frequency expression to obtain the switching frequency corresponding to the switch tube at the current moment.

[0041] According to formula (1), the switching frequency corresponding to the phase compensation angle can be calculated: .

[0042] S150, inputting the phase compensation angle and the switching frequency into the pulse modulation unit, so that the pulse modulation unit inputs a corresponding driving signal to each switch tube.

[0043] The actual value of the phase angle and switching frequency The input is input into the pulse modulation unit (PWM modulation unit), and the corresponding driving signal can be input to each switch tube through the pulse modulation unit, so as to output the driving signal to the first switch tube Q1, the second switch tube Q2, the third switch tube Q3, the fourth switch tube Q4, the fifth switch tube Q5 and the sixth switch tube Q6 as required.

[0044] In a more specific embodiment, the phase compensation angle and the switching frequency are input into the pulse modulation unit 14 so that the pulse modulation unit 14 inputs a corresponding drive signal to each switch tube, including: when the grid-side input voltage is greater than or equal to zero, the fourth switch tube Q4 and the sixth switch tube Q6 are controlled by the drive signal to remain in the on state, and when the grid-side input voltage is less than zero, the third switch tube Q3 and the fifth switch tube Q5 are controlled by the drive signal to remain in the on state; a complete switching cycle includes the first half of the switching cycle and the second half of the switching cycle, the first half of the switching cycle includes the first time period and the second time period, and the second half of the switching cycle includes the third time period and the fourth time period; when the grid-side input voltage is greater than or equal to zero, the first half In the first half of the switching cycle and the second half of the switching cycle, the first switch tube Q1 and the second switch tube Q2 are controlled to be alternately turned on by the driving signal, and the third switch tube Q3 and the fifth switch tube Q5 are controlled to be alternately turned on at a phase shift angle relative to the first switch tube Q1 and the second switch tube Q2, and the conduction control is symmetrical in the first half of the switching cycle and the second half of the switching cycle; when the grid-side input voltage is less than zero, in the first half of the switching cycle and the second half of the switching cycle, the first switch tube Q1 and the second switch tube Q2 are controlled to be alternately turned on by the driving signal, and the fourth switch tube Q4 and the sixth switch tube Q6 are controlled to be alternately turned on at a phase shift angle relative to the first switch tube Q1 and the second switch tube Q2, and the conduction control is symmetrical in the first half of the switching cycle and the second half of the switching cycle.

[0045] Among them, during the first period when the grid-side input voltage is less than zero, the first switch tube Q1, the third switch tube Q3, the fourth switch tube Q4 and the fifth switch tube Q5 are controlled to be turned on, and the second switch tube Q2 and the sixth switch tube Q6 are controlled to be turned off. lk The voltage across both ends and leakage current The same as the second period in which the grid side input voltage is greater than or equal to zero; in the second period in which the grid side input voltage is less than zero, the first switch tube Q1, the third switch tube Q3, the fifth switch tube Q5 and the sixth switch tube Q6 are controlled to be turned on, and the second switch tube Q2 and the fourth switch tube Q4 are controlled to be turned off, and the equivalent leakage inductance Llk The voltage across both ends and leakage current The same as the first period when the grid-side input voltage is greater than or equal to zero.

[0046] S160, collecting the output current value in real time through the current sensor.

[0047] Collect the actual value of the output current at the current moment as the output current value .

[0048] S170, subtracting the output current value from the corresponding calculated value to obtain a current error value.

[0049] To obtain the current amplitude of the inverter output, that is, the calculated value of the output current at the current moment, the output current value Subtract calculated value , the current error value can be obtained .

[0050] S180. Update the compensation value according to the current error value.

[0051] Get the current error value and combine it with the grid side voltage The amplitude at the current moment can be used to obtain the new compensation value corresponding to the phase angle. , so as to achieve the compensation value If the compensation value is updated, the updated compensation value can be used in the next calculation process. .

[0052] See also Figure 4 , Figure 4 This is an output current waveform diagram of a single-phase dual-active half-bridge inverter provided by an embodiment of the present invention. The present invention applies the above control method to the topological circuit of a single-phase dual-active half-bridge inverter and performs simulation tests. The waveform of the output current is collected by an oscilloscope. The waveform diagram shows that the amplitude of the output current meets the requirements, the phase is in phase with the grid voltage, there is almost no distortion, and stable AC output can be achieved.

[0053] The present invention discloses a topological circuit, control system and control method of a single-phase dual-active half-bridge inverter, wherein the topological circuit includes a primary half-bridge circuit, a transformer and a secondary half-bridge circuit; the primary half-bridge circuit includes a first capacitor, a second capacitor, a first switch tube and a second switch tube; the secondary half-bridge circuit includes a third capacitor, a fourth capacitor, a third switch tube, a fourth switch tube, a fifth switch tube and a sixth switch tube. The topological circuit adopts a unipolar structure, which reduces the loss of power transmission during the use of the inverter; reduces the number of switch tubes used, reduces the switching loss caused by the operation of the device, thereby improving the operating efficiency and power density of the inverter; and linearizes the nonlinear function of the closed-loop control, optimizes the control method for regulating the inverter, and reduces the control difficulty of the inverter.

[0054] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A topology circuit of a single-phase dual active half-bridge inverter, characterized in that: The topology circuit includes a primary half-bridge circuit, a transformer and a secondary half-bridge circuit; The primary half-bridge circuit includes a first capacitor, a second capacitor, a first switch tube and a second switch tube; the secondary half-bridge circuit includes a third capacitor, a fourth capacitor, a third switch tube, a fourth switch tube, a fifth switch tube and a sixth switch tube; One end of the first capacitor is connected to the drain of the first switch tube, and the connection point is used as the positive electrode of the DC power supply; one end of the second capacitor is connected to the source of the second switch tube, and the connection point is used as the negative electrode of the DC power supply; the other end of the first capacitor is connected to the other end of the second capacitor and the primary opposite-name terminal of the transformer, and the source of the first switch tube is connected to the drain of the second switch tube and the primary same-name terminal of the transformer; One end of the third capacitor is connected to the drain of the third switch tube, and the connection point serves as an AC input terminal; one end of the fourth capacitor is connected to the drain of the sixth switch tube, and the connection point serves as another AC input terminal; the source of the third switch tube is connected to the source of the fourth switch tube, and the drain of the fourth switch tube is connected to the drain of the fifth switch tube and the secondary same-name terminal of the transformer; the source of the sixth switch tube is connected to the source of the fifth switch tube; the other end of the third capacitor is connected to the other end of the fourth capacitor and the secondary opposite-name terminal of the transformer, and the equivalent leakage inductance of the transformer is connected in series between the secondary same-name terminal and the drain of the fourth switch tube; The load is arranged in parallel between the two AC input terminals.

2. The topology circuit of the single-phase dual active half-bridge inverter according to claim 1, characterized in that: The capacitance values ​​of the first capacitor and the second capacitor are equal, and the capacitance values ​​of the third capacitor and the fourth capacitor are equal.

3. The topology circuit of the single-phase dual active half-bridge inverter according to claim 2, characterized in that: The topology circuit further includes a filter circuit, which is arranged in parallel between two AC input terminals of the secondary half-bridge circuit.

4. The topology circuit of the single-phase dual active half-bridge inverter according to claim 3, characterized in that: The filter circuit includes a first inductor, a second inductor and a fifth capacitor; One end of the first inductor is connected to one end of the third capacitor, the other end of the first inductor is connected to one end of the fifth capacitor and one end of the second inductor, the other end of the second inductor is connected to one end of the load; the other end of the fifth capacitor is connected to the other end of the load.

5. The topology circuit of the single-phase dual active half-bridge inverter according to claim 2 or 3, characterized in that: The first switch tube, the second switch tube, the third switch tube, the fourth switch tube, the fifth switch tube and the sixth switch tube are all insulated gate bipolar transistors or metal-oxide semiconductor field effect transistors.

6. A control system for a topology circuit of a single-phase dual active half-bridge inverter, characterized in that: The control system includes a controller, a voltage sensor, a current sensor, a pulse modulation unit and a topology circuit of a single-phase dual active half-bridge inverter according to any one of claims 1 to 5; The two voltage detection terminals of the voltage sensor are electrically connected to the two AC input terminals respectively to measure the grid-side input voltage; The controller is respectively connected to the detection output end of the voltage sensor, the detection output end of the current sensor and the control receiving end of the pulse modulation unit, and the pulse signal output end of the pulse modulation unit is respectively connected to the control end of each switch tube in the topology circuit of the single-phase dual active half-bridge inverter; The detection end of the current sensor is connected in series to one of the AC input ends.

7. A control method for a topology circuit of a single-phase dual-active half-bridge inverter, characterized in that: The control method is applied to a controller of a control system of a topology circuit of a single-phase dual-active half-bridge inverter as claimed in claim 6, and the control method comprises: The voltage sensor collects the amplitude and angular frequency of the grid-side input voltage connected to the two AC input terminals in real time; The angular frequency is analyzed according to a preset phase shift angle expression to calculate the phase angle corresponding to the angular frequency at the current moment; Adding the phase angle to the compensation value of the angular frequency at the current moment to obtain a phase compensation angle; The phase compensation angle is calculated according to a preset switching frequency expression to obtain the switching frequency corresponding to the switch tube at the current moment; Inputting the phase compensation angle and the switching frequency into the pulse modulation unit, so that the pulse modulation unit inputs a corresponding driving signal to each switch tube; The output current value is collected in real time through the current sensor; Subtracting the output current value from the corresponding calculated value to obtain a current error value; The compensation value is updated according to the current error value.

8. The control method of the topology circuit of the single-phase dual active half-bridge inverter according to claim 7, characterized in that: The step of inputting the phase compensation angle and the switching frequency into the pulse modulation unit so that the pulse modulation unit inputs a corresponding driving signal to each switch tube includes: When the grid-side input voltage is greater than or equal to zero, the fourth switch tube and the sixth switch tube are controlled to remain in the on state through the driving signal; when the grid-side input voltage is less than zero, the third switch tube and the fifth switch tube are controlled to remain in the on state through the driving signal; A complete switching cycle includes the first half switching cycle and the second half switching cycle, the first half switching cycle includes the first time period and the second time period, and the second half switching cycle includes the third time period and the fourth time period; When the grid-side input voltage is greater than or equal to zero, the first switch tube and the second switch tube are controlled to be alternately turned on by the driving signal in the first half switching cycle and the second half switching cycle, and the third switch tube and the fifth switch tube are controlled to be alternately turned on at a phase shift angle relative to the first switch tube and the second switch tube, and the conduction control is symmetrical in the first half switching cycle and the second half switching cycle; When the grid-side input voltage is less than zero, the first switch tube and the second switch tube are controlled to be alternately turned on by a driving signal in the first half of the switching cycle and the second half of the switching cycle, and the fourth switch tube and the sixth switch tube are controlled to be alternately turned on at a phase shift angle relative to the first switch tube and the second switch tube, and the conduction control is symmetrical in the first half of the switching cycle and the second half of the switching cycle.

9. The control method of the topology circuit of the single-phase dual active half-bridge inverter according to claim 8, characterized in that: In the first period when the input voltage on the grid side is greater than or equal to zero, the first switch tube, the fourth switch tube, the fifth switch tube and the sixth switch tube are controlled to be turned on, and the second switch tube and the third switch tube are controlled to be turned off. The voltage across the equivalent leakage inductance is for: ; Where N is the ratio of the number of turns of the primary winding to the number of turns of the secondary winding in the transformer, is the DC input voltage, is the grid side input voltage; Leakage current of equivalent leakage inductance The instantaneous expression of is: ;in, is the leakage current exist The current value at the moment, is the inductance of the equivalent leakage inductance.

10. The control method of the topology circuit of the single-phase dual active half-bridge inverter according to claim 9, characterized in that: During the second period when the grid-side input voltage is greater than or equal to zero, the first switch tube, the third switch tube, the fourth switch tube and the sixth switch tube are controlled to be turned on, and the second switch tube and the fifth switch tube are controlled to be turned off. The voltage across the equivalent leakage inductance is for: ; Leakage current of equivalent leakage inductance The instantaneous expression of is: ;in, is the leakage current exist The current value at the moment; During the first period when the grid-side input voltage is less than zero, the first switch tube, the third switch tube, the fourth switch tube and the fifth switch tube are controlled to be turned on, and the second switch tube and the sixth switch tube are controlled to be turned off. The voltage across the equivalent leakage inductance is and leakage current The same as the second period when the grid-side input voltage is greater than or equal to zero; During the second period when the grid-side input voltage is less than zero, the first switch tube, the third switch tube, the fifth switch tube and the sixth switch tube are controlled to be turned on, and the second switch tube and the fourth switch tube are controlled to be turned off. The voltage across the equivalent leakage inductance is and leakage current The same as the first period when the grid-side input voltage is greater than or equal to zero.

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