High-gain direct-current converter with multiple coupling inductors, device and control method

Abstract

The invention provides a high-gain direct-current converter with multiple coupling inductors, a device and a control method. The high-gain direct-current converter with the multiple coupling inductors comprises an input end, a switching tube S, a three-winding coupling inductor, a double-winding coupling inductor, an inductor L1, a plurality of capacitors, a plurality of diodes and an output circuit. According to the invention, a mode of combining a three-winding coupling inductor and a double-winding coupling inductor is adopted, and a circuit topology is constructed with the inductor, a plurality of capacitors, a plurality of diodes, a switching tube S, an input end and each element of an output circuit through a specific connection mode. According to the structural design of the multi-coupling inductor, the coupling effect between the inductors can be more effectively utilized, higher voltage gain is achieved, in addition, the turn ratio of the multiple coupling inductors can be reasonably selected, the voltage gain range can be flexibly designed, the situation that the extreme duty ratio occurs in the working process of a switching tube is avoided, and the working efficiency is improved. The whole circuit is simple in structure and control and high in working efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy storage grid-connected technology, and in particular to a high-gain DC converter with multiple coupled inductors, a device and a control method. Background Art

[0002] In the renewable energy power generation system, it is necessary to convert renewable energy into electrical energy. Its output voltage is generally between 20 volts (V) and 50V, which cannot directly meet the inverter requirements. Therefore, a boost DC converter is needed to boost the low DC voltage to a high DC voltage (generally 400V) suitable for inverter conversion, so as to meet the inverter AC / DC conversion and complete grid connection. New energy storage systems such as solar energy and wind energy are widely used, but there is a high demand for grid connection voltage during the grid connection process. Therefore, boost converters with high voltage gain play a very important role in new energy storage systems. On the other hand, during the power generation process of renewable energy such as solar energy and wind energy, the input voltage will fluctuate significantly due to changes in light and wind power. In order to ensure the stability of the output voltage, the boost converter needs to have a wider voltage gain range.

[0003] In the related art, the actual voltage gain of ordinary Boost converters is not high, the voltage gain range is narrow, and the duty cycle of the switch tube is high under normal operation, and the conduction time is too long, which will increase the conduction loss and reduce the service life. In view of this defect, the prior art proposes a high boost DC converter based on a coupled inductor structure, which can not only relieve the pressure of the switch tube and improve the voltage gain by adjusting the turns ratio of the coupled inductor, but also use its leakage inductance to alleviate the diode reverse recovery problem caused by low duty cycle operation.

[0004] However, as the power level of new energy power generation systems continues to increase, the requirements for the voltage gain of boost converters are also getting higher and higher. Conventional DC converters based on coupled inductor structures still have the problem of insufficient voltage gain, and the operating duty cycle of the switching tube is extreme and the boost efficiency is low. Summary of the invention

[0005] The embodiments of the present invention provide a high-gain DC converter, device and control method with multiple coupled inductors to solve the problem of insufficient voltage gain in conventional DC converters based on coupled inductor structures in the prior art, and the problem of low boost efficiency due to a high duty cycle of the switching tube.

[0006] In a first aspect, an embodiment of the present invention provides a high-gain DC converter with multiple coupled inductors, comprising: an input end, a switch tube S, a three-winding coupled inductor, a double-winding coupled inductor, an inductor L1, multiple capacitors, multiple diodes, and an output circuit; The three-winding coupled inductor comprises: a primary winding N1, a secondary winding N2 and a secondary winding N3; The dual-winding coupled inductor comprises: a primary winding n1 and a secondary winding n2; The positive electrode of the input end is connected to one end of the inductor L1, and the other end of the inductor L1 is respectively connected to the drain of the switch tube S, the positive electrode of the diode D1, the opposite end of the primary winding N1 and the same end of the secondary winding N3; The negative electrode of the input end is respectively connected to the source electrode of the switch tube S, the negative electrode of the capacitor C1 and the negative electrode of the output circuit; The same-name end of the primary winding N1 is respectively connected to the positive electrode of the capacitor C1 and the negative electrode of the capacitor C2, the positive electrode of the capacitor C2 is connected to the opposite-name end of the secondary winding N2, and the same-name end of the secondary winding N2 is respectively connected to the negative electrode of the diode D1, the positive electrode of the diode D2 and the negative electrode of the capacitor C3; The opposite-name end of the secondary winding N3 is connected to the negative electrode of the capacitor C4, the positive electrode of the capacitor C4 is respectively connected to the negative electrode of the diode D2, the positive electrode of the diode D3, the negative electrode of the capacitor C5 and the opposite-name end of the primary winding n1, and the same-name end of the primary winding n1 is connected to the positive electrode of the capacitor C3; The like-name ends of the secondary winding n2 are respectively connected to the positive electrode of the capacitor C5 and the positive electrode of the diode D4, the different-name ends of the secondary winding n2 are respectively connected to the negative electrode of the diode D3 and the negative electrode of the capacitor C6, the positive electrode of the capacitor C6 is respectively connected to the negative electrode of the diode D4 and the positive electrode of the diode D5, and the negative electrode of the diode D5 is connected to the positive electrode of the output circuit.

[0007] In a possible implementation, the primary winding N1 includes a leakage inductance L k1 and the magnetizing inductance L m1 The primary winding n1 includes a leakage inductance L k2 and the magnetizing inductance L m2 .

[0008] In a possible implementation, the output circuit includes: a capacitor C7 and a load; The cathode of the diode D5 is respectively connected to the anode of the capacitor C7 and one end of the load, and the other end of the load is respectively connected to the cathode of the capacitor C7, the cathode of the input end, the source of the switch tube S and the cathode of the capacitor C1.

[0009] In a possible implementation, a working cycle of the DC converter includes a first working mode, a second working mode and a third working mode; The on or off of the switch tube S is used to control the switching of the working mode of the DC converter. In a possible implementation, the first working mode is: the switch tube S is turned on, the diode D2, the diode D3 and the diode D4 are turned on, and the diode D1 and the diode D5 are blocked; The input end charges the inductor L1, and the current of the inductor L1 increases linearly; The capacitor C1 is the leakage inductance L k1 and the magnetizing inductance L m1 charging, the leakage inductance L k1 and the magnetizing inductance L m1 The current increases linearly; The capacitor C1, the capacitor C2, the secondary winding N2 and the secondary winding N3 charge the capacitor C4 through the diode D2; The capacitor C3 is the leakage inductance L k2 and the magnetizing inductance L m2 charging, the leakage inductance L k2 and the magnetizing inductance L m2 The charging current increases linearly; The secondary winding n2 charges the capacitor C5 through the diode D3 and also charges the capacitor C6 through the diode D4.

[0010] In a possible implementation, the second working mode is: the switch tube S is turned off, the diode D1 and the diode D5 are turned on, and the diode D2, the diode D3 and the diode D4 are blocked; The input terminal and the inductor L1 charge the capacitor C1; The capacitor C2, the excitation inductor L m1 , the secondary winding N2 and the secondary winding N3 charge the capacitor C3 and the capacitor C4; The input end, the inductor L1, the secondary winding N3, the secondary winding n2, the capacitor C4, the capacitor C5 and the capacitor C6 charge the capacitor C7; The inductor L1 and the excitation inductor L m1 , the excitation inductance L m2 , the leakage inductance L k1 And the leakage inductance L k2 The current decreases, and the capacitor C2 recovers the leakage inductance L through the diode D1. k1 The energy of the diode D1 is increased, and the current of the diode D1 decreases. When the current of the diode D1 decreases to zero, the second working mode is terminated and the third working mode is entered.

[0011] In a possible implementation, the third working mode is: the switch tube S is turned off, the diode D5 is turned on, and the diode D1, the diode D2, the diode D3 and the diode D4 are blocked; The input terminal and the inductor L1 charge the capacitor C1; The capacitor C2, the excitation inductor L m1 , the secondary winding N2 and the secondary winding N3 charge the capacitor C3 and the capacitor C4; The input end, the inductor L1, the secondary winding N3, the secondary winding n2, the capacitor C4, the capacitor C5 and the capacitor C6 charge the capacitor C7; The capacitor C7 supplies power to the load.

[0012] In a possible implementation manner, a calculation formula for a gain G of the output voltage of the output circuit relative to the input voltage of the input end is: ;in, represents the turns ratio of the secondary winding N2 to the primary winding N1, represents the turns ratio of the secondary winding N3 to the primary winding N1, represents the turns ratio of the secondary winding n2 to the primary winding n1, and D represents the duty cycle of the switch tube S.

[0013] In a second aspect, an embodiment of the present invention provides a high-gain DC converter device with multiple coupled inductors, comprising: a controller, a voltage sampling sensor, and the high-gain DC converter with multiple coupled inductors provided in the first aspect of the embodiment of the present invention; Among them, the positive pole of the voltage sampling sensor is connected to the positive pole of the output circuit of the converter, the negative pole of the voltage sampling sensor is connected to the negative pole of the output circuit of the converter, the output end of the voltage sampling sensor is connected to the input end of the controller, and the output end of the controller is connected to the switch tube S.

[0014] In a third aspect, an embodiment of the present invention provides a control method, which is applied to the high-gain DC converter with multiple coupled inductors provided in the first aspect of the embodiment of the present invention, or the high-gain DC converter with multiple coupled inductors provided in the second aspect, comprising: collecting an output voltage of the output circuit; Calculating an error value between the output voltage and the target voltage, and adjusting the duty cycle of the switch tube S according to the error value; The pulse width modulation (PWM) wave signal generated by the adjusted duty cycle is input to the switch tube S to control the switch tube S to be turned on or off.

[0015] The embodiment of the present invention provides a high-gain DC converter, device and control method of multiple coupled inductors, which adopts a combination of three-winding coupled inductors and two-winding coupled inductors, and constructs a circuit topology with inductors, multiple capacitors, multiple diodes, switch tubes S, input terminals and output circuit components through a specific connection method. The structural design of this multiple coupled inductor can more effectively utilize the coupling effect between inductors to achieve a higher voltage gain, and can achieve a flexible design voltage gain range by reasonably selecting multiple coupled inductor turn ratios to avoid extreme duty cycles in the operation of the switch tube. The entire circuit control is simple and the working efficiency is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of a high-gain DC converter with multiple coupled inductors provided in an embodiment of the present invention; Figure 2 is a schematic structural diagram of another high-gain DC converter with multiple coupled inductors provided in an embodiment of the present invention; Figure 3 is a schematic diagram of a circuit structure in a first working mode provided by an embodiment of the present invention; Figure 4 is a schematic diagram of a circuit structure in a second working mode provided by an embodiment of the present invention; Figure 5 is a schematic diagram of a circuit structure in a third working mode provided by an embodiment of the present invention; Figure 6 is a schematic structural diagram of a high-gain DC conversion device with multiple coupled inductors provided in an embodiment of the present invention; Figure 7 is a schematic diagram of an implementation flow of a control method provided by an embodiment of the present invention; DETAILED DESCRIPTION In order to enable people in the technical field to better understand the present solution, the technical solution in the embodiment of the present solution will be clearly described below in conjunction with the drawings in the embodiment of the present solution. Obviously, the described embodiment is an embodiment of a part of the present solution, not all of the embodiments. Based on the embodiments in the present solution, all other embodiments obtained by ordinary technicians in the field without creative work should fall within the scope of protection of the present solution.

[0017] The term "including" and any other variations in the specification and claims of this solution and the above drawings mean "including but not limited to", and is intended to cover non-exclusive inclusions and is not limited to the examples listed in the text. In addition, the terms "first" and "second" are used to distinguish different objects, not to describe a specific order.

[0018] In the related art, in order to solve the problem that the actual voltage gain of ordinary Boost converters is not high, the voltage gain range is narrow, and the duty cycle of the switch tube is relatively high under normal operation, and the conduction time is too long, which will increase the conduction loss and reduce the service life. A high-boost DC converter based on a coupled inductor structure is proposed. The coupling method is usually a single multi-unit coupled inductor, that is, one primary winding and two or three secondary windings. The pressure on the switch tube is relieved and the voltage gain is improved by adjusting the turns ratio of the coupled inductor. However, the requirements of new energy power generation systems for the voltage gain of boost converters are getting higher and higher. Conventional DC converters based on coupled inductor structures still have the problem of insufficient voltage gain, and the working duty cycle of the switch tube is extreme and the conversion efficiency of the entire circuit is low.

[0019] In view of the problems existing in the prior art, the present invention adopts a combination of three-winding coupled inductors and two-winding coupled inductors, and constructs a circuit topology through a specific connection method with inductors, multiple capacitors, multiple diodes, switch tubes S, input terminals, and output circuit components. This structural design of multiple coupled inductors can more effectively utilize the coupling effect between inductors to achieve a higher voltage gain, and can achieve a flexible design voltage gain range by reasonably selecting multiple coupled inductor turn ratios to avoid extreme duty cycles in the operation of the switch tube. The entire circuit is simple to control and has high working efficiency.

[0020] The following is a detailed description of the implementation of the present invention in conjunction with the specific drawings: Figure 1 A schematic diagram of the structure of a high-gain DC converter with multiple coupled inductors provided by an embodiment of the present invention. Figure 1 The high-gain DC converter with multiple coupled inductors includes: an input terminal (denoted as V in ), switch tube S, three-winding coupled inductor, double-winding coupled inductor, inductor L1, multiple capacitors, multiple diodes and output circuit; The three-winding coupled inductor comprises: a primary winding N1, a secondary winding N2 and a secondary winding N3; The dual-winding coupled inductor comprises: a primary winding n1 and a secondary winding n2; The positive electrode of the input end is connected to one end of the inductor L1, and the other end of the inductor L1 is respectively connected to the drain of the switch tube S, the positive electrode of the diode D1, the opposite end of the primary winding N1 and the same end of the secondary winding N3; The negative electrode of the input end is respectively connected to the source electrode of the switch tube S, the negative electrode of the capacitor C1 and the negative electrode of the output circuit; The same-name end of the primary winding N1 is respectively connected to the positive electrode of the capacitor C1 and the negative electrode of the capacitor C2, the positive electrode of the capacitor C2 is connected to the opposite-name end of the secondary winding N2, and the same-name end of the secondary winding N2 is respectively connected to the negative electrode of the diode D1, the positive electrode of the diode D2 and the negative electrode of the capacitor C3; The opposite-name end of the secondary winding N3 is connected to the negative electrode of the capacitor C4, the positive electrode of the capacitor C4 is respectively connected to the negative electrode of the diode D2, the positive electrode of the diode D3, the negative electrode of the capacitor C5 and the opposite-name end of the primary winding n1, and the same-name end of the primary winding n1 is connected to the positive electrode of the capacitor C3; The like-name ends of the secondary winding n2 are respectively connected to the positive electrode of the capacitor C5 and the positive electrode of the diode D4, the different-name ends of the secondary winding n2 are respectively connected to the negative electrode of the diode D3 and the negative electrode of the capacitor C6, the positive electrode of the capacitor C6 is respectively connected to the negative electrode of the diode D4 and the positive electrode of the diode D5, and the negative electrode of the diode D5 is connected to the positive electrode of the output circuit.

[0021] In this embodiment, the input end is connected to the new energy power generation system, and the electric energy generated by the new energy power generation system is input into the boost circuit through the input end. Therefore, when constructing the circuit topology of the high-gain DC converter, the input end can be equivalent to an input power supply, and the electric energy provided by the input power supply to the circuit is the electric energy generated by the new energy power generation system.

[0022] In this embodiment, a plurality of capacitors (C1-C6) and a plurality of diodes (D1-D5) form a charge pump circuit, which stores and transfers energy through charging and discharging.

[0023] This embodiment adopts a combination of three-winding coupled inductors and two-winding coupled inductors, and constructs a circuit topology through a specific connection method with inductors, multiple capacitors, multiple diodes, switch tubes S, input terminals, and output circuit components. This multi-coupled inductor (three-winding and two-winding) structural design can more effectively utilize the magnetic coupling between inductors to superimpose energy, and then combine with a charge pump structure composed of multiple capacitors and multiple diodes to form a multi-stage voltage boost mechanism to double the voltage, achieving a higher voltage gain, and by reasonably selecting multiple coupled inductor turn ratios and adjusting the switch tube S duty cycle, the output voltage can be greatly increased to meet high gain requirements, and a flexible design voltage gain range can be achieved to avoid extreme duty cycles in the switch tube. The entire circuit control is simple and the work efficiency is high. The efficient transmission and conversion of energy can be achieved through the magnetic coupling between the three windings and the double windings. Compared with the traditional single multi-unit coupled inductor structure, the circuit structure is simple, the manufacturing cost is low, and it has higher power density and conversion efficiency. The use of multiple coupled inductor structures can have multiple energy sources, avoiding excessive voltage stress in the circuit; and it also has the advantages of continuous input current, low voltage stress on the switch tube S, and common grounding of the input energy source and the load.

[0024] In one possible embodiment, see Figure 2 The output circuit includes: a capacitor C7 and a load; the cathode of the diode D5 is respectively connected to the anode of the capacitor C7 and one end of the load, and the other end of the load is respectively connected to the cathode of the capacitor C7, the cathode of the input end, the source of the switch tube S and the cathode of the capacitor C1.

[0025] In this embodiment, the load may be a resistor R, and the capacitor C7 supplies power to the load, and a stable voltage (denoted as V o ).

[0026] It can be understood that the primary winding N1 can be equivalent to an ideal coil and the excitation inductance L m1 After connecting in parallel with the leakage inductance L k1 Series; the primary winding n1 is equivalent to an ideal coil and the excitation inductance L m2 After connecting in parallel with the leakage inductance L k2 Series connection.

[0027] In the circuit topology provided in this embodiment, the leakage inductance L k1 and leakage inductance L k2 The leakage inductance energy can be recovered through components such as diode D1 to avoid leakage inductance energy loss and improve the overall efficiency of the circuit.

[0028] In a possible implementation, a working cycle of the high-gain DC converter includes a first working mode, a second working mode and a third working mode; the on or off of the switch tube S is used to control the switching of the working mode of the DC converter.

[0029] In a possible implementation, the first working mode is: the switch tube S is turned on, the diode D2, the diode D3 and the diode D4 are turned on, and the diode D1 and the diode D5 are blocked; The input end charges the inductor L1, and the current of the inductor L1 increases linearly; The capacitor C1 is the leakage inductance L k1 and the magnetizing inductance L m1 charging, the leakage inductance L k1 and the magnetizing inductance L m1 The current increases linearly; The capacitor C1, the capacitor C2, the secondary winding N2 and the secondary winding N3 charge the capacitor C4 through the diode D2; The capacitor C3 is the leakage inductance L k2 and the magnetizing inductance L m2 charging, the leakage inductance L k2 and the magnetizing inductance L m2 The charging current increases linearly; The secondary winding n2 charges the capacitor C5 through the diode D3 and also charges the capacitor C6 through the diode D4.

[0030] Specifically, refer to Figure 3 In the circuit structure shown in the figure, the first working mode is: the switch tube S is turned on, the diodes D2, D3, and D4 are turned on, and the diodes D1 and D5 are blocked. in The inductor L1 is charged, so the current of the inductor L1 increases linearly; the leakage inductor L k1 and the magnetizing inductance L m1 As a whole, the capacitor C1 is charged, and the leakage inductance L k1 and the magnetizing inductance L m1 The current rises linearly together; capacitors C1, C2 and secondary windings N2, N3 release energy to capacitor C4 through diode D2; capacitor C3 discharges to leakage inductance L k2 and the magnetizing inductance L m2 Charging, leakage inductance L k2 and the magnetizing inductance L m2 The current of the secondary winding n2 rises linearly together; the secondary winding n2 charges the capacitors C5 and C6 through the diodes D3 and D4 at the same time.

[0031] In this embodiment, the energy stored in the capacitors C4, C5, and C6 in the first working mode will be delivered to the load in the second working mode and the third working mode to increase the output voltage, and the output capacitor C7 only supplies power to the load R.

[0032] In a possible implementation, the second working mode is: the switch tube S is turned off, the diode D1 and the diode D5 are turned on, and the diode D2, the diode D3 and the diode D4 are blocked; The input terminal and the inductor L1 charge the capacitor C1; The capacitor C2, the excitation inductor L m1 , the secondary winding N2 and the secondary winding N3 charge the capacitor C3 and the capacitor C4; The input end, the inductor L1, the secondary winding N3, the secondary winding n2, the capacitor C4, the capacitor C5 and the capacitor C6 charge the capacitor C7; The inductor L1 and the excitation inductor L m1 , the excitation inductance L m2 , the leakage inductance L k1 And the leakage inductance L k2 The current decreases, and the capacitor C2 recovers the leakage inductance L through the diode D1. k1 The energy of the diode D1 is increased, and the current of the diode D1 decreases. When the current of the diode D1 decreases to zero, the second working mode is terminated and the third working mode is entered.

[0033] Specifically, refer to Figure 4 The circuit structure shown in the figure, in the second working mode: the switch tube S is turned off, the diodes D1 and D5 are turned on, and the diodes D2, D3, and D4 are blocked; the input power supply V in Together with inductor L1, it releases energy to charge capacitor C1; capacitor C2 and excitation inductor L m1 , the secondary windings N2 and N3 together charge the capacitors C3 and C4; the input power supply and inductor L1 together with the secondary winding N3, the secondary winding n2 and the capacitors C4, C5 and C6 charge the capacitor C7, so the inductor L1 and the excitation inductor L m1 , L m2 , leakage inductance L k1 , L k2 The currents all decrease; capacitor C2 recovers the leakage inductance energy through diode D1, and this mode ends when the current of diode D1 drops to zero.

[0034] In a possible implementation, the third working mode is: the switch tube S is turned off, the diode D5 is turned on, and the diode D1, the diode D2, the diode D3 and the diode D4 are blocked; The input terminal and the inductor L1 charge the capacitor C1; The capacitor C2, the excitation inductor L m1 , the secondary winding N2 and the secondary winding N3 charge the capacitor C3 and the capacitor C4; The input end, the inductor L1, the secondary winding N3, the secondary winding n2, the capacitor C4, the capacitor C5 and the capacitor C6 charge the capacitor C7; The capacitor C7 supplies power to the load.

[0035] Specifically, refer to Figure 5 In the circuit structure shown in the third working mode, the switch tube S is still turned off, and all diodes except the diode D5 are blocked; the input power supply V in and inductor L1 continue to charge capacitor C1; capacitor C2 and excitation inductor L m1 , the secondary windings N2 and N3 continue to charge the capacitors C3 and C4; the input power supply V in The inductor L1 and the secondary winding N3, the secondary winding n2 and the capacitors C4, C5 and C6 continue to charge the capacitor C7.

[0036] In this embodiment, different working states are switched by controlling the switch tube S, thereby realizing precise control and regulation of the output voltage, so that the DC converter can realize specific power conversion and transmission in different working stages, which helps to improve the efficiency and stability of the converter; in different working modes, the cooperative working mode between each inductor, capacitor and diode can realize energy storage, transfer and release, which not only meets the needs of high-gain DC conversion, but also the magnetic field coupling characteristics of the coupled inductor enable energy to be efficiently transferred between windings, and with the energy storage buffering effect of the capacitor, the current stress of the switch tube and the voltage stress of the diode can be reduced, and the switching loss and conduction loss can be reduced. In addition, components such as capacitors and diodes are reused in different working modes, reducing the need for additional components. At the same time, under the magnetic energy distribution of the coupled inductor, the working stress of components such as capacitors and diodes is more balanced and the utilization rate is higher. For example, capacitors C1-C6 not only participate in energy storage, but also work together in the charge pump circuit, simplifying the circuit topology.

[0037] It can be seen from the circuit topology of the high-gain DC converter provided in this embodiment that the calculation formula of the gain G of the output voltage of the output circuit relative to the input voltage of the input end is: ;in, represents the turns ratio of the secondary winding N2 to the primary winding N1, represents the turns ratio of the secondary winding N3 to the primary winding N1, represents the turns ratio of the secondary winding n2 to the primary winding n1, and D represents the duty cycle of the switch tube S.

[0038] It can be clearly seen from the voltage gain calculation formula that by adjusting the turns ratio of the coupled inductor and adjusting the duty cycle of the switch tube S, the voltage gain range can be flexibly adjusted to achieve a higher voltage gain. For example, when the duty cycle is D=0.5 and the turns ratio of the coupled inductor is 2, the voltage gain can reach 42 times.

[0039] Figure 6 Schematic diagram of the structure of a high-gain DC converter with multiple coupled inductors provided in an embodiment of the present invention. Figure 6 As shown, the high-gain DC converter of multiple coupled inductors provided in this embodiment includes: a controller, a voltage sampling sensor, and the high-gain DC converter of multiple coupled inductors provided in the above embodiment; Among them, the positive pole of the voltage sampling sensor is connected to the positive pole of the output circuit of the converter, the negative pole of the voltage sampling sensor is connected to the negative pole of the output circuit of the converter, the output end of the voltage sampling sensor is connected to the input end of the controller, and the output end of the controller is connected to the switch tube S.

[0040] In this embodiment, the voltage sampling sensor may be, but is not limited to, a Hall voltage sampling sensor, and the controller may be, but is not limited to, a proportional-integral (PI) controller.

[0041] In this embodiment, the output voltage V of the high-gain DC converter is collected by a Hall voltage sampling sensor. o The collected output voltage is sent to the PI controller, which stores the target voltage. The PI controller receives the output voltage V o After that, the error value between the output voltage and the target voltage is calculated, and the proportional coefficient kp and the integral coefficient ki are adjusted according to the error value, so that the PI controller reduces the error value and generates a pulse width modulation (PWM) wave signal, and sends the PWM wave signal to the switch tube S to control the on and off of the switch tube S, so as to realize the switching of the working mode of the high-gain DC converter and make the output voltage V o stabilize to the target voltage value.

[0042] It should be noted that the value of the target voltage is determined according to the voltage value required in the actual application scenario. For example, in the actual application scenario, the high-gain DC conversion device is required to boost the low DC voltage to a high DC voltage suitable for inverter conversion (generally 400V), then the target voltage is set to 400V.

[0043] In the PI controller, the proportional part (kp) outputs the control signal in proportion to the error value between the current output voltage and the target voltage. When the output voltage of the high-gain DC converter deviates from the target voltage value, the proportional link can react quickly, generate the corresponding control amount, adjust the working state of the switch tube, and make the output voltage change in the direction of the target voltage value. For example, if the output voltage is lower than the target voltage, the proportional link (kp) will increase the control signal, increase the on-time of the switch tube, allow more energy to be transferred to the output end, and increase the output voltage. The integral part (ki) integrates the error value and accumulates the error from the beginning to the current moment. Over time, even if the error is very small, the integral term will continue to increase, and the control amount will continue to be adjusted until the steady-state error is eliminated, so that the output voltage is stabilized at the target voltage value. For example, during long-term operation, a small steady-state error is generated due to load changes or power supply fluctuations, and the integral link can gradually correct it to keep the output voltage stable. The PI controller generates the duty cycle of the PWM wave signal according to the processed error signal. By changing the duty cycle of the PWM wave, it directly controls the on and off time of the switch tube S in the high-gain DC converter, thereby adjusting the output voltage. For example, when the duty cycle increases, the on time of the switch tube becomes longer and the output voltage increases; conversely, the output voltage decreases.

[0044] In this embodiment, the PI controller can optimize the dynamic performance of the high-gain DC converter, so that it can quickly adjust the output when facing interference such as input voltage fluctuations and load mutations, maintain stable operation, maintain output voltage stability, and enhance the robustness of the system. In addition, the output voltage is collected by the voltage sampling sensor and fed back to the controller. The controller adjusts the duty cycle of the switch tube according to the error between the output voltage and the target voltage, forming a closed-loop control system. This closed-loop control method can monitor and adjust the output voltage of the high-gain DC converter in real time, improving the overall stability and reliability of the circuit.

[0045] Figure 7 is a schematic diagram of the implementation flow of the control method provided by an embodiment of the present invention; Figure 7 As shown, the method provided in this embodiment includes the following steps: S701, collecting the output voltage of the output circuit.

[0046] S702, calculating an error value between the output voltage and the target voltage, and adjusting the duty cycle of the switch tube S according to the error value.

[0047] S703, generating a pulse width modulation (PWM) wave signal with the adjusted duty cycle and inputting it into the switch tube S to control the switch tube S to be turned on or off.

[0048] In this embodiment, the execution body of step S701 may be a voltage sampling sensor, and the execution body of steps S702 and S703 may be a PI controller.

[0049] In this embodiment, the output voltage of the high-gain DC converter is automatically collected, and the duty cycle of the switch tube S is automatically adjusted according to the error value between the output voltage and the target voltage, and the PWM wave signal generated by the adjusted duty cycle is input to the switch tube S to control the on or off of the switch tube S, thereby realizing a closed-loop control method of the high-gain DC converter, being able to monitor and adjust the output voltage of the high-gain DC converter in real time, being able to stabilize the output voltage at the target voltage value, and improving the overall stability and reliability of the circuit.

[0050] It should be noted that the detailed implementation process of the method provided in this embodiment can refer to the description in the above-mentioned embodiment of the high-gain branch current conversion device with multiple coupled inductors, and will not be repeated here.

[0051] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-gain DC converter with multiple coupled inductors, characterized in that: include: Input end, switch tube S, three-winding coupled inductor, two-winding coupled inductor, inductor L1, multiple capacitors, multiple diodes and output circuit; The three-winding coupled inductor comprises: a primary winding N1, a secondary winding N2 and a secondary winding N3; The dual-winding coupled inductor comprises: a primary winding n1 and a secondary winding n2; The positive electrode of the input end is connected to one end of the inductor L1, and the other end of the inductor L1 is respectively connected to the drain of the switch tube S, the positive electrode of the diode D1, the opposite end of the primary winding N1 and the same end of the secondary winding N3; The negative electrode of the input end is respectively connected to the source electrode of the switch tube S, the negative electrode of the capacitor C1 and the negative electrode of the output circuit; The same-name end of the primary winding N1 is respectively connected to the positive electrode of the capacitor C1 and the negative electrode of the capacitor C2, the positive electrode of the capacitor C2 is connected to the opposite-name end of the secondary winding N2, and the same-name end of the secondary winding N2 is respectively connected to the negative electrode of the diode D1, the positive electrode of the diode D2 and the negative electrode of the capacitor C3; The opposite-name end of the secondary winding N3 is connected to the negative electrode of the capacitor C4, the positive electrode of the capacitor C4 is respectively connected to the negative electrode of the diode D2, the positive electrode of the diode D3, the negative electrode of the capacitor C5 and the opposite-name end of the primary winding n1, and the same-name end of the primary winding n1 is connected to the positive electrode of the capacitor C3; The like-name ends of the secondary winding n2 are respectively connected to the positive electrode of the capacitor C5 and the positive electrode of the diode D4, the different-name ends of the secondary winding n2 are respectively connected to the negative electrode of the diode D3 and the negative electrode of the capacitor C6, the positive electrode of the capacitor C6 is respectively connected to the negative electrode of the diode D4 and the positive electrode of the diode D5, and the negative electrode of the diode D5 is connected to the positive electrode of the output circuit.

2. The high-gain DC converter with multiple coupled inductors as claimed in claim 1, characterized in that: The primary winding N1 includes a leakage inductance L k1 and the magnetizing inductance L m1 The primary winding n1 includes a leakage inductance L k2 and the magnetizing inductance L m2 .

3. The high-gain DC converter with multiple coupled inductors as claimed in claim 2, characterized in that: The output circuit includes: a capacitor C7 and a load; The cathode of the diode D5 is respectively connected to the anode of the capacitor C7 and one end of the load, and the other end of the load is respectively connected to the cathode of the capacitor C7, the cathode of the input end, the source of the switch tube S and the cathode of the capacitor C1.

4. The high-gain DC converter with multiple coupled inductors as claimed in claim 3, characterized in that: One working cycle of the DC converter includes a first working mode, a second working mode and a third working mode; The on or off of the switch tube S is used to control the switching of the working mode of the DC converter.

5. The high-gain DC converter with multiple coupled inductors as claimed in claim 4, characterized in that: The first working mode is: the switch tube S is turned on, the diode D2, the diode D3 and the diode D4 are turned on, and the diode D1 and the diode D5 are blocked; The input end charges the inductor L1, and the current of the inductor L1 increases linearly; The capacitor C1 is the leakage inductance L k1 and the magnetizing inductance L m1 charging, the leakage inductance L k1 and the magnetizing inductance L m1 The current increases linearly; The capacitor C1, the capacitor C2, the secondary winding N2 and the secondary winding N3 charge the capacitor C4 through the diode D2; The capacitor C3 is the leakage inductance L k2 and the magnetizing inductance L m2 charging, the leakage inductance L k2 and the magnetizing inductance L m2 The charging current increases linearly; The secondary winding n2 charges the capacitor C5 through the diode D3 and also charges the capacitor C6 through the diode D4.

6. The high-gain DC converter with multiple coupled inductors as claimed in claim 5, characterized in that: The second working mode is: the switch tube S is turned off, the diode D1 and the diode D5 are turned on, and the diode D2, the diode D3 and the diode D4 are blocked; The input terminal and the inductor L1 charge the capacitor C1; The capacitor C2, the excitation inductor L m1 , the secondary winding N2 and the secondary winding N3 charge the capacitor C3 and the capacitor C4; The input end, the inductor L1, the secondary winding N3, the secondary winding n2, the capacitor C4, the capacitor C5 and the capacitor C6 charge the capacitor C7; The inductor L1 and the excitation inductor L m1 , the excitation inductance L m2 , the leakage inductance L k1 And the leakage inductance L k2 The current decreases, and the capacitor C2 recovers the leakage inductance L through the diode D1. k1 The energy of the diode D1 is increased, and the current of the diode D1 decreases. When the current of the diode D1 decreases to zero, the second working mode is terminated and the third working mode is entered.

7. The high-gain DC converter with multiple coupled inductors as claimed in claim 6, characterized in that: The third working mode is: the switch tube S is turned off, the diode D5 is turned on, and the diode D1, the diode D2, the diode D3 and the diode D4 are blocked; The input terminal and the inductor L1 charge the capacitor C1; The capacitor C2, the excitation inductor L m1 , the secondary winding N2 and the secondary winding N3 charge the capacitor C3 and the capacitor C4; The input end, the inductor L1, the secondary winding N3, the secondary winding n2, the capacitor C4, the capacitor C5 and the capacitor C6 charge the capacitor C7; The capacitor C7 supplies power to the load.

8. The high-gain DC converter with multiple coupled inductors according to any one of claims 1 to 7, characterized in that: The calculation formula of the gain G of the output voltage of the output circuit relative to the input voltage of the input terminal is: ;in, represents the turns ratio of the secondary winding N2 to the primary winding N1, represents the turns ratio of the secondary winding N3 to the primary winding N1, represents the turns ratio of the secondary winding n2 to the primary winding n1, and D represents the duty cycle of the switch tube S.

9. A high-gain DC conversion device with multiple coupled inductors, characterized in that: include: A controller, a voltage sampling sensor, and a high-gain DC converter with multiple coupled inductors as claimed in any one of claims 1 to 8; Among them, the positive pole of the voltage sampling sensor is connected to the positive pole of the output circuit of the converter, the negative pole of the voltage sampling sensor is connected to the negative pole of the output circuit of the converter, the output end of the voltage sampling sensor is connected to the input end of the controller, and the output end of the controller is connected to the switch tube S.

10. A control method, applied to the high-gain DC converter with multiple coupling inductors according to any one of claims 1 to 8 or the high-gain DC converter with multiple coupling inductors according to claim 9, characterized in that: include: collecting an output voltage of the output circuit; Calculating an error value between the output voltage and the target voltage, and adjusting the duty cycle of the switch tube S according to the error value; The pulse width modulation (PWM) wave signal generated by the adjusted duty cycle is input to the switch tube S to control the switch tube S to be turned on or off.

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