High-gain boost inductance circuit

Abstract

A high-gain boost inductance circuit solves the problem of high-gain boost when the voltage fluctuation range is large, and comprises diodes Da1,..., Dan; dm1,... Dm (n-1), Dm1,... Dm (n-1); db1,... Db (n + 1); inductors L1,... Ln; one end of the inductor Ln is connected with the negative electrode of the Dan, the other end of the inductor Ln is connected with the positive electrode of the Dbn, the positive electrodes of the Dm1,..., Dm (n-1) are connected with the positive electrodes of the Db1,..., Db (n-1), the negative electrodes of the Dm1,..., Dm (n-1) are connected with the negative electrodes of the Da2,..., Dan, the positive electrodes of the Da1,..., Dan are connected to the terminal A, the negative electrodes of the Db1,..., Dbn are connected to the terminal B, the positive electrode end of the Db (n + 1) is connected with the positive electrode of the Dbn, and the negative electrode of the Db (n + 1) is connected with the terminal C.

Description

Technical Field

[0001] The utility model relates to a high-gain boost inductor circuit, in particular to a high-gain boost circuit which uses an inductor and a diode element combination for boosting. Background Art

[0002] Renewable energy sources such as wind power and solar energy are random, and the electric energy generated by new energy power sources has the characteristic of a large output voltage variation range. For example, the output DC voltage of a solar cell module is high when the sun is directly shining, and its output voltage is low when the sun is blocked, and its open circuit voltage and dark state voltage differ greatly. For this working condition, the traditional DC-DC boost circuit can only output power within a small voltage range on the DC side; lithium batteries and supercapacitors used for energy storage also have the characteristic of low single-cell output voltage. The low output voltage of the DC converter results in low energy utilization.

[0003] The development of high-gain boost circuits can improve the economic benefits of renewable energy power generation efficiency. Existing high-gain DC-DC circuits can be divided into two categories according to the application of transformers: circuits using transformers and circuits not using transformers. The magnetic circuit of the circuit using transformers is complex, and its power increase is limited by the volume and weight of the transformer, which limits its practicality. The boost circuit using transformer isolation is larger in size and weight, has a complex magnetic circuit, and is inconvenient to use. High-gain circuits that do not use transformers can be divided into three categories: using switched capacitor boost, using inductor boost, and hybrid boost.

[0004] The typical circuit using capacitor switching to boost voltage is the switched capacitor circuit. The switched capacitor boost circuit has the disadvantage that the boost ratio is not continuously adjustable.

[0005] The circuits that use inductors to store energy and boost voltage are divided into cascade inductor type and coupled inductor type. The disadvantage of coupled inductor circuits is that there is leakage inductance and low efficiency.

[0006] CN105281569A discloses a single-phase high-gain boost converter, which uses a coupled inductor to increase the voltage. Its voltage gain is shown in formula (2), and the coupled inductor gain is related to the number of coupled inductor turns. In situations where the boost voltage is high and the power is high, the number of coupled inductor turns and the circuit power will be limited by the volume and weight of the coupled inductor.

[0007] The switched inductor method can improve the boost gain, but the number of inductor cascades is only two, so the boost gain is still limited.

[0008] CN106655761A discloses a high-gain boost DC converter. It adopts the mode of series charging and series discharging of inductors, and its voltage gain is 1 / (1-D) n, where D is the on-duty cycle of the controllable switch. The disadvantage of this converter is that when there are more series inductors, the inductor charging time will be correspondingly extended, thereby reducing the boost current response time. In addition, its duty cycle D will increase with the increase of series devices, so the number of cascades is limited.

[0009] In summary, the existing high-gain boost circuit using the switching inductor method has the disadvantage that the output voltage gain is difficult to improve due to the limitation of the circuit structure. The voltage gain of the improved switching inductor method circuit is also limited because the duty cycle is limited.

[0010] A hybrid boost circuit is generally a mixture of an inductive boost circuit and a capacitive boost circuit, and has the disadvantages of both circuits. In addition, the hybrid boost circuit generally brings about a problem of complex structure.

[0011] CN104283419A discloses a quadratic high-gain boost converter with a switched capacitor and a coupled inductor. The introduction of the coupled inductor reduces efficiency and the structure is complex. Utility Model Content

[0012] The utility model proposes a high-gain boost inductor circuit to solve the high-gain boost problem when the voltage fluctuation range is large. The voltage gain can be cascaded and expanded to improve the voltage gain effect, reduce the application of switch elements in the structure switching process, and reduce the use cost of the circuit. The same switch element is used to switch the circuit state during the boost process, making the switch element control simpler.

[0013] The technical solution adopted by the utility model is:

[0014] A high-gain boost inductor circuit, comprising:

[0015] Diodes Da1, Da2, Da3, ... Dan, n in total;

[0016] Diodes Dm1, Dm2, Dm3, ... Dm(n-1), n-1 in total;

[0017] Diodes Db1, Db2, Db3, ... Db(n+1), n+1 in total;

[0018] There are n inductors L1, L2, L3, L4, ..., Ln in total; n is a positive integer between 2 and 20;

[0019] The above components are connected according to the following network relationship:

[0020] One end of inductor Ln is connected to the cathode of diode Dan, and the other end of inductor Ln is connected to the anode of diode Dbn. The anodes of diodes Dm1, Dm2, Dm3, ..., Dm(n-1) are connected to the corresponding anodes of diodes Db1, Db2, Db3, ..., Db(n-1). The cathodes of diodes Dm1, Dm2, Dm3, ..., Dm(n-1) are connected to the corresponding cathodes of diodes Da2, Da3, ...Dan. The anodes of diodes Da1, Da2, Da3, ...Dan are connected to the same terminal A. The cathodes of diodes Db1, Db2, Db3, ...Dbn are connected to the same terminal B. The anode end of diode Db(n+1) is connected to the anode end of diode Dbn, and the cathode end of diode Db(n+1) is connected to terminal C.

[0021] Further, n=4-10.

[0022] Furthermore, terminal B is connected to the system ground via a switching element.

[0023] Furthermore, the switching element is a switching tube, an IGBT or a thyristor.

[0024] Furthermore, the terminal C is connected to the system ground via a high-voltage capacitor.

[0025] The working principle of the boost inductor circuit is as follows:

[0026] The boost process consists of two steps, the first step is the parallel charging of the inductors, and the second step is the series discharge of the inductors.

[0027] In the parallel charging stage of the inductors, the voltage at end A is high and the voltage at end B is low; diodes Da1, Da2, Da3, ..., Dan and diodes Db1, Db2, Db3, ..., Dbn are turned on and diodes Dm1, Dm2, Dm3, ..., Dm(n-1) are turned off; inductors L1, L2, L3, L4, ..., Ln are connected in parallel and the current flowing through the inductors gradually increases.

[0028] In the discharge stage of the inductor series connection, the voltage at the A terminal remains unchanged, the B terminal is open, and the diodes Db2, Db3, ..., Dbn are disconnected. Due to the switching moment, the current of the inductors L1, L2, L3, L4, ..., Ln remains unchanged, and the terminal voltage remains unchanged in the open circuit state. Under the action of the terminal voltage of the inductor, the positive terminal voltage of the diodes Dm1, Dm2, Dm3, ..., Dm(n-1) connected to the inductor is high, and the negative terminal voltage of the diodes Dm1, Dm2, Dm3, ..., Dm(n-1) connected to the inductor is low, so the diodes Dm1, Dm2, Dm3, ..., Dmn-1 are turned on. The inductors L1, ..., Ln are connected in series through the diodes Dm1, Dm2, Dm3, ..., Dm(n-1); the voltage between the terminals A and C is the sum of the voltages at both ends of the inductors L1, ..., Ln. At this stage, the effect of increasing the output voltage gain is achieved by superimposing the voltages of multiple inductors.

[0029] The beneficial effects of the utility model are:

[0030] 1. The circuit has a high-gain boost characteristic. The output voltage is the superposition of the voltages of multiple inductors. By increasing the number of cascaded inductors, the voltage gain can be increased, so that the output voltage gain can increase with the increase of cascaded inductors, and the number of cascades is not limited by the circuit structure.

[0031] 2. The circuit duty cycle does not change with the number of cascaded modules. When the number of inductor cascades increases, the duty cycle does not change and the output voltage gain can still be maintained at 1 / (1-D). n .

[0032] 3. The cascade structure is easy to drive. The circuit uses the on-off characteristics of the diode to convert the inductor connection relationship. Since the diode does not require a driving circuit, the circuit structure is simple.

[0033] 4. The circuit is easy to expand. Compared with the existing switch inductor method, for different voltage gains, it is only necessary to change the number of cascade inductors and corresponding diodes. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a circuit schematic diagram in the embodiment of the utility model.

[0035] Figure 2 It is a schematic diagram of the circuit structure in the embodiment of the utility model (n=4).

[0036] Figure 3 It is a schematic diagram of the parallel charging stage in the embodiment of the utility model (n=4).

[0037] Figure 4 It is a schematic diagram of the series discharge stage in an embodiment of the utility model (n=4). DETAILED DESCRIPTION

[0038] The utility model is further described below in conjunction with the accompanying drawings and embodiments.

[0039] There are many application scenarios in specific implementation. The following example illustrates the application of a high-gain boost inductor circuit in a BOOST circuit.

[0040] like Figure 1 As shown, assuming n is a positive integer, the high-gain boost inductor circuit is composed of the following components:

[0041] Diodes Da1, Da2, Da3, ..., Dan, n in total;

[0042] Diodes Dm1, Dm2, Dm3, ..., Dm(n-1), n-1 in total;

[0043] Diodes Db1, Db2, Db3, ..., Db(n+1), n+1 in total;

[0044] There are n inductors L1, L2, L3, L4, ..., Ln in total;

[0045] The above components are connected according to the following network relationship:

[0046] One end of the inductor Ln is connected to the cathode of the diode Dan, and the other end of the inductor Ln is connected to the anode of the diode Dbn. The anodes of the diodes Dm1, Dm2, Dm3, ..., Dm(n-1) are connected to the anodes of the corresponding diodes Db1, Db2, Db3, ..., Db(n-1), and the cathodes of the diodes Dm1, Dm2, Dm3, ..., Dm(n-1) are connected to the cathodes of the corresponding diodes Db2, Db3, Db4, ..., Dbn. The first ends of the diodes Da1, Da2, Da3, ..., Dan are connected to the same terminal A. The tail ends of the diodes Db1, Db2, Db3, ..., Dbn are connected to the same terminal B. The anode end of the diode Db(n+1) is connected to the anode end of the diode Dbn, and the cathode end of the diode Db(n+1) is connected to the terminal C.

[0047] The utility model is described in detail below with reference to specific examples.

[0048] like Figure 2 As shown, n=4, the high gain boost circuit includes: 4 diodes Da1, Da2, Da3, Da4; 3 diodes Dm1, Dm2, Dm3; 5 diodes Db1, Db2, Db3, Db4) Db5; 4 inductors L1, L2, L3, L4; power module Vs, switch element Sw, filter capacitor C1, and load resistor Rl.

[0049] In the figure, the inductor is 0.5uH, the power module Vs voltage is 3V, the filter capacitor C1 is 8800μF, and the load resistor Rl is 1000Ω.

[0050] Switching cycle 10 -4 s. The duty cycle is 99%.

[0051] The positive terminal of the power module Vs is connected to the positive electrodes of diodes Da1, Da2, Da3 and Da4.

[0052] One ends of the inductors L1, L2, L3, L4 are connected to the cathodes of the diodes Da1, Da2, Da3, Da4, respectively, and the other ends of the inductors L1, L2, L3, L4 are connected to the anodes of the diodes Db1, Db2, Db3, Db4, respectively.

[0053] The anodes of diodes Dm1, Dm2, and Dm3 are connected to the anodes of diodes Db1, Db2, and Db3, and the cathodes of diodes Dm1, Dm2, and Dm3 are connected to the cathodes of diodes Db2, Db3, and Db4.

[0054] The diodes Da1, Da2, Da3, and Da4 have their head ends connected to the same terminal A. The diodes Db1, Db2, Db3, and Db4 have their tail ends connected to the same terminal B. The anode of the diode Db5 is connected to the anode of the diode Db4. The cathode of the diode Db5 is connected to the terminal C.

[0055] Terminal C is connected to one end of filter capacitor C1. The other end of filter capacitor C1 is connected to the negative terminal of power supply Vs. Terminal C is connected to one end of load resistor R1. The other end of load resistor R1 is connected to the negative terminal of power supply Vs. Terminal B is connected to one end of switch element Sw. The other end of switch element Sw is connected to the negative terminal of power supply Vs.

[0056] The duty cycle of the switch element is 90-95%.

[0057] like Figure 3 In the parallel charging stage, the inductors L1, L2, L3, and L4 are connected in parallel between the terminals A and B.

[0058] like Figure 4 As described above, in the series discharge stage, inductors L1, L2, L3, and L4 are connected in series between terminals A and C.

[0059] The above are only specific embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A high-gain boost inductor circuit, characterized in that: include: Diodes Da1, Da2, Da3, ... Dan, n in total; Diodes Dm1, Dm2, Dm3, ... Dm(n-1), n-1 in total; Diodes Db1, Db2, Db3, ... Db(n+1), n+1 in total; There are n inductors L1, L2, L3, L4, ..., Ln in total; n is a positive integer between 2 and 20; The above components are connected according to the following network relationship: One end of inductor Ln is connected to the cathode of diode Dan, and the other end of inductor Ln is connected to the anode of diode Dbn. The anodes of diodes Dm1, Dm2, Dm3, ..., Dm(n-1) are connected to the corresponding anodes of diodes Db1, Db2, Db3, ..., Db(n-1). The cathodes of diodes Dm1, Dm2, Dm3, ..., Dm(n-1) are connected to the corresponding cathodes of diodes Da2, Da3, ...Dan. The anodes of diodes Da1, Da2, Da3, ...Dan are connected to the same terminal A. The cathodes of diodes Db1, Db2, Db3, ...Dbn are connected to the same terminal B. The anode end of diode Db(n+1) is connected to the anode end of diode Dbn, and the cathode end of diode Db(n+1) is connected to terminal C.

2. The high-gain boost inductor circuit according to claim 1, characterized in that: n＝4-10。 3. The high-gain boost inductor circuit according to claim 1, characterized in that: Terminal B is connected to the system ground through the switching element.

4. The high-gain boost inductor circuit according to claim 3, characterized in that: The switch element is a switch tube, an IGBT or a thyristor.

5. The high-gain boost inductor circuit according to claim 1, characterized in that: The terminal C is connected to the system ground via a high voltage capacitor.

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