Proportional coupled inductor X-source DC boost network converter and control method thereof

Abstract

The present invention relates to a proportional coupled inductor X-source DC boost network converter and a control method thereof, and belongs to the technical field of power electronic converters. The proportional coupled inductor X-source DC boost network converter comprises a DC voltage source, two coupled inductor units, two auxiliary boost capacitors, and an X-source structure. Each coupled inductor is a coupled inductor connected to two windings, and the X-source structure is composed of two cross switches. The proportional coupled inductor X-source DC boost network converter greatly improves the voltage gain and realizes continuous input current.

Description

Technical Field

[0001] The present invention belongs to the technical field of power electronic converters, and in particular relates to a proportional coupled inductor X-source DC boost network converter and a control method thereof. Background Art

[0002] Boost converters are widely used as pre-converters in distributed power systems to achieve a voltage boost. The traditional boost converter circuit topology is a boost circuit. In theory, the voltage gain of a boost circuit increases with the duty cycle. However, considering the parasitic equivalent series impedance in actual circuits, the actual gain of a boost circuit does not always increase with increasing duty cycle. Therefore, its boost capability is very limited, making it unsuitable for high-gain DC power conversion applications. Furthermore, its switching voltage is the same as the output voltage, making low on-resistance power switches unusable, leading to increased system costs and losses. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to address the deficiencies of the above-mentioned background technology and propose a proportional coupled inductor X-source DC boost network converter and a control method thereof.

[0004] The present invention is achieved through the following technical solutions:

[0005] The present invention proposes a proportional coupled inductor X-source DC boost network converter, which includes a DC voltage source V in , output capacitor C o , capacitor C1, capacitor C2, coupled inductor winding N1, coupled inductor winding N2, coupled inductor winding N3, coupled inductor winding N4, output diode D o , diode D1, diode D2 and resistor R;

[0006] DC voltage source V in The positive electrode of the coupled inductor is connected to the drain of the power switch S1 and the positive electrode of the coupled inductor winding N1; the cathode of the coupled inductor N1 is connected to the cathode of the capacitor C1 and the positive electrode of the diode D1; the positive electrode of the capacitor C1 is connected to the positive electrode of the coupled inductor winding N2; the cathode of the coupled inductor winding N2 is connected to the positive electrode of the diode D1 and the output diode D o The positive electrode of the power switch S2 is connected to the drain of the power switch S2; the source of the power switch S2 is connected to the cathode of the coupled inductor winding N4, the cathode of the diode D2, and the DC voltage source V in The cathode of the coupled inductor winding N4 is connected to the positive electrode of the capacitor C2; the cathode of the capacitor C2 is connected to the positive electrode of the diode D2 and the cathode of the coupled inductor winding N3; the positive electrode of the coupled inductor winding N3 is connected to the source of the power switch S1 and the output capacitor C o The cathode of the resistor R is connected to the output diode D oThe cathode and output capacitor C o and the other end of the resistor R.

[0007] The present invention also proposes a control method for a proportional coupled inductor X source DC boost network converter, wherein the control method is as follows: the proportional coupled inductor X source DC boost network converter control signal V gs , which controls the on and off of the power switches S1 and S2, and the winding currents i N1 、i N2 、i N3 、i N4 , the voltage of diode D1 is V D1 , the voltage of diode D2 is V D2 , output diode D o The voltage V Do , the voltage V of power switches S1 and S2 S1 、V S2 The working process is divided into two switching modes, namely switching mode 1 and switching mode 2, which are described as follows:

[0008] Switching mode 1, corresponding to the time period [t1, t2]: In this stage, the power switches S1 and S2 are turned on at the same time, and the DC voltage V in The coupled inductor winding N1 is charged through the diode D1 and the power switch tube S2, and the coupled inductor winding N2 charges the capacitor C1 through the diode D1; the DC voltage charges the coupled inductor winding N3 through the diode D2 and the power switch tube S1, and the coupled inductor winding N4 charges the capacitor C2 through the diode D2; the output diode D o Reverse bias, output capacitor C o The load resistor R is powered independently, and switching mode 1 ends;

[0009] Switching mode 2, corresponding to the time period [t2, t3]: the power switches S1 and S2 are turned off at the same time, the diodes D1 and D2 are turned off, and the DC voltage V in , capacitors C1 and C2, two coupled inductor windings N1, N2, N3 and N4 through the output diode D o Give the load R and output capacitor C o Power supply, when the two coupled inductor winding current i N1 、i N3 When it drops to the lowest point, switch mode 2 ends;

[0010] From the above analysis, the gain expression can be obtained as:

[0011]

[0012] Where D is the conduction duty cycle of the power switch tubes S1 and S2, and its operating range is (0,1). The turns ratios of the two coupled inductors are n 21 =N2:N1 and n 43 =N4:N3.

[0013] The beneficial effects of the present invention are:

[0014] The machine control method for a proportional coupled inductor X-source DC boost network converter proposed in the present invention reduces system cost and system loss, makes the input current continuous, and has a high output gain. In addition, the power switch voltage is low, lower than the output voltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a proportional coupled inductor X-source DC boost network converter;

[0016] Figure 2 It is the main waveform diagram of the proportional coupled inductor X-source DC boost network converter;

[0017] Figure 3 (a) is the equivalent circuit diagram of the proportional coupled inductor X-source DC boost network converter switching mode 1;

[0018] Figure 3 (b) is the equivalent circuit diagram of the proportional coupled inductor X-source DC boost network converter switching mode 2;

[0019] Figure 4 This is the experimental waveform when the input voltage Vin=40V and the output voltage Vo=300V.

[0020] Description of the symbols in the figure: V in is a DC voltage source, S1 is a power switch tube, S2 is a second power switch tube, D1 is a first auxiliary diode, D2 is a second auxiliary diode, C1 is a first auxiliary boost capacitor, C2 is a second auxiliary boost capacitor, D o is the output diode, C o is the output capacitor, R is the load, N1 and N2 are the two windings of the coupled inductor, N3 and N4 are the two windings of another coupled inductor, and the turn ratios of the two coupled inductors are n 21 =N2:N1 and n 43 =N4:N3. DETAILED DESCRIPTION

[0021] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0022] like Figure 1 As shown, the present invention proposes a proportional coupled inductor X-source DC boost network converter, the converter includes a DC voltage source V in , output capacitor C o , capacitor C1, capacitor C2, coupled inductor winding N1, coupled inductor winding N2, coupled inductor winding N3, coupled inductor winding N4, output diode D o , diode D1, diode D2 and resistor R;

[0023] DC voltage source V in The positive electrode of the coupled inductor is connected to the drain of the power switch S1 and the positive electrode of the coupled inductor winding N1; the cathode of the coupled inductor N1 is connected to the cathode of the capacitor C1 and the positive electrode of the diode D1; the positive electrode of the capacitor C1 is connected to the positive electrode of the coupled inductor winding N2; the cathode of the coupled inductor winding N2 is connected to the positive electrode of the diode D1 and the output diode D o The positive electrode of the power switch S2 is connected to the drain of the power switch S2; the source of the power switch S2 is connected to the cathode of the coupled inductor winding N4, the cathode of the diode D2, and the DC voltage source V in The cathode of the coupled inductor winding N4 is connected to the positive electrode of the capacitor C2; the cathode of the capacitor C2 is connected to the positive electrode of the diode D2 and the cathode of the coupled inductor winding N3; the positive electrode of the coupled inductor winding N3 is connected to the source of the power switch S1 and the output capacitor C o The cathode of the resistor R is connected to the output diode D o The cathode and output capacitor C o and the other end of the resistor R.

[0024] Continuous input current and common ground performance are achieved while achieving high voltage gain.

[0025] The present invention also proposes a control method for a proportional coupled inductor X source DC boost network converter, characterized in that the control method is specifically as follows: the proportional coupled inductor X source DC boost network converter control signal V gs , which controls the on and off of the power switches S1 and S2, and the winding currents i N1 、i N2 、i N3 、i N4 , the voltage of diode D1 is V D1, the voltage of diode D2 is V D2 , output diode D o The voltage V Do , the voltage V of power switches S1 and S2 S1 、V S2 The waveform is as Figure 2 As shown, its working process is divided into two switching modes, namely switching mode 1 and switching mode 2, which are described in detail as follows:

[0026] Switch mode 1, corresponding to Figure 2 The time period [t1, t2]: The equivalent circuit is as follows Figure 3 As shown in (a), at this stage, the power switches S1 and S2 are turned on at the same time, and the DC voltage V in The coupled inductor winding N1 is charged through the diode D1 and the power switch tube S2. Due to the principle of magnetic induction, the coupled inductor winding N2 charges the capacitor C1 through the diode D1. At the same time, the DC voltage charges the coupled inductor winding N3 through the diode D2 and the power switch tube S1. Due to the principle of magnetic induction, the coupled inductor winding N4 charges the capacitor C2 through the diode D2. The output diode D o Reverse bias, output capacitor C o The load resistor R is powered independently, and switching mode 1 ends;

[0027] Switch mode 2, corresponding to Figure 2 The time period [t2, t3]: The equivalent circuit is as follows Figure 3 As shown in (b), the power switches S1 and S2 are turned off at the same time, the diodes D1 and D2 are turned off, and the DC voltage V in , capacitors C1 and C2, two coupled inductor windings N1, N2, N3 and N4 through the output diode D o Give the load R and output capacitor C o Power supply, when the two coupled inductor winding current i N1 、i N3 When it drops to the lowest point, switch mode 2 ends;

[0028] From the above analysis, the gain expression can be obtained as:

[0029]

[0030] Where D is the conduction duty cycle of the power switch tubes S1 and S2, and its operating range is (0,1). The turns ratios of the two coupled inductors are n 21 =N2:N1 and n 43 =N4:N3.

[0031] The following is an illustration of the beneficial effects of the structure of the present invention using data from specific experiments:

[0032] like Figure 4 As shown, the input voltage V in =40V, output voltage V o =300V, n 21 =n 43 =2. Figure 4 (a) is the input voltage of 40V and the output capacitor voltage of about 300V. Figure 4 (b) The voltage of capacitor C1 is about 78V and the voltage of capacitor C2 is about 78V. Figure 4 (c) The peak voltage of diode D1 is about 110V and the peak voltage of diode D2 is about 110V. Figure 4 (d) is the voltage of power switches S1 and S2, both of which are 166V. Figure 4 (e, f) are the currents of the coupled inductor windings N1, N2, N3, and N4. As can be seen from the figure, the input current is continuous and has a high output gain, and the power switch voltage is low, lower than the output voltage.

Claims

1. A proportional coupled inductor X-source DC boost network converter, characterized in that: The converter includes a DC voltage source V in , output capacitor C o , capacitor C1, capacitor C2, coupled inductor winding N1, coupled inductor winding N2, coupled inductor winding N3, coupled inductor winding N4, output diode D o , diode D1, diode D2 and resistor R; DC voltage source V in The positive electrode of the coupled inductor is connected to the drain of the power switch S1 and the positive electrode of the coupled inductor winding N1; the cathode of the coupled inductor N1 is connected to the cathode of the capacitor C1 and the positive electrode of the diode D1; the positive electrode of the capacitor C1 is connected to the positive electrode of the coupled inductor winding N2; the cathode of the coupled inductor winding N2 is connected to the negative electrode of the diode D1 and the output diode D o The positive electrode of the power switch S2 is connected to the drain of the power switch S2; the source of the power switch S2 is connected to the cathode of the coupled inductor winding N4, the cathode of the diode D2, and the DC voltage source V in The cathode of the coupled inductor winding N4 is connected to the cathode of the capacitor C2; the cathode of the capacitor C2 is connected to the cathode of the diode D2 and the cathode of the coupled inductor winding N3; the cathode of the coupled inductor winding N3 is connected to the source of the power switch S1 and the output capacitor C o The cathode of the resistor R is connected to the output diode D o The cathode and output capacitor C o and the other end of resistor R.

2. The control method of a proportional coupled inductor X-source DC boost network converter according to claim 1, characterized in that: The control method is specifically as follows: a proportional coupled inductor X-source DC boost network converter control signal V gs , which controls the on and off of the power switches S1 and S2. The winding currents i N1 、i N2 、i N3 、i N4 , the voltage of diode D1 is V D1 , the voltage of diode D2 is V D2 , output diode D o The voltage V Do , power switch S 1、 The voltage of S2 is V S1 、V S2 The working process is divided into two switching modes, namely switching mode 1 and switching mode 2, which are described as follows: Switching mode 1, corresponding to the time period [t1, t2]: In this stage, the power switches S1 and S2 are turned on at the same time, and the DC voltage V in The coupled inductor winding N1 is charged through the diode D1 and the power switch tube S2, and the coupled inductor winding N2 charges the capacitor C1 through the diode D1; the DC voltage charges the coupled inductor winding N3 through the diode D2 and the power switch tube S1, and the coupled inductor winding N4 charges the capacitor C2 through the diode D2; the output diode D o Reverse bias, output capacitor C o The load resistor R is powered independently, and the switching mode 1 ends; Switching mode 2, corresponding to the time period [t2, t3]: the power switches S1 and S2 are turned off at the same time, the diodes D1 and D2 are turned off, and the DC voltage V in , capacitors C1 and C2, two coupled inductor windings N1, N2, N3 and N4 through the output diode D o to the load R and output capacitor C o When the two coupled inductor windings have current i N1 、i N3 When it drops to the lowest level, switch mode 2 ends; From the above analysis, the gain expression can be obtained as: Where D is the conduction duty cycle of the power switch tubes S1 and S2, and its operating range is (0,1). The turns ratios of the two coupled inductors are n 21 =N2:N1 and n 43 =N4:N3.

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