Switched inductor-coupled inductor series DC-DC boost converter

Abstract

This invention relates to a switched inductor-coupled inductor-series DC-DC boost converter, belonging to the field of power electronic inverter technology. It solves the problem of limited boost capability caused by the limited shoot-through time of existing boost circuits. The invention includes a DC voltage source V. in The circuit consists of diodes D0 to D6, capacitors C0 to C2, inductors L1 to L2, a coupling inductor, and a power switch S. Inductors L1 and L2, along with diodes D3 to D5, constitute the switching inductor. Diode D0, capacitor C0, and load resistor R constitute the output unit of the boost converter, which can significantly increase the voltage gain. This invention is primarily used for DC-DC boost conversion.

Description

Technical Field

[0001] This invention belongs to the field of power electronic inverter technology, specifically relating to a switched inductor coupled inductor series type DC boost converter. Background Technology

[0002] Boost converters are widely used in the front-end converters of distributed power systems to achieve voltage boosting. Through a series structure of switching inductors and coupled inductors, this converter can achieve high voltage gain with a relatively small number of components. This structure allows for effective voltage boosting to higher output levels even with low input voltages, meeting the needs of applications requiring high voltage, such as high-voltage direct current transmission and high-voltage battery charging for electric vehicles. Theoretically, the voltage gain of a boost circuit increases with the duty cycle. However, considering the parasitic equivalent series impedance in practical circuits, the actual gain of a boost circuit does not always increase with the duty cycle. Its limited shoot-through time results in a relatively small boost capability, making it unsuitable for high-voltage gain DC power conversion applications. Summary of the Invention

[0003] The purpose of this invention is to solve the problem of limited boost capability caused by the limited shoot-through time of existing Boost circuits. This invention provides a switched inductor-coupled inductor series DC-DC boost converter.

[0004] Switched inductively coupled inductor series DC-DC boost converter, including DC voltage source V in Diodes D0 to D6, capacitors C0 to C2, inductors L1 to L2, coupling inductor, and power switch S; wherein, capacitor C0 serves as the output capacitor, and the voltage across its terminals serves as the output voltage V0 of the boost converter;

[0005] Inductors L1 and L2, and diodes D3 to D5 constitute the switching inductor;

[0006] DC voltage source V inThe positive terminal of the capacitor is connected to one end of the capacitor C2 and the same-name terminal of the primary winding N1 of the coupling inductor. The anode of the diode D1 is connected to the opposite-name terminal of the primary winding N1 of the coupling inductor and the same-name terminal of its secondary winding N2. The opposite-name terminal of the secondary winding N2 of the coupling inductor is connected to the anode of the diode D2. One end of the capacitor C1 is connected to the cathode of the diode D1, the cathode of the diode D2, and the anode of the diode D6. The cathode of the diode D6 is connected to the anode of the diode D3, the other end of the capacitor C2, and one end of the inductor L1. The anode of the diode D4 is connected to the other end of the inductor L1 and the anode of the diode D5. The cathode of the diode D4 is connected to one end of the inductor L2 and the cathode of the diode D3. The drain of the power switch S is connected to the cathode of the diode D5, the other end of the inductor L2, the other end of the capacitor C1, and the anode of the diode D0. The cathode of the diode D0 is connected to one end of the capacitor C0 and one end of the load resistor R.

[0007] DC voltage source V in The negative terminal of the diode is connected to the source terminal of the power switch S, the other end of the capacitor C0, and the other end of the load resistor R. The diode D0, the capacitor C0, and the load resistor R constitute the output unit.

[0008] Preferably, the voltage gain of the boost converter is... D is the duty cycle of the power switch S, and n1 is the turns ratio of the secondary winding N2 to the primary winding N1 of the coupled inductor.

[0009] Preferably, the boost converter has two operating modes within one switching cycle: the on state and the off state.

[0010] Preferably, in the on-state operating mode, the power switch S is turned on, and the DC voltage source V... in Capacitor C1 charges the primary winding N1 of the coupling inductor. Due to the principle of magnetic induction, diode D2 is reverse-biased and cut off, while D1 is forward-biased and conducts. Simultaneously, the DC voltage source V... in Capacitor C2 charges inductors L1 and L2, diodes D4 and D6 are reverse biased and cut off; diode D0 is reverse biased and cut off, and capacitor C0 independently supplies power to the load resistor R.

[0011] Preferably, in the off-state operating mode, the power switch S remains off, diodes D2 and D6 are forward-biased and conducting, diode D1 is reverse-biased and cut off, inductors L1 and L2 charge capacitor C1, and the primary winding N1 and secondary winding N2 of the coupling inductor charge capacitor C2. Simultaneously, the DC voltage source V... in The output electrical energy passes sequentially through the primary winding N1 and secondary winding N2 of the coupling inductor, as well as inductors L1, L2 and diode D0, before supplying power to the load resistor R and capacitor C0.

[0012] Preferably, the duty cycle of the power switch S is adjustable within the range of (0, 0.29).

[0013] Preferably, the optimal duty cycle of the power switch S is 0.25.

[0014] Advantages of this invention:

[0015] The present invention proposes a switched inductor-coupled inductor series DC-DC boost converter, with DC voltage source V in Directly connecting the primary winding N1 of the coupled inductor ensures continuous input current, providing a relatively stable energy supply to the circuit. The coupled inductor's turns ratio increases the circuit's amplification factor. Simultaneously, due to magnetic induction, the voltage of the secondary winding N2 increases, charging capacitor C2. During discharge, capacitor C1 prevents instability in the inductor voltage caused by discontinuous current, which could lead to voltage drops in the DC link and distortion of the output waveform. The voltages of capacitors C1 and C2 are significantly lower than the output voltage, allowing the diode voltage to fluctuate over time. This prevents the diode from being constantly at a high voltage, reducing energy loss and lowering voltage stress on the components. Furthermore, the charging and discharging characteristics of capacitor C2 further optimize voltage distribution, reducing the previous requirement for high voltage gain with a large duty cycle and improving boost capability. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the switch-inductor coupled-inductor series DC-DC boost converter described in this invention;

[0017] Figure 2 The equivalent circuit diagram of the switch-inductor-coupled-inductor-series DC-DC boost converter of the present invention is shown when the power switch S is on and off; wherein,

[0018] Figure 2 a is the equivalent circuit diagram of the boost converter when power switch S is turned on;

[0019] Figure 2 b is the equivalent circuit diagram of the boost converter when the power switch S is turned off;

[0020] Figure 3 When using the switched inductor-coupled inductor series DC-DC boost converter described in this invention for boost conversion, when the input voltage V in =50V, and the experimental waveform diagram when the output voltage V0 is approximately 500V; where,

[0021] Figure 3 a is the input voltage V of the boost converter. in Waveform comparison chart of 50V and output voltage V0 approximately 500V;

[0022] Figure 3 b is a waveform comparison diagram of the output diode D0 voltage and the power switch S voltage;

[0023] Figure 3 c is a comparison diagram of the voltage waveforms of diode D6 and capacitor C2;

[0024] Figure 3 d is a comparison diagram of the voltage waveforms of capacitor C1 and diode D5. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0027] Specific Implementation Method 1: Combination Figure 1 As shown, this embodiment provides a switched inductor-coupled inductor series-type DC-DC boost converter, including a DC voltage source V. in Diodes D0 to D6, capacitors C0 to C2, inductors L1 to L2, coupling inductor, and power switch S; wherein, capacitor C0 serves as the output capacitor, and the voltage across its terminals serves as the output voltage V0 of the boost converter;

[0028] Inductors L1 and L2, and diodes D3 to D5 constitute the switching inductor;

[0029] DC voltage source V inThe positive terminal of the capacitor is connected to one end of the capacitor C2 and the same-name terminal of the primary winding N1 of the coupling inductor. The anode of the diode D1 is connected to the opposite-name terminal of the primary winding N1 of the coupling inductor and the same-name terminal of its secondary winding N2. The opposite-name terminal of the secondary winding N2 of the coupling inductor is connected to the anode of the diode D2. One end of the capacitor C1 is connected to the cathode of the diode D1, the cathode of the diode D2, and the anode of the diode D6. The cathode of the diode D6 is connected to the anode of the diode D3, the other end of the capacitor C2, and one end of the inductor L1. The anode of the diode D4 is connected to the other end of the inductor L1 and the anode of the diode D5. The cathode of the diode D4 is connected to one end of the inductor L2 and the cathode of the diode D3. The drain of the power switch S is connected to the cathode of the diode D5, the other end of the inductor L2, the other end of the capacitor C1, and the anode of the diode D0. The cathode of the diode D0 is connected to one end of the capacitor C0 and one end of the load resistor R.

[0030] DC voltage source V in The negative terminal of the diode is connected to the source terminal of the power switch S, the other end of the capacitor C0, and the other end of the load resistor R. The diode D0, the capacitor C0, and the load resistor R constitute the output unit.

[0031] In this embodiment, the DC voltage source V in Directly connecting the primary winding N1 of the coupled inductor ensures continuous input current, providing a relatively stable energy supply to the circuit. The coupled inductor's turns ratio increases the circuit's amplification factor. Simultaneously, due to magnetic induction, the voltage of the secondary winding N2 increases, charging capacitor C2. During discharge, capacitor C1 prevents instability in the inductor voltage caused by discontinuous current, which could lead to voltage drops in the DC link and distortion of the output waveform. The voltages of capacitors C1 and C2 are significantly lower than the output voltage, allowing the diode voltage to fluctuate over time. This prevents the diode from being constantly at a high voltage, reducing energy loss and lowering voltage stress on the components. Furthermore, the charging and discharging characteristics of capacitor C2 further optimize voltage distribution, reducing the previous requirement for high voltage gain with a large duty cycle and improving boost capability.

[0032] The connection relationship of each component in the aforementioned switched inductively coupled inductive series DC-DC boost converter greatly reduces the voltage stress across the diodes and improves the service life of the components.

[0033] Furthermore, the voltage gain of the boost converter D represents the duty cycle of power switch S, and n1 represents the turns ratio of the secondary winding N2 to the primary winding N1 of the coupled inductor. The duty cycle of power switch S can be adjusted within the range of (0, 0.29). In practical applications, the optimal duty cycle for power switch S is 0.25.

[0034] In this preferred embodiment, it can be seen from the voltage gain expression that a very high voltage gain can be obtained with a very small duty cycle, which reduces the previous requirement of obtaining a high voltage gain with a large duty cycle. At the same time, the voltage distribution is optimized and the voltage stress on the components is reduced.

[0035] A boost converter has two operating modes within one switching cycle: on-state and off-state. See also... Figure 2 Specifically,

[0036] See Figure 2 a. In the on-state operating mode, the power switch S is turned on, and the DC voltage source V... in Capacitor C1 charges the primary winding N1 of the coupling inductor. Due to the principle of magnetic induction, diode D2 is reverse-biased and cut off, while D1 is forward-biased and conducts. Simultaneously, the DC voltage source V... in Capacitor C2 charges inductors L1 and L2, diodes D4 and D6 are reverse biased and cut off; diode D0 is reverse biased and cut off, and capacitor C0 independently supplies power to the load resistor R.

[0037] See Figure 2 b. In the off-state operating mode, the power switch S remains off, diodes D2 and D6 are forward-biased and conducting, diode D1 is reverse-biased and cut off, inductors L1 and L2 charge capacitor C1, and the primary winding N1 and secondary winding N2 of the coupling inductor charge capacitor C2. Simultaneously, the DC voltage source V... in The output electrical energy passes sequentially through the primary winding N1 and secondary winding N2 of the coupling inductor, as well as inductors L1, L2 and diode D0, before supplying power to the load resistor R and capacitor C0.

[0038] In this preferred embodiment, the two operating modes optimize voltage distribution, preventing components from always being under high voltage, thereby improving energy transfer efficiency.

[0039] Verification experiment:

[0040] like Figure 3 As shown, the input voltage V in =50V, the output voltage is approximately V o =500V, D=0.25, n1=2, load resistance R=200Ω.

[0041] Figure 3 a is the input voltage V of the boost converter. in Waveform comparison chart of output voltage V0 = 500V and output voltage V0 = 500V; from Figure 3 As can be seen from a, with a DC input voltage of 50V, the output voltage is 500V, which is a tenfold increase, demonstrating a very high voltage gain.

[0042] Figure 3 b is a waveform comparison diagram of the output diode D0 voltage and the power switch S voltage; from Figure 3 As can be seen in b, the waveform comparison diagram of the output diode D0 voltage and the power switch S voltage shows that the component voltage fluctuates over time to prevent the component from always being in a high voltage state;

[0043] Figure 3 c is a comparison diagram of the voltage waveforms of diode D6 and capacitor C2; from Figure 3 As can be seen in c, the waveforms of diode D6 and capacitor C2 show that the voltage of the components fluctuates over time, reflecting the energy exchange process and optimizing voltage distribution.

[0044] Figure 3 Figure d shows a comparison of the voltage waveforms of capacitor C1 and diode D5. (The text repeats itself here.) Figure 3 A comparison of the voltage waveforms of capacitor C1 and diode D5 in section d shows that the voltage stress on the components is not high.

[0045] While the invention has been described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the invention. Therefore, it should be understood that many modifications can be made to the exemplary embodiments, and other arrangements can be designed without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood that different dependent claims and features described herein can be combined in ways different from those described in the original claims. It is also understood that features described in conjunction with individual embodiments can be used in other described embodiments.

Claims

1. A switched inductor-coupled inductor series-type DC-DC boost converter, characterized in that, Including DC voltage sources V in ,diode D 0 to D 6. Capacitors C 0 to C 2. Inductance L 1 to L 2. Coupled inductors and power switches S ; Among them, capacitor C 0 is used as the output capacitor, and the voltage across it is used as the output voltage of the boost converter. V 0; inductance L 1 and L 2 and diodes D 3 to D 5 constitutes the switching inductor; DC voltage source V in The positive terminal and the capacitor C 2, one end of the primary winding of the coupling inductor N Connect the same terminal of diode 1 simultaneously. D The anode of 1 is connected to the primary winding of the coupling inductor. N The opposite-named terminal of 1 and its secondary winding N The terminals of type 2 are connected simultaneously, and the secondary winding of the coupling inductor is connected. N 2's opposite terminal and diode D The anode of 2 is connected, and one end of capacitor C1 is connected to diode. D 1. Cathode, Diode D 2 Cathode and Diode D The anodes of diodes 6 are connected simultaneously. D 6 Cathode and Diode D 3 Anode, Capacitor C The other end of 2 and the inductor L One end of 1 is connected simultaneously, diode D 4's anode and inductance L The other end of 1, diode D The anodes of diodes 5 and 6 are connected simultaneously. D 4 Cathode and Inductor L One end of 2 is connected to the diode. D The cathodes of 3 are connected simultaneously, power switch S Drain and diode D 5 Cathode, Inductor L The other end of 2, capacitor C The other end of 1 and the diode D The anode of 0 is connected simultaneously, diode D 0 cathode and capacitor C 0 terminal and load resistor R One end is connected simultaneously; DC voltage source V in negative terminal and power switch S source, capacitor C The other end of 0 and the load resistor R The other end is connected simultaneously, and the diode D 0. Capacitor C 0 and load resistance R Construct an output unit; Voltage gain of boost converter , for power switch S The duty cycle of the coupling inductor is the secondary winding. N 2 with the primary winding N A turns ratio of 1.

2. The switched inductor-coupled inductor series DC-DC boost converter according to claim 1, characterized in that, A boost converter has two operating modes within a switching cycle: the on state and the off state.

3. The switched inductor-coupled inductor series DC-DC boost converter according to claim 2, characterized in that, In the on-state operating mode, the power switch transistor S On, DC voltage source V in and capacitor C 1. The primary winding of the coupled inductor N 1. Charging, due to the principle of magnetic induction, the diode... D 2. Back bias cutoff, D 1. Forward bias conduction; simultaneously, DC voltage source V in and capacitor C 2. Inductor L 1 and L 2. Charging, Diode D 4 and D 6. Reverse bias cutoff; Diode D 0 reverse bias cutoff, capacitor C 0 for load resistance R Independent power supply.

4. The switched inductor-coupled inductor series DC-DC boost converter according to claim 2, characterized in that, In the off-state operating mode, the power switch transistor S Keep off, diode D 2 and D 6. Forward bias conduction, diode D 1. Reverse bias cutoff, inductor L 1 and L 2. Give capacitor C 1. Charging, primary winding of the coupling inductor N 1 and secondary winding N 2. Give capacitor C 2. Charging, simultaneously, DC voltage source V in The output electrical energy passes sequentially through the primary winding of the coupling inductor. N 1 and secondary winding N 2. Inductance L 1. Inductor L 2 and diode D 0 after the load resistor R and capacitor C 0 power supply.

5. The switched inductor-coupled inductor series DC-DC boost converter according to claim 1, characterized in that, Power switching transistors S The duty cycle adjustment range is (0, 0.29).

6. The switched inductor-coupled inductor series DC-DC boost converter according to claim 1, characterized in that, Power switching transistors S The duty cycle is 0.25.

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