Tap inductor quasi-Z-source Boost converter

Abstract

The invention discloses a tap inductor quasi-Z-source Boost converter, and belongs to the technical field of power electronic converters. The problems that a traditional Z-source impedance network boost converter is low in voltage gain, few in control strategy and high in element voltage stress, energy efficiency conversion is low, and the boost capacity is limited are solved. The circuit comprises a DC voltage source Vin, diodes D0 to D7, capacitors C0 to C1, inductors L1 to L2, a coupling inductor and a power switch S, the tap inductor quasi Z source Boost converter can greatly improve the voltage gain. The invention is mainly used for DC boost conversion.

Description

Technical Field

[0001] The invention belongs to the technical field of power electronic converters. Background Art

[0002] Boost converters are widely used in the front-stage converters of distributed power systems to achieve the boost function. The traditional Z-source network circuit topology is a quasi-Z-source Boost circuit. The traditional Z-source impedance network boost converter has low voltage gain, few control strategies, and high component voltage stress, resulting in low energy efficiency conversion. At the same time, considering the parasitic equivalent series impedance in the actual circuit, the actual gain of the Boost circuit does not always increase with the increase of the duty cycle. Therefore, its boost capability is very limited and is not suitable for high voltage gain DC power conversion occasions. The above problems need to be solved urgently. Summary of the invention

[0003] The purpose of the present invention is to solve the problems of low voltage gain, few control strategies and high component voltage stress in traditional Z-source impedance network boost converter, which lead to low energy efficiency conversion and limited boost capability, and provide a tapped inductor quasi-Z-source Boost converter.

[0004] The tapped inductor quasi-Z source Boost converter includes a DC voltage source V in , diodes D0 to D7, capacitors C0 to C1, inductors L1 to L2, a coupled inductor and a power switch S; wherein the capacitor C0 serves as an output capacitor, and the voltage across it serves as the output voltage V0 of the Boost converter;

[0005] DC voltage source V in The positive electrode is connected to the anode of the diode D1, one end of the inductor L1 and one end of the capacitor C1 at the same time;

[0006] The anode of the diode D2 is connected to the other end of the inductor L1 and the anode of the diode D3 at the same time, the cathode of the diode D2 is connected to the cathode of the diode D1 and one end of the inductor L2 at the same time, the other end of the inductor L2 is connected to the cathode of the diode D3, the anode of the diode D4 and the anode of the diode D5 at the same time, the cathode of the diode D5 is connected to the cathode of the diode D6, the opposite end of the secondary winding N2 of the coupled inductor, the anode of the diode D0 and the drain of the power switch S at the same time;

[0007] The other end of the capacitor C1 is connected to the cathode of the diode D4 and the same-name end of the primary winding N1 of the coupled inductor at the same time, the opposite-name end of the primary winding N1 is connected to the anode of the diode D6 and the anode of the diode D7 at the same time, and the cathode of the diode D7 is connected to the same-name end of the secondary winding N2;

[0008] The cathode of the diode D0 is connected to one end of the capacitor C0 and one end of the load resistor R at the same time;

[0009] DC voltage source V in The negative electrode of is connected to the source of the power switch S and the other end of the capacitor C0 and the other end of the load resistor R at the same time.

[0010] Preferably, the voltage gain of the Z-source Boost converter is

[0011] D is the on-duty cycle of the power switch S, and n1 is the turns ratio of the secondary winding to the primary winding of the coupled inductor.

[0012] Preferably, the Boost converter has two operating modes in one switching cycle, namely an on state and an off state.

[0013] Preferably, in the on-state operating mode, the power switch tube S remains on, and the DC voltage source V in The inductor L2 is charged through the diode D1, the diode D2 is reverse biased and cut off, and the diode D3 is forward biased and turned on; at the same time, the DC voltage source V in The primary winding N1 of the coupled inductor is charged through capacitor C1, diodes D5 and D6 are forward biased and turned on, and diode D4 is reverse biased and turned off. Due to the principle of magnetic induction, the secondary winding N2 of the coupled inductor causes diodes D7 and diode D o The reverse bias is cut off, and the capacitor C0 supplies power to the load resistor R independently.

[0014] Preferably, in the off-state operating mode, the power switch tube S remains off, the diodes D1, D3, D5 and D6 are reverse biased and cut off, and the diode D o , D2, D4 and D7 are forward biased, and the inductor L1 and the inductor L2 charge the capacitor C1 together. At the same time, the DC voltage source V in , inductors L1 and L2, and the primary winding N1 and secondary winding N2 of the coupled inductor through diode D o Power the load resistor R and capacitor C0.

[0015] Preferably, the on-duty cycle adjustment range of the power switch tube S is (0, 1).

[0016] Preferably, the optimal conduction duty cycle of the power switch tube S is 0.4.

[0017] Advantages of the present invention:

[0018] DC voltage source V inDirectly connect the inductor L1, because the inductor current is continuous, it can continuously provide relatively stable energy to the circuit, making the waveform changes of the output capacitor C0 voltage, DC link voltage, etc. relatively stable. Avoid the instability of the inductor voltage caused by discontinuous current, which in turn causes the DC link voltage to drop and other unstable conditions, thereby causing the output waveform distortion.

[0019] The voltages of diodes D1 and D3 are much lower than the output voltage, and the currents of inductors L1 and L2 do not fluctuate greatly, which reduces energy loss and component voltage stress, thereby improving energy conversion efficiency and boost capability.

[0020] The power switch S is used in the converter of the present invention, so that the converter has multiple working modes, and the working modes are divided into on-state and off-state, which further optimizes the voltage distribution. This working mode allows the components to withstand appropriate voltages at different stages, avoiding some components from being subjected to excessively high voltages, thereby reducing component voltage stress and further improving energy conversion efficiency and boosting capability. At the same time, the power switch S has a large adjustable range of on-duty cycle, which increases the diversity of control strategies, and can be applied to different application scenarios by changing different on-duty cycles.

[0021] It has been verified that the tapped inductor quasi-Z-source Boost converter described in the present invention can greatly improve the voltage gain. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural diagram of a tapped inductor quasi-Z-source Boost converter;

[0023] Figure 2 is the equivalent circuit diagram of the tapped inductor quasi-Z source Boost converter when the power switch S is turned on and off; Figure 2 a is the equivalent circuit diagram of the tapped inductor quasi-Z-source Boost converter when the power switch S is turned on; Figure 2 b is the equivalent circuit diagram of the tapped inductor quasi-Z-source Boost converter when the power switch S is turned off;

[0024] Figure 3 When the tapped inductor quasi-Z-source Boost converter of the present invention is used for boost conversion, when the input voltage V in =50V, the experimental waveform diagram when the output voltage V0 = 350V; where,

[0025] Figure 3 a is the waveform diagram when the DC input voltage is 50V and the output capacitor C0 voltage is about 350V;

[0026] Figure 3 b is the waveform diagram of the voltage of the output diode D0 and the voltage of the switching diode S;

[0027] Figure 3 c is the waveform of the voltage of diode D1 and the voltage of diode D5;

[0028] Figure 3 d is the waveform of the currents of inductors L1, L2 and the coupled inductor N1. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0031] Specific implementation method 1. Figure 1 The tapped inductor quasi-Z-source Boost converter described in this embodiment includes a DC voltage source V in , diodes D0 to D7, capacitors C0 to C1, inductors L1 to L2, a coupled inductor and a power switch S; wherein the capacitor C0 serves as an output capacitor, and the voltage across it serves as the output voltage V0 of the Boost converter;

[0032] DC voltage source V in The positive electrode is connected to the anode of the diode D1, one end of the inductor L1 and one end of the capacitor C1 at the same time;

[0033] The anode of the diode D2 is connected to the other end of the inductor L1 and the anode of the diode D3 at the same time, the cathode of the diode D2 is connected to the cathode of the diode D1 and one end of the inductor L2 at the same time, the other end of the inductor L2 is connected to the cathode of the diode D3, the anode of the diode D4 and the anode of the diode D5 at the same time, the cathode of the diode D5 is connected to the cathode of the diode D6, the opposite end of the secondary winding N2 of the coupled inductor, the anode of the diode D0 and the drain of the power switch S at the same time;

[0034] The other end of the capacitor C1 is connected to the cathode of the diode D4 and the same-name end of the primary winding N1 of the coupled inductor at the same time, the opposite-name end of the primary winding N1 is connected to the anode of the diode D6 and the anode of the diode D7 at the same time, and the cathode of the diode D7 is connected to the same-name end of the secondary winding N2;

[0035] The cathode of the diode D0 is connected to one end of the capacitor C0 and one end of the load resistor R at the same time;

[0036] DC voltage source V inThe negative electrode of is connected to the source of the power switch S and the other end of the capacitor C0 and the other end of the load resistor R at the same time.

[0037] The coupled inductor is an inductor having a tap, and the tap of the coupled inductor is connected to the anode of the diode D6.

[0038] Specifically, the capacitor C0, the diode D0 and the load resistor R constitute a DC converter output unit.

[0039] In this embodiment, the DC voltage source V in Directly connect the inductor L1. Since the inductor current is continuous, it can continuously provide relatively stable energy to the circuit, making the waveform changes of the output capacitor C0 voltage, DC link voltage, etc. relatively stable, improving the voltage gain, energy conversion efficiency, and boost capability. Avoid instability of the inductor voltage due to discontinuous current, which in turn causes the DC link voltage to drop and other unstable conditions, thereby causing distortion of the output waveform. The voltages of diodes D1 and D3 are much lower than the output voltage, and the currents of inductors L1 to L2 do not fluctuate significantly, reducing energy loss and reducing component voltage response, thereby improving energy conversion efficiency and boost capability.

[0040] Furthermore, the voltage gain of the Z-source Boost converter

[0041] D is the on-duty cycle of the power switch S, and n1 is the turns ratio of the secondary winding to the primary winding of the coupled inductor. The on-duty cycle of the power switch tube S ranges from (0,1) and is adjustable within this range. In specific applications, the optimal on-duty cycle of the power switch tube S is 0.4. The on-duty cycle of the power switch S has a large adjustable range, which increases the diversity of the control strategy. By changing different on-duty cycles, it can be applied to different application scenarios.

[0042] The tapped inductor quasi-Z-source Boost converter of the present invention has two operating modes in one switching cycle, namely, an on state and an off state. Specifically,

[0043] See also Figure 2 a. In the on-state working mode, the power switch tube S remains on, and the DC voltage source V in The inductor L2 is charged through the diode D1, the diode D2 is reverse biased and cut off, and the diode D3 is forward biased and turned on; at the same time, the DC voltage source V in The primary winding N1 of the coupled inductor is charged through capacitor C1, diodes D5 and D6 are forward biased and turned on, and diode D4 is reverse biased and turned off. Due to the principle of magnetic induction, the secondary winding N2 of the coupled inductor causes diodes D7 and diode D o The reverse bias is cut off, and the capacitor C0 supplies power to the load resistor R independently.

[0044] See also Figure 2 b. In the off-state operating mode, the power switch tube S remains off, diodes D1, D3, D5 and D6 are reverse biased and cut off, and diode D o , D2, D4 and D7 are forward biased, and the inductor L1 and the inductor L2 charge the capacitor C1 together. At the same time, the DC voltage source V in , inductors L1 and L2, and the primary winding N1 and secondary winding N2 of the coupled inductor through diode D o Power the load resistor R and capacitor C0.

[0045] In this preferred embodiment, the working mode is divided into an on state and an off state, which further optimizes the voltage distribution. This working mode allows the components to withstand appropriate voltages at different stages, avoiding certain components from being subjected to excessively high voltages, thereby reducing component voltage stress.

[0046] Verification test:

[0047] Figure 3 Given the input voltage V in =50V, the voltage across the output capacitor C0 is V o =350V experimental waveform; especially from Figure 3 It can be seen from (a) that the tapped inductor quasi-Z-source Boost converter of the present invention has a very high voltage output voltage gain.

[0048] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the present invention. It should therefore be understood that many modifications may be made to the exemplary embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in a manner different from that described in the original claims. It should also be understood that features described in conjunction with individual embodiments may be used in other described embodiments.

Claims

1. A tapped inductor quasi-Z-source Boost converter, characterized in that: Including DC voltage source V in , diodes D0 to D7, capacitors C0 to C1, inductors L1 to L2, coupled inductors and power switch S; Wherein, capacitor C0 is used as an output capacitor, and the voltage across it is used as the output voltage V0 of the Boost converter; DC voltage source V in The positive electrode is connected to the anode of the diode D1, one end of the inductor L1 and one end of the capacitor C1 at the same time; The anode of the diode D2 is connected to the other end of the inductor L1 and the anode of the diode D3 at the same time, the cathode of the diode D2 is connected to the cathode of the diode D1 and one end of the inductor L2 at the same time, the other end of the inductor L2 is connected to the cathode of the diode D3, the anode of the diode D4 and the anode of the diode D5 at the same time, the cathode of the diode D5 is connected to the cathode of the diode D6, the opposite end of the secondary winding N2 of the coupled inductor, the anode of the diode D0 and the drain of the power switch S at the same time; The other end of the capacitor C1 is connected to the cathode of the diode D4 and the same-name end of the primary winding N1 of the coupled inductor at the same time, the opposite-name end of the primary winding N1 is connected to the anode of the diode D6 and the anode of the diode D7 at the same time, and the cathode of the diode D7 is connected to the same-name end of the secondary winding N2; The cathode of the diode D0 is connected to one end of the capacitor C0 and one end of the load resistor R at the same time; DC voltage source V in The negative electrode of is connected to the source of the power switch S and the other end of the capacitor C0 and the other end of the load resistor R at the same time.

2. The tapped inductor quasi-Z-source Boost converter according to claim 1, characterized in that: Voltage Gain of Z-Source Boost Converter D is the on-duty cycle of the power switch S, and n1 is the turns ratio of the secondary winding to the primary winding of the coupled inductor.

3. The tapped inductor quasi-Z-source Boost converter according to claim 1, characterized in that: The Boost converter has two operating modes in one switching cycle, namely the on state and the off state.

4. The tapped inductor quasi-Z-source Boost converter according to claim 3, characterized in that: In the on-state operating mode, the power switch tube S remains on and the DC voltage source V in The inductor L2 is charged through the diode D1, the diode D2 is reverse biased and cut off, and the diode D3 is forward biased and turned on; at the same time, the DC voltage source V in The primary winding N1 of the coupled inductor is charged through capacitor C1, diodes D5 and D6 are forward biased and turned on, and diode D4 is reverse biased and turned off. Due to the principle of magnetic induction, the secondary winding N2 of the coupled inductor causes diodes D7 and diode D o The reverse bias is cut off, and the capacitor C0 supplies power to the load resistor R independently.

5. The tapped inductor quasi-Z-source Boost converter according to claim 3, characterized in that: In the off-state operating mode, the power switch tube S remains off, the diodes D1, D3, D5 and D6 are reverse biased and cut off, and the diode D o , D2, D4 and D7 are forward biased, and the inductor L1 and the inductor L2 charge the capacitor C1 together. At the same time, the DC voltage source V in , inductors L1 and L2, and the primary winding N1 and secondary winding N2 of the coupled inductor through diode D o Power the load resistor R and capacitor C0.

6. The tapped inductor quasi-Z-source Boost converter according to claim 1, characterized in that: The on-duty cycle adjustment range of the power switch tube S is (0,1).

7. The tapped inductor quasi-Z-source Boost converter according to claim 6, characterized in that: The optimal conduction duty cycle of the power switch tube S is 0.4.

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