Low voltage stress port continuous dc-dc converter

Abstract

The application provides a novel low-voltage stress port current continuous DC-DC converter, which uses two switching tubes and two diodes or four switching tubes, changes the circuit structure of the converter, reduces the voltage stress of the switching device, and maintains the characteristics of input and output port current continuity.

Description

Technical Field

[0001] This invention belongs to the field of power electronic circuit DC-DC converters, specifically relating to a low-voltage stress port continuous DC-DC converter. Background Technology

[0002] Superboost converters are DC-DC converters commonly used in applications requiring continuous input and output current. The voltage stress on its switching transistors and diodes is the output voltage, which is relatively high. This requires the use of semiconductor devices with high voltage ratings, resulting in higher cost and lower performance. Summary of the Invention

[0003] This invention addresses the shortcomings of existing technologies by proposing a low-voltage-stress, continuous-current DC-DC converter. This converter can utilize low-voltage-stress semiconductor devices to achieve DC-DC conversion while maintaining continuous input and output current.

[0004] Based on the above concept, the present invention has the following four converter configurations.

[0005] A low-voltage-stress port continuous DC-DC converter includes a first diode, a second diode, a first switching device, a second switching device, a first inductor, a second inductor, a first capacitor, and a second capacitor;

[0006] The cathode of the first diode is connected to the positive terminal of the converter input, one side of the second switching device, and the anode of the second diode;

[0007] The anode of the first diode is connected to one side of the first inductor and the other side of the first switching device;

[0008] The other side of the first inductor is connected to the other side of the second switching device and one side of the first capacitor;

[0009] The other side of the first capacitor is connected to one side of the second inductor and the cathode of the second diode;

[0010] The other side of the second inductor is connected to one side of the second capacitor and the positive terminal of the converter output.

[0011] The other side of the first switching device is connected to the negative terminal of the converter input, the other side of the second capacitor, and the negative terminal of the converter output.

[0012] A low-voltage stress port continuous DC-DC converter includes a first switching device, a second switching device, a third switching device, a fourth switching device, a first inductor, a second inductor, a first capacitor, and a second capacitor;

[0013] One side of the second switching device is connected to the positive terminal of the converter input, one side of the third switching device, and one side of the fourth switching device;

[0014] The other side of the second switching device is connected to one side of the first inductor and one side of the first switching device;

[0015] The other side of the first inductor is connected to the other side of the third switching device and one side of the first capacitor;

[0016] The other side of the first capacitor is connected to one side of the second inductor and the other side of the fourth switching device;

[0017] The other side of the second inductor is connected to one side of the second capacitor and the positive terminal of the converter output.

[0018] The other side of the first switching device is connected to the negative terminal of the converter input, the other side of the second capacitor, and the negative terminal of the converter output.

[0019] A low-voltage-stress port continuous DC-DC converter includes a first diode, a second diode, a first switching device, a second switching device, a first inductor, a second inductor, a first capacitor, and a second capacitor;

[0020] One side of the first switching device is connected to the positive terminal of the converter input, one side of the second capacitor, the cathode of the second diode, and one side of the second switching device;

[0021] The other side of the first switching device is connected to one side of the first inductor and the cathode of the first diode;

[0022] The anode of the first diode is connected to the negative terminal of the converter input, the other side of the second capacitor, and the negative terminal of the converter output;

[0023] The other side of the first inductor is connected to the anode of the second diode and one side of the first capacitor;

[0024] The other side of the first capacitor is connected to the other side of the second switching device and one side of the second inductor;

[0025] The other side of the second inductor is connected to the positive terminal of the converter output.

[0026] A low-voltage stress port continuous DC-DC converter includes a first switching device, a second switching device, a third switching device, a fourth switching device, a first inductor, a second inductor, a first capacitor, and a second capacitor;

[0027] One side of the second switching device is connected to the positive terminal of the converter output, one side of the second capacitor, one side of the third switching device, and one side of the fourth switching device;

[0028] The other side of the second switching device is connected to one side of the first inductor and one side of the first switching device;

[0029] The other side of the first inductor is connected to the other side of the third switching device and one side of the first capacitor;

[0030] The other side of the first capacitor is connected to one side of the second inductor and the other side of the fourth switching device;

[0031] The other side of the second inductor is connected to the positive terminal of the converter input.

[0032] The other side of the first switching device is connected to the negative terminal of the converter output, the other side of the second capacitor, and the negative terminal of the converter input.

[0033] Based on the above scheme, the first switching device, the second switching device, the third switching device, and the fourth switching device are field-effect transistors.

[0034] The beneficial effects of this invention are:

[0035] This invention proposes a novel low-voltage-stress, continuous-port-current DC-DC converter. By changing the converter's circuit structure, the voltage stress of the switching devices is reduced while maintaining the continuous input and output port current characteristic. Attached Figure Description

[0036] The present invention includes the following figures:

[0037] Figure 1 This is a circuit diagram of a current-technology Superboost converter;

[0038] Figure 2 The control signals and main waveforms of existing Superboost converters are shown below.

[0039] Figure 3 This is a circuit diagram of a first specific embodiment of the present invention;

[0040] Figure 4 The control signal and main waveforms are shown in the first specific embodiment of the present invention;

[0041] Figure 5 This is a circuit diagram of a second specific embodiment of the present invention;

[0042] Figure 6 This is a circuit diagram of a third specific embodiment of the present invention;

[0043] Figure 7 This is a circuit diagram of the fourth specific embodiment of the present invention. Detailed Implementation

[0044] To make the objectives, advantages, and features of the present invention more apparent, the following description is provided in conjunction with the appendix. Figure 1-7 The present invention will be further described in detail below with reference to specific embodiments.

[0045] The Superboost converter is a commonly used DC-DC converter in applications requiring continuous input and output current. Its circuit diagram is shown below. Figure 1 As shown in the diagram. Vin is the input DC power supply, S is the switching transistor, D is the diode, L1 and L2 are inductors, C1 and C2 are capacitors, and C3 is the capacitor. out For capacitor R L For the output-side load. In continuous inductor current mode, the control signals and main waveforms of the Superboost converter are as follows: Figure 2 As shown, d is the duty cycle of the switching transistor S, and Ts is the switching period of the converter.

[0046] The modal analysis of the Superboost converter is as follows:

[0047] Mode 1 (t0~t1): Switch S is in the on state, diode D is in the off state, and capacitors C1 and C2 are in steady-state operation. out Since the voltages are equal, the voltage across inductors L1 and L2 is equal to the input voltage V. in According to the volt-ampere characteristic of an inductor, its current rises at a fixed slope. Input current i in Equal to the two inductor currents i L1 and i L2 The sum of these, the output current equals i L2 The voltage stress of diode D is the output voltage V. out .

[0048] Mode 2 (t1~t2): Switch S is in the off state, diode D is in the on state, and under steady-state operation, the voltages across capacitors C1 and C2 are equal. Therefore, the voltages across inductors L1 and L2 are equal to the input voltage V. in With output voltage V out The difference in current, according to the inductor's volt-ampere characteristic, causes the current to decrease at a fixed slope. Input current i in Equal to the two inductor currents i L1 and i L2 The sum of the output current i out equals i L2 The voltage stress on the switching transistor S is the output voltage V. out .

[0049] The voltage gain of the Superboost converter is:

[0050]

[0051] This invention proposes a novel low-voltage stress port current continuous DC-DC converter. In a specific embodiment, its circuit diagram is as follows: Figure 3 As shown. Where V inThis is the input-side DC power supply. S1 and S3 are switching transistors, D2 and D4 are diodes, L1 and L2 are inductors, and C1 and C2 are inductors. out For capacitor R L For the output-side load. In continuous inductor current mode, the proposed converter's control signals and main waveforms are as follows: Figure 4 As shown, d is the duty cycle of switches S1 and S3, and T... s This represents the switching cycle of the converter.

[0052] This converter uses two switching transistors and two diodes. By changing the converter's circuit structure, the voltage stress on the switching devices is reduced, while maintaining the continuous current characteristics of the input and output ports.

[0053] The modal analysis of the proposed converter is as follows:

[0054] Mode 1 (t0~t1): Switches S1 and S3 are in the on state, diodes D2 and D4 are in the off state, and the voltage across inductor L1 is equal to the input voltage V. in The voltage across inductor L2 is determined by the input voltage V. in V C1 and V out Provided, based on the inductor's volt-ampere characteristic, its current rises at a fixed slope. Input current i in Equal to the two inductor currents i L1 and i L2 The sum of these, the output current equals i L2 The voltage stress on diode D2 is the input voltage V. in The voltage stress of D4 is V C1 .

[0055] Mode 2 (t1~t2): Switches S1 and S3 are in the off state, diodes D2 and D4 are in the on state, and the voltage across inductor L1 is equal to V. C1 The voltage across inductor L2 is equal to the input voltage V. in With output voltage V out The difference in current, according to the inductor's volt-ampere characteristic, causes the current to decrease at a fixed slope. Input current i in and output current i out All equal to i L2 The voltage stress on switch S1 is the input voltage V. in The voltage stress of S3 is V C1 .

[0056] The voltage gain of the proposed converter is

[0057]

[0058] like Figure 5As shown in the second specific embodiment, Vin is the input-side DC power supply, S1, S2, S3, and S4 are switching transistors, L1 and L2 are inductors, and C1 and C2 are inductors. out For capacitor R L For the output side load.

[0059] like Figure 6 As shown, in specific embodiment three, V in This is the input-side DC power supply. S2 and S4 are switching transistors, D1 and D3 are diodes, L1 and L2 are inductors, and C1 and C2 are inductors. out For capacitor R L For the output side load.

[0060] like Figure 7 As shown, in specific embodiment four, V in This is the input-side DC power supply. S1, S2, S3, and S4 are switching transistors, L1 and L2 are inductors, and C1 and C2 are capacitors. out For capacitor R L For the output side load.

[0061] In summary, the circuit proposed in Embodiment 1 of the present invention is suitable for unidirectional power transmission from left to right. The circuit proposed in Embodiment 2 of the present invention is suitable for power transmission from left to right, and uses synchronous rectification. The circuit proposed in Embodiment 3 of the present invention is suitable for power transmission from right to left, and uses diode rectification. The circuit proposed in Embodiment 4 of the present invention is suitable for power transmission from right to left, and uses synchronous rectification.

[0062] The above embodiments are for illustrative purposes only and are not intended to limit the scope of this invention. Those skilled in the art can make various changes and modifications without departing from the essence and scope of this invention. Therefore, all equivalent technical solutions also fall within the scope of this invention, and the patent protection scope of this invention should be defined by the claims. Content not described in detail in this specification is prior art known to those skilled in the art.

Claims

1. A low-voltage-stress port continuous DC-DC converter, characterized in that, It includes a first diode, a second diode, a first switching device, a second switching device, a first inductor, a second inductor, a first capacitor, and a second capacitor; The cathode of the first diode is connected to the positive terminal of the converter input, one side of the second switching device, and the anode of the second diode; The anode of the first diode is connected to one side of the first inductor and the other side of the first switching device; The other side of the first inductor is connected to the other side of the second switching device and one side of the first capacitor; The other side of the first capacitor is connected to one side of the second inductor and the cathode of the second diode; The other side of the second inductor is connected to one side of the second capacitor and the positive terminal of the converter output. The other side of the first switching device is connected to the negative terminal of the converter input, the other side of the second capacitor, and the negative terminal of the converter output. The first and second switching devices are driven synchronously, with the same duty cycle and sharing the same switching cycle. During one switching cycle, the first and second switching devices are turned on simultaneously from t0 to t1, while the first and second diodes are turned off. During the t1 to t2 phase, the first and second switching devices are turned off simultaneously, while the first and second diodes conduct freewheeling current, maintaining continuous input and output port current throughout the entire process.

2. A low-voltage-stress port continuous DC-DC converter, characterized in that, It includes a first switching device, a second switching device, a third switching device, a fourth switching device, a first inductor, a second inductor, a first capacitor, and a second capacitor; One side of the second switching device is connected to the positive terminal of the converter input, one side of the third switching device, and one side of the fourth switching device; The other side of the second switching device is connected to one side of the first inductor and one side of the first switching device; The other side of the first inductor is connected to the other side of the third switching device and one side of the first capacitor; The other side of the first capacitor is connected to one side of the second inductor and the other side of the fourth switching device; The other side of the second inductor is connected to one side of the second capacitor and the positive terminal of the converter output. The other side of the first switching device is connected to the negative terminal of the converter input, the other side of the second capacitor, and the negative terminal of the converter output.

3. A low-voltage-stress port continuous DC-DC converter, characterized in that, It includes a first diode, a second diode, a first switching device, a second switching device, a first inductor, a second inductor, a first capacitor, and a second capacitor; One side of the first switching device is connected to the positive terminal of the converter input, one side of the second capacitor, the cathode of the second diode, and one side of the second switching device; The other side of the first switching device is connected to one side of the first inductor and the cathode of the first diode; The anode of the first diode is connected to the negative terminal of the converter input, the other side of the second capacitor, and the negative terminal of the converter output; The other side of the first inductor is connected to the anode of the second diode and one side of the first capacitor; The other side of the first capacitor is connected to the other side of the second switching device and one side of the second inductor; The other side of the second inductor is connected to the positive terminal of the converter output.

4. A low-voltage-stress port continuous DC-DC converter, characterized in that, It includes a first switching device, a second switching device, a third switching device, a fourth switching device, a first inductor, a second inductor, a first capacitor, and a second capacitor; One side of the second switching device is connected to the positive terminal of the converter output, one side of the second capacitor, one side of the third switching device, and one side of the fourth switching device; The other side of the second switching device is connected to one side of the first inductor and one side of the first switching device; The other side of the first inductor is connected to the other side of the third switching device and one side of the first capacitor; The other side of the first capacitor is connected to one side of the second inductor and the other side of the fourth switching device; The other side of the second inductor is connected to the positive terminal of the converter input. The other side of the first switching device is connected to the negative terminal of the converter output, the other side of the second capacitor, and the negative terminal of the converter input.

5. A low-voltage-stress port continuous DC-DC converter as described in any one of claims 1-4, characterized in that, The first, second, third, and fourth switching devices are field-effect transistors.

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