Multi-output voltage direct current converter

Abstract

The utility model discloses a direct current converter with multiple output voltages, which has the capability of reducing input current ripples, adopts two switch tubes which are driven simultaneously, can provide multiple output voltages, and independently changes positive and negative output voltages by changing duty ratio and tuning turn ratio of a coupling inductor. The two voltages can be equal or unequal, so that the balance capability of multiple paths of output voltages under different load conditions is improved; the maximum voltage stress between the switching tubes is far lower than the output voltage, and the second switching tube and all the diodes are effective under the soft switching condition, so that the efficiency of the converter is greatly improved; a high boost conversion ratio under low input current ripples and low voltage spikes is realized.

Description

Technical Field

[0001] The utility model belongs to the technical field of switch power supply, in particular to a multi-output voltage direct current converter. Background Art

[0002] At present, with the prosperity and development of the new energy power industry, the scale of power electronics continues to expand, and the application of DC converters is becoming more and more extensive, which puts higher requirements on the performance of the converter. How to ensure the efficiency of the DC converter under the conditions of low input current ripple, high boost ratio and multiple loads has become a major challenge for the industry; in traditional solutions, the method to improve the boost ratio is to cascade inductors and capacitors. The increase in components will make the efficiency worse. The traditional multi-output DC converter balancing different loads will cause the control to become complicated, the boost ratio to decrease and the adverse effects of high output current ripple, which is not conducive to the improvement of power supply performance. Utility Model Content

[0003] The utility model aims to provide a multi-output voltage DC converter to overcome the problems of large input current ripple, low efficiency and poor ability to balance different loads in traditional multi-output DC converters.

[0004] A multi-output voltage DC converter includes an input power supply V in , input capacitor C in , input inductance L in , switch tube Q a , switch tube Q b , capacitor C1, capacitor C2, capacitor C3, capacitor C4, diode D1, diode D2, diode D3, diode D4, dual winding coupled inductor, excitation inductor L m , leakage inductance L k , output resistor R1, output resistor R2, output resistor R3, ground GND;

[0005] Input power V in The positive terminal of the input capacitor C in The first end and input inductor L in The first end of the input inductor L in The second end is connected to the switch tube Q a The drain of the capacitor C1 and the first end of the capacitor C4 are connected. The second end of the capacitor C1 is connected to the positive end of the diode D1 and the switch tube Q b The source of the switch tube Q b The drain of the dual winding coupled inductor N1 is connected to the first end of the winding, the excitation inductor L m The first end of the double-winding coupled inductor N1 is connected to the positive end of the diode D3, and the second end of the winding is connected to the excitation inductor L m The second terminal and leakage inductance L kThe first end of the diode D3 is connected to the first end of the capacitor C2, the first end of the output resistor R1 and the first end of the output resistor R3;

[0006] The negative terminal of the power supply, the input capacitor C in The second end of the switch tube Q a The source of the diode D1, the negative terminal of the diode D1, the leakage inductance L k The second end of the capacitor C2 and the second end of the output resistor R1 are all connected to the ground GND. k The second end of the output resistor R1 is connected to the negative end of the diode D2, the second end of the capacitor C2 is connected to the first end of the capacitor C3, and the second end of the output resistor R1 is connected to the first end of the output resistor R2;

[0007] The second end of the output resistor R2 is connected to the second end of the output resistor R3, the second end of the capacitor C3 and the positive end of the diode D4, the negative end of the diode D4 is connected to the positive end of the diode D2 and the first end of the dual-winding coupled inductor N2 winding, and the second end of the dual-winding coupled inductor N2 winding is connected to the second end of the capacitor C4.

[0008] Preferably, the switch tube Q a And the switch tube Q b Connect to the same drive source.

[0009] Preferably, the diode D1 is a common diode.

[0010] Preferably, the switch tube Q a Adopt field effect tube enhancement P-MOS.

[0011] Preferably, the switch tube Q b Adopt field effect tube enhancement P-MOS.

[0012] Preferably, the diode D2 is a common diode.

[0013] Preferably, the diode D3 is a common diode.

[0014] Preferably, the diode D4 is a common diode.

[0015] Compared with the prior art, the utility model has the following beneficial technical effects:

[0016] The utility model provides a DC converter with multiple output voltages, which has the ability to reduce input current ripple. The DC converter adopts two simultaneously driven switch tubes, which can provide multiple output voltages. The positive and negative output voltages are independently changed by changing the duty cycle and the turn ratio of the tuned coupling inductor. The two voltages can be equal or unequal, which improves the balancing ability of multiple output voltages under different load conditions. The maximum voltage stress between the switch tubes is much lower than the output voltage, and is effective for the second switch tube and all diodes under soft switching conditions, which greatly improves the efficiency of the converter. A high step-up conversion ratio under low input current ripple and low voltage spike is achieved.

[0017] Preferably, a regenerative passive clamp circuit is used to suppress the voltage spike on the switch tube; the switch tube Q can be b The current shape of diodes D2, D3 and D4 is sinusoidal, thereby reducing the switching tube Q b The turn-off loss of the diode D2, the diode D3 and the diode D4 is eliminated, and the efficiency of the converter is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a circuit diagram of a multi-output voltage DC converter in an embodiment of the utility model.

[0019] Figure 2 1 is a circuit diagram of mode 1 in a switching cycle of a multi-output voltage DC converter in an embodiment of the utility model.

[0020] Figure 3 It is a circuit diagram of mode 2 in a switching cycle of a multi-output voltage DC converter in an embodiment of the utility model.

[0021] Figure 4 1 is a circuit diagram of mode 3 in a switching cycle of a multi-output voltage DC converter in an embodiment of the utility model.

[0022] Figure 5 It is a circuit diagram of mode 4 in one switching cycle of a multi-output voltage DC converter in an embodiment of the utility model. DETAILED DESCRIPTION

[0023] In order to enable those skilled in the art to better understand the solution of the utility model, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is only a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the utility model.

[0024] It should be noted that the terms "first", "second", etc. in the specification and claims of the utility model and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the utility model described here can be implemented in an order other than those illustrated or described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0025] like Figure 1 As shown, the utility model provides a multi-output voltage DC converter, including an input power supply V in , input capacitor C in , input inductance L in , switch tube Q a , switch tube Q b , capacitor C1, capacitor C2, capacitor C3, capacitor C4, diode D1, diode D2, diode D3, diode D4, dual winding coupled inductor, excitation inductor L m , leakage inductance L k , output resistor R1, output resistor R2, output resistor R3, ground GND;

[0026] Input power V in The positive terminal of the input capacitor C in The first end and input inductor L in The first end of the input inductor L in The second end is connected to the switch tube Q a The drain of the capacitor C1 and the first end of the capacitor C4 are connected. The second end of the capacitor C1 is connected to the positive end of the diode D1 and the switch tube Q b The source of the switch tube Q b The drain of the dual winding coupled inductor N1 is connected to the first end of the winding, the excitation inductor L m The first end of the double-winding coupled inductor N1 is connected to the positive end of the diode D3, and the second end of the winding is connected to the excitation inductor L m The second terminal and leakage inductance L k The first end of the diode D3 is connected to the first end of the capacitor C2, the first end of the output resistor R1 and the first end of the output resistor R3;

[0027] The negative terminal of the power supply, the input capacitor C in The second end of the switch tube Q a The source of the diode D1, the negative terminal of the diode D1, the leakage inductance Lk The second end of the capacitor C2 and the second end of the output resistor R1 are all connected to the ground GND. k The second end of the output resistor R1 is connected to the negative end of the diode D2, the second end of the capacitor C2 is connected to the first end of the capacitor C3, and the second end of the output resistor R1 is connected to the first end of the output resistor R2;

[0028] The second end of the output resistor R2 is connected to the second end of the output resistor R3, the second end of the capacitor C3 and the positive end of the diode D4, the negative end of the diode D4 is connected to the positive end of the diode D2 and the first end of the dual-winding coupled inductor N2 winding, and the second end of the dual-winding coupled inductor N2 winding is connected to the second end of the capacitor C4. The present application forms a multi-channel output DC converter through a dual-winding coupled inductor, two switching tubes, an input capacitor, an input inductor, four diodes, and four capacitors. Based on secondary boost, two switching tubes are driven simultaneously, and the dual-winding coupled inductor is used to achieve the effect of multi-channel output voltage and feed electric energy to different loads; a regenerative passive clamping circuit is used to suppress the voltage spike on the switching tube, and the resonant cavity of the parasitic inductance and capacitance of the dual-winding coupled inductor can be used to suppress the switching tube Q b The current shape of diodes D2, D3 and D4 is sinusoidal, thereby reducing the switching tube Q b The turn-off loss is reduced, eliminating the reverse recovery problem of diodes D2, D3 and D4.

[0029] Diode D1, diode D2, diode D3 and diode D4 are all ordinary diodes.

[0030] Switching tube Q a , switch tube Q b Both use field effect transistor enhanced P-MOS.

[0031] The capacitors C1, C2, C3 and C4 have large capacitance values ​​and their terminal voltages are constant.

[0032] like Figures 2 to 5 As shown, the working principle of the utility model in one switching cycle is described in detail, and its main working states are briefly described as follows:

[0033] Mode 1: If Figure 2 As shown, the switch tube Q a And the switch tube Q b At the same time, diodes D3 and D4 are turned on, and diodes D1 and D2 are reverse biased; at this time, the input inductor L in Accept the voltage of DC input power supply, excitation inductance L m Accepts the voltage of capacitor C1; therefore, the input inductor L in and the magnetizing inductance L mThe current increases linearly, and the secondary side of the double-winding coupled inductor makes the current of diode D4 reach zero at the end of the mode without reverse recovery problems.

[0034] Mode 2: If Figure 3 As shown, the switch tube Q a And the switch tube Q b Keep conducting. At the beginning of this mode, diode D2 is conducting. Same as mode 1, input inductor L in Accept the voltage of DC input power supply, excitation inductance L m Receiving the voltage of capacitor C1, capacitor C4 is charged from the secondary side of the dual-winding coupled inductor, and a resonant cavity is generated with capacitor C1 and leakage inductance. Due to the resonance, the switch tube Q b , diode D2 and leakage inductance L k The current becomes sinusoidal; therefore, at the end of this mode, the switch tube Q b The current is reduced to a low value, reducing the open tube loss.

[0035] Mode 3: If Figure 4 As shown, this mode starts when the current of diode D2 reaches zero. When the current is zero, the leakage inductance L k Current and magnetizing inductance L m The currents are equal and this modal capacitor C2 and capacitor C3 provide voltage to the load.

[0036] The switching tube Q can be controlled by using the resonant cavity of the parasitic inductance and capacitance of the dual-winding coupled inductor. b The current shape of diodes D2, D3 and D4 is sinusoidal, thereby reducing the switching tube Q b The turn-off loss is reduced, eliminating the reverse recovery problem of diodes D2, D3 and D4.

[0037] Mode 4: If Figure 5 As shown, the switch tube Q a And the switch tube Q b Turn off, diode D1, diode D3 and diode D4 are forward biased at the same time; Q a The voltage stress of the switch tube Q is limited to a low value by capacitor C1; in addition, b The voltage stress is also limited by capacitor C2 and is much lower than the overall output voltage V o3 ; Capacitor C1 from the input inductor L in The current on the secondary side of the dual-winding coupled inductor is charged; during this period, the excitation inductance L m The energy in the diode is transferred to the output load; similar to Mode 2, due to the presence of the resonant cavity, the current through diode D1, diode D3 and diode D4 changes in a sinusoidal shape, reducing the reverse recovery problem.

[0038] The regenerative passive clamp circuit D1 and C1 are used to suppress the switch tube Q a voltage spike on the .

[0039] The circuit provided in this application is based on secondary boost, and uses a dual-winding coupled inductor to output a positive voltage and a negative voltage, which can be equal or unequal in size, and can provide a positive output voltage V o1 , negative output voltage V o2 And the total voltage V o3 , voltage can be fed to three different loads at the same time.

[0040] The utility model solves the problems of high power consumption, poor output balancing ability for different loads and large input current ripple in the traditional multi-output DC converter in the related technology. The utility model proposes a high-efficiency multi-output voltage DC converter to improve the shortcomings of the traditional multi-output DC converter, can achieve low input ripple current and high-efficiency operation, improve the balancing ability between multiple outputs, and improve the performance of the DC converter.

[0041] The preferred embodiments of the utility model disclosed above are only used to help explain the utility model. The preferred embodiments do not describe all the details in detail, nor do they limit the utility model to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the utility model, so that technicians in the relevant technical field can well understand and use the utility model. The utility model is limited only by the claims and their full scope and equivalents.

Claims

1. A multi-output voltage DC converter, characterized in that: Including input power supply V in , input capacitor C in , input inductance L in , switch tube Q a , switch tube Q b , capacitor C1, capacitor C2, capacitor C3, capacitor C4, diode D1, diode D2, diode D3, diode D4, dual winding coupled inductor, excitation inductor L m , leakage inductance L k , output resistor R1, output resistor R2, output resistor R3, ground GND; Input power V in The positive terminal of the input capacitor C in The first end and input inductor L in The first end of the input inductor L in The second end is connected to the switch tube Q a The drain of the capacitor C1 and the first end of the capacitor C4 are connected. The second end of the capacitor C1 is connected to the positive end of the diode D1 and the switch tube Q b The source of the switch tube Q b The drain of the dual winding coupled inductor N1 is connected to the first end of the winding, the excitation inductor L m The first end of the double-winding coupled inductor N1 is connected to the positive end of the diode D3, and the second end of the winding is connected to the excitation inductor L m The second terminal and leakage inductance L k The first end of the diode D3 is connected to the first end of the capacitor C2, the first end of the output resistor R1 and the first end of the output resistor R3; The negative terminal of the power supply, the input capacitor C in The second end of the switch tube Q a The source of the diode D1, the negative terminal of the diode D1, the leakage inductance L k The second end of the capacitor C2 and the second end of the output resistor R1 are all connected to the ground GND. k The second end of the output resistor R1 is connected to the negative end of the diode D2, the second end of the capacitor C2 is connected to the first end of the capacitor C3, and the second end of the output resistor R1 is connected to the first end of the output resistor R2; The second end of the output resistor R2 is connected to the second end of the output resistor R3, the second end of the capacitor C3 and the positive end of the diode D4, the negative end of the diode D4 is connected to the positive end of the diode D2 and the first end of the dual-winding coupled inductor N2 winding, and the second end of the dual-winding coupled inductor N2 winding is connected to the second end of the capacitor C4.

2. A multi-output voltage DC converter according to claim 1, characterized in that: Switching tube Q a And the switch tube Q b Connect to the same drive source.

3. The multi-output voltage DC converter according to claim 1, characterized in that: Switching tube Q a Adopt field effect tube enhancement P-MOS.

4. The multi-output voltage DC converter according to claim 1, characterized in that: Switching tube Q b Adopt field effect tube enhancement P-MOS.

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