Power converter

Abstract

The invention relates to a power converter, each conversion unit comprises a sub-input end, a sub-output end and an input capacitor, the sub-input end of each conversion unit is connected to the input end to receive an input voltage, and the sub-output end of each conversion unit is connected to the output end. The input capacitor of each conversion unit is connected to the sub-input end of the corresponding conversion unit, the linear voltage regulator reduces the voltage when receiving the input voltage, the first switch element is connected between the conversion unit and the auxiliary power supply, the second switch element is connected between the linear voltage regulator and the auxiliary power supply, and when any conversion unit is started, the first switch element and the second switch element are switched on. When the first switching element is turned off and the second switching element is turned on, the input voltage is supplied to the auxiliary power supply through the linear voltage regulator and the second switching element; when the capacitance voltage of the input capacitor in the conversion unit reaches dynamic balance, the second switching element is turned off and the first switching element is turned on, so that the conversion unit is used as an energy source to be supplied to the auxiliary power supply through the first switching element.

Description

Technical Field

[0001] This case relates to the field of electric energy conversion, and particularly to a power converter. Background Art

[0002] With the continuous expansion of the scale of data centers and the development of artificial intelligence technology, the power demand per rack has increased linearly. In order to meet the power demand of the rack, server power supplies are developing in the direction of high power, high efficiency and small volume. Among them, the possibilities of the bus input voltage received by the power converter are increasing. For example, in addition to the traditional 48V, the bus input voltage has more different voltage levels.

[0003] In order to meet the requirements of rack power improvement and diversified bus input voltage, the power converter includes a plurality of conversion units and an auxiliary power supply. Among them, the plurality of conversion units are connected in series or in parallel. Each conversion unit includes an input end and an output end. Each conversion unit receives the bus input voltage through the input end and outputs the output voltage through the output end. The auxiliary power supply is used to supply power to the additional logic control circuit. The auxiliary power supply of the traditional power converter receives the bus input voltage in two ways. The first way is that the auxiliary power supply is directly connected to the bus input voltage. However, in order to meet the requirements of receiving the bus input voltage, the volume and stress of the auxiliary power supply are large, resulting in large volume and stress of the overall power converter. The second way is to additionally set a linear voltage regulator in the power converter, which is connected between the bus input voltage and the auxiliary power supply. The linear voltage regulator steps down the bus input voltage and provides it to the auxiliary power supply. However, since the loss on the linear voltage regulator is determined by the voltage drop between the input end and the output end multiplied by the current flowing through the linear voltage regulator, when the bus input voltage is in a steady state and the load increases, the current on the linear voltage regulator increases, resulting in an increase in the loss on the linear voltage regulator, a high damage rate of the linear voltage regulator, and a decrease in the stability of the overall power converter.

[0004] Therefore, it is necessary to develop a power converter to solve the problems faced by the prior art. Summary of the Invention

[0005] The purpose of this case is to provide a power converter. When any conversion unit is started, the first switching element is turned off and the second switching element is turned on, so that the input voltage is provided to the auxiliary power supply through the linear voltage regulator and the second switching element. When the capacitor voltage on the input capacitor in the conversion unit reaches dynamic balance and is in a steady state, the second switching element is turned off and the first switching element is turned on, so that at least one conversion unit is used as an energy source and provided to the auxiliary power supply through the first switching element. Therefore, the power converter in this case can use the components in the conversion unit to supply power in a steady state, reduce the loss of the linear voltage regulator, and make the overall power converter have higher stability.

[0006] To achieve the above object, the present case provides a power converter, which includes an input terminal, an output terminal, a plurality of conversion units, an auxiliary power supply, a linear voltage regulator, a first switching element, and a second switching element. The power converter receives an input voltage via the input terminal and outputs an output voltage via the output terminal. Each conversion unit includes a sub-input terminal, a sub-output terminal, and an input capacitor. The sub-input terminal of each conversion unit is connected to the input terminal to receive the input voltage. The sub-output terminal of each conversion unit is connected to the output terminal. The input capacitor of each conversion unit is connected to the sub-input terminal of the corresponding conversion unit. The linear voltage regulator is connected to the input terminal to step down the voltage when receiving the input voltage. The first switching element is connected between at least one conversion unit and the auxiliary power supply. The second switching element is connected between the linear voltage regulator and the auxiliary power supply. When any one of the conversion units is started, the first switching element is turned off and the second switching element is turned on, so that the input voltage is supplied to the auxiliary power supply via the linear voltage regulator and the second switching element. When the capacitor voltage on the input capacitor in at least one conversion unit reaches dynamic balance, the second switching element is turned off and the first switching element is turned on, so that at least one conversion unit serves as an energy source and is supplied to the auxiliary power supply via the first switching element. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 FIG. is a circuit topology diagram of the first embodiment of the power converter of the present case;

[0008] Figure 2 FIG. is a circuit topology diagram of the second embodiment of the power converter of the present case

[0009] Figure 3 FIG. is a circuit topology diagram of the third embodiment of the power converter of the present case;

[0010] Figure 4 FIG. is a circuit topology diagram of the fourth embodiment of the power converter of the present case;

[0011] Figure 5 FIG. is a circuit topology diagram of the fifth embodiment of the power converter of the present case;

[0012] Figure 6 FIG. is a circuit topology diagram of the sixth embodiment of the power converter of the present case; and

[0013] Figure 7 FIG. is a circuit topology diagram of the seventh embodiment of the power converter of the present case.

[0014] Among them, the description of the reference numerals is as follows:

[0015] 1, 1a, 1b, 1c, 1d, 1e, 1f: power converter

[0016] 21: input terminal

[0017] 22: output terminal

[0018] 3: Transformation Unit

[0019] 31: Sub-input Terminal

[0020] 32: Sub-output Terminal

[0021] Cin: Input Capacitance

[0022] M1: First Switch

[0023] M2: Second Switch

[0024] Cr: Resonant Capacitance

[0025] Lr: Resonant Inductance

[0026] T1: Primary Winding

[0027] T2: First Secondary Winding

[0028] T3: Second Secondary Winding

[0029] M3: Third Switch

[0030] M4: Fourth Switch

[0031] A: Connection Point

[0032] 4: Auxiliary Power Supply

[0033] 5: Linear Voltage Regulator

[0034] 61: First Switching Element

[0035] 62: Second Switching Element

[0036] T4: Auxiliary Winding

[0037] 8: Control Module Detailed Implementation Manner

[0038] Some typical embodiments embodying the features and advantages of the present case will be described in detail in the following description. It should be understood that the present case can have various variations in different aspects, all of which do not depart from the scope of the present case, and the descriptions and drawings therein are for illustrative purposes in essence and not for limiting the present case.

[0039] Please refer to Figure 1, which is the circuit topology diagram of the first embodiment of the power converter in this case. As shown in the figure, the power converter 1 of this embodiment includes an input terminal 21, an output terminal 22, a plurality of conversion units 3, an auxiliary power supply 4, a linear voltage regulator 5, a first switching element 61, and a second switching element 62. The power converter 1 receives an input voltage via the input terminal 21 and outputs an output voltage via the output terminal 22. The power converter 1 of this embodiment includes two conversion units 3. Of course, the number of conversion units 3 can be adjusted according to requirements. Each conversion unit 3 can be, but is not limited to, a resonant converter, a full-bridge circuit, or a flyback circuit, and each conversion unit 3 includes a sub-input terminal 31, a sub-output terminal 32, and an input capacitor Cin. The sub-input terminal 31 of each conversion unit 3 is connected to the input terminal 21 of the power converter 1. In this embodiment, the sub-input terminals 31 of the two conversion units 3 are connected in series and connected to the input terminal 21 of the power converter 1. The sub-output terminal 32 of each conversion unit 3 is connected to the output terminal 22 of the power converter 1. In this embodiment, the sub-output terminals 32 of the two conversion units 3 are connected in parallel and connected to the output terminal 22 of the power converter 1. The input capacitor Cin of each conversion unit 3 is connected to the sub-input terminal 31 of the corresponding conversion unit 3.

[0040] The auxiliary power supply 4 is connected to the input negative terminal in the input terminal 21 of the power converter 1 and is connected to the logic control circuit (not shown) of the power converter 1 to supply power to the logic control circuit. The linear voltage regulator 5 can be, but is not limited to, a low-dropout linear voltage regulator, and is connected to the input positive terminal in the input terminal 21 of the power converter 1 to step down the voltage when receiving the input voltage. The first switching element 61 is a diode and is connected between the second conversion unit 3 and the auxiliary power supply 4. The anode of the first switching element 61 is connected to the input capacitor Cin of the corresponding conversion unit 3, and the cathode of the first switching element 61 is connected to the auxiliary power supply 4. When the voltage on the input capacitor Cin of the second conversion unit 3 is greater than the output voltage of the linear voltage regulator 5, the first switching element 61 conducts, and then the first switching element 61 can transfer the voltage on the input capacitor Cin of the second conversion unit 3 to the auxiliary power supply 4 to supply power to the auxiliary power supply 4. The second switching element 62 is a diode and is connected between the linear voltage regulator 5 and the auxiliary power supply 4. The anode of the second switching element 62 is connected to the linear voltage regulator 5, and the cathode of the second switching element 62 is connected to the auxiliary power supply 4. When the output voltage of the linear voltage regulator 5 (i.e., the voltage at one end connected to the second switching element 62) is greater than the voltage on the input capacitor Cin of the second conversion unit 3, the second switching element 62 conducts, and then the second switching element 62 can transfer the voltage output by the linear voltage regulator 5 to the auxiliary power supply 4 to supply power to the auxiliary power supply 4.

[0041] When any transformation unit 3 is started, an input source (not shown, the voltage of the input source is Vin) charges the input capacitor Cin in the transformation unit 3, and at the same time, the linear voltage regulator 5 steps down the input voltage. At this time, the output voltage of the linear voltage regulator 5 is greater than the voltage on the input capacitor Cin of the second transformation unit 3, so that the first switching element 61 is turned off and the second switching element 62 is turned on, and the input voltage is supplied to the auxiliary power supply 4 via the linear voltage regulator 5 and the second switching element 62. When the input source charges the input capacitor Cin in the transformation unit 3 until the capacitance voltage on the input capacitor Cin in the transformation unit 3 reaches dynamic balance and becomes stable, at this time, the capacitance voltage on the input capacitor Cin is greater than the output voltage of the linear voltage regulator 5, so that the second switching element 62 is turned off and the first switching element 61 is turned on, and at least one transformation unit 3 is used as an energy source to be supplied to the auxiliary power supply 4 via the first switching element 61. In this embodiment, the first switching element 61 is connected to the input capacitor Cin of the second transformation unit 3, and the capacitance on the input capacitor Cin of the second transformation unit 3 is used as an energy source to supply power to the auxiliary power supply 4 via the first switching element 61.

[0042] As can be seen from the above, when any transformation unit 3 of the power converter 1 in this case is started, the first switching element 61 is turned off and the second switching element 62 is turned on, and the input voltage is supplied to the auxiliary power supply 4 via the linear voltage regulator 5 and the second switching element 62; when the capacitance voltage on the input capacitor Cin in the transformation unit 3 reaches dynamic balance and becomes stable, the second switching element 62 is turned off and the first switching element 61 is turned on, and at least one transformation unit 3 is used as an energy source to be supplied to the auxiliary power supply 4 via the first switching element 61. Therefore, compared with the traditional power converter that uses a linear voltage regulator to step down the voltage both at startup and in the steady state, the power converter 1 in this case can use the components in the transformation unit 3 to supply power in the steady state, reducing the loss of the linear voltage regulator 5 and making the overall power converter 1 have higher stability.

[0043] Please continue to refer to Figure 1, each conversion unit 3 of the power converter 1 in this embodiment further includes a first switch M1, a second switch M2, a resonant capacitor Cr, a resonant inductor Lr, a primary winding T1, a first secondary winding T2, a second secondary winding T3, a third switch M3, and a fourth switch M4. The first switch M1 and the second switch M2 are connected in series and are in parallel with the input capacitor Cin, and the connection point between the first switch M1 and the second switch M2 constitutes a connection point A. The resonant capacitor Cr, the resonant inductor Lr, and the primary winding T1 are connected in series between the connection point A and one end of the input capacitor Cin. The first secondary winding T2 and the second secondary winding T3 are connected in series and are mutually coupled with the primary winding T1. The connection point between the first secondary winding T2 and the second secondary winding T3 is connected to the positive output terminal of the sub-output terminal 32, and it is a center-tapped structure. The third switch M3 is connected between the first secondary winding T2 and the negative output terminal of the sub-output terminal 32, and the fourth switch M4 is connected between the second secondary winding T3 and the negative output terminal of the sub-output terminal 32.

[0044] Please refer to Figure 2 , which is the circuit topology diagram of the second embodiment of the power converter in this case. As shown in the figure, the power converter 1a in this embodiment is similar to Figure 1 the power converter 1 shown. Compared with Figure 1 the first switching element 61 of the power converter 1 shown is connected to the input capacitor Cin of the conversion unit 3, the power converter 1a in this embodiment includes an auxiliary winding T4, and the auxiliary winding T4 is mutually coupled with the primary winding T1, the first secondary winding T2, and the second secondary winding T3 of at least one of the two conversion units 3, wherein the first switching element 61 is connected between the auxiliary winding T4 and the auxiliary power supply 4.

[0045] In this embodiment, when any conversion unit 3 is started, the linear voltage regulator 5 simultaneously steps down the input voltage. At this time, the output voltage of the linear voltage regulator 5 is greater than the voltage on the auxiliary winding T4, so that the first switching element 61 is turned off and the second switching element 62 is turned on, and the input voltage is supplied to the auxiliary power supply 4 through the linear voltage regulator 5 and the second switching element 62. When the capacitor voltage on the input capacitor Cin in the conversion unit 3 reaches dynamic balance and is in a steady state, at this time, the voltage on the winding coupled with the auxiliary winding T4 is greater than the output voltage of the linear voltage regulator 5, so that the second switching element 62 is turned off and the first switching element 61 is turned on, and the winding coupled with the auxiliary winding T4 serves as an energy source and is supplied to the auxiliary power supply 4 through the first switching element 61. In some embodiments, the number of the auxiliary windings T4 can be greater than one and is coupled with multiple windings, and the multiple windings coupled with the auxiliary winding T4 serve as energy sources, which will not be elaborated here.

[0046] During actual design, the gains, turns ratios, or topologies of each conversion unit 3 may not be exactly the same. Or, in order to more flexibly match the input voltage received by the power converter, the connection relationships between the sub-input terminals and sub-output terminals of multiple conversion units 3 can be adjusted according to requirements. Please refer to Figure 3 , which is the circuit topology diagram of the third embodiment of the power converter in this case. As Figure 3 shown, the power converter 1b in this embodiment is similar to Figure 1 the power converter 1 shown. Compared with Figure 1 the parallel connection of the sub-output terminals 32 of the two conversion units 3 of the power converter 1 shown, the sub-output terminals 32 of the two conversion units 3 of the power converter 1b in this embodiment are connected in series, enabling the power converter 1b to achieve the function of large current output.

[0047] Please refer to Figure 4 , which is the circuit topology diagram of the fourth embodiment of the power converter in this case. As shown in the figure, the power converter 1c in this embodiment is similar to Figure 1 the power converter 1 shown. Compared with Figure 1 the series connection of the sub-input terminals 31 of the two conversion units 3 of the power converter 1 shown, the sub-input terminals 31 of the two conversion units 3 of the power converter 1c in this embodiment are connected in parallel.

[0048] Please refer to Figure 5 , which is the circuit topology diagram of the fifth embodiment of the power converter in this case. As shown in the figure, the power converter 1d in this embodiment is similar to Figure 1 the power converter 1 shown. Compared with Figure 1 the series connection of the sub-input terminals 31 of the two conversion units 3 and the parallel connection of the sub-output terminals 32 of the two conversion units 3 of the power converter 1 shown, the sub-input terminals 31 of the two conversion units 3 of the power converter 1c in this embodiment are connected in parallel, and the sub-output terminals 32 of the two conversion units 3 are connected in series.

[0049] Of course, in some embodiments, the number of conversion units of the power converter may not only be two, but also greater than two. Please refer to Figure 6 , which is the circuit topology diagram of the sixth embodiment of the power converter in this case. As shown in the figure, the power converter 1e in this embodiment is similar to Figure 1 the power converter 1 shown. Compared with Figure 1The power converter 1 shown includes two conversion units 3, and the power converter 1e of this embodiment includes three conversion units 3. The sub-input terminals 31 of the three conversion units 3 are connected in series in sequence, and the sub-output terminals 32 of the three conversion units 3 are connected in parallel. In this embodiment, the first switching element 61 is connected to the input capacitor Cin of the second conversion unit 3, so that the capacitor voltages on the input capacitor Cin of the second conversion unit 3 and the input capacitor Cin of the third conversion unit 3 are added together, and used as an energy source to supply power to the auxiliary power supply 4 via the first switching element 61.

[0050] In some embodiments, the first switching element and the second switching element can be composed not only of diodes but also of switching tubes. Please refer to Figure 7 , which is the circuit topology diagram of the seventh embodiment of the power converter of this case. As shown in the figure, the power converter 1f of this embodiment is similar to Figure 1 the power converter 1 shown. Compared with Figure 1 the two switching elements of the power converter 1 shown being diodes, the first switching element 61 and the second switching element 62 of the power converter 1f of this embodiment are switching tubes. And the power converter 1f of this embodiment further includes a control module 8, which is connected to the two conversion units 3, the first switching element 61 and the second switching element 62. When the control module 8 confirms that any one of the conversion units 3 is started, it controls the first switching element 61 to turn off and the second switching element 62 to turn on, and when it confirms that the capacitor voltages on the input capacitors Cin in at least one conversion unit 3 reach dynamic balance, it controls the second switching element 62 to turn off and the first switching element 61 to turn on. Of course, the first switching element 61 and the second switching element 62 can also be composed of any electronic device that can switch between short circuit and open circuit. In some embodiments, the control module 8 can also only control the first switching element 61 and the second switching element 62, without controlling the switches in the conversion unit.

[0051] In summary, for the power converter of this case, when any one of the conversion units is started, the first switching element turns off and the second switching element turns on, so that the input voltage is supplied to the auxiliary power supply via the linear voltage regulator and the second switching element; when the capacitor voltages on the input capacitors in the conversion unit reach dynamic balance and are in a steady state, the second switching element turns off and the first switching element turns on, so that at least one conversion unit is used as an energy source to supply power to the auxiliary power supply via the first switching element. Therefore, the power converter of this case can supply power by using the components in the conversion unit in the steady state, reducing the loss of the linear voltage regulator and making the overall power converter have higher stability.

Claims

1. A power converter, comprising: an input terminal and an output terminal, wherein the power converter receives an input voltage via the input terminal and outputs an output voltage via the output terminal; A plurality of conversion units, wherein each of the conversion units comprises a sub-input terminal, a sub-output terminal and an input capacitor, and the sub-input terminal of each of the conversion units is connected to the input terminal to receive the input voltage, the sub-output terminal of each of the conversion units is connected to the output terminal, and the input capacitor of each of the conversion units is connected to the sub-input terminal of the corresponding conversion unit; an auxiliary power supply; a linear regulator connected to the input terminal to step down the voltage when receiving the input voltage; a first switch element connected between at least one of the conversion units and the auxiliary power supply; as well as a second switch element connected between the linear regulator and the auxiliary power supply; When any of the conversion units is started, the first switch element is turned off and the second switch element is turned on, so that the input voltage is provided to the auxiliary power supply via the linear regulator and the second switch element; when a capacitor voltage on the input capacitor in at least one of the conversion units reaches a dynamic balance, the second switch element is turned off and the first switch element is turned on, so that at least one of the conversion units is provided to the auxiliary power supply as an energy source via the first switch element. 2 . The power converter as claimed in claim 1 , wherein the number of the plurality of conversion units is N, and the energy source is formed by the input capacitors of M of the conversion units connected in series, wherein 1≤M≤N. 3 . The power converter as claimed in claim 1 , wherein each of the conversion units comprises a transformer, and the transformer comprises a plurality of windings.

4. A power converter as described in claim 2, wherein the power converter includes an auxiliary winding, the auxiliary winding is coupled to the multiple windings of at least one of the conversion units, the first switching element is connected between the auxiliary winding and the auxiliary power supply, and the energy source is the multiple windings coupled to the auxiliary winding.

5. A power converter as described in claim 2, wherein the power converter includes a plurality of auxiliary windings connected in series, the plurality of auxiliary windings are coupled to the plurality of windings of at least one of the conversion units, the first switching element is connected between the plurality of auxiliary windings and the auxiliary power source, and the energy source is the plurality of windings coupled to the plurality of auxiliary windings.

6. The power converter as claimed in claim 2, wherein the first switch element and the second switch element are diodes respectively, and when the capacitor voltage on the input capacitor in at least one of the conversion units reaches a dynamic balance, the second switch element is turned off and the first switch element is turned on.

7. A power converter as described in claim 2, wherein the first switch element and the second switch element are switch tubes, and the power converter further includes a control module connected to the multiple conversion units, the first switch element and the second switch element, the control module controls the first switch element to be turned off and the second switch element to be turned on when it is confirmed that any of the conversion units is started, and controls the second switch element to be turned off and the first switch element to be turned on when it is confirmed that the capacitor voltage on the input capacitor in at least one of the conversion units reaches a dynamic balance. 8 . The power converter as claimed in claim 1 , wherein the sub-input ends of the plurality of conversion units of the power converter are connected in series, and the sub-output ends of the plurality of conversion units of the power converter are connected in series. 9 . The power converter as claimed in claim 1 , wherein the sub-input ends of the plurality of conversion units of the power converter are connected in parallel, and the sub-output ends of the plurality of conversion units of the power converter are connected in parallel. 10 . The power converter as claimed in claim 1 , wherein the sub-input ends of the plurality of conversion units of the power converter are connected in series, and the sub-output ends of the plurality of conversion units of the power converter are connected in parallel. 11 . The power converter as claimed in claim 1 , wherein the sub-input ends of the plurality of conversion units of the power converter are connected in parallel, and the sub-output ends of the plurality of conversion units of the power converter are connected in series. 12 . The power converter as claimed in claim 1 , wherein each of the conversion units is a resonant converter, a full-bridge circuit or a flyback circuit.

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