阅读说明：本技术 可延长保持时间的电源供应器 (Power supply capable of prolonging holding time ) 是由 方毅雄 于 2018-06-05 设计创作，主要内容包括：一种可延长保持时间的电源供应器,包含一功因校正单元、一LLC谐振转换单元及一检测控制单元。该功因校正单元包含一稳压电容,该LLC谐振转换单元连接该功因校正单元,该LLC谐振转换单元包含一变压器,该变压器具有一初级绕组及一次级绕组,该初级绕组包含一第一子绕组及一与该第一子绕组串联的第二子绕组。该检测控制单元连接该稳压电容,该检测控制单元具有一比较电位,并包含一当该稳压电容电位高于该比较电位时导通该第一子绕组与该第二子绕组的第一模式及一当该稳压电容的电位低于该比较电位时仅导通该第一子绕组的第二模式,于该第二模式,该变压器匝数比与该LLC谐振转换单元的电感比改变,该LLC谐振转换单元电压增益提高而延长保持时间。(A power supply capable of prolonging retention time comprises a power factor correction unit, an LLC resonance conversion unit and a detection control unit. The power factor correction unit comprises a voltage stabilizing capacitor, the LLC resonance conversion unit is connected with the power factor correction unit, the LLC resonance conversion unit comprises a transformer, the transformer is provided with a primary winding and a secondary winding, and the primary winding comprises a first sub-winding and a second sub-winding connected with the first sub-winding in series. The detection control unit is connected with the voltage-stabilizing capacitor, has a comparison potential and comprises a first mode of conducting the first sub-winding and the second sub-winding when the potential of the voltage-stabilizing capacitor is higher than the comparison potential and a second mode of conducting only the first sub-winding when the potential of the voltage-stabilizing capacitor is lower than the comparison potential, and in the second mode, the turn ratio of the transformer and the inductance ratio of the LLC resonance conversion unit are changed, and the voltage gain of the LLC resonance conversion unit is improved to prolong the holding time.)

1. A power supply capable of extending a retention time, comprising:

A power factor correction unit including a voltage-stabilizing capacitor having a voltage-stabilizing potential after being energized;

An LLC resonant converting unit connected to the power factor correcting unit, the LLC resonant converting unit including a bridge switching circuit connected in parallel with the voltage-stabilizing capacitor, a resonant inductor connected to the bridge switching circuit, a resonant capacitor connected in series with the resonant inductor, and a transformer having a primary winding connected in series with the resonant capacitor and a secondary winding magnetically coupled to the primary winding when the primary winding is energized, the primary winding including a first sub-winding and a second sub-winding connected in series with the first sub-winding; and

And the detection control unit is provided with a comparison potential and comprises a first mode for conducting the first sub-winding and the second sub-winding when the voltage stabilization potential is higher than the comparison potential and a second mode for conducting only the first sub-winding when the voltage stabilization potential is lower than the comparison potential, when the detection control unit enters the second mode, the turn ratio of the transformer and the inductance ratio of the LLC resonance conversion unit are changed, and the voltage gain of the LLC resonance conversion unit is improved to prolong the holding time of the power supply.

2. the power supply of claim 1, wherein the first sub-winding has a first input terminal and a first output terminal connected to the second sub-winding, the second sub-winding has a second input terminal connected to the first output terminal and a second output terminal connected to a power reference point of the LLC resonant converting unit, the detection control unit has a first switch connecting the first output terminal, the second input terminal and the power reference point, the first switch short-circuits the second sub-winding only to make the first sub-winding conductive when the detection control unit enters the second mode.

3. The power supply of claim 2, wherein the first switch is a relay, a bjt, a fet, an igbt, a thyristor, or a turn-off thyristor.

4. a power supply as claimed in any one of claims 1 to 3, wherein the power factor correction unit has a thermistor connected in series with the voltage-stabilizing capacitor, the detection control unit has a second switch connected in parallel with the thermistor, the detection control unit turns on the second switch to short-circuit the thermistor in the first mode, and the detection control unit turns off the second switch in the second mode to enable the thermistor to eliminate inrush current into the power factor correction unit.

5. The power supply of claim 4, wherein the second switch is a relay, a BJT, a FET, an IGBT, a thyristor, or a turn-off thyristor.

6. The power supply of claim 4, wherein the power supply has a rectifying input unit connected to the power factor correction unit and to an AC power source.

7. The power supply of claim 6, wherein the power supply has a rectifying output unit connected to the secondary winding of the transformer.

Technical Field

the present invention relates to a power supply, and more particularly, to a power supply capable of extending Hold-up Time.

Background

in order to respond to the sudden interruption of the ac power source, the conventional power supply has a function of continuously supplying power for a period of time even when the ac power source is suddenly interrupted, so that the load can complete necessary storage or control actions and can be safely shut down. The working Time of the above-mentioned sustainable power supply is referred to as Hold-up Time (Hold-up Time). However, as the demand for power supply stability increases, the retention time of the power supply is also required to be prolonged, and the retention time of the power supply of the computer must be more than 17 ms under the rated power output of the power supply of the computer, which is more standardized by intel corporation.

Patent technologies for prolonging the retention time include CN101420175, TW I562514, TW I542124, TW I439036, and the like.

Furthermore, it is a well-established and popular technology to apply the LLC resonant converter to the power supply. However, the retention time is proportional to the capacitance of a voltage-stabilizing capacitor disposed in the power factor correction circuit and the voltage gain of the LLC resonant converter, but the capacitance of the voltage-stabilizing capacitor is proportional to the volume of the voltage-stabilizing capacitor, so that the power supply has a limitation of size specification, and the voltage-stabilizing capacitor cannot be selected at will and is limited.

Moreover, the inductance ratio of the LLC resonant converter is the ratio of transformer excitation inductance to resonant inductance, and the LLC resonant converter has a lower excitation current at a higher inductance ratio, thereby reducing line loss and improving LLC resonant converter efficiency. However, the high inductance ratio has a problem of low voltage gain, which shortens the holding time. In contrast, LLC resonant converters have a low inductance ratio, which in particular extends the hold-up time, but a low inductance ratio has a high excitation current, resulting in high line losses and a reduced overall efficiency. On the other hand, the turn ratio of the transformer is the ratio of the turns of the primary winding to the turns of the secondary winding, the voltage gain of the LLC resonant converter is more inversely proportional to the turn ratio of the transformer, and the reduction of the turn ratio of the transformer can improve the voltage gain of the LLC resonant converter, but also causes larger line loss on the primary side of the transformer. Therefore, if the transformer turns ratio is increased to reduce the line loss on the primary side of the transformer, it will be disadvantageous to the modulation design of the LLC resonant converter when the input voltage varies in a wide range.

Disclosure of Invention

The main objective of the present invention is to solve the problem that the efficiency of the power supply will be reduced once the retention time is extended in the conventional architecture.

To achieve the above objective, the present invention provides a power supply capable of prolonging a retention time, the power supply comprising a power factor correction unit, an LLC resonance converting unit and a detection control unit. The power factor correction unit comprises a voltage-stabilizing capacitor, and the voltage-stabilizing capacitor has a voltage-stabilizing potential after being electrified. The LLC resonant conversion unit is connected with the power factor correction unit, the LLC resonant conversion unit comprises a bridge switch circuit connected in parallel with the voltage-stabilizing capacitor, a resonant inductor connected with the bridge switch circuit, a resonant capacitor connected in series with the resonant inductor, and a transformer, the transformer is provided with a primary winding connected in series with the resonant capacitor and a secondary winding magnetically coupled with the primary winding after the primary winding is electrified, and the primary winding comprises a first sub-winding and a second sub-winding connected in series with the first sub-winding. The detection control unit is connected with the voltage-stabilizing capacitor to receive the voltage-stabilizing potential, the detection control unit has a comparison potential and comprises a first mode of conducting the first sub-winding and the second sub-winding when the voltage-stabilizing potential is higher than the comparison potential and a second mode of conducting only the first sub-winding when the voltage-stabilizing potential is lower than the comparison potential, when the detection control unit enters the second mode, the transformer turn ratio and the inductance ratio of the LLC resonance conversion unit are changed, and the voltage gain of the LLC resonance conversion unit is improved to prolong the holding time of the power supply.

In one embodiment, the first sub-winding has a first input terminal and a first output terminal connected to the second sub-winding, the second sub-winding has a second input terminal connected to the first output terminal and a second output terminal connected to the power reference point of the LLC resonant conversion unit, the detection control unit has a first switch connected to the first output terminal, the second input terminal and the power reference point, the first switch short-circuits the second sub-winding when the detection control unit enters the second mode, and only makes the first sub-winding conductive.

In one embodiment, the first switch is a relay, a bipolar junction transistor, a field effect transistor, an insulated gate bipolar transistor, a thyristor, or a turn-off thyristor.

In one embodiment, the power factor correction unit has a thermistor connected in series with the voltage stabilizing capacitor, the detection control unit has a second switch connected in parallel with the thermistor, the detection control unit turns on the second switch to short-circuit the thermistor in the first mode, and the detection control unit turns off the second switch in the second mode to enable the thermistor to eliminate a surge current entering the power factor correction unit.

In one embodiment, the second switch is a relay, a bipolar junction transistor, a field effect transistor, an insulated gate bipolar transistor, a thyristor, or a turn-off thyristor.

In one embodiment, the power supply has a rectifying input unit connected to the power factor correction unit and to an ac power source.

In one embodiment, the power supply has a rectified output unit connected to the secondary winding of the transformer.

Compared with the prior art, the invention has the following characteristics: when the Hold Time (Hold-up Time) needs to be prolonged, the power supply changes the inductance ratio of the LLC resonance conversion unit and the turn ratio of the transformer at the same Time, thereby achieving the purpose of prolonging the Hold Time under the condition of not losing the efficiency of the LLC resonance conversion unit. In addition, the detection control unit can control the thermistor for surge protection, so that the power supply can simultaneously achieve the purpose of protecting the whole circuit without adding an additional detection circuit, and the circuit is prevented from being complicated.

Drawings

Fig. 1 is a schematic diagram of a unit composition according to an embodiment of the present invention.

Fig. 2 is a schematic circuit diagram of a detection control unit in a first mode according to an embodiment of the present invention.

FIG. 3 is a partial circuit diagram according to an embodiment of the present invention.

Fig. 4 is a circuit diagram illustrating a detection control unit in a second mode according to an embodiment of the invention.

FIG. 5 is a schematic diagram of a voltage stabilization timing sequence according to an embodiment of the invention.

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Detailed Description

The present invention is described in detail and technical content with reference to the accompanying drawings, wherein:

Referring to fig. 1 to 5, the present invention provides a power supply 100 capable of extending a retention time, wherein the power supply 100 at least includes a power factor correction unit 10, an LLC resonant conversion unit 11, and a detection control unit 13. The Power Factor Correction unit 10 is a PFC Circuit (Power Factor Correction Circuit) in the art, and further, the Power Factor Correction unit 10 may be implemented as an interleaved Power Factor Correction Circuit, a bridgeless Power Factor Correction Circuit, or other circuits with Power Factor adjustment function. The power factor correction unit 10 further includes a voltage stabilizing capacitor 101, when the power factor correction unit 10 receives power, the voltage stabilizing capacitor 101 is powered on to have a voltage stabilizing potential 102, the voltage stabilizing potential 102 changes according to whether the power factor correction unit 10 is powered on, when the power factor correction unit 10 normally obtains power, the voltage stabilizing capacitor 101 is charged and finally kept at a high point potential 103, otherwise, when the power factor correction unit 10 cannot obtain power required by the power factor correction unit, the voltage stabilizing capacitor 101 starts to discharge, and the voltage stabilizing potential 102 starts to fall. Referring back to fig. 5, when the regulated voltage level 102 drops to a low point level 104, the regulated voltage level 102 cannot maintain the normal output voltage of the LLC resonant conversion unit 11 to complete the necessary storage or control of the load, and the load is shut down safely. Further, the Hold Time 20(Hold-up Time) herein refers to the Time that the regulated voltage potential 102 is discharged from the high point potential 103 to the low point potential 104.

The LLC resonance conversion unit 11 is connected to the power factor correction unit 10 to receive the power transmitted by the power factor correction unit 10. The LLC resonant converting unit 11 includes a bridge switch circuit 111 connected in parallel with the voltage stabilizing capacitor 101, a resonant inductor 112 connected to the bridge switch circuit 111, a resonant capacitor 113 connected in series with the resonant inductor 112, and a transformer 114. The bridge switch circuit 111 may be a half-bridge switch circuit or a full-bridge switch circuit, and the half-bridge switch is illustrated in the drawings, but the disclosure is not limited thereto. Moreover, the power supply 100 may further have a pulse control unit 14 connected to the bridge switch circuit 111, and the pulse control unit 14 outputs a driving signal to the plurality of switch elements 115 belonging to the bridge switch circuit 111 when the power supply 100 is started, so that the switch elements 115 operate according to the driving signal.

On the other hand, referring back to fig. 2 and 3, the transformer 114 has a primary winding 116 connected in series with the resonant capacitor 113 and a secondary winding 117 magnetically coupled to the primary winding 116 when the primary winding 116 is energized. The primary winding 116 and the secondary winding 117 are respectively wound around an iron core (not shown), and the primary winding 116 and the secondary winding 117 are magnetically coupled by the iron core. Further, the present invention completes the LLC resonant converting unit 11 with the resonant inductor 112, the resonant capacitor 113 and the primary winding 116 of the transformer 114. In addition, the transformer 114 of the present invention employs a series sandwich winding method to wind the primary winding 116, so that the primary winding 116 has a plurality of outlet nodes, i.e. the primary winding 116 includes a first sub-winding 118 and a second sub-winding 119 connected in series with the first sub-winding 118. More specifically, the first sub-winding 118 has a first input end 120 and a first output end 121 connected to the second sub-winding 119, and the second sub-winding 119 has a second input end 122 connected to the first output end 121 and a second output end 124 connected to the power reference point 123 of the LLC resonant conversion unit 11. Wherein the power reference point 123 is a reference potential of the LLC resonant conversion unit 11, and in one embodiment, the power reference point 123 can be regarded as Ground (GND).

Furthermore, the detection control unit 13 is connected to the voltage-stabilizing capacitor 101 to obtain the voltage-stabilizing potential 102, and the detection control unit 13 is further connected to the primary winding 116 to control the conduction states of the first sub-winding 118 and the second sub-winding 119 according to the voltage-stabilizing potential 102. The detection control unit 13 may be a Microchip (MCU), a comparator circuit, or other circuit scheme capable of achieving detection control, and the detection control unit 13 may operate with the standby power (5VSB) generated by the power supply 100 or operate as the operation power of the detection control unit 13 by using the power internally generated by the power supply 100. The detection control unit 13 has a comparison potential 131, the comparison potential 131 is set before implementation, the comparison potential 131 is set to be smaller than the regulated potential 102 of the regulated capacitor 101 when the power supply 100 can normally obtain power from an ac power source 15 (i.e. the comparison potential 131 is lower than the high point potential 103 of the regulated potential 102), and the comparison potential 131 is also set to be larger than the regulated potential 102 when the regulated capacitor 101 cannot make the LLC resonant conversion unit 11 maintain normal output voltage to the load (i.e. the comparison potential 131 is higher than the low point potential 104 of the regulated potential 102), and the potential value of the comparison potential 131 can be adjusted according to actual requirements, and is not limited herein. Accordingly, the detection control unit 13 includes a first mode for turning on the first sub-winding 118 and the second sub-winding 119 when the regulated voltage potential 102 is higher than the comparison potential 131, and a second mode for turning on only the first sub-winding 118 when the regulated voltage potential 102 is lower than the comparison potential 131. More specifically, the detection control unit 13 has a first switch 132 connecting the first output terminal 121, the second input terminal 122 and the power reference point 123, and the first switch 132 short-circuits the second sub-winding 119 when the detection control unit 13 enters the second mode, so as to only turn on the first sub-winding 118. Further, the first switch 132 is a Relay (Relay), a Bipolar Junction Transistor (BJT), a Field Effect Transistor (FET), an Insulated Gate Bipolar Transistor (IGBT), a thyristor (SCR), or a turn-off thyristor (GTO).

Referring back to fig. 2 and 5, the power factor correction unit 10 is described in a state where it can normally obtain power from the ac power source 15 for operation. In this state, the voltage-stabilizing capacitor 101 normally receives power, the voltage-stabilizing potential 102 is greater than the comparison potential 131, the detection control unit 13 enters the first mode, the first switch 132 is in an open state, and the first sub-winding 118 and the second sub-winding 119 are both turned on. At this time, the number of turns of the primary winding 116 is equal to the number of turns of the first sub-winding 118 plus the number of turns of the second sub-winding 119. On the other hand, referring to fig. 4 and fig. 5, when the power supply 100 cannot normally obtain power from the ac power source 15, the voltage-stabilizing capacitor 101 starts to discharge, and the voltage-stabilizing potential 102 gradually decreases. Meanwhile, once the regulated voltage potential 102 is lower than the comparison potential 131, the detection control unit 13 switches from the first mode to the second mode, the first switch 132 is turned on to connect the first output terminal 121 and the second input terminal 122 to the power reference point 123, and the second sub-winding 119 is therefore short-circuited, so that the number of turns of the primary winding 116 is equal to that of the first sub-winding 118. In this way, in addition to the reduction of the turn ratio of the transformer 114, the inductance ratio of the LLC resonant conversion unit 11 is also reduced, so that the voltage gain of the LLC resonant conversion unit 11 is increased, the power supply 100 can prolong the time of outputting power, thereby achieving the purpose of prolonging the holding time of the power supply 100, and the electronic components connected to the power supply 100 have more time to perform a normal shutdown procedure. In addition, the implementation of the present invention further preserves the high efficiency of the LLC resonant conversion unit 11 in the first mode of operation.

Referring to fig. 2 and 4 again, the surge current (also called surge current) generated at the moment of recovery of the ac power source 15 is avoided. In one embodiment, the power factor correction unit 10 has a thermistor 105 connected in series with the voltage-stabilizing capacitor 101, the detection control unit 13 has a second switch 133 connected in parallel with the thermistor 105, and the second switch 133 can also be a Relay (Relay), a Bipolar Junction Transistor (BJT), a Field Effect Transistor (FET), an Insulated Gate Bipolar Transistor (IGBT), a thyristor (SCR) or a turn-off thyristor (GTO). The second switch 133 is controlled by the detection control unit 13, and the thermistor 105 is in a short-circuited state when the second switch 133 is turned on, and the thermistor 105 is in an un-short-circuited state when the second switch 133 is turned off. Further, the detection control unit 13 turns on the second switch 133 in the first mode to short-circuit the thermistor 105 to reduce the line loss, and the detection control unit 13 turns off the second switch 133 in the second mode to make the thermistor 105 eliminate the inrush current entering the power factor correction unit 10. Therefore, the power supply 100 can achieve the purpose of protecting the whole circuit without adding an additional detection circuit, thereby avoiding the circuit complexity. Furthermore, although the thermistor 105 disclosed in the present invention is connected in series with the voltage stabilizing capacitor 101, the position disclosed in the drawings is not limited thereto.

Referring to fig. 1 and 2, the power supply 100 may further include a rectifying input unit 16 connected to the power factor correction unit 10 and connected to the ac power source 15, and a rectifying output unit 17 connected to the secondary winding 117 of the transformer 114, in addition to the aforementioned units. Furthermore, in an embodiment, if the power factor correction unit 10 is a bridgeless power factor correction circuit, the power supply 100 does not need to have the rectifying input unit 16. Accordingly, the rectification output unit 17 may further include a power modulation function, such as synchronous rectification, so that the power supply 100 can output ATX-standard power.