TWI709295B - Control circuit having extend hold-up time and conversion system having extend hold-up time - Google Patents

Abstract

A control circuit having extend hold-up time is coupled to a bus path of a conversion circuit, and the control circuit includes a bypass circuit, an energy-storage capacitor and an auxiliary power supply circuit. The auxiliary power supply circuit supplies an energy-storage voltage to the storage capacitor according to an operating voltage provided by the conversion circuit. When a bus voltage of the bus path is less than or equal to the energy-storage voltage, the energy-storage voltage is supplied to the bus path through the bypass circuit, so that the bus voltage is greater than or equal to a predetermined voltage during a hold-up time.

Description

Control circuit with extended maintenance time and conversion system with extended maintenance time Unify

The present invention relates to a control circuit with prolonged maintenance time, in particular to a control circuit with prolonged maintenance time that maintains a voltage greater than or equal to a predetermined voltage during the maintenance time.

In recent years, as electronic products have become more and more popular, and in order to stably supply the power quality of the operation of electronic products, the power supply requirements for power supply devices have gradually increased along with the popularity of electronic products and their emphasis on power quality. The safety regulations of the power supply device stipulate that if the power supply device is powered off when the power supply device is supplying power to the electronic product, the power supply device must still maintain the power supply device to continuously output power for a short period of time.

In order to meet the requirements of safety regulations, a common practice is to increase the capacity of the energy storage capacitor at the output end of the power supply device. When the capacity of the energy storage capacitor is larger, the maintenance time can be maintained for a long time, and it can meet the requirements of safety regulations. However, this method will cause the volume of the energy storage capacitor to increase due to the increased capacity of the energy storage capacitor required. In addition, since the energy storage capacitor is directly coupled to the live terminal and the ground terminal of the output terminal of the power supply device, the withstand voltage of the energy storage capacitor must also be greater than the output voltage of the output terminal of the power supply device (for example, but not limited to, 400V) , To avoid the energy storage capacitor from being damaged due to insufficient withstand voltage. However, increasing the withstand voltage of the energy storage capacitor also means that the volume of the energy storage capacitor becomes larger.

Therefore, how to design a control circuit with extended maintenance time and a conversion system with extended maintenance time? In addition to using the control circuit to control the energy storage capacitor to extend the maintenance time, a special structure design can be used to reduce the energy storage capacitor Withstand voltage, thereby reducing the volume of energy storage capacitors and saving costs, are important topics studied by the creators of this case.

In order to solve the above-mentioned problems, the present invention provides a control circuit with extended maintenance time to overcome the problems of the prior art. Therefore, the control circuit with extended maintenance time of the present invention is coupled to the bus path of the conversion circuit, and the control circuit includes a bypass circuit coupled to the live terminal of the bus path. The energy storage capacitor includes a first terminal and a second terminal. The first terminal is coupled to the bypass circuit, and the second terminal is coupled to the ground terminal of the bus path. And the auxiliary power circuit is coupled to the bypass circuit and the conversion circuit. Among them, the auxiliary power supply circuit provides energy storage voltage to the energy storage capacitor according to the operating voltage provided by the conversion circuit; when the bus voltage of the bus path is less than or equal to the energy storage voltage, the energy storage voltage is provided to the bus path through the bypass circuit, so that the bus voltage The voltage is greater than or equal to the predetermined voltage during the maintenance time.

In an embodiment, the auxiliary power supply circuit includes a conversion unit coupled to the conversion circuit. The voltage stabilizing circuit is coupled to the conversion unit. And the charging path is coupled to the voltage stabilizing circuit, the energy storage capacitor and the bypass circuit. Among them, the conversion unit converts the working voltage into an auxiliary voltage, and the voltage stabilizing circuit generates a regulated voltage according to the auxiliary voltage; the regulated voltage conducts the charging path, and the regulated voltage charges the energy storage capacitor through the charging path, so that the energy storage capacitor establishes a storage capacity. Energy voltage: When the bus voltage is less than or equal to the energy storage voltage, the energy storage voltage is provided to the bus path through the bypass circuit.

In one embodiment, the conversion unit is an induction coil, and the induction coil is coupled to a transformer of the conversion circuit, and the working voltage of the transformer is converted into an auxiliary voltage by means of electromagnetic coupling.

In one embodiment, the conversion unit is a switching power converter, which is coupled to the bus path, and uses the bus voltage as the working voltage to convert the working voltage into the auxiliary voltage.

In one embodiment, the conversion unit is a linear power converter, and the linear power converter is coupled to the bus path and uses the bus voltage as the working voltage to convert the working voltage into the auxiliary voltage.

In one embodiment, the conversion circuit includes an AC-DC converter; the conversion unit is coupled to the AC-DC converter, and obtains a working voltage according to the operation of the AC-DC converter to convert the working voltage into an auxiliary voltage.

In one embodiment, the conversion circuit includes a DC-DC converter; the conversion unit is coupled to the DC-DC converter, and obtains a working voltage according to the operation of the DC-DC converter to convert the working voltage into an auxiliary voltage.

In one embodiment, the bypass circuit is a first diode; when the bus voltage is less than or equal to the energy storage voltage, the first diode is forward biased, and when the bus voltage is greater than the energy storage voltage, the first diode is Reverse bias.

In an embodiment, the bypass circuit includes a voltage detection circuit coupled to the bus path. The control unit is coupled to the voltage detection circuit. The switch unit is coupled to the bus path, the energy storage capacitor and the control unit. Among them, the voltage detection circuit detects the voltage signal of the bus voltage, and the control unit determines whether the switch unit is turned on according to the voltage signal; when the switch unit is turned on, the energy storage voltage supplements the bus voltage through the switch unit.

In one embodiment, the auxiliary power circuit further includes a current limiting resistor, which is coupled to the voltage stabilizing circuit and the charging path. Among them, the current-limiting resistor limits the charging current for charging the energy storage capacitor.

In one embodiment, the auxiliary power circuit further includes a transistor, which is coupled to the voltage stabilizing circuit. The thyristor unit is coupled to the voltage stabilizing circuit and the transistor. And current detection resistor, coupled to transistor and thyristor unit. The thyristor unit controls the transistor to provide a charging current with a fixed current value to charge the energy storage capacitor according to the voltage across the current detection resistor.

In one embodiment, the current adjustment unit formed by the transistor, the thyristor unit and the current detection resistor is the charging path.

In one embodiment, the charging path is a diode element.

In one embodiment, the energy storage voltage is the regulated voltage minus the switch-on voltage of the charging path.

In one embodiment, the auxiliary power supply circuit further includes: a voltage stabilizing unit coupled to the voltage stabilizing circuit, the charging path and the energy storage capacitor. Among them, the voltage stabilizing unit limits the gate voltage of the charging path to be less than or equal to the rated voltage.

In one embodiment, the withstand voltage of the energy storage capacitor is less than the maximum voltage of the bus voltage.

In an embodiment, the auxiliary power circuit further includes: a second diode coupled to the voltage stabilizing circuit and the charging path. Wherein, when the bus voltage is less than the regulated voltage, the second diode is forward biased, so that the regulated voltage is released to the bus path.

In order to solve the above problems, the present invention provides a conversion system to overcome the problems of the prior art. Therefore, the conversion system of the present invention includes: a conversion circuit, including: a first-stage conversion unit, which converts the input power to the bus voltage. And the second-level conversion unit, coupled to the first-level conversion unit through the bus path, and convert the bus voltage into an output power. And a control circuit, coupled to the bus path, and including a bypass circuit, coupled to the live terminal of the bus path. The energy storage capacitor includes a first terminal and a second terminal. The first terminal is coupled to the bypass circuit, and the second terminal is coupled to the ground terminal of the bus path. And the auxiliary power circuit is coupled to the bypass circuit and the conversion circuit. Among them, the auxiliary power supply circuit provides the energy storage voltage to the energy storage capacitor according to the operating voltage provided by the conversion circuit; when the bus voltage of the bus path is less than or equal to the energy storage voltage, the energy storage The voltage is provided to the bus path through the bypass circuit, so that the bus voltage is greater than or equal to the predetermined voltage within the maintenance time.

In order to further understand the technology, means and effects of the present invention to achieve the intended purpose, please refer to the following detailed description and drawings of the present invention. I believe that the purpose, features and characteristics of the present invention can be obtained from this in depth and For specific understanding, however, the accompanying drawings are only provided for reference and illustration, and are not intended to limit the present invention.

100: Conversion system

10: Conversion circuit

12: The first level conversion unit

14: The second level conversion unit

142: Transformer

N: induction coil

16: bus path

162: Fireside

164: Ground terminal

20: Control circuit

22, 22’: Bypass circuit

222: Voltage detection circuit

224: control unit

226: switch unit

D1: The first diode

24: Energy storage capacitor

242: first end

244: second end

26: auxiliary power circuit

262, 262’, 262": conversion unit

Dr: rectifier unit

Qp: Power switch

264: voltage regulator circuit

R1: first resistance

ZD1: The first voltage stabilizing unit

266: charging path

D: Dip pole

S: source

G: Gate

268, 268’: Current adjustment unit

Rs: current limiting resistor

Qt: Transistor

C: Collector

B: base

E: emitter

U1: thyristor unit

X: Input

Y: output

Z: control end

Ri: Current detection resistance

ZD2: The second voltage stabilizing unit

D2: The second diode

200: load

Vin: input power

Vo: output power

Vbus: bus voltage

Vw: working voltage

Vs: energy storage voltage

Va: auxiliary voltage

Vr: Regulated voltage

Vgs(th): Switch on voltage

Vg: Gate voltage

Vzd: rated voltage

Ic: charging current

Sv: Voltage signal

Fig. 1 is a circuit block diagram of the conversion system with extended sustain time of the present invention; Fig. 2 is a circuit block diagram of the auxiliary power circuit of the present invention; Fig. 3A is a circuit block diagram of the first embodiment of the conversion unit of the present invention; Fig. 3B is Fig. 3C is a circuit block diagram of the third embodiment of the conversion unit of the present invention; Fig. 4A is a circuit block diagram of the first embodiment of the bypass circuit of the present invention; 4B is a circuit block diagram of the second embodiment of the bypass circuit of the present invention; FIG. 5 is a detailed circuit structure diagram of the auxiliary power circuit of the present invention; FIG. 6A is a circuit structure diagram of the first embodiment of the current adjustment unit of the present invention; and 6B is a circuit structure diagram of the second embodiment of the current adjustment unit of the present invention.

The technical content and detailed description of the present invention are described as follows in conjunction with the drawings: Please refer to FIG. 1 for a circuit block diagram of the conversion system with extended sustaining time of the present invention. The conversion system 100 includes a conversion circuit 10 and a control circuit 20 with extended maintenance time. The conversion circuit 10 includes a first-level conversion unit 12, a second-level conversion unit 14 and a bus path 16. The first-level conversion unit 12 receives the input power Vin, and is coupled to the second-level conversion unit 14 through the bus path 16, and the second-level conversion unit 14 is coupled to the load 200. The input power Vin can be AC power or DC power. If the input power Vin is AC power, the first-stage conversion unit 12 is an AC-DC converter. If the input power Vin is DC power, the first-stage conversion unit 12 is DC -DC converter. The second-level conversion unit 14 is similar to the first-level conversion unit 12, and can be a DC-AC converter or a DC-DC converter. The first-level conversion unit 12 converts the input power Vin into a bus voltage Vbus, and provides the bus voltage Vbus to the second-level conversion unit 14 through the bus path 16. The second-level conversion unit 14 converts the bus voltage Vbus into the output power Vo, and provides the output power Vo to the load 200. It is worth mentioning that, in an embodiment of the present invention, the conversion circuit 10 can be a power supply or a power supply device.

The control circuit 20 is coupled to the second-level conversion unit 14, the live terminal 162 and the ground terminal 164 (ie, the ground terminal) of the bus path 16, and includes a bypass circuit 22, an energy storage capacitor 24 and an auxiliary power circuit 26. Specifically, the bypass circuit 22 is coupled to the live terminal 162 of the bus path 16 and the first terminal 242 of the energy storage capacitor 24, and the second terminal 244 of the energy storage capacitor 24 is coupled to the ground terminal 164. The auxiliary power circuit 26 is coupled to the bypass circuit 22 and the conversion circuit 10 and receives the working voltage Vw provided by the conversion circuit 10. When the conversion circuit 10 normally converts the input power Vin to the output power Vo, the auxiliary power circuit 26 converts the working voltage Vw into the energy storage voltage Vs, and provides the energy storage voltage Vs to the energy storage capacitor 24, so that the energy storage capacitor 24 The energy storage voltage Vs is established at the two ends (242, 244) of the. When the conversion circuit 10 is abnormal (for example, but not limited to, the input power Vin is cut off or the first-level conversion unit 12 is damaged), the bus voltage Vbus will gradually decrease. When the bus voltage Vbus decreases to less than or equal to the energy storage voltage Vs, the energy storage voltage Vs is provided to the bus path 16 through the bypass circuit 22 to supplement the shortage of the bus voltage Vbus. Therefore, the bus voltage Vbus can be maintained at a voltage greater than or equal to a predetermined voltage during the hold up time. The predetermined voltage may be the minimum input voltage required for the normal operation of the second-level conversion unit 14.

Furthermore, as shown in FIG. 1, since the first end 242 of the energy storage capacitor 24 is not coupled to the live terminal 162 of the bus path 16, the capacitor withstand voltage design of the energy storage capacitor 24 need not be limited to at least equal to The maximum value of the bus voltage Vbus is based on the design point voltage of the auxiliary power circuit 26 to select the capacitor withstand voltage of the energy storage capacitor 24. Since the design point voltage of the auxiliary power circuit 26 can be much smaller than the bus voltage Vbus, the volume of the energy storage capacitor 24 can be greatly reduced, so as to greatly improve the capacitance utilization of the energy storage capacitor 24. It is worth mentioning that, in one embodiment of the present invention, the capacitance withstand voltage of the storage capacitor 24 can be less than the maximum voltage of the bus voltage Vbus, and can also be a stable or unstable voltage, but will not exceed the voltage of the bus voltage Vbus. Maximum value. In addition, in an embodiment of the present invention, the control circuit 20 may be included in the primary or secondary side of the first-level conversion unit 12 or inside the second-level conversion unit 14, or may not be included in the conversion circuit 10. .

Please refer to FIG. 2 for the circuit block diagram of the auxiliary power circuit of the present invention, and refer to FIG. 1 for complex cooperation. The auxiliary power supply circuit 26 includes a conversion unit 262, a voltage stabilizing circuit 264, and a charging path 266. The conversion unit 262 is coupled to the conversion circuit 10 and receives the working voltage Vw provided by the conversion circuit 10. The voltage stabilizing circuit 264 is coupled to the conversion unit 262 and the charging path 266, and the charging path 266 is coupled to the energy storage capacitor 24 and the bypass circuit 22. The conversion unit 262 converts the working voltage Vw into an auxiliary voltage Va, and provides the auxiliary voltage Va to the voltage stabilizing circuit 264. The voltage stabilizing circuit 264 generates a regulated voltage Vr according to the auxiliary voltage Va, and the regulated voltage Vr conducts the charging path 266. At this time, the voltage stabilizing circuit 264 generates a charging current Ic according to the voltage difference between the regulated voltage Vr and the energy storage capacitor 24, and charges the energy storage capacitor 24 through the charging path 266, so that the two ends (242, 244) of the energy storage capacitor 24 are established Energy storage voltage Vs. When the energy storage voltage Vs is charged to the regulated voltage Vr minus the switch-on voltage Vgs(th) of the charging path 266, the energy storage voltage Vs and the regulated voltage Vr are balanced, and the stabilizing circuit 264 stops charging the energy storage capacitor 24. Therefore, the size of the energy storage voltage Vs is determined by the regulated voltage Vr. When the bus voltage Vbus is less than or equal to the energy storage voltage Vs, the energy storage voltage Vs is provided to the bus path 16 through the bypass circuit 22.

Please refer to FIG. 3A for the circuit block diagram of the first embodiment of the conversion unit of the present invention, and refer to FIGS. 1 and 2 for compound cooperation. Taking the second-level conversion unit 14 as an isolated converter as an example, the second-level conversion unit 14 includes a transformer 142. The conversion unit 262 is an induction coil N, and the induction coil N is coupled to the transformer 142. When the second-stage conversion unit 14 is normal, the transformer 142 generates a working voltage Vw, and the working voltage Vw is converted into an auxiliary voltage Va by means of electromagnetic coupling and the relationship between the induction coil N and the winding ratio of the transformer 142. It is worth mentioning that in an embodiment of the present invention, if the auxiliary voltage Va induced by the induction coil N is not a stable DC source, it can be rectified into a stable DC source by the rectifier unit Dr as shown in FIG. 3A.

Please refer to FIG. 3B for the circuit block diagram of the second embodiment of the conversion unit of the present invention, and refer to FIGS. 1 to 3A for complex cooperation. The difference between the conversion unit 262' of this embodiment and the conversion unit 262 of FIG. 3A is that the conversion unit 262' is a switching or linear power converter. The switching power converter can be, for example, a booster, a buck, or other converters. The purpose is to provide a set of power converters with a designable voltage range, and the switching power converter is coupled to the bus path 16. Since the conversion unit 262' is coupled to the bus path 16, the conversion unit 262' uses the bus voltage Vbus as the working voltage Vw, and uses the internal power switch Qp of the conversion unit 262' to switch the working voltage Vw into the auxiliary voltage Va. .

Please refer to FIG. 3C, which is a circuit block diagram of the third embodiment of the conversion unit of the present invention, and in conjunction with FIGS. The difference between the conversion unit 262" of this embodiment and the conversion unit 262 of FIG. 3A is that the conversion unit 262" is coupled to the first-stage conversion unit 12, and the first-stage conversion unit 12 is an AC-DC converter or a DC-DC converter . When the first-stage conversion unit 12 is an AC-DC converter, the input power Vin received by the first-stage conversion unit 12 is an AC power source, and the conversion unit 262" is coupled to the DC after the internal bridge rectifier of the AC-DC converter Terminal, and obtain the working voltage Vw according to the operation of the AC-DC converter, and use the internal power switch (not shown) of the conversion unit 262" to switch the working voltage Vw into the auxiliary voltage Va. When the first-stage conversion unit 12 is a DC-DC converter, the input power Vin received by the first-stage conversion unit 12 is a DC power source, and the conversion unit 262" is coupled to any DC terminal inside the DC-DC converter , And the working voltage Vw is obtained according to the operation of the DC-DC converter, and the working voltage Vw is converted into the auxiliary voltage Va by means of high-frequency switching of the internal power switch (not shown) of the conversion unit 262".

It is worth mentioning that, in an embodiment of the present invention, the implementation of the conversion unit 262 is not limited to the above-mentioned FIGS. 3A, 3B, and 3C. For example, the types of conversion units that can obtain a stable DC source, and the coupling points of the conversion units, All should be included in the scope of this embodiment. For example, but not limited to, the conversion unit 262 may also be a linear power converter (not shown). A linear power converter (not shown) is coupled to the bus path 16 or the first-stage conversion unit 12, and uses the bus voltage Vbus or the DC voltage inside the first-stage conversion unit 12 as the working voltage Vw to convert the working voltage Vw to a linear The conversion method is converted into auxiliary voltage Va. In addition, in an embodiment of the present invention, the conversion unit 262" of FIG. 3C may also be coupled to the second-level conversion unit 14 (meaning that the second-level conversion unit 14 is also a DC-DC converter), And the operating voltage Vw is obtained according to the operation of the second-level conversion unit 14. The difference from FIG. 3A is that the conversion unit 262" does not need to obtain the operating voltage Vw in the electromagnetic coupling manner of FIG. 3A, but is coupled to the second-level conversion Any DC terminal inside the unit 14 is obtained.

Please refer to FIG. 4A for the circuit block diagram of the first embodiment of the bypass circuit of the present invention, and refer to FIGS. 1 to 3B for complex cooperation. The bypass circuit 22 is a first diode D1, and the anode of the first diode D1 is coupled to the energy storage capacitor 24, and the cathode of the first diode D1 is coupled to the bus path 16. When the bus voltage Vbus is less than or equal to the energy storage voltage Vs, the first diode D1 is forward biased, so that the energy storage voltage Vs supplements the bus voltage Vbus through the first diode D1. When the bus voltage Vbus is greater than the energy storage voltage Vs, the first diode D1 is reverse biased, so that the energy storage voltage Vs cannot supplement the bus voltage Vbus through the first diode D1.

Please refer to FIG. 4B for the circuit block diagram of the second embodiment of the bypass circuit of the present invention, and refer to FIGS. 1 to 4A for complex cooperation. The difference between the bypass circuit 22' of this embodiment and the bypass circuit 22 of FIG. 4A is that the bypass circuit 22' includes a voltage detection circuit 222, a control unit 224, and a switch unit 226. The voltage detection circuit 222 is coupled to the bus path 16 and detects the voltage signal Sv of the bus voltage Vbus. The control unit 224 is coupled to the voltage detection circuit 222, and the switch unit 226 is coupled to the bus path 16, the energy storage capacitor 24 and the control unit 224. The control unit 224 receives the voltage signal Sv, and determines whether the switch unit 226 is turned on according to the voltage signal Sv. When the control unit 224 determines that the bus voltage Vbus is less than the reference voltage of the voltage detection circuit according to the voltage signal Sv, The control unit 224 controls the switch unit 226 to turn on, so that the energy storage voltage Vs supplements the bus voltage Vbus through the switch unit 226. When the control unit 224 determines that the bus voltage Vbus is greater than the reference voltage of the voltage detection circuit according to the voltage signal Sv, the control unit 224 controls the switch unit 226 to be non-conductive, so that the energy storage capacitor 24 and the bus path 16 are disconnected. It is worth mentioning that, in an embodiment of the present invention, the operating point at which the switch unit 226 is turned on is not limited to any voltage, and the control unit 224 can determine the operating point at which the switch unit 226 is turned on according to usage conditions. This means that the control unit 224 can set the threshold voltage. When the line voltage Vbus is lower than the threshold voltage, the control unit 224 controls the switch unit 226 to turn on, and the bus voltage Vbus does not have to be greater than the energy storage voltage Vs to turn off the switch unit 226. In addition, if the control unit 224 can determine the operating point at which the switch unit 226 is turned on according to the usage conditions, the capacitance withstand voltage of the energy storage capacitor 24 can also be adjusted with the setting of the threshold voltage.

Please refer to FIG. 5 for a detailed circuit structure diagram of the auxiliary power supply circuit of the present invention, and refer to FIGS. 1 to 4B for complex cooperation. The voltage stabilizing circuit 264 includes a first resistor R1 and a first voltage stabilizing unit ZD1, the first resistor R1 is coupled to the conversion unit 262 and the first voltage stabilizing unit ZD1, and the first voltage stabilizing unit ZD1 is coupled to the ground terminal. The charging path 266 is a MOSFET. The MOSFET includes a drain D, a source S, and a gate G. The drain D is coupled to the first resistor R1 and the conversion unit 262. The gate G of the MOSFET is coupled to the first resistor R1 and the first voltage stabilizing unit ZD1, and the source S is coupled to the energy storage capacitor 24 and the bypass circuit 22. The first resistor R1 is used for current limiting. The auxiliary voltage Va establishes a stabilized voltage Vr in the first stabilized unit ZD1, and the stabilized voltage Vr makes the gate G and source S of the MOSFET establish a switch-on voltage Vgs(th) makes the drain D and source S of the MOSFET conductive. At this time, the voltage stabilizing circuit 264 generates a charging current Ic according to the voltage difference between the stabilizing voltage Vr and the energy storage capacitor 24, and the drain D and the source S are turned on to charge the energy storage capacitor 24. Among them, the energy storage voltage Vs is the regulated voltage Vr minus the switch-on voltage Vgs(th) of the gate G and the source S.

As shown in FIG. 5, the auxiliary power circuit 26 further includes a current adjustment unit 268, a second voltage stabilizing unit ZD2, and a second diode D2. The current adjustment unit 268 is coupled between the voltage stabilizing circuit 264 and the drain D of the MOSFET, and is used to adjust the charging current Ic for charging the energy storage capacitor 24 to avoid energy storage The capacitor 24 is damaged by overcurrent. The second voltage stabilizing unit ZD2 is coupled between the source S and the gate G of the MOSFET, and establishes a rated voltage Vzd between the source S and the gate G to limit the gate voltage Vg to be less than or equal to Rated voltage Vzd, and avoid the damage of metal oxide half field effect transistor over voltage. Specifically, if the gate voltage Vg exceeds, for example, but not limited to 40V (depending on the type of metal oxide half field effect transistor), it will cause breakdown between the source S and the gate G, resulting in metal oxide The half-field effect transistor is damaged. Therefore, the second voltage stabilizing unit ZD2 clamps the gate voltage Vg below 40V (for example, but not limited to, 20V) to prevent the gate voltage Vg from being too high and causing damage to the MOSFET.

The second diode D2 is coupled to the first resistor R1, the first voltage stabilizing unit ZD1, the gate G of the MOSFET, the second voltage stabilizing unit ZD2, and the live terminal 162 of the bus path 16, and when the bus voltage When Vbus is less than the regulated voltage Vr on the first stabilizing unit ZD1, the second diode D2 will be forward biased, so that the stabilizing voltage Vr on the first stabilizing unit ZD1 is released to the bus path 16. At this time, the regulated voltage Vr will be reduced to substantially equal to the bus voltage Vbus. Since the stabilized voltage Vr is substantially equal to the bus voltage Vbus, the energy storage voltage Vs on the energy storage capacitor 24 decreases as the stabilized voltage Vr decreases, so as to avoid the voltage between the energy storage voltage Vs and the bus voltage Vbus. The difference is too large, causing excessive energy to be poured into the bus path 16 instantaneously. Furthermore, since the second-level conversion unit 14 is usually a switching power converter, when the input end of the second-level conversion unit 14 (that is, on the bus path 16) is lower than the energy storage voltage Vs and does not directly drop to At zero hour, it is avoided that the auxiliary voltage Va continuously releases energy to the bus voltage Vbus, causing extra energy to be accumulated at the input terminal and causing energy waste. Therefore, reducing the regulated voltage Vr to substantially equal to the bus voltage Vbus can improve the overall efficiency of the conversion system 100. In addition, the second diode D2 can also be coupled to the power output terminal of the second-level conversion unit 14 (as shown in FIG. 1, the positive terminal of the output power Vo), so as to avoid the difference between the energy storage voltage Vs and the output power Vo. The pressure difference is too large, causing too much energy to be poured into the power output terminal in a moment. The circuit action and effect are the same as those of the second diode D2 coupled to the live terminal 162 of the bus path 16, and will not be repeated here. It is worth mentioning that, in one embodiment of the present invention, the detailed circuit architecture of the auxiliary power circuit 26 may have various circuits, components, controllers, and even software and hardware implementations. Therefore, all circuits, components, controllers, and software and hardware that can achieve the above circuit effects should be included in the scope of this embodiment.

Please refer to FIG. 6A for the circuit structure diagram of the first embodiment of the current adjustment unit of the present invention. The current adjustment unit 268 may be a current-limiting resistor Rs, one end of the current-limiting resistor Rs is coupled to the first resistor R1, and the other end is coupled to the drain D of the MOSFET. The current-limiting resistor Rs limits the charging current Ic for charging the energy storage capacitor 24, so as to avoid the instantaneous large current of the energy storage capacitor 24, which may reduce the lifetime. It is worth mentioning that, in an embodiment of the present invention, the current limiting resistor Rs may also be coupled after the charging path 266 or before the voltage stabilizing circuit 264. That is, the current limiting resistor Rs can be coupled to the path from the conversion unit 262 to the energy storage capacitor 24.

Please refer to FIG. 6B for the circuit structure diagram of the second embodiment of the current adjustment unit of the present invention, and refer to FIGS. 1 to 6A for complex cooperation. The difference between the current adjustment unit 268' of this embodiment and the current adjustment unit 268 of FIG. 6A is that the current adjustment unit 268' includes a transistor Qt, a thyristor unit U1, and a current detection resistor Ri. The transistor Qt includes a collector C, a base B and an emitter E, and the thyristor unit U1 includes an input terminal X, an output terminal Y and a control terminal Z. The collector C of the transistor Qt is coupled to the voltage stabilizing circuit 264, and the base B is coupled to the input terminal X of the thyristor unit U1 and the voltage stabilizing circuit 264. One end of the current detecting resistor Ri is coupled to the emitter E of the transistor Qt and the control terminal Z of the thyristor unit U1, and the other end of the current detecting resistor Ri is coupled to the output terminal Y of the thyristor unit U1 and the metal oxide half-field effect The source S of the transistor. When the charging current Ic flows through the current detecting resistor Ri, a voltage difference is generated across the current detecting resistor Ri. The thyristor unit U1 learns the voltage difference between the two ends of the current detection resistor Ri through the output terminal Y and the control terminal Z, and adjusts the current at the input terminal X of the thyristor unit U1 according to the voltage difference. At this time, since the transistor Qt has the function of adjusting the current of the emitter E by the current of the base B, when the current at the input terminal X of the thyristor unit U1 is adjusted, the current of the emitter E of the transistor Qt is also adjusted at the same time. Therefore, when the charging current Ic is too large, the voltage difference between the two ends of the current detection resistor Ri becomes larger, so that the current at the input terminal X of the thyristor unit U1 is reduced, and the current at the emitter E of the transistor Qt is reduced. Moreover, when the charging current Ic becomes smaller, the voltage difference between the two ends of the current detection resistor Ri becomes smaller, so that the current at the input terminal X of the thyristor unit U1 is adjusted to increase. And increase the current of the emitter E of the transistor Qt. The thyristor unit U1 controls the transistor Qt to provide a charging current Ic with a fixed current value to charge the energy storage capacitor 24 according to the voltage across the current detection resistor Ri. It is worth mentioning that, in an embodiment of the present invention, the current adjusting units 268, 268' are not limited to only be composed of the above-mentioned components. In other words, it can also be achieved using, but not limited to, a linear constant current regulator (CCR), a constant current diode (CRD), or a controller with a circuit. Therefore, any element or circuit with a current adjustment function should be included in the scope of this embodiment. In addition, since the current adjustment unit 268' includes a transistor Qt, a thyristor unit U1, and a current detection resistor Ri, the function of the charging path 266 can be replaced by the current adjustment unit 268'. This means that the current adjusting unit 268' is the charging path 266, and the current detecting resistor Ri in the current adjusting unit 268' is directly coupled to the first end 242 of the energy storage capacitor 24, and the current of Ic is adjusted through the transistor Qt to make the storage The energy capacitor 24 establishes the energy storage voltage Vs. Alternatively, the charging path 266 is a diode element (not shown). The anode of the diode element is coupled to the current detection resistor Ri, and the cathode of the diode element is coupled to the energy storage capacitor 24.

However, the above are only detailed descriptions and drawings of the preferred embodiments of the present invention. However, the features of the present invention are not limited thereto, and are not intended to limit the present invention. The full scope of the present invention should be referred to the following application The scope of the patent shall prevail. All embodiments that conform to the spirit of the scope of the patent application of the present invention and similar variations should be included in the scope of the present invention. Anyone familiar with the art in the field of the present invention can easily think of it. Changes or modifications can be covered in the following patent scope of this case. In addition, the features mentioned in the patent application scope and the specification can be implemented individually or in any combination.

100: Conversion system

10: Conversion circuit

12: The first level conversion unit

14: The second level conversion unit

16: bus path

162: Fireside

164: Ground terminal

20: Control circuit

22: Bypass circuit

24: Energy storage capacitor

242: first end

244: second end

26: auxiliary power circuit

200: load

Vin: input power

Vo: output power

Vbus: bus voltage

Vw: working voltage

Vs: energy storage voltage

Claims (19)

A control circuit with extended maintenance time, coupled to a bus path of a conversion circuit, the control circuit comprising: a bypass circuit, coupled to a live terminal of the bus path; an energy storage capacitor, including a first terminal and a At the second end, the first end of the energy storage capacitor is coupled to the bypass circuit, and the second end of the energy storage capacitor is coupled to a ground terminal of the bus path; and an auxiliary power circuit is coupled to the The bypass circuit and the conversion circuit; wherein the auxiliary power supply circuit provides a storage voltage to the storage capacitor according to a working voltage provided by the conversion circuit; when the conversion circuit is abnormal, a bus voltage of the bus path When the energy storage voltage is less than or equal to the energy storage voltage, the energy storage voltage is provided to the bus path through the bypass circuit, so that the bus voltage is greater than or equal to a predetermined voltage within a maintenance time. The control circuit with prolonged sustaining time as described in claim 1, wherein the auxiliary power circuit includes: a conversion unit coupled to the conversion circuit; a voltage stabilizing circuit coupled to the conversion unit; and a charging path , Coupled to the voltage stabilizing circuit, the energy storage capacitor and the bypass circuit; wherein the conversion unit converts the working voltage into an auxiliary voltage, and the voltage stabilizing circuit generates a regulated voltage according to the auxiliary voltage; The voltage conducts the charging path, and the stabilized voltage charges the energy storage capacitor through the charging path, so that the energy storage capacitor establishes the energy storage voltage; when the bus voltage is less than or equal to the energy storage voltage, the energy storage voltage passes The bypass circuit provides a path to the bus. The control circuit with extended sustaining time as described in item 2 of the patent application, wherein the conversion unit is an induction coil, the induction coil is coupled to a transformer of the conversion circuit, and the operating voltage of the transformer is electromagnetically coupled The way to convert to this auxiliary voltage. The control circuit with extended sustaining time as described in the scope of patent application, wherein the conversion unit is a switching power converter, the switching power converter is coupled to the bus path, and the bus voltage is used as the work Voltage to convert the operating voltage to the auxiliary voltage. The control circuit with prolonged sustaining time as described in item 2 of the scope of patent application, wherein the conversion unit is a linear power converter, the linear power converter is coupled to the bus path, and the bus voltage is used as the operating voltage, To convert the operating voltage to the auxiliary voltage. The control circuit with extended maintenance time as described in item 2 of the scope of patent application, wherein the conversion circuit includes an AC-DC converter; the conversion unit is coupled to the AC-DC converter, and according to the AC-DC converter The operating voltage is obtained to convert the operating voltage into the auxiliary voltage. The control circuit with extended maintenance time as described in item 2 of the scope of patent application, wherein the conversion circuit includes a DC-DC converter; the conversion unit is coupled to the DC-DC converter, and according to the DC-DC converter The operating voltage is obtained to convert the operating voltage into the auxiliary voltage. As described in the first item of the scope of patent application, the control circuit with extended maintenance time, wherein the bypass circuit is a first diode; when the bus voltage is less than or equal to the energy storage voltage, the first diode is a forward When the bus voltage is greater than the energy storage voltage, the first diode is reverse biased. The control circuit with extended maintenance time as described in the first item of the patent application, wherein the bypass circuit includes: a voltage detection circuit coupled to the bus path; a control unit coupled to the voltage detection circuit; The switch unit is coupled to the bus path, the energy storage capacitor and the control unit; Wherein, the voltage detection circuit detects a voltage signal of the bus voltage, and the control unit determines whether the switch unit is turned on according to the voltage signal; when the switch unit is turned on, the energy storage voltage supplements the bus through the switch unit Voltage. The control circuit with extended maintenance time as described in item 2 of the scope of patent application, wherein the auxiliary power circuit further includes: a current-limiting resistor coupled to the voltage stabilizing circuit and the charging path; wherein the current-limiting resistor limits the pair A charging current for charging the energy storage capacitor. As described in the second item of the scope of patent application, the auxiliary power circuit further includes: a transistor coupled to the voltage stabilizing circuit; a thyristor unit coupled to the stabilizing circuit and the A transistor; and a current detection resistor coupled to the transistor and the thyristor unit; wherein the thyristor unit controls the transistor to provide a charging current pair with a fixed current value according to the voltage across the current detection resistor The energy storage capacitor is charged. The control circuit with extended maintenance time as described in item 11 of the scope of patent application, wherein a current adjustment unit constituted by the transistor, the thyristor unit and the current detection resistor is the charging path. As described in item 11 of the scope of patent application, the control circuit with extended maintenance time, wherein the charging path is a diode element. As described in the second item of the scope of patent application, the control circuit with extended maintenance time, wherein the energy storage voltage is the regulated voltage minus a switch-on voltage of the charging path. The control circuit with prolonged maintenance time as described in item 2 of the scope of patent application, wherein the auxiliary power circuit further includes: a voltage stabilizing unit coupled to the voltage stabilizing circuit, the charging path and the energy storage capacitor; Wherein, the voltage stabilizing unit limits a gate voltage of the charging path to be less than or equal to a rated voltage. As described in the first item of the scope of patent application, the control circuit with extended maintenance time, wherein a capacitor withstand voltage of the energy storage capacitor is less than a maximum voltage of the bus voltage. The control circuit with extended sustaining time as described in the scope of patent application, wherein the auxiliary power circuit further includes: a second diode coupled to the voltage stabilizing circuit and the charging path; wherein the bus voltage is less than When the regulated voltage is applied, the second diode is forward biased, so that the regulated voltage is released to the bus path. The control circuit with extended sustaining time as described in item 2 of the scope of patent application, wherein the auxiliary power circuit further includes: a second diode coupled to the voltage stabilizing circuit and a power output terminal of the conversion circuit; wherein When an output power output by the conversion circuit is less than the regulated voltage, the second diode is forward biased, so that the regulated voltage is released to the power output terminal. A conversion system with extended maintenance time includes: a conversion circuit, including: a first-level conversion unit that converts an input power to a bus voltage; and a second-level conversion unit that is coupled to the second-level conversion unit through a bus path A first-level conversion unit, and converts the bus voltage into an output power; and a control circuit, coupled to the bus path, and includes: a bypass circuit coupled to a live terminal of the bus path; and an energy storage capacitor, including A first end and a second end, the first end of the energy storage capacitor is coupled to the bypass circuit, and the second end of the energy storage capacitor is coupled to a ground terminal of the bus path; and an auxiliary A power circuit, coupled to the bypass circuit and the conversion circuit; Wherein, the auxiliary power circuit provides an energy storage voltage to the energy storage capacitor according to a working voltage provided by the conversion circuit; when the conversion circuit is abnormal and a bus voltage of the bus path is less than or equal to the energy storage voltage, The energy storage voltage is provided to the bus path through the bypass circuit, so that the bus voltage is greater than or equal to a predetermined voltage for a maintenance time.

Images