Power converter and power conversion system

Abstract

The invention provides a power converter and a power conversion system. The power converter comprises a hold time circuit and a conversion circuit, the hold time circuit is provided with a first energy storage unit, a second energy storage unit, a first charging unit, a second charging unit and a first switching unit, and the first energy storage unit, the second energy storage unit, the first charging unit and the second charging unit are connected in series. The first switching unit is connected in parallel with a series path formed by the first charging unit and the second charging unit; the conversion circuit is electrically connected with the hold time circuit. When the first switching unit of the hold time circuit is switched on, the first energy storage unit of the hold time circuit and the second energy storage unit of the hold time circuit are connected in series and discharge to the conversion circuit.

Description

Technical Field

[0001] The present invention relates to a power converter, and more particularly to a power converter with a time keeping circuit and a power conversion system. Background Art

[0002] In the prior art, if an alternating current (AC) power source is to be rectified, half-wave rectification or full-wave rectification is adopted according to the requirements; when the voltage source stability requirement is high, full-wave rectification is mostly adopted for rectification. The most common full-wave rectification method is to use a full-bridge rectifier. However, when the full-bridge rectifier is in the positive half cycle or the negative half cycle of the AC power source, the diode in the circuit of the full-bridge rectifier will be turned on, thereby causing the full-bridge rectifier to have a certain power consumption loss.

[0003] In order to reduce the power loss caused by the full-bridge rectifier, a bridgeless architecture is developed. However, many power factor correction (PFC) circuits are configured using the bridgeless architecture, but it is rare to find someone designing a bridgeless flyback architecture using the bridgeless architecture.

[0004] Among them, single-stage flyback converters mostly combine the functions of power factor correction circuit (Power Factor Correction, PFC) and flyback converter, which can reduce the size and cost compared with the traditional two-stage structure. However, general single-stage flyback converters stop operating immediately after the AC power is cut off. If used in information power products, it will cause malfunctions.

[0005] Therefore, how to overcome the problem that the prior art stops operating after the AC power is cut off and how to enable the bridgeless single-stage flyback converter to have the effect of extending the holding time is the technical difficulty that the inventor of this case wants to solve and overcome. Summary of the invention

[0006] In view of the above problems of the prior art, the main purpose of the present invention is to provide a power converter and a power conversion system, which can effectively extend the retention time after the power is cut off, so that the load elements connected to the subsequent stage can continue to operate after the power is cut off.

[0007] A technical means adopted to achieve the above-mentioned purpose is that the power converter comprises: A holding time circuit, comprising a first energy storage unit, a second energy storage unit, a first charging unit, a second charging unit and a first switching unit, wherein the first energy storage unit, the second energy storage unit, the first charging unit and the second charging unit are connected in series, and the first switching unit is connected in parallel with a series path formed by the first charging unit and the second charging unit; and A conversion circuit, electrically connected to the holding time circuit; When the first switching unit is turned on, the first energy storage unit and the second energy storage unit are connected in series and discharged to the conversion circuit.

[0008] Another technical means adopted to achieve the above-mentioned purpose is that the power conversion system comprises: AC power supply; a holding time circuit, electrically connected to the AC power source and comprising a first energy storage unit, a second energy storage unit, a first charging unit, a second charging unit and a first switching unit, wherein the first energy storage unit, the second energy storage unit, the first charging unit and the second charging unit are connected in series, and the first switching unit is connected in parallel with a series path formed by the first charging unit and the second charging unit; and A conversion circuit, electrically connected to the holding time circuit; When the first switching unit is turned on, the first energy storage unit and the second energy storage unit are connected in series and discharged to the conversion circuit.

[0009] By turning on the first switching unit, the first energy storage unit and the second energy storage unit are connected in series and discharged to the conversion circuit, so that the present invention can achieve the effect of extending the holding time. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 FIG. 1 is a block diagram of a first embodiment of the present invention. Figure 2 FIG. 1 is a schematic diagram of the structure of the first embodiment of the present invention. Figure 3 FIG. 4 is a schematic diagram of a first time circuit loop of the first embodiment of the present invention. Figure 4 FIG. 1 is a schematic diagram of a second time circuit loop according to the first embodiment of the present invention. Figure 5 FIG. 4 is a schematic diagram of a third time circuit loop of the first embodiment of the present invention. Figure 6 FIG. 4 is a schematic diagram of a fourth timing circuit loop according to the first embodiment of the present invention. Figure 7 The block diagram of the first embodiment of the present invention is to add a detection circuit. Figure 8Schematic diagram of the circuit loop at the fifth time after the AC power supply is cut off in the first embodiment of the present invention. Fig. 9 Schematic diagram of the circuit loop at the sixth time after the AC power supply is cut off in the first embodiment of the present invention. Fig.10 FIG. 4 is a block diagram of a second embodiment of the present invention. Fig.11 FIG. 1 is a schematic diagram of the structure of the second embodiment of the present invention. Fig.12 FIG. 1 is a schematic diagram of the seventh time circuit loop of the second embodiment of the present invention. Fig.13 FIG. 1 is a schematic diagram of an eighth time circuit loop of the second embodiment of the present invention. Fig.14 FIG. 1 is a schematic diagram of a ninth time circuit loop of the second embodiment of the present invention. Fig.15 FIG. 1 is a schematic diagram of the tenth time circuit loop of the second embodiment of the present invention. Fig.16 A block diagram of an additional detection circuit according to the second embodiment of the present invention. Fig.17 This is a schematic diagram of the first time circuit loop of the series connection after the AC power supply is cut off in the second embodiment of the present invention. Fig.18 This is a schematic diagram of a series second time circuit loop after the AC power supply is cut off in the second embodiment of the present invention. Fig.19 This is a schematic diagram of a parallel first time circuit loop after the AC power supply is cut off in the second embodiment of the present invention. Fig. 20 This is a schematic diagram of a parallel second time circuit loop after the AC power supply is cut off in the second embodiment of the present invention. DETAILED DESCRIPTION

[0011] For the power conversion system of the first embodiment of the present invention, please refer to Figure 1 , 2 As shown, the power conversion system includes an alternating current power source AC, a holding time circuit 1, a conversion circuit 2 and an external load A. The alternating current power source AC has a first terminal AC1, a second terminal AC2, a positive half cycle and a negative half cycle, the positive half cycle has a first time and a second time, and the negative half cycle has a third time and a fourth time. The holding time circuit 1 is connected to the first terminal AC1 and the second terminal AC2 of the alternating current power source AC. One side of the conversion circuit 2 is coupled to the holding time circuit 1, and the other side of the conversion circuit 2 is connected to the external load A.

[0012] In this embodiment, the holding time circuit 1 and the conversion circuit 2 may constitute a power converter; wherein the holding time circuit 1 is provided with a first energy storage unit C1, a first charging unit D1, a second energy storage unit C2, a second charging unit D2 and a first switching unit Q1, wherein the first energy storage unit C1, the second energy storage unit C2, the first charging unit D1 and the second charging unit D2 are connected in series, and the first switching unit Q1 is connected in parallel with the series path formed by the first charging unit D1 and the second charging unit D2; the conversion circuit 2 is electrically connected to the holding time circuit 1; when the first switching unit Q1 of the holding time circuit 1 is turned on, the first energy storage unit C1 and the second energy storage unit C2 are connected in series and discharged to the conversion circuit 2. In this embodiment, the alternating current power source AC charges the first energy storage unit C1 in the positive half cycle, and the alternating current power source AC charges the second energy storage unit C2 in the negative half cycle.

[0013] In this embodiment, the holding time circuit 1 may also include a second switching unit Q2 and a third switching unit Q3; the second switching unit Q2 is connected in parallel with the series path formed by the first charging unit D1, the second charging unit D2 and the second energy storage unit C2, and the third switching unit Q3 is connected in parallel with the series path formed by the first energy storage unit C1, the first charging unit D1 and the second charging unit D2; wherein, when the first switching unit Q1 is turned off, and the second switching unit Q2 and the third switching unit Q3 are both turned on, the first energy storage unit C1 and the second energy storage unit C2 are connected in parallel and discharged to the conversion circuit 2.

[0014] In addition, in the present embodiment, the second switching unit Q2 and the third switching unit Q3 may not be arranged in the holding time circuit 1 to constitute another power converter. In the present embodiment, the conversion circuit 2 may further include a first transformer T1, a second transformer T2, the second switching unit Q2, the third switching unit Q3, a first unidirectional conduction unit D3, a second unidirectional conduction unit D4, a third unidirectional conduction unit D5, a fourth unidirectional conduction unit D6 and an output capacitor Co; the primary side of the first transformer T1 is electrically connected to the first energy storage unit C1, the first unidirectional conduction unit D3, the second switching unit Q2 and the AC power source AC, the secondary side of the first transformer T1 is electrically connected to the third unidirectional conduction unit D5 and the output capacitor Co, and the primary side of the second transformer T2 is electrically connected to the first charging unit D1, the second charging unit D2, the second unidirectional conduction unit D4, the third switching unit Q3 and the AC power source AC.

[0015] In this embodiment, the positive half cycle of the AC power source AC has a first time and a second time, and the negative half cycle of the AC power source AC has a third time and a fourth time; at the first time, the second switching unit Q2 is turned on and the first transformer T1 stores energy, and at the second time, the second switching unit Q2 is turned off and the first transformer T1 releases its stored energy; at the third time, the third switching unit Q3 is turned on and the second transformer T2 stores energy, and at the fourth time, the third switching unit Q3 is turned off and the second transformer T2 releases its stored energy.

[0016] To specifically describe the power conversion system of this embodiment, the first energy storage unit C1 and the second energy storage unit C2 of the holding time circuit 1 both have a positive terminal and a negative terminal, the first charging unit D1 and the second charging unit D2 both have an anode and a cathode, and the anode and cathode of the first charging unit D1 and the second charging unit D2 are respectively composed of a P terminal and an N terminal; the positive terminal of the first energy storage unit C1 is electrically connected to the first terminal AC1 of the alternating current power source AC and the negative terminal of the first energy storage unit C1 is connected to the anode (P terminal) of the first charging unit D1, and the first charging unit The cathode (N end) of the element D1 is connected to the second end AC2 of the alternating current power source AC and the anode (P end) of the second charging unit D2, the cathode (N end) of the second charging unit D2 is connected to the positive end of the second energy storage unit C2, and the negative end of the second energy storage unit C2 is connected to the grounding point 3, wherein one end of the first switching unit Q1 is arranged between the negative end of the first energy storage unit C1 and the anode (P end) of the first charging unit D1, and the other end of the first switching unit Q1 is arranged between the cathode (N end) of the second charging unit D2 and the positive end of the second energy storage unit C2.

[0017] In the conversion circuit 2, the first transformer T1 and the second transformer T2 respectively have a primary side and a secondary side, the first unidirectional conduction unit D3, the second unidirectional conduction unit D4, the third unidirectional conduction unit D5 and the fourth unidirectional conduction unit D6 are all provided with an anode and a cathode, and the anode and cathode of the first unidirectional conduction unit D3, the second unidirectional conduction unit D4, the third unidirectional conduction unit D5 and the fourth unidirectional conduction unit D6 are respectively formed by a P terminal and an N terminal, and the output capacitor Co is provided with a positive terminal and a negative terminal; one end of the primary side of the first transformer T1 is provided at the first end AC1 of the alternating current power source AC, the other end of the primary side of the first transformer T1 is connected to one end of the second switching unit Q2, the other end of the second switching unit Q2 is connected to one end of the resistor unit R1, the other end of the resistor unit R1 is connected to the grounding point 3, the cathode (N terminal) of the first unidirectional conduction unit D3 is electrically connected to the first end AC1 of the alternating current power source AC, and the anode (P terminal) of the first unidirectional conduction unit D3 is electrically connected to the grounding point 3, and the cathode (N end) of the second unidirectional conduction unit D4 is electrically connected to the second end AC2 of the alternating current power source AC, and the anode (P end) of the second unidirectional conduction unit D4 is electrically connected to the grounding point 3; one end of the secondary side of the first transformer T1 is connected to the anode (P end) of the third unidirectional conduction unit D5, and the cathode (N end) of the third unidirectional conduction unit D5 is connected to the positive end of the output capacitor Co, and the other end of the secondary side of the first transformer T1 and the negative end of the output capacitor Co are connected to the grounding point 3; One end of the primary side of the second transformer T2 is arranged at the second end AC2 of the AC power supply AC, the other end of the primary side of the second transformer T2 is connected to one end of the third switching unit Q3, the other end of the third switching unit Q3 is connected to one end of the resistance unit R1, one end of the secondary side of the second transformer T2 is connected to the anode (P end) of the fourth unidirectional conduction unit D6, the cathode (N end) of the fourth unidirectional conduction unit D6 is connected to the positive end of the output capacitor Co, and the other end of the secondary side of the second transformer T2 is connected to the grounding point 3.

[0018] Please refer to Figure 3, when the AC power source AC is in the first time of its positive half cycle, the second switching unit Q2 is in the conducting state and the first and third switching units Q1 and Q3 are in the non-conducting state to form a first loop L1 and a second loop L2; the first loop L1 charges the first energy storage unit C1 from the first end AC1 of the AC power source AC through the positive end of the first energy storage unit C1 and enters from the negative end of the first energy storage unit C1 to the anode (P end) of the first charging unit D1, and returns to the second end AC2 of the AC power source AC through the cathode (N end) of the first charging unit D1; the second loop L2 is connected from the first end AC1 of the AC power source AC The terminal AC1 enters one end of the primary side of the first transformer T1 and from the other end of the primary side of the first transformer T1 to one end of the second switching unit Q2, flows through the other end of the second switching unit Q2 through the resistor unit R1 to the anode (P end) of the first unidirectional conduction unit D3, and returns to the second terminal AC2 of the AC power source AC through the cathode (N end) of the first unidirectional conduction unit D3; wherein the secondary side of the first transformer T1 outputs a reverse voltage to make the third unidirectional conduction unit D5 reverse non-conductive, so that the first transformer T1 stores energy and the positive terminal of the output capacitor Co discharges to an external load (not shown).

[0019] Please refer to Figure 4 , when the AC power source AC is in the second time of its positive half cycle, the first, second and third switching units Q1, Q2, Q3 are in a non-conducting state to form a third loop L3 and a fourth loop L4; the third loop L3 charges the first energy storage unit C1 from the first end AC1 of the AC power source AC through the positive end of the first energy storage unit C1 and enters from the negative end of the first energy storage unit C1 to the anode (P end) of the first charging unit D1, and returns to the second end A of the AC power source AC through the cathode (N end) of the first charging unit D1. C2; wherein the second switching unit Q2 is non-conductive so that the first transformer T1 releases its stored energy, and the secondary side of the first transformer T1 outputs a positive voltage to form the fourth loop L4, and the fourth loop L4 outputs the positive voltage from one end of the secondary side of the first transformer T1, and then is forward-conducted through the anode (P end) of the third unidirectional conductive unit D5 and enters the positive side of the output capacitor Co from its cathode (N end); wherein the secondary side of the first transformer T1 charges the output capacitor Co and supplies power to the load (not shown).

[0020] Please refer to Figure 5, when the AC power source AC is in the third time of its negative half cycle, the third switching unit Q3 is in the conducting state and the first and second switching units Q1 and Q2 are in the non-conducting state to form a fifth loop L5 and a sixth loop L6; the fifth loop L5 is forward-conducted from the second end AC2 of the AC power source AC through the anode (P end) of the second charging unit D2, enters the positive side of the second energy storage unit C2 through the cathode (N end) of the second charging unit D2 to charge the second energy storage unit C2, and enters from the negative end of the second energy storage unit C2 to the anode (P end) of the first unidirectional conducting unit D3, and returns to the AC power source through the cathode (N end) of the first unidirectional conducting unit D3. The sixth loop L6 flows from the second end AC2 of the AC power source AC through one end of the primary side of the second transformer T2 and from the other end of the primary side of the second transformer T2 to one end of the third switching unit Q3, flows through the other end of the third switching unit Q3 through the resistor unit R1 to the P end of the first unidirectional conduction unit D3, and returns to the first end AC1 of the AC power source AC through the cathode (N end) of the first unidirectional conduction unit D3; wherein the secondary side of the second transformer T2 outputs a reverse voltage to make the fourth unidirectional conduction unit D6 reverse non-conductive, so that the second transformer T2 stores energy and the output capacitor Co discharges the load (not shown).

[0021] Please refer to Figure 6 , when the AC power source AC is in the fourth time of its negative half cycle, the first, second and third switching units Q1, Q2, Q3 are in a non-conducting state to form a seventh loop L7 and an eighth loop L8; the seventh loop L7 is forwardly conducted from the second end AC2 of the AC power source AC through the anode (P end) of the second charging unit D2, and then enters the positive end of the second energy storage unit C2 from the cathode (N end) of the second charging unit D2 to charge the second energy storage unit C2, and enters from the negative end of the second energy storage unit C2 to the anode (P end) of the first unidirectional conducting unit D3, and passes through the first unidirectional conducting unit The cathode (N terminal) of D3 returns to the first terminal AC1 of the AC power supply AC; wherein the third switching unit Q3 is non-conductive so that the second transformer T2 releases its stored energy, and the secondary side of the second transformer T2 outputs a positive voltage to form the eighth loop L8, and the eighth loop L8 is output by one end of the secondary side of the second transformer T2, and the positive voltage is forwardly conducted through the anode (P terminal) of the fourth unidirectional conducting unit D6, and then enters the positive side of the output capacitor Co through its cathode (N terminal); wherein the secondary side of the second transformer T2 charges the output capacitor Co and supplies power to the load (not shown).

[0022] See also Figure 7, the present invention may further be provided with a detection circuit 4 and a control circuit 5; the detection circuit 4 is coupled to the AC power source AC, and the detection circuit 4 is used to detect whether the output of the AC power source AC is normal and whether the power supply is stable. When the AC power source AC is open or disconnected, the detection circuit 4 will drive the first switching unit Q1 to turn it on, which will generate a first discharge path DP1 (Discharge Path), a fifth time and a sixth time; the control circuit 5 is coupled to the detection circuit 4 and the first switching unit Q1, and when the output of the AC power source AC is abnormal, the control circuit 5 turns on the first switching unit Q1. Further, when the holding time circuit 1 also has the second switching unit Q2 and the third switching unit Q3, the control circuit 5 is further coupled to the second switching unit Q2 and the third switching unit Q3; when the output of the AC power source AC is abnormal, the control circuit 5 turns on the first switching unit Q1 or turns on the second switching unit Q2 and the third switching unit Q3. In this embodiment, the abnormal output of the AC power source AC means that the output of the AC power source AC is zero.

[0023] Please continue reading Figure 8 , when the AC power source AC is open at the fifth time, the second switching unit Q2 is turned on and the third switching unit Q3 is turned off, wherein the first energy storage unit C1 and the second energy storage unit C2 are connected in series, and the first discharge loop DP1 is from the positive end of the first energy storage unit C1 to one end of the primary side of the first transformer T1 and from the other end of the primary side of the first transformer T1 to one end of the second switching unit Q2, through the other end of the second switching unit Q2 through the resistor unit R1 to the negative end of the second energy storage unit C2, and then from the positive end of the second energy storage unit C2 through the first switching unit Q1 to the negative end of the first energy storage unit C1; wherein the secondary side of the first transformer T1 outputs a reverse voltage to make the third unidirectional conduction unit D5 reversely non-conductive, so that the first transformer T1 stores energy and the output capacitor Co discharges the load (not shown).

[0024] Please continue reading Fig. 9 , when the AC power source AC is open at the sixth time, the first switching unit Q1 is turned on and the second and third switching units Q2 and Q3 are not turned on, the second switching unit Q2 is not turned on to make the first transformer T1 release its stored energy, and the secondary side output forward voltage of the first transformer T1 is forward-conducted by the P end of the third unidirectional conduction unit D5 and then enters the positive side of the output capacitor Co from its N end; wherein the secondary side of the first transformer T1 charges the output capacitor Co and supplies power to the load (not shown).

[0025] During the first time of the positive half cycle or the third time of the negative half cycle of the AC power source AC, the first or second energy storage unit C1, C2 of the holding time circuit 1 is charged and the first or second transformer T1, T2 of the conversion circuit 2 is stored, and at this time, the output capacitor Co supplies power to the external load A; and during the second time of the positive half cycle or the fourth time of the negative half cycle of the AC power source, the conversion circuit 2 releases the stored energy of the first or second transformer T1, T2 to charge the output capacitor Co and supply power to the external load A at the same time; when the AC power source AC is open, the first switching unit Q of the holding time circuit 1 will be triggered. 1 is turned on, and the first and second energy storage units C1 and C2 will supply power; when the fifth time is, the second switching unit Q2 is in the on state and the first and second energy storage units C1 and C2 will continue to supply power to the first transformer T1 for continuous energy storage; when the sixth time is, the second switching unit Q2 is in the non-conducting state, and the first transformer T1 releases its stored energy so that the secondary side of the first transformer T1 outputs the forward voltage to charge the output capacitor Co and supplies power to the external load A at the same time, so that the present invention can achieve the effect of extending the holding time through the first and second energy storage units C1 and C2 after the AC power source AC is opened.

[0026] Among them, the first and second times can be in chronological order or in an alternating order, that is, in the positive half cycle, the first half cycle can be the first time and the second half cycle can be the second time, or vice versa; in the positive half cycle, the first time and the second time are repeatedly and alternately executed to perform the cycle of charging, energy storage, energy release and discharge; the third and fourth times or the fifth and sixth times can also be in chronological order or in an alternating order.

[0027] Regarding the second embodiment of the present invention, the main technical content is substantially the same as that of the first embodiment, please refer to Fig.10 , 11 As shown, it includes an alternating current power source AC, a holding time circuit 1, a conversion circuit 2, a control circuit 5 and an external load A.

[0028] The alternating current power source AC has a first terminal AC1, a second terminal AC2, a positive half cycle and a negative half cycle, the positive half cycle has a first time and a second time, and the negative half cycle has a third time and a fourth time. The holding time circuit 1 is electrically connected to the first terminal AC1 and the second terminal AC2 of the alternating current power source AC. The control circuit 5 is coupled to the holding time circuit 1. The conversion circuit 2 is electrically connected to the rear stage of the holding time circuit 1. The specific components and connection relationship inside the holding time circuit 1 and the conversion circuit 2 are the same as those in the first embodiment of the present invention, so they are not repeated here. The difference lies in the control circuit 5.

[0029] The control circuit 5 is provided with a third switching unit Q4 and a second switching unit Q5, one end of the third switching unit Q4 is connected to the first end AC1 of the alternating current power source AC, and the other end of the third switching unit Q4 is connected between the cathode (N end) of the second charging unit D2 and the positive end of the second energy storage unit C2, and one end of the second switching unit Q5 is connected between the negative end of the first energy storage unit C1 and the anode (P end) of the first charging unit D1, and the other end of the second switching unit Q5 is connected to the negative end of the second energy storage unit C2.

[0030] Please refer to Fig.12 When the alternating current power source AC is in the first time of its positive half cycle, the second switching unit Q2 is in the conducting state and the first to third switching units Q1, Q2, Q3 are in the non-conducting state to form a first loop L1 and a second loop L2; wherein the actions of the first and second loops L1, L2 are the same as the first time of the positive half cycle of the alternating current power source AC described in the first embodiment of the present invention, and therefore will not be repeated here.

[0031] Please refer to Fig.13 When the AC power source AC is in the second time of its positive half cycle, the first to third switching units Q1, Q2, and Q3 are in a non-conducting state to form a third loop L3 and a fourth loop L4, wherein the actions of the third and fourth loops L3 and L4 are the same as those of the AC power source AC in the first embodiment of the present invention in the second time of its positive half cycle, and thus will not be repeated here.

[0032] Please refer to Fig.14 When the alternating current power source AC is at the third time of its negative half cycle, the third switching unit Q3 is in a conducting state and the first to third switching units Q1, Q2, and Q3 are in a non-conducting state to form a fifth loop L5 and a sixth loop L6; wherein the actions of the fifth and sixth loops L5 and L6 are the same as the third time of the negative half cycle of the alternating current power source AC described in the first embodiment of the present invention, and therefore will not be repeated here.

[0033] Please refer to Fig.15 When the AC power source AC is at the fourth time of its negative half cycle, the first to third switching units Q1, Q2, and Q3 are in a non-conducting state to form a seventh loop L7 and an eighth loop L8, wherein the actions of the seventh and eighth loops L7 and L8 are the same as the fourth time of the negative half cycle of the AC power source AC described in the first embodiment of the present invention, and thus will not be repeated here.

[0034] See also Fig.16The present invention may further include a detection circuit 4 having the same function as the first embodiment of the present invention. The detection circuit 4 is also used to detect whether the AC power source AC is open circuit. When the AC power source AC is disconnected or open circuit, the detection circuit 4 will drive the first switching unit Q1 to conduct to form a second discharge loop DP2, a first time in series and a second time in series. Fig.17 , 18 shown.

[0035] Please refer to Fig.17 , when the series connection is at the first time, the second switching unit Q2 is turned on and the third and second switching units Q3 and Q2 are not turned on, wherein the first and second energy storage units C1 and C2 are connected in series, and the second discharge loop DP2 enters from the positive terminal of the first energy storage unit C1 to one end of the primary side of the first transformer T1 and from the other end of the primary side of the first transformer T1 to one end of the second switching unit Q2, flows through the other end of the second switching unit Q2 through the resistor unit R1 to the negative end of the second energy storage unit C2, and then enters from the positive end of the second energy storage unit C2 through the first switching unit Q1 to the negative end of the first energy storage unit C1; wherein the secondary side of the first transformer T1 outputs a reverse voltage to make the third unidirectional conduction unit D5 reversely non-conductive, so that the first transformer T1 stores energy and the output capacitor Co discharges the external load A.

[0036] Please refer to Fig.18 , when the second series connection time is reached, the first switching unit Q1 is turned on and the second and third switching units Q2 and Q3 are not turned on, the second switching unit Q2 is not turned on to make the first transformer T1 release its stored energy, and the positive voltage outputted from one end of the secondary side of the first transformer T1 is forward-conducted through the anode (P end) of the third unidirectional conductive unit D5 and then enters the positive side of the output capacitor Co from its cathode (N end); wherein the secondary side of the first transformer T1 charges the output capacitor Co and supplies power to the external load A.

[0037] The charging and discharging operation principles of the first and second time periods of the positive half cycle and the third and fourth time periods of the negative half cycle of the AC power source AC are the same as those of the first embodiment, and will not be repeated here. The difference is that when the AC power source AC is open, the first switching unit Q1 of the holding time circuit 1 will be triggered to be turned on. During the first series connection time, the first and second energy storage units C1 and C2 are connected in series to supply power and the second switching unit Q2 is turned on while the third and second switching units Q3 and Q2 are not turned on, so that the first transformer T1 stores energy; during the second series connection time, the second and third switching units Q2 and Q3 are not turned on, and the first transformer T1 releases its stored energy so that the secondary side of the first transformer T1 outputs the forward voltage to charge the output capacitor Co and simultaneously supplies power to the external load A, so that the present invention can achieve the effect of extending the holding time through the first and second energy storage units C1 and C2 after the AC power source AC is open.

[0038] In the present embodiment, when the first and second energy storage units C1 and C2 are connected in series, their total capacitance value will decrease, and the first and second energy storage units C1 and C2 are charged during the first time of the positive half cycle and the third time of the negative half cycle respectively, and the charge amount of the first and second energy storage units C1 and C2 will not be reduced. Therefore, the output voltage value of the first and second energy storage units can be increased, so that the present embodiment can be applied to situations with high power requirements and at the same time achieve the effect of extending the holding time.

[0039] In another embodiment, when the detection circuit 4 detects that the AC power source AC is disconnected or open, the detection circuit 4 will drive the third and second switching units Q3 and Q2 to conduct to form a third discharge loop DP3, paralleling the first time and the second time, such as Fig.19 , 20 shown.

[0040] Please refer to Fig.19, when the parallel connection is at the first time, the second switching unit Q2 is turned on and the first and third switching units Q1 and Q3 are not turned on, so that the first energy storage unit C1 and the second energy storage unit C2 are connected in parallel, and the third discharge loop DP3 is electrically connected to one end of the primary side of the first transformer T1 by the positive terminal of the first energy storage unit C1 and the positive terminal of the second energy storage unit C2 and enters from the other end of the primary side of the first transformer T1 to one end of the second switching unit Q2, flows through the other end of the second switching unit Q2 through the resistor unit R1 to the negative terminal of the second energy storage unit C2 and through the third switching unit Q4 to the negative terminal of the first energy storage unit C1, and then from the positive terminal of the second energy storage unit C2 to the positive terminal of the first energy storage unit C1 through the second switching unit Q5; wherein the secondary side of the first transformer T1 outputs a reverse voltage to make the third unidirectional conduction unit D5 reversely non-conductive, so that the first transformer T1 stores energy and the output capacitor Co discharges the external load A.

[0041] Please refer to Fig. 20 , when the parallel connection is in the second time, the third and second switching units Q3, Q2 are turned on and the first, second and third switching units Q1, Q2, Q3 are not turned on; wherein the second switching unit Q2 is not turned on to make the first transformer T1 release its stored energy, and the positive voltage outputted from one end of the secondary side of the first transformer T1 is forwardly conducted through the anode (P end) of the third unidirectional conducting unit D5 and then enters the positive side of the output capacitor Co from its cathode (N end); wherein the secondary side of the first transformer T1 charges the output capacitor Co and supplies power to the external load A.

[0042] The charging and discharging operation principles of the first and second time periods of the positive half cycle and the third and fourth time periods of the negative half cycle of the AC power source AC are the same as those of the first embodiment, so they will not be repeated here. The difference is that when the AC power source AC is open, the third and second switching units Q4 and Q5 of the holding time circuit 1 will be triggered to be turned on. During the first parallel time period, the first and second energy storage units C1 and C2 supply power in parallel and the second switching unit Q2 is turned on while the first and third switching units Q1 and Q3 are not turned on, so that the first transformer T1 stores energy. During the second parallel time period, the first, second and third switching units Q1, Q2 and Q3 are not turned on, and the first transformer T1 releases its stored energy so that the secondary side of the first transformer T1 outputs the forward voltage to charge the output capacitor Co and simultaneously supplies power to the external load A, so that the present invention can achieve the effect of extending the holding time through the first and second energy storage units C1 and C2 after the AC power source AC is open.

[0043] In this embodiment, when the first and second energy storage units C1 and C2 are connected in parallel, their total capacitance value will increase, and the first and second energy storage units C1 and C2 are charged during the first time of the positive half cycle and the third time of the negative half cycle respectively, and the charge amount of the first and second energy storage units C1 and C2 will not be reduced. Therefore, the output voltage value of the first and second energy storage units can be reduced. In addition, this embodiment can be used in situations where the output voltage needs to be reduced and at the same time achieve the effect of extending the holding time.

[0044] Among them, the first and second times can be in chronological order or in an alternating order, that is, in the positive half cycle, the first half cycle can be the first time and the second half cycle can be the second time, or vice versa; in the positive half cycle, the first time and the second time can be repeatedly and alternately executed to perform the cycle of charging, energy storage, energy release and discharge; the third and fourth times or the series first time and the series second time or the parallel first time and the parallel second time can also be in chronological order or in an alternating order.

[0045] However, the above is only an embodiment of the present invention and is not intended to limit the scope of the present invention. For example, the terms "connected", "set", "connected" or "connected" used herein may refer to physical and / or electrical connections or settings. In addition, the terms "first", "second" and "third" are used only for descriptive purposes and cannot be understood as indicating or implying relative importance or their order relationship.

[0046] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the meanings commonly understood by those of ordinary skill in the art. It will be further understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meanings in the context of the relevant technology and the present invention, and will not be interpreted as idealized or overly formal meanings unless explicitly defined as such herein.

Claims

1. A power converter, characterized in that: It contains: A holding time circuit, comprising a first energy storage unit, a second energy storage unit, a first charging unit, a second charging unit and a first switching unit, wherein the first energy storage unit, the second energy storage unit, the first charging unit and the second charging unit are connected in series, and the first switching unit is connected in parallel with a series path formed by the first charging unit and the second charging unit; as well as A conversion circuit, electrically connected to the holding time circuit; When the first switching unit is turned on, the first energy storage unit and the second energy storage unit are connected in series and discharged to the conversion circuit.

2. The power converter according to claim 1, characterized in that: Also includes: A detection circuit coupled to the AC power source and detecting whether the output of the AC power source is normal; as well as The control circuit is coupled to the detection circuit and the first switching unit. When the output of the AC power source is abnormal, the control circuit turns on the first switching unit.

3. The power converter according to claim 1, wherein: The abnormal output of the AC power source means that the output of the AC power source is zero.

4. The power converter according to claim 1, wherein: The holding time circuit further comprises: a second switching unit connected in parallel with a series path formed by the first charging unit, the second charging unit, and the second energy storage unit; and a third switching unit connected in parallel with a series path formed by the first energy storage unit, the first charging unit and the second charging unit; When the first switching unit is turned off, and the second switching unit and the third switching unit are both turned on, the first energy storage unit and the second energy storage unit are connected in parallel and discharged to the conversion circuit.

5. The power converter according to claim 4, characterized in that: Also includes: A detection circuit coupled to the AC power source and detecting whether the output of the AC power source is normal; as well as The control circuit is coupled to the detection circuit, the first switching unit, the second switching unit and the third switching unit. When the output of the AC power source is abnormal, the control circuit turns on the first switching unit or turns on the second switching unit and the third switching unit.

6. The power converter according to claim 1, wherein: The conversion circuit comprises a first transformer, a second transformer, a second switching unit, a third switching unit, a first unidirectional conduction unit, a second unidirectional conduction unit, a third unidirectional conduction unit, a fourth unidirectional conduction unit and an output capacitor, the primary side of the first transformer is electrically connected to the first energy storage unit, the first unidirectional conduction unit, the second switching unit and an AC power supply, the secondary side of the first transformer is electrically connected to the third unidirectional conduction unit and the output capacitor, and the primary side of the second transformer is electrically connected to the first charging unit, the second charging unit, the second unidirectional conduction unit, the third switching unit and the AC power supply.

7. The power converter according to claim 6, characterized in that: The AC power source has a positive half cycle and a negative half cycle, the positive half cycle has a first time and a second time, during the first time, the second switching unit is turned on and the first transformer stores energy, during the second time, the second switching unit is turned off and the first transformer releases its stored energy.

8. The power converter according to claim 7, characterized in that: The negative half cycle has a third time and a fourth time. During the third time, the third switching unit is turned on and the second transformer stores energy. During the fourth time, the third switching unit is turned off and the second transformer releases its stored energy.

9. The power converter according to claim 1, wherein: The holding time circuit is electrically connected to an AC power source, and the AC power source charges the first energy storage unit in a positive half cycle, and charges the second energy storage unit in a negative half cycle.

10. A power conversion system electrically connected to a load, characterized in that: The power conversion system comprises: AC power supply; a holding time circuit, electrically connected to the AC power source and comprising a first energy storage unit, a second energy storage unit, a first charging unit, a second charging unit and a first switching unit, wherein the first energy storage unit, the second energy storage unit, the first charging unit and the second charging unit are connected in series, and the first switching unit is connected in parallel with a series path formed by the first charging unit and the second charging unit; as well as A conversion circuit, electrically connected to the holding time circuit; When the first switching unit is turned on, the first energy storage unit and the second energy storage unit are connected in series and discharged to the conversion circuit.

11. The power conversion system according to claim 10, characterized in that: The first energy storage unit and the second energy storage unit both have a positive terminal and a negative terminal, and the first charging unit and the second charging unit both have an anode and a cathode; the positive terminal of the first energy storage unit is electrically connected to the first terminal of the AC power supply and the negative terminal of the first energy storage unit is connected to the anode of the first charging unit, the cathode of the first charging unit is connected to the second terminal of the AC power supply and the anode of the second charging unit, the cathode of the second charging unit is connected to the positive terminal of the second energy storage unit, and the negative terminal of the second energy storage unit is connected to a grounding point, wherein one end of the first switching unit is arranged between the negative terminal of the first energy storage unit and the anode of the first charging unit, and the other end of the first switching unit is arranged between the cathode of the second charging unit and the positive terminal of the second energy storage unit; The conversion circuit is provided with a first transformer, a second switching unit, a resistance unit, a second transformer, a third switching unit, a first unidirectional conduction unit, a second unidirectional conduction unit, a third unidirectional conduction unit, a fourth unidirectional conduction unit and an output capacitor, wherein the first transformer and the second transformer respectively have a primary side and a secondary side, the first unidirectional conduction unit, the second unidirectional conduction unit, the third unidirectional conduction unit and the fourth unidirectional conduction unit all have an anode and a cathode, and the output capacitor has a positive terminal and a negative terminal; one end of the primary side of the first transformer is provided at the first end of the AC power supply, the other end of the primary side of the first transformer is connected to one end of the second switching unit, and the The other end of the second switching unit is connected to one end of the resistance unit, the other end of the resistance unit is connected to the grounding point, the cathode of the first unidirectional conductive unit is electrically connected to the first end of the AC power supply, and the anode of the first unidirectional conductive unit is electrically connected to the grounding point, the cathode of the second unidirectional conductive unit is electrically connected to the second end of the AC power supply, and the anode of the second unidirectional conductive unit is electrically connected to the grounding point, one end of the secondary side of the first transformer is connected to the anode of the third unidirectional conductive unit, and the cathode of the third unidirectional conductive unit is connected to the positive terminal of the output capacitor, and the other end of the secondary side of the first transformer is connected to the negative terminal of the output capacitor; One end of the primary side of the second transformer is arranged at the second end of the AC power supply, the other end of the primary side of the second transformer is connected to one end of the third switching unit, the other end of the third switching unit is connected to one end of the resistance unit, one end of the secondary side of the second transformer is connected to the anode of the fourth unidirectional conductive unit, and the cathode of the fourth unidirectional conductive unit is connected to the positive terminal of the output capacitor.

12. The power conversion system according to claim 11, characterized in that: The AC power source has a positive half cycle and a negative half cycle. During the first time of the positive half cycle, the second switching unit is in a conducting state and the first, third and second switching units are in a non-conducting state to form a first loop and a second loop. The first loop charges the first energy storage unit from the first end of the AC power source through the positive end of the first energy storage unit and enters from the negative end of the first energy storage unit to the anode of the first charging unit, and returns to the second end of the AC power source through the cathode of the first charging unit. The second loop enters from the first end of the AC power supply through one end of the primary side of the first transformer and from the other end of the primary side of the first transformer to one end of the second switching unit, flows through the resistance unit via the other end of the second switching unit to the anode of the first unidirectional conductive unit, and returns to the second end of the AC power supply through the cathode of the first unidirectional conductive unit; wherein the secondary side of the first transformer outputs a reverse voltage to make the third unidirectional conductive unit non-conductive in the reverse direction, so that the first transformer stores energy and the positive terminal of the output capacitor discharges the load.

13. The power conversion system according to claim 12, characterized in that: During the second time of the positive half cycle, the first, second and third switching units are in a non-conducting state to form a third loop and a fourth loop; the third loop charges the first energy storage unit from the first end of the AC power supply through the positive end of the first energy storage unit and enters from the negative end of the first energy storage unit to the anode of the first charging unit, and returns to the second end of the AC power supply through the cathode of the first charging unit; Wherein, the second switching unit is non-conductive so that the first transformer releases its stored energy, and the secondary side of the first transformer outputs a forward voltage to form the fourth loop, and the fourth loop is formed by outputting the forward voltage from one end of the secondary side of the first transformer, which is forward-conducted through the anode of the third unidirectional conductive unit and then enters the positive side of the output capacitor from its cathode; wherein the secondary side of the first transformer charges the output capacitor and supplies power to the load.

14. The power conversion system according to claim 13, characterized in that: At the third time of the negative half cycle, the third switching unit is in the conducting state and the first, second and third switching units are in the non-conducting state to form a fifth loop and a sixth loop; the fifth loop is forwardly conducted from the second end of the AC power supply through the anode of the second charging unit, enters the positive side of the second energy storage unit from the cathode of the second charging unit to charge the second energy storage unit, and enters from the negative end of the second energy storage unit to the anode of the first unidirectional conducting unit, and returns to the first end of the AC power supply through the cathode of the first unidirectional conducting unit; The sixth loop enters from the second end of the AC power supply through one end of the primary side of the second transformer and from the other end of the primary side of the second transformer to one end of the third switching unit, flows through the resistor unit via the other end of the third switching unit to the anode of the first unidirectional conductive unit, and returns to the first end of the AC power supply through the cathode of the first unidirectional conductive unit; The secondary side of the second transformer outputs a reverse voltage to make the fourth unidirectional conducting unit non-conductive in the reverse direction, so that the second transformer stores energy and the output capacitor discharges the load.

15. The power conversion system according to claim 14, characterized in that: At the fourth time of the negative half cycle, the first, second and third switching units are in a non-conducting state to form a seventh loop and an eighth loop; the seventh loop is forwardly conducted from the second end of the AC power source through the anode of the second charging unit, enters the positive side of the second energy storage unit from the cathode of the second charging unit to charge the second energy storage unit, and enters from the negative end of the second energy storage unit to the anode of the first unidirectional conducting unit, and returns to the first end of the AC power source through the cathode of the first unidirectional conducting unit; The third switching unit is non-conductive so that the second transformer releases its stored energy, and the secondary side of the second transformer outputs a positive voltage to form the eighth loop, and the eighth loop is formed by the positive voltage outputted from one end of the secondary side of the second transformer, which is forward-conducted through the anode of the fourth unidirectional conductive unit and then enters the positive side of the output capacitor through its cathode; The secondary side of the second transformer charges the output capacitor and supplies power to the load.

16. The power conversion system according to claim 15, characterized in that: It is further provided with a detection circuit, and when the detection circuit detects that the AC power supply is open, it drives the first switching unit to conduct to form a second discharge loop, a first time in series connection, and a second time in series connection; when the first time in series connection, the second switching unit is conducted and the third and second switching units are not conducted, wherein the first energy storage unit and the second energy storage unit are connected in series, and the second discharge loop is from the positive terminal of the first energy storage unit to one end of the primary side of the first transformer and from the other end of the primary side of the first transformer to one end of the second switching unit, flows through the resistor unit through the other end of the second switching unit to the negative terminal of the second energy storage unit, and then enters from the positive terminal of the second energy storage unit through the first switching unit to the negative terminal of the first energy storage unit; The secondary side of the first transformer outputs a reverse voltage to make the third unidirectional conducting unit non-conductive in the reverse direction, so that the first transformer stores energy and the output capacitor discharges the load.

17. The power conversion system according to claim 16, characterized in that: When the second series connection time is reached, the first switching unit is turned on and the second and third switching units are turned off, the second switching unit is turned off so that the first transformer releases its stored energy, and the positive voltage output by one end of the secondary side of the first transformer enters the positive side of the output capacitor through the cathode after being forward-conducted by the anode of the third unidirectional conductive unit; The secondary side of the first transformer charges the output capacitor and supplies power to the load.

18. The power conversion system according to claim 15, characterized in that: It is further provided with a detection circuit, and when the detection circuit detects that the AC power source is open, it drives the third switching unit and the second switching unit to conduct to form a third discharge loop, parallel to the first time and parallel to the second time; During the first parallel connection time, the second switching unit is turned on and the first and third switching units are turned off, wherein the first energy storage unit and the second energy storage unit are connected in parallel, and the third discharge loop is electrically connected to one end of the primary side of the first transformer from the positive terminal of the first energy storage unit and the positive terminal of the second energy storage unit and enters from the other end of the primary side of the first transformer to one end of the second switching unit, flows through the resistor unit to the negative terminal of the second energy storage unit and through the third switching unit to the negative terminal of the first energy storage unit via the other end of the second switching unit, and then the positive terminal of the second energy storage unit is connected to the positive terminal of the first energy storage unit through the second switching unit; The secondary side of the first transformer outputs a reverse voltage to make the third unidirectional conducting unit non-conductive in the reverse direction, so that the first transformer stores energy and the output capacitor discharges the load.

19. The power conversion system according to claim 18, characterized in that: During the second parallel connection time, the third and second switching units are conducting and the first, second and third switching units are not conducting; wherein the second switching unit is not conducting so that the first transformer releases its stored energy, and a positive voltage output from one end of the secondary side of the first transformer is forwardly conducted through the anode of the third unidirectional conducting unit and then enters the positive side of the output capacitor from its cathode; The secondary side of the first transformer charges the output capacitor and supplies power to the load.

Images