Ac-dc circuit and power supply device

Abstract

The application provides an ACDC circuit and a power supply device. The circuit comprises a rectification module, a leakage module and a direct current conversion module; the direct current conversion module comprises an output capacitor; the rectification module, a first output end of which is connected with a first end of the leakage module and a first input end of the direct current conversion module respectively, and a second output end of which is connected with a second input end of the direct current conversion module; the direct current conversion module, a first output end and a second output end of which are used for connecting a load, and the first output end is further connected with a second end of the leakage module; the output capacitor is connected between the first output end and the second output end of the direct current conversion module; when an output voltage of the rectification module is greater than the sum of a voltage between the leakage module and the output capacitor, the output voltage of the rectification module is discharged to the output capacitor and the load through the leakage module. When a peak voltage appears at the output end of the rectification module, the peak voltage is discharged to the output capacitor and the load through the leakage module, and there is no problem of device selection and explosion.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power supply, in particular to an ACDC circuit and a power supply device. BACKGROUND

[0002] The traditional AC-DC circuit topology usually adopts a rectification topology including a rectifier bridge or a thyristor to convert input alternating current into direct current, and then adopts an isolated or non-isolated direct current conversion topology to perform step-up / down processing on the rectified direct current to supply power to a load. However, due to the existence of input line inductance, the rectified direct current may have a sharp voltage at the input surge or at the input closing moment, and the sharp voltage may act on the semiconductor devices in the direct current conversion topology, possibly causing damage or destruction of the semiconductor devices.

[0003] In order to solve the above problem, a TVS (Transient Voltage Suppressor) or a varistor is usually added after the rectification topology or on the three-phase line of the input alternating current. When there is a sharp voltage, the TVS or the varistor is instantly turned on to discharge the energy of the line inductance, thereby achieving the purpose of suppressing the voltage spike. However, the TVS and the varistor are uncontrolled devices, and their operating voltage values are in the form of discrete steps. For different circuits, the TVS and the varistor with a suitable operating voltage may not be selected; in addition, once the TVS and the varistor are turned on, they will remain on until they are destroyed unless the front-end energy is discharged to the safe voltage value of the TVS and the varistor. SUMMARY

[0004] The embodiments of the present application provide an ACDC circuit and a power supply device to solve the problems that the TVS and the varistor cannot be applied to all circuits as protection devices due to the non-continuous step form of the operating voltage values of the TVS and the varistor, and the TVS and the varistor may be destroyed once they are turned on.

[0005] In a first aspect, the embodiments of the present application provide an ACDC circuit, comprising a rectification module, a discharge module and a direct current conversion module; the direct current conversion module comprises an output capacitor;

[0006] The input end of the rectification module is used to connect an external power supply, the first output end of the rectification module is connected with the first end of the discharge module and the first input end of the direct current conversion module respectively, the second output end of the rectification module is connected with the second input end of the direct current conversion module; the first output end of the direct current conversion module and the second output end of the direct current conversion module are used to connect a load, the first output end of the direct current conversion module is further connected with the second end of the discharge module, and the output capacitor is connected between the first output end of the direct current conversion module and the second output end of the direct current conversion module.

[0007] When the output voltage of the rectifying module is greater than the sum of the voltage across the bleeder module and the voltage across the output capacitor, the output voltage of the rectifying module bleeds through the bleeder module to the output capacitor and the load.

[0008] In a possible implementation, when the output voltage of the rectifying module is less than the sum of the voltage across the bleeder module and the voltage across the output capacitor, a bleeder loop inside the bleeder module works to reduce the voltage across the bleeder module until the output voltage of the rectifying module is equal to the sum of the voltage across the bleeder module and the voltage across the output capacitor.

[0009] In a possible implementation, the bleeder module comprises a unidirectional conduction element and a bleeder loop.

[0010] The first end of the unidirectional conduction element is connected to the first end of the bleeder module, the second end of the unidirectional conduction element is connected to the first end of the bleeder loop, and the second end of the bleeder loop is connected to the second end of the bleeder module.

[0011] In a possible implementation, the bleeder loop comprises a first capacitor and a first resistor connected in parallel.

[0012] When the output voltage of the rectifying module is greater than the sum of the voltage across the first capacitor and the voltage across the output capacitor, the output voltage of the rectifying module bleeds through the unidirectional conduction element and the first capacitor to the output capacitor and the load.

[0013] In a possible implementation, when the output voltage of the rectifying module is less than the sum of the voltage across the first capacitor and the voltage across the output capacitor, the first capacitor is discharged through the first resistor to reduce the voltage across the first capacitor until the output voltage of the rectifying module is equal to the sum of the voltage across the first capacitor and the voltage across the output capacitor.

[0014] In a possible implementation, the bleeder module further comprises a second resistor.

[0015] The second end of the bleeder loop is connected to the second end of the bleeder module through the second resistor.

[0016] In a possible implementation, the unidirectional conduction element comprises a diode.

[0017] The anode of the diode is connected to the first end of the bleeder module, and the cathode of the diode is connected to the first end of the bleeder loop.

[0018] In a possible implementation, the direct current conversion module is a non-isolated circuit.

[0019] In a possible implementation, the direct current conversion module comprises a buck-boost circuit, and the rectifying module comprises a rectifying circuit.

[0020] In a second aspect, an embodiment of the present application provides a power supply device, comprising the ACDC circuit according to the first aspect or any possible implementation of the first aspect.

[0021] The ACDC circuit and the power supply device provided by the embodiments of the present application can quickly discharge the output voltage of the rectifier module to the output capacitor and the load through the discharge module when the output voltage of the rectifier module is greater than the sum of the voltage across the discharge module and the voltage across the output capacitor, so as to charge the output capacitor and be consumed by the load, and the output voltage of the rectifier module can be quickly discharged to the output of the ACDC circuit through the discharge module, so as to stabilize the output voltage of the rectifier module. Compared with the TVS and the voltage-dependent resistor, the discharge speed is more timely, the discharge voltage does not need to reach the specified grading voltage of the TVS or the voltage-dependent resistor, and the excess energy is absorbed by the load, so that the energy is not converted into heat energy in the ACDC circuit, the temperature rise of the ACDC circuit is increased, and the device selection problem and the explosion problem of the TVS and the voltage-dependent resistor do not exist. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0023] Figure 1 is a structural schematic diagram of the ACDC circuit provided by an embodiment of the present application;

[0024] Figure 2 is a structural schematic diagram of the ACDC circuit provided by another embodiment of the present application;

[0025] Figure 3 is a structural schematic diagram of the ACDC circuit provided by another embodiment of the present application. DETAILED DESCRIPTION

[0026] In the following description, specific details such as specific system structures, techniques, etc. are presented in order to thoroughly understand the embodiments of the present application. However, it should be clear to those skilled in the art that the present application can also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits and methods are omitted to avoid unnecessary details that hinder the description of the present application.

[0027] In order to make the objects, technical solutions and advantages of the present application clearer, the following will be described in detail with specific embodiments in conjunction with the accompanying drawings.

[0028] As mentioned above, since the TVS and the voltage-dependent resistor are both uncontrolled devices, the action voltage values thereof are in the form of discrete grades, and for different circuits, the TVS and the voltage-dependent resistor with appropriate action voltage values cannot be selected. For example, for the TVS, the action voltage values of two adjacent grades thereof are 400V and 500V respectively, and for the circuit with the requirement of 400V and 500V, the appropriate TVS cannot be selected.

[0029] In addition, since the TVS and the voltage-dependent resistor are both uncontrolled devices, once they are turned on, they will be always turned on until they are destroyed, unless the front-end energy is discharged to the safe voltage value considered by the TVS and the voltage-dependent resistor.

[0030] In view of the above problems, the embodiment of the present application proposes an ACDC circuit, which is described in detail as follows.

[0031] Referring to Figure 1 , a structural schematic diagram of the ACDC circuit is shown. The ACDC circuit comprises a rectification module 12, a discharge module 13 and a direct-current conversion module 14; the direct-current conversion module 14 comprises an output capacitor Cout;

[0032] The input end of the rectification module 12 is used for connecting an external power supply 11, the first output end of the rectification module 12 is connected with the first end of the discharge module 13 and the first input end of the direct-current conversion module 14 respectively, the second output end of the rectification module 12 is connected with the second input end of the direct-current conversion module 14; the first output end of the direct-current conversion module 14 and the second output end of the direct-current conversion module 14 are used for connecting a load Rload, the first output end of the direct-current conversion module 14 is further connected with the second end of the discharge module 13, and the output capacitor Cout is connected between the first output end of the direct-current conversion module 14 and the second output end of the direct-current conversion module 14;

[0033] When the output voltage of the rectification module 12 is greater than the sum of the voltage between the discharge module 13 and the voltage between the output capacitor Cout, the output voltage of the rectification module 12 is discharged to the output capacitor Cout and the load Rload through the discharge module 13.

[0034] Wherein, ACDC circuit is the circuit of AC to DC. The external power supply 11 outputs AC. The rectifier module 12 is used to convert the AC output by the external power supply 11 into DC. The DC conversion module 14 is used to step up or down the DC output by the rectifier module 12 and supply the processed DC to the load Rload. The discharge module 13 is used to discharge the output voltage of the rectifier module 12 when the output voltage is too high, discharge it to the circuit output, charge the output capacitor Cout, and be consumed by the load Rload to avoid damaging the device.

[0035] In this embodiment, when the output voltage of the rectifier module 12 is greater than the sum of the voltage across the discharge module 13 and the voltage across the output capacitor Cout, the discharge module 13 starts to work and discharges the output voltage of the rectifier module 12 to the output capacitor Cout and the load Rload, charges the output capacitor Cout, and is consumed by the load Rload. When the output voltage of the rectifier module 12 is too high, it can be quickly discharged to the output of the entire circuit to stabilize the output voltage of the rectifier module 12.

[0036] The discharge module 13 is equivalent to the positive feedback link in the loop control, which can disturb the output voltage of the rectifier module 12 (the input voltage of the DC conversion module) without passing through the loop control, and quickly discharge it to the output of the DC conversion module 14 to stabilize the output voltage of the rectifier module 12 (the input voltage of the DC conversion module).

[0037] The ACDC circuit of this embodiment includes a rectifier module 12, a discharge module 13, and a DC conversion module 14. The DC conversion module 14 includes an output capacitor Cout. When the output voltage of the rectifier module 12 is greater than the sum of the voltage across the discharge module 13 and the voltage across the output capacitor Cout, the output voltage of the rectifier module 12 is discharged to the output capacitor Cout and the load Rload through the discharge module 13. When a spike voltage appears at the output of the rectifier module 12, it can be discharged to the output capacitor Cout and the load Rload through the discharge module 13, charge the output capacitor Cout, and be consumed by the load Rload. The discharge module 13 can quickly discharge the output voltage of the rectifier module 12 to the output of the ACDC circuit to stabilize the output voltage of the rectifier module 12. Compared with TVS and varistor, the discharge speed is more timely, the discharge voltage does not need to reach the specified grading voltage of TVS or varistor, and the excess energy is absorbed by the load Rload without being converted into heat energy inside the ACDC circuit, which increases the temperature rise of the ACDC circuit. There is no device selection problem and explosion problem as in TVS and varistor.

[0038] In some embodiments, when the output voltage of the rectifier module 12 is less than the sum of the voltage across the bleeder module 13 and the voltage across the output capacitor Cout, the bleeder circuit inside the bleeder module 13 works to reduce the voltage across the bleeder module 13 until the output voltage of the rectifier module 12 is equal to the sum of the voltage across the bleeder module 13 and the voltage across the output capacitor Cout.

[0039] In some embodiments, when the output voltage of the rectifier module 12 is less than the sum of the voltage across the bleeder module 13 and the voltage across the output capacitor Cout, the bleeder circuit inside the bleeder module 13 works to reduce the voltage across the bleeder module 13 until the output voltage of the rectifier module 12 is equal to the sum of the voltage across the bleeder module 13 and the voltage across the output capacitor Cout.

[0040] In some embodiments, referring to Figure 2 , the bleeder module 13 comprises a unidirectional conducting element 131 and a bleeder circuit 132;

[0041] The first end of the unidirectional conducting element 131 is connected to the first end of the bleeder module 13, the second end of the unidirectional conducting element 131 is connected to the first end of the bleeder circuit 132, and the second end of the bleeder circuit 132 is connected to the second end of the bleeder module 13.

[0042] In some embodiments, referring to Figure 3 , the bleeder circuit 132 comprises a first capacitor C1 and a first resistor R1 connected in parallel;

[0043] When the output voltage of the rectifier module 12 is greater than the sum of the voltage across the first capacitor C1 and the voltage across the output capacitor Cout, the output voltage of the rectifier module 12 is discharged to the output capacitor Cout and the load Rload through the unidirectional conducting element 131 and the first capacitor C1.

[0044] In this embodiment, when the output voltage of the rectifier module 12 is greater than the sum of the voltage across the first capacitor C1 and the voltage across the output capacitor Cout, the unidirectional conducting element 131 is turned on, and the output voltage of the rectifier module 12 is discharged to the output capacitor Cout and the load Rload through the unidirectional conducting element 131 and the first capacitor C1, charging the output capacitor Cout, and the load Rload consumes power, i.e., path 1 in Figure 3

[0045] ​In some embodiments, when the output voltage of the rectifying module 12 is less than the sum of the voltage across the first capacitor C1 and the voltage across the output capacitor Cout, the first capacitor C1 is discharged through the first resistor R1 to reduce the voltage across the first capacitor C1 until the output voltage of the rectifying module 12 is equal to the sum of the voltage across the first capacitor C1 and the voltage across the output capacitor Cout.

[0046] In the present embodiment, when the output voltage of the rectifying module 12 is less than the sum of the voltage across the first capacitor C1 and the voltage across the output capacitor Cout, the unidirectional conducting element 131 is cut off, the first capacitor C1 is discharged through the first resistor R1 (i.e. path 2 in Figure 3 ), the voltage across the first capacitor C1 gradually decreases until the output voltage of the rectifying module 12 is equal to the sum of the voltage across the first capacitor C1 and the voltage across the output capacitor Cout, the first capacitor C1 stops discharging and is ready to discharge the next peak voltage of the rectifying module 12.

[0047] In some embodiments, referring to Figure 3 , the discharging module 13 further comprises a second resistor R2;

[0048] The second end of the discharging loop 132 is connected to the second end of the discharging module 13 through the second resistor R2.

[0049] In some embodiments, referring to Figure 3 , the unidirectional conducting element 131 comprises a diode D1;

[0050] The anode of the diode D1 is connected to the first end of the discharging module 13, and the cathode of the diode D1 is connected to the first end of the discharging loop 132.

[0051] In other embodiments, the unidirectional conducting element 131 can be a controllable switch, such as a MOS tube, a triode or an IGBT, etc. The controllable switch is turned on to discharge energy according to the timing of energy discharge.

[0052] In some embodiments, the direct current conversion module 14 can be a non-isolated circuit or an isolated circuit.

[0053] The present embodiment is applicable to the case where the direct current conversion module is a non-isolated circuit.

[0054] In some embodiments, the direct current conversion module 14 comprises a boost-buck circuit, and the rectifying module 12 comprises a rectifying circuit.

[0055] The boost-buck circuit can be used for voltage boosting or voltage bucking, and can be an existing boost-buck circuit, which is not specifically limited herein. The boost-buck circuit can be a non-isolated circuit or an isolated circuit.

[0056] The rectifier circuit for converting alternating current into direct current can include a rectifier bridge or thyristor, etc.

[0057] Corresponding to the above-mentioned ACDC circuit, the embodiment of the present application also provides a power supply device, comprising any one of the above-mentioned ACDC circuits, having the beneficial effects of any one of the above-mentioned ACDC circuits.

[0058] It can be clearly understood by those skilled in the art that, for the convenience and brevity of description, only the above-mentioned division of each functional unit and module is exemplified, and in actual application, the above-mentioned functions can be completed by different functional units and modules according to needs, that is, the internal structure of the device is divided into different functional units or modules to complete all or part of the functions described above. Each functional unit and module in the embodiment can be integrated in one processing unit, or each unit can exist physically, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or in the form of software functional unit. In addition, the specific name of each functional unit and module is only for easy distinction, and does not limit the protection scope of the present application.

[0059] In the above-mentioned embodiments, the description of each embodiment has its own emphasis, and the parts not described or recorded in detail in a certain embodiment can be referred to the related description of other embodiments.

[0060] Those skilled in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be realized in electronic hardware or in combination of computer software and electronic hardware. Whether the functions are realized in hardware or software depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to realize the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0061] In the embodiments provided by the present application, it should be understood that the disclosed ACDC circuit and device can be implemented in other ways. For example, the above-mentioned ACDC circuit embodiments are only schematic, for example, the division of the modules or units is only a logical function division, and actual implementation can have another division manner, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units shown or discussed can be indirect coupling or communication connection through some interface, device or unit, and can be electrical, mechanical or other forms.

[0062] The units described as separate components may or may not be physically separate, and the components displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Part or all of the units can be selected to achieve the purpose of the embodiment scheme according to actual needs.

[0063] In addition, each functional unit in each embodiment of the application can be integrated in one processing unit, or each unit can exist physically, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or in the form of a software functional unit.

[0064] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. An ACDC circuit, characterized by The ACDC circuit comprises a rectifier module, a bleeder module and a DC conversion module; the DC conversion module comprises an output capacitor; an input end of the rectifier module is used for connecting an external power supply, a first output end of the rectifier module is connected with a first end of the bleeder module and a first input end of the DC conversion module respectively, a second output end of the rectifier module is connected with a second input end of the DC conversion module; a first output end of the DC conversion module and a second output end of the DC conversion module are used for connecting a load, the first output end of the DC conversion module is further connected with a second end of the bleeder module, and the output capacitor is connected between the first output end of the DC conversion module and the second output end of the DC conversion module; when an output voltage of the rectifier module is greater than a sum of a voltage between the bleeder module and the output capacitor, the output voltage of the rectifier module is discharged to the output capacitor and the load through the bleeder module.

2. An ACDC circuit according to claim 1, characterised in that, when the output voltage of the rectifier module is less than the sum of the voltage between the bleeder module and the output capacitor, a bleeder loop inside the bleeder module works to reduce the voltage between the bleeder module, until the output voltage of the rectifier module is equal to the sum of the voltage between the bleeder module and the output capacitor.

3. An ACDC circuit according to claim 1, characterised in that, The bleeder module comprises a unidirectional conduction element and a bleeder loop; a first end of the unidirectional conduction element is connected with the first end of the bleeder module, a second end of the unidirectional conduction element is connected with a first end of the bleeder loop, and a second end of the bleeder loop is connected with the second end of the bleeder module.

4. An ACDC circuit according to claim 3, characterised in that, The bleeder loop comprises a first capacitor and a first resistor connected in parallel; when the output voltage of the rectifier module is greater than a sum of a voltage between the first capacitor and the output capacitor, the output voltage of the rectifier module is discharged to the output capacitor and the load through the unidirectional conduction element and the first capacitor.

5. An ACDC circuit according to claim 4, wherein, when the output voltage of the rectifier module is less than the sum of the voltage between the first capacitor and the output capacitor, the first capacitor is discharged through the first resistor to reduce the voltage between the first capacitor, until the output voltage of the rectifier module is equal to the sum of the voltage between the first capacitor and the output capacitor.

6. An ACDC circuit according to claim 3, wherein, The bleeder module further comprises a second resistor; the second end of the bleeder loop is connected with the second end of the bleeder module through the second resistor.

7. An ACDC circuit according to claim 3, wherein, The unidirectional conduction element comprises a diode; a positive electrode of the diode is connected with the first end of the bleeder module, and a negative electrode of the diode is connected with the first end of the bleeder loop.

8. An ACDC circuit according to any one of claims 1 to 7, characterised in that, The DC conversion module is a non-isolated circuit.

9. An ACDC circuit according to any one of claims 1 to 7, characterised in that, The DC conversion module comprises a buck-boost circuit; and the rectifier module comprises a rectifier circuit.

10. A power supply device characterized by comprising: The ACDC circuit comprises the ACDC circuit according to any one of claims 1 to 9.

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