CN114244090A - Step-down conversion circuit, alternating current converter and direct current power supply system - Google Patents
Step-down conversion circuit, alternating current converter and direct current power supply system Download PDFInfo
- Publication number
- CN114244090A CN114244090A CN202111311354.4A CN202111311354A CN114244090A CN 114244090 A CN114244090 A CN 114244090A CN 202111311354 A CN202111311354 A CN 202111311354A CN 114244090 A CN114244090 A CN 114244090A
- Authority
- CN
- China
- Prior art keywords
- capacitor
- output side
- bus
- inductor
- type
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000006243 chemical reaction Methods 0.000 title claims abstract description 36
- 239000003990 capacitor Substances 0.000 claims abstract description 108
- 230000009467 reduction Effects 0.000 claims abstract description 8
- 230000009471 action Effects 0.000 abstract description 8
- 230000002349 favourable effect Effects 0.000 abstract 1
- 206010014357 Electric shock Diseases 0.000 description 13
- 238000010586 diagram Methods 0.000 description 8
- 208000027418 Wounds and injury Diseases 0.000 description 7
- 230000006378 damage Effects 0.000 description 7
- 208000014674 injury Diseases 0.000 description 7
- 230000005669 field effect Effects 0.000 description 4
- 208000003663 ventricular fibrillation Diseases 0.000 description 3
- 230000000712 assembly Effects 0.000 description 2
- 238000000429 assembly Methods 0.000 description 2
- 238000004891 communication Methods 0.000 description 2
- 230000001681 protective effect Effects 0.000 description 2
- 239000004065 semiconductor Substances 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000002457 bidirectional effect Effects 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000004146 energy storage Methods 0.000 description 1
- 238000005286 illumination Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 244000144972 livestock Species 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 230000002441 reversible effect Effects 0.000 description 1
- 230000001360 synchronised effect Effects 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/32—Means for protecting converters other than automatic disconnection
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M3/00—Conversion of dc power input into dc power output
- H02M3/02—Conversion of dc power input into dc power output without intermediate conversion into ac
- H02M3/04—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M3/00—Conversion of dc power input into dc power output
- H02M3/02—Conversion of dc power input into dc power output without intermediate conversion into ac
- H02M3/04—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters
- H02M3/06—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using resistors or capacitors, e.g. potential divider
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M3/00—Conversion of dc power input into dc power output
- H02M3/02—Conversion of dc power input into dc power output without intermediate conversion into ac
- H02M3/04—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters
- H02M3/10—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M3/145—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
- H02M3/155—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M3/156—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M3/00—Conversion of dc power input into dc power output
- H02M3/02—Conversion of dc power input into dc power output without intermediate conversion into ac
- H02M3/04—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters
- H02M3/10—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M3/145—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
- H02M3/155—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M3/156—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators
- H02M3/158—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators including plural semiconductor devices as final control devices for a single load
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Dc-Dc Converters (AREA)
Abstract
The application relates to a step-down conversion circuit, an alternating current converter and a direct current power supply system, wherein the step-down conversion circuit comprises a first switch component, a first inductor, a first capacitor, a second capacitor and a freewheeling diode; the first end of the first switch component is connected with the first type input side bus, the second end of the first switch component is connected with the first end of the first inductor, and the second end of the first inductor is connected with the first type output side bus; the first capacitor is connected with the second capacitor in series, and the formed common end is grounded; the other end of the first capacitor is connected with a first type output side bus; the other end of the second capacitor is connected with a second type output side bus; the anode of the freewheeling diode is connected with the second type input side bus and the second type output side bus; the cathode of the freewheeling diode is connected with the first end of the first inductor. The voltage reduction conversion circuit limits the amplitude of the voltage to earth of the positive bus and the negative bus on the output side by utilizing the clamping action of the first capacitor and the second capacitor, and is favorable for improving the use safety of the circuit.
Description
Technical Field
The application relates to the technical field of current conversion, in particular to a voltage reduction conversion circuit, an alternating current converter and a direct current power supply system.
Background
The step-down conversion circuit is a direct current-direct current conversion circuit for reducing voltage, the voltage of an output end of the step-down conversion circuit is lower than that of an input end of the step-down conversion circuit, and the step-down conversion circuit is widely applied to the fields of low-voltage loads such as lamp illumination, an ammeter system and the like. The step-down conversion circuit is generally directly connected with a load through a positive bus and a negative bus of an output end, and during use, an electric shock accident of a human body can be caused by the fault of the positive bus and the negative bus of the output end.
According to the traditional step-down conversion circuit, the output side negative bus is directly connected with the input side negative bus, the voltage to ground of the output side positive bus is small, but the amplitude of the voltage to ground of the output side negative bus is half of the amplitude of the input voltage, and serious electric shock injury is easily caused in the human body electric shock process. Therefore, the conventional buck conversion circuit has the disadvantage of poor safety in use.
Disclosure of Invention
In view of the above, it is desirable to provide a step-down converter circuit, an ac converter, and a dc power supply system that are safe to use.
In a first aspect, the present application provides a buck conversion circuit. The voltage reduction conversion circuit comprises a first switch component, a first inductor, a first capacitor, a second capacitor and a freewheeling diode;
the first end of the first switch assembly is connected with a first type input side bus, the second end of the first switch assembly is connected with the first end of the first inductor, and the second end of the first inductor is connected with a first type output side bus;
the first capacitor is connected with the second capacitor in series, and a formed common end is grounded; the other end of the first capacitor is connected with a first type output side bus; the other end of the second capacitor is connected with a second type output side bus;
the anode of the freewheeling diode is connected with a second type input side bus and the second type output side bus; and the cathode of the freewheeling diode is connected with the first end of the first inductor.
In one embodiment, the first capacitor and the second capacitor have equal capacitance.
In one embodiment, the first type output side bus is an output side positive bus, and the capacitance of the first capacitor is larger than that of the second capacitor.
In one embodiment, the buck conversion circuit further comprises a second switch component and a second inductor, wherein a first end of the second switch component is connected with an anode of the freewheeling diode, and a second end of the second switch component is connected with the second-type input-side bus; the first end of the second inductor is connected with the second type output side bus, and the second end of the second inductor is connected with the first end of the second switch assembly;
the second switch assembly and the first switch assembly are switched on and off simultaneously.
In one embodiment, the first inductor and the second inductor are the same type of inductor.
In one embodiment, the second switch component is an insulated gate bipolar transistor.
In one embodiment, the first switch component is an insulated gate bipolar transistor.
In a second aspect, the present application further provides an ac converter. The alternating current converter comprises a rectifying circuit and the voltage reduction conversion circuit; the output side of the rectifying circuit is connected with the input side of the voltage reduction conversion circuit; the input side of the rectification circuit is used for connecting an alternating current power supply; the output side of the step-down conversion circuit is used for connecting a load.
In one embodiment, the rectification circuit is an AC/DC converter.
In a third aspect, the present application further provides a dc power supply system. The direct current power supply system comprises an alternating current power supply and the alternating current converter, and the alternating current converter is connected with the alternating current power supply.
According to the voltage reduction conversion circuit, the alternating current converter and the direct current power supply system, the first capacitor and the second capacitor which are connected in series are arranged between the first type output side bus and the second type output side bus, namely the output side positive bus and the output side negative bus, the common end of the first capacitor and the common end of the second capacitor are grounded, the voltage amplitude of the output side positive bus and the output side negative bus to the ground is limited by the clamping action of the first capacitor and the second capacitor, and the use safety of the circuit is improved.
Drawings
FIG. 1 is a schematic circuit diagram of a buck converter circuit in one embodiment;
FIG. 2 is an equivalent circuit diagram of the first switch element S1 of FIG. 1 when it is turned on;
FIG. 3 is an equivalent circuit diagram of the first switch module S1 of FIG. 1 when it is turned off;
FIG. 4 is a schematic circuit diagram of a buck converter circuit in another embodiment;
FIG. 5 is an equivalent circuit diagram of the first switch module S1 and the second switch module S2 of FIG. 4 when they are turned on;
FIG. 6 is an equivalent circuit diagram of the first switch module S1 and the second switch module S2 of FIG. 4 when they are turned off;
FIG. 7 is a block diagram of the components of an AC converter in one embodiment;
fig. 8 is a block diagram of the dc power supply system according to an embodiment.
Detailed Description
In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.
It will be understood that, as used herein, the terms "first," "second," and the like may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, a first capacitance may be referred to as a second capacitance, and similarly, a second capacitance may be referred to as a first capacitance, without departing from the scope of the present application. The first and second capacitances are both capacitances, but they are not the same capacitance.
It is to be understood that "connection" in the following embodiments is to be understood as "electrical connection", "communication connection", and the like if the connected circuits, modules, units, and the like have communication of electrical signals or data with each other.
As used herein, the singular forms "a", "an" and "the" may include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises/comprising," "includes" or "including," etc., specify the presence of stated features, integers, steps, operations, components, parts, or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof. Also, as used in this specification, the term "and/or" includes any and all combinations of the associated listed items.
As described in the background art, the conventional buck conversion circuit has a disadvantage of poor safety, and the inventors have found through research that the reason for this problem is as follows: on one hand, in a direct current system, the fault current generated by a positive bus on a human body flows to hands, and the fault current generated by a negative bus flows to hands, and according to the standard GB/T13870.5-2016 'effect of current on people and livestock', the current amplitude required by the direct current flowing upwards through the human body from two feet to two hands to generate ventricular fibrillation is smaller than that required by the ventricular fibrillation generated in the downward direction, and the ventricular fibrillation threshold value corresponding to the direct current in the downward direction is about twice as large as that in the upward direction, namely, even if the voltage amplitudes of the positive bus and the negative bus to the ground are the same, the electric shock injury generated by the human body contacting the negative bus is larger than that generated by contacting the positive bus; on the other hand, in the conventional buck conversion circuit, the voltage to ground of the output side positive bus is small, but the amplitude of the voltage to ground of the output side negative bus is half of the amplitude of the input voltage, although the electric shock injury caused by the fault of the output side positive bus is reduced, the electric shock hazard caused by the output side negative bus is larger, and the electric shock injury of the output side negative bus can be caused even if the system contains a Residual Current Protective Device (RCD) and other electric shock Protective measures along with the increase of the output voltage level. Further, in the conventional step-down conversion circuit, under an extreme condition that the output voltage is half of the input voltage, since the voltage to ground of the output-side negative bus is half of the amplitude of the input voltage, and the voltage to ground of the output-side positive bus is zero, a phenomenon that the ground fault of the output-side positive bus cannot be identified may occur, which may cause potential safety hazards.
Based on this, the application provides a step-down converting circuit, an alternating current converter and a direct current power supply system, and improves the use safety of the circuit through the improvement of the circuit structure. In one embodiment, as shown in fig. 1, the buck conversion circuit includes a first switching component S1, a first inductor L1, a first capacitor C1, a second capacitor C2, and a freewheeling diode D1. The first terminal of the first switch module S1 is connected to the first type input side bus, the second terminal of the first switch module S1 is connected to the first terminal of the first inductor L1, and the second terminal of the first inductor L1 is connected to the first type output side bus. The first capacitor C1 is connected with the second capacitor C2 in series, and the formed common end is grounded; the other end of the first capacitor C1 is connected with a first type output side bus; the other end of the second capacitor C2 is connected to the second-type output-side bus. The anode of the freewheeling diode D1 is connected to the second-type input-side bus and the second-type output-side bus; the cathode of the freewheeling diode D1 is connected to the first terminal of the first inductor L1.
The type of the first switch element S1 is not exclusive, and may be a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) or an IGBT (Insulated Gate Bipolar Transistor), for example. The parameters of the first capacitor C1 and the second capacitor C2 may be the same or different, and the types of the two capacitors are not unique, and may be, for example, an organic dielectric capacitor, an inorganic dielectric capacitor, an electrolytic capacitor, or the like. The first inductor L1 may be a single inductor or an inductor assembly formed by connecting a plurality of inductors in series. Similarly, the first capacitor C1 and the second capacitor C2 may be a single capacitor or a capacitor assembly composed of a plurality of capacitors. The connection mode of the plurality of capacitors can be series connection, parallel connection or series-parallel connection. For convenience of understanding, as shown in fig. 1, the following description will be given by taking a case where the first inductor L1 is a single inductor and the first capacitor C1 and the second capacitor C2 are single capacitors, respectively, as an example.
Further, the first type input side bus bar is an input side positive/negative bus bar, and correspondingly, the second type input side bus bar is an input side negative/positive bus bar. Similarly, the first type output side bus is an output side positive/negative bus, and correspondingly, the second type output side bus is an output side negative/positive bus. The positive and negative polarities of the first type input side bus bar and the first type output side bus bar are the same, and the positive and negative polarities of the second type input side bus bar and the second type output side bus bar are the same. For easy understanding, as shown in fig. 1, the first type input side bus is hereinafter used as the input side positive bus l1+The second type input side bus is the input side negative bus1-The first type output side bus is the output side positive bus l2+The second type output side bus is an output side negative bus l2-The following description will be given by way of example.
Specifically, when the first switch assembly S1 is turned on, as shown in FIG. 2The freewheeling diode D1 is shown in the off state, with the input voltage UdcThe first inductor L1 and the first and second capacitors C1, C2 are charged and power is supplied to the load R. At this time, the output side positive bus l2+Is clamped by a first capacitor C1 at the output side, and a negative bus l at the output side2-Is clamped by the second capacitor C2 on the output side. When the first switching component S1 is turned off, as shown in fig. 3, the freewheeling diode D1 is in a conducting state, the first inductor L1 supplies power to the load R through the freewheeling diode D1, and the first capacitor C1 and the second capacitor C2 also supply power to the load R. At this time, the step-down converting circuit is not directly electrically connected with the preceding stage circuit, the output voltage of the step-down converting circuit is stabilized by the first capacitor C1, the second capacitor C2 and the first inductor L1, and since the operating frequency of the circuit is very high and the capacities of the inductor and the capacitor are large, the output voltage and the output current are approximately considered to be unchanged before and after the first switch module S1 is turned off.
That is, by reasonably selecting the types of the first capacitor C1 and the second capacitor C2, the output side negative bus l can be prevented from appearing2-A phenomenon in which voltage to ground is high. For example, in the case that the first type of output side bus is the output side positive bus, the capacitance of the first capacitor C1 may be made greater than or equal to the capacitance of the second capacitor C2, or the capacitance of the second capacitor C2 may be made smaller than a predetermined threshold value, so as to lower the output side negative bus l2-To the magnitude of the voltage to ground.
In one embodiment, the capacitance of the first capacitor C1 is equal to the capacitance of the second capacitor C2, and the voltages to ground of the positive and negative buses on the output side are u respectivelyL2+＝Udc1/2，uL2-＝-Udc1/2, i.e. the amplitude of the positive and negative bus to ground voltage is less than UdcThe output side negative bus l can be reduced while the workload of device model selection is reduced2-The voltage to ground of (2) and then the safety in utilization of the circuit is improved.
In another embodiment, the first type of output side bus is an output side positive bus, the capacitance of the first capacitor C1 is greater than the capacitance of the second capacitor C2, and the output side positive busThread l2+To ground voltage uL2+＞Udc1Output side negative bus bar2-Amplitude-u of voltage to groundL2+＜Udc1And 2, under the condition that the voltages of the positive bus and the negative bus to the ground are the same in amplitude, the electric shock injury generated when a human body contacts the negative bus is larger than that generated when the human body contacts the positive bus, so that the electric shock injury generated when the human body is in electric shock can be reduced, and the use safety of the circuit is further improved.
The step-down conversion circuit is formed by arranging the first type output side bus and the second type output side bus, namely the output side positive bus l2+And output side negative bus l2-The first capacitor C1 and the second capacitor C2 are arranged in series, the common end of the first capacitor C1 and the common end of the second capacitor C2 are grounded, and the clamping action of the first capacitor C1 and the clamping action of the second capacitor C2 are utilized, so that on one hand, the amplitude of the voltage to the ground of the positive bus and the negative bus on the output side can be limited, the use safety of the circuit is improved, on the other hand, the extreme condition that the output voltage is half of the input voltage can be avoided, and the negative bus l on the output side is caused2-The voltage to ground is half of the amplitude of the input voltage, and the output side positive bus l2+The ground voltage is zero, and the phenomenon that the ground fault of the positive bus at the output side cannot be identified further improves the use safety of the circuit.
In one embodiment, as shown in fig. 4, the buck conversion circuit further includes a second switching element S2 and a second inductor L2. A first end of the second switch assembly S2 is connected with the anode of a freewheeling diode D1, and a second end of the second switch assembly S2 is connected with the second type input side bus; a first end of the second inductor L2 is connected to the second type output side bus bar, and a second end of the second inductor L2 is connected to a first end of the second switch module S2. The second switch assembly S2 is turned on and off simultaneously with the first switch assembly S1.
For specific limitations of the second switch assembly S2, refer to the limitations of the first switch assembly S1, and are not described herein again. The manner of controlling the second switch assembly S2 to be turned on and off simultaneously with the first switch assembly S1 is not exclusive, e.g., the same controller may be used to send the same control signals to the first switch assembly S1 and the second switch assembly S2 simultaneously; different controllers can also be used to control different switch assemblies respectively, and the control signals are kept synchronous through clock signals. Further, the parameters of the first inductance L1 and the second inductance L2 may be the same or different, and the types of the two are not unique, and may be, for example, an adjustable inductor or a choke inductor. In one embodiment, the first inductor L1 and the second inductor L2 are inductors of the same type, so that the workload of device type selection can be reduced, and the working efficiency of circuit construction is improved.
The second type input side bus is also used as the input side negative bus l1-And the second type output side bus is an output side negative bus l2-For example, when the first switch assembly S1 and the second switch assembly S2 are turned on, as shown in fig. 5, the freewheeling diode D1 is in the off state and the input voltage U isdcThe first inductor L1, the second inductor L2, and the first capacitor C1, the second capacitor C2 are charged, and energy is provided to the load R. At this time, the output side positive bus l2+Is clamped by a first capacitor C1 at the output side, and a negative bus l at the output side2-Is clamped by the second capacitor C2 on the output side. As shown in fig. 6, when the first switching component S1 and the second switching component S2 are turned off, the freewheeling diode D1 is in a conducting state, the first inductor L1 and the second inductor L2 supply power to the load R through the freewheeling diode D1, and the first capacitor C1 and the second capacitor C2 also supply power to the load R. At this time, the step-down converting circuit is not directly electrically connected with the preceding stage circuit, the output voltage of the step-down converting circuit is stabilized by the first capacitor C1, the second capacitor C2, the first inductor L1 and the second inductor L2, and the output voltage and the output current are approximately considered to be unchanged before and after the switching component is turned off due to the high operating frequency of the circuit and the large capacitance of the inductor and the capacitor.
Similarly, the output side negative bus l can be avoided by reasonably selecting the types of the first capacitor C1 and the second capacitor C22-A phenomenon in which voltage to ground is high. For example, the capacitance of the first capacitor C1 may be greater than or equal to the capacitance of the second capacitor C2, or the capacitance of the second capacitor C2 may be less than a predetermined threshold to reduce the outputSide negative bus bar2-To the magnitude of the voltage to ground. Taking the case that the capacitance of the first capacitor C1 is equal to the capacitance of the second capacitor C2 as an example, at this time, the voltages to ground of the positive and negative buses on the output side are uL2+＝Udc1/2，uL2-＝-Udc1/2, i.e. the amplitude of the positive and negative bus to ground voltage is less than Udc/2, the reduction of the negative bus l at the output side can be achieved2-To ground voltage amplitude purposes.
In one embodiment, the buck conversion circuit has a symmetrical circuit structure, that is, the device models of the first switch module S1 and the second switch module S2 are the same, the device models of the first capacitor C1 and the second capacitor C2 are the same, and the device models of the first inductor L1 and the second inductor L2 are the same. At this time, the voltages to ground of the positive and negative buses on the output side are respectively uL2+＝Udc1/2，uL2-＝-Udc1The voltage to ground of the positive bus and the negative bus on the output side is in a symmetrical state, so that the electric shock injury generated when the electric shock accident occurs to the negative bus on the output side is reduced, the device model selection workload is reduced, and the circuit building efficiency is improved.
In the above embodiment, the switch assemblies and the inductors are respectively arranged between the first type input side bus and the first type output side bus, and between the second type input side bus and the second type output side bus, so that the amplitude of the voltage to ground of the output side negative bus can be further ensured to be smaller than that of the input side negative bus, and the use safety of the circuit can be further improved.
In one embodiment, the first switch assembly S1 and/or the second switch assembly S2 is an insulated gate bipolar transistor.
The Insulated Gate Bipolar Transistor (IGBT) is a composite fully-controlled voltage-driven power semiconductor device consisting of a transistor and an insulated gate field effect transistor, and has the advantages of high input impedance of the insulated gate field effect transistor and low conduction voltage drop of the transistor. The saturation voltage of the transistor is reduced, the current-carrying density is high, but the driving current is high; the insulated gate field effect transistor has small driving power, high switching speed, large conduction voltage drop and small current-carrying density. The insulated gate bipolar transistor integrates the advantages of the two devices, and has the characteristics of high input impedance, low voltage control power consumption, simple control circuit, high voltage resistance, large current bearing capacity and the like.
Specifically, as shown in fig. 4, the equivalent circuit of the igbt includes a transistor and a freewheeling diode. Among them, the free wheel diode is provided particularly for protecting a weak reverse withstand voltage of the IGBT. The on-off of the triode can be controlled by inputting a control signal to the control end of the triode, so that the on-off of the IGBT is controlled.
In the above embodiment, the first switch module S1 and/or the second switch module S2 are/is an insulated gate bipolar transistor, and the performance of the step-down conversion circuit is favorably improved based on the advantages of high input impedance, low voltage control power consumption, simple control circuit, high voltage resistance, large current bearing capacity and the like of the insulated gate bipolar transistor.
In one embodiment, as shown in fig. 7, there is provided an ac converter including a rectifying circuit 110 and the above-mentioned step-down converting circuit 120; the output side of the rectifying circuit 110 is connected to the input side of the step-down converting circuit 120; the input side of the rectifying circuit 110 is used for connecting an alternating current power supply; the output side of the buck converter circuit 120 is used to connect a load.
The specific limitations of the buck converter circuit 120 are as described above, and are not described herein again. The rectifier circuit 110 is a circuit that can convert ac power into dc power. The rectifying circuit 110 is composed of rectifying diodes, and the voltage after passing through the rectifying circuit is not an alternating voltage but a unidirectional pulsating direct voltage. Further, the rectifier circuit 110 may be a half-wave rectifier circuit, a full-wave rectifier circuit, a bridge rectifier circuit, a voltage doubler rectifier circuit, or the like. In summary, the present embodiment does not limit the type and specific device configuration of the rectifier circuit 110.
Specifically, the output side of the rectifying circuit 110 is specifically connected to the input side positive and negative bus bars of the step-down converting circuit 120, and the step-down converting circuit 120 is specifically connected to the load through the output side positive and negative bus bars. The input side of the rectifying circuit 110 is used for connecting an ac power supply, converting ac power output by the ac power supply into dc power, outputting the dc power to the step-down converting circuit 120, and performing step-down processing on the dc power by the step-down converting circuit 120 to obtain dc power required by load operation. It should be understood that the ac power source may be a three-phase commercial power or an ac power grid.
The AC converter, wherein the step-down converting circuit 120 is arranged between the first type output side bus and the second type output side bus, i.e. the output side positive bus l2+And output side negative bus l2-The first capacitor C1 and the second capacitor C2 are arranged in series, the common end of the first capacitor C1 and the common end of the second capacitor C2 are grounded, and the clamping action of the first capacitor C1 and the clamping action of the second capacitor C2 are utilized, so that on one hand, the amplitude of the voltage to the ground of the positive bus and the negative bus on the output side can be limited, the use safety of the circuit is improved, on the other hand, the extreme condition that the output voltage is half of the input voltage can be avoided, and the negative bus l on the output side is caused2-The voltage to ground is half of the amplitude of the input voltage, and the output side positive bus l2+The ground voltage is zero, and the phenomenon that the ground fault of the positive bus at the output side cannot be identified further improves the use safety of the circuit.
In one embodiment, the rectification circuit 110 is an AC/DC converter.
The AC/DC converter is a device for converting AC power into DC power, and the power flow direction thereof may be bidirectional, the power flow from the power source to the load is called rectification, and the power flow from the load back to the power source is called active inversion. The rectifying circuit 110 is an AC/DC converter, which has both rectifying and inverting functions, and when the AC power supply is an AC power grid, the AC converter is a grid-connected converter, which is beneficial to expanding the application scenarios of the AC converter.
In one embodiment, as shown in fig. 8, a dc power supply system is provided, which includes an ac power source 200 and the ac converter 100 described above, wherein the ac converter 100 is connected to the ac power source 200.
The ac power supply 200 may be an ac power plug, which obtains ac power by connecting to the mains, or an energy storage ac power supply. Specifically, the ac power supplied by the ac power supply 200 passes through the ac converter 100 to obtain the dc power required by the subsequent load, and supplies power to the load.
In the dc power supply system, the step-down converting circuit 120 in the ac converter 100 is provided on the first type output side bus and the second type output side bus, i.e., the output side positive bus l2+And output side negative bus l2-The first capacitor C1 and the second capacitor C2 are arranged in series, the common end of the first capacitor C1 and the common end of the second capacitor C2 are grounded, and the clamping action of the first capacitor C1 and the clamping action of the second capacitor C2 are utilized, so that on one hand, the amplitude of the voltage to the ground of the positive bus and the negative bus on the output side can be limited, the use safety of the circuit is improved, on the other hand, the extreme condition that the output voltage is half of the input voltage can be avoided, and the negative bus l on the output side is caused2-The voltage to ground is half of the amplitude of the input voltage, and the output side positive bus l2+The ground voltage is zero, and the phenomenon that the ground fault of the positive bus at the output side cannot be identified further improves the use safety of the circuit.
The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above examples only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.
Claims (10)
1. A buck conversion circuit is characterized by comprising a first switch component, a first inductor, a first capacitor, a second capacitor and a freewheeling diode;
the first end of the first switch assembly is connected with a first type input side bus, the second end of the first switch assembly is connected with the first end of the first inductor, and the second end of the first inductor is connected with a first type output side bus;
the first capacitor is connected with the second capacitor in series, and a formed common end is grounded; the other end of the first capacitor is connected with the first type output side bus; the other end of the second capacitor is connected with a second type output side bus;
the anode of the freewheeling diode is connected with a second type input side bus and the second type output side bus; and the cathode of the freewheeling diode is connected with the first end of the first inductor.
2. The buck converter circuit according to claim 1, wherein the first capacitor and the second capacitor have equal capacitance.
3. The buck converter circuit according to claim 1, wherein the first type of output side bus is an output side positive bus, and wherein a capacitance of the first capacitor is greater than a capacitance of the second capacitor.
4. The buck conversion circuit according to claim 2, further comprising a second switching component and a second inductor, wherein a first end of the second switching component is connected to an anode of the freewheeling diode, and a second end of the second switching component is connected to the second-type input-side bus; the first end of the second inductor is connected with the second type output side bus, and the second end of the second inductor is connected with the first end of the second switch assembly;
the second switch assembly and the first switch assembly are switched on and off simultaneously.
5. The buck conversion circuit according to claim 4, wherein the first inductor and the second inductor are the same type of inductor.
6. The buck conversion circuit according to claim 4, wherein the second switch component is an insulated gate bipolar transistor.
7. The buck converter circuit according to any one of claims 1 to 6, wherein the first switch component is an insulated gate bipolar transistor.
8. An ac converter comprising a rectifying circuit and the step-down converting circuit according to any one of claims 1 to 7; the output side of the rectifying circuit is connected with the input side of the voltage reduction conversion circuit; the input side of the rectification circuit is used for connecting an alternating current power supply; the output side of the step-down conversion circuit is used for connecting a load.
9. An alternating current converter according to claim 8, wherein the rectifying circuit is an AC/DC converter.
10. A dc power supply system comprising an ac power source and an ac converter according to claim 8 or 9, said ac converter being connected to said ac power source.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111311354.4A CN114244090A (en) | 2021-11-08 | 2021-11-08 | Step-down conversion circuit, alternating current converter and direct current power supply system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111311354.4A CN114244090A (en) | 2021-11-08 | 2021-11-08 | Step-down conversion circuit, alternating current converter and direct current power supply system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114244090A true CN114244090A (en) | 2022-03-25 |
Family
ID=80748771
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111311354.4A Pending CN114244090A (en) | 2021-11-08 | 2021-11-08 | Step-down conversion circuit, alternating current converter and direct current power supply system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114244090A (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002153063A (en) * | 2000-11-08 | 2002-05-24 | Fuji Electric Co Ltd | Dc boosting/deboosting circuit |
| CN104124866A (en) * | 2013-04-26 | 2014-10-29 | 丰郅(上海)新能源科技有限公司 | Step-on and step-down two-way direct-current converter topology |
| KR102282679B1 (en) * | 2021-02-03 | 2021-07-28 | (주)그린파워 | Direct Charging Device for Electric Vehicle |
-
2021
- 2021-11-08 CN CN202111311354.4A patent/CN114244090A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002153063A (en) * | 2000-11-08 | 2002-05-24 | Fuji Electric Co Ltd | Dc boosting/deboosting circuit |
| CN104124866A (en) * | 2013-04-26 | 2014-10-29 | 丰郅(上海)新能源科技有限公司 | Step-on and step-down two-way direct-current converter topology |
| KR102282679B1 (en) * | 2021-02-03 | 2021-07-28 | (주)그린파워 | Direct Charging Device for Electric Vehicle |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106663940B (en) | Three-class power topology | |
| US20130070504A1 (en) | Non-isolated inverter and related control manner thereof and application using the same | |
| CN109167524A (en) | A kind of three-phase alternating current-direct current buck translation circuit and its control method | |
| WO2003107522A1 (en) | Impedance source power converter | |
| CN106605360A (en) | Inverter | |
| CN105141019A (en) | Electric vehicle charging system | |
| WO2015096613A1 (en) | Online interactive uninterruptible power supply and control method therefor | |
| Suresh et al. | A novel dual-leg DC-DC converter for wide range DC-AC conversion | |
| CN102158110A (en) | Main circuit of non-isolated photovoltaic grid inverter and control realizing method thereof | |
| CN102291019A (en) | Full-bridge rectification-direct-current push-pull inversion AC-DC (alternating current-to-direct current) converter | |
| CN103647448B (en) | Integrated step-down-flyback type high power factor constant current circuit and device | |
| US11990830B2 (en) | Power conversion system and virtual DC voltage generator circuit | |
| CN108141147A (en) | The five-electrical level inverter topological circuit of high voltage gain | |
| CN105958855B (en) | A kind of quasi- Z-source inverter of high-gain | |
| US10917004B2 (en) | Snubber circuit and power conversion system using same | |
| CN111509992B (en) | Alternating current power supply circuit, control method thereof and alternating current power supply | |
| CN112713792A (en) | Full bridge inverter with single polarity switching scheme and method of operating the same | |
| KR101993846B1 (en) | Power Conversion Apparatus for ESS | |
| US7791914B1 (en) | High efficiency power supply front end | |
| CN114244090A (en) | Step-down conversion circuit, alternating current converter and direct current power supply system | |
| CN115765507A (en) | Three-level double-step-down conversion circuit for energy storage and inversion integrated device rear stage | |
| CN105048827B (en) | Voltage doubling rectifing circuit | |
| CN204349788U (en) | The pre-charge circuit of DC bus and converter system | |
| CN210405105U (en) | Frequency converter and frequency converter system | |
| CN204835962U (en) | Voltage doubler rectifier circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |