Charging Circuit

Abstract

The present invention discloses a charging circuit, including a capacitor; a DC power supply, the negative electrode of the DC power supply is connected to one end of the capacitor; a unidirectional conduction unit, the output end of the unidirectional conduction unit is connected to the positive electrode of the DC power supply, and the input end of the unidirectional conduction unit is connected to the other end of the capacitor; a DC switching power supply, the DC switching power supply is connected in parallel with the capacitor, and the DC switching power supply is used to charge the DC power supply. The circuit connects a unidirectional conduction unit in series between the capacitor and the positive electrode of the DC power supply, the input end of the unidirectional conduction unit is connected to the capacitor, and the output end is connected to the positive electrode of the DC power supply, thereby preventing the DC power supply from pouring into the capacitor, avoiding the impact caused by the large pressure difference at both ends of the capacitor, preventing the capacitor from bursting or other components from being damaged, and the circuit is simple and reliable.

Description

Technical Field

[0001] The present invention relates to the technical field of circuits, and in particular to a charging circuit. Background Art

[0002] In a general circuit, such as Figure 1 As shown, a circuit connected in parallel with a capacitor is usually provided with a pre-charging circuit to charge the capacitor to prevent a huge voltage difference from being generated across the capacitor when the capacitor is put into the circuit, thereby forming a large impact and causing the capacitor to explode or damage other components.

[0003] However, the above-mentioned charging circuit in the form of a pre-charging loop has the following problems:

[0004] 1) The circuit structure is complex and the control is complex;

[0005] 2) Two devices are needed to realize the anti-shock function of the capacitor, which is large in size and high in cost. Summary of the invention

[0006] The present invention aims to solve one of the technical problems in the related art to at least a certain extent. To this end, one object of the present invention is to provide a charging circuit that can avoid the impact caused by the large voltage difference between the two ends of the capacitor, prevent the capacitor from bursting or other components from being damaged, and the circuit is simple and reliable.

[0007] To achieve the above-mentioned purpose, the present invention proposes a charging circuit, comprising a capacitor, and also comprising: a DC power supply, wherein the negative electrode of the DC power supply is connected to one end of the capacitor; a unidirectional conducting unit, wherein the output end of the unidirectional conducting unit is connected to the positive electrode of the DC power supply, and the input end of the unidirectional conducting unit is connected to the other end of the capacitor; and a DC switching power supply, wherein the DC switching power supply is connected in parallel with the capacitor, and the DC switching power supply is used to charge the DC power supply.

[0008] According to the charging circuit of the embodiment of the present invention, a unidirectional conduction unit is connected in series between the capacitor and the positive electrode of the DC power supply, the input end of the unidirectional conduction unit is connected to the capacitor, and the output end is connected to the positive electrode of the DC power supply. The reverse cutoff function of the unidirectional conduction unit is utilized to prevent the DC power supply electric energy from entering the capacitor, avoid the impact caused by the large voltage difference across the capacitor, prevent the capacitor from exploding or other components from being damaged, and the circuit is simple and reliable, ensuring simple and efficient DC power supply charging control, while improving economic benefits.

[0009] In addition, the charging circuit of the above embodiment of the present invention may also have the following additional technical features:

[0010] According to an embodiment of the present invention, the charging circuit further includes: a controller, the controller is connected to the DC switching power supply, and the controller is used to control the DC switching power supply to adjust the output voltage.

[0011] According to one embodiment of the present invention, the charging circuit further includes: a controllable switch, which is connected in series with the unidirectional conductive unit; wherein the controller is also connected to the controllable switch, and the controller is used to control the closing and opening of the controllable switch.

[0012] According to one embodiment of the present invention, the charging circuit further includes: a first voltage sampling circuit, which is connected in parallel with the DC power supply and is used to collect the voltage across the DC power supply; a second voltage sampling circuit, which is connected in parallel with the capacitor and is used to collect the voltage across the capacitor; wherein the controller is also connected to the first voltage sampling circuit and the second voltage sampling circuit respectively, and the controller is used to control the DC switching power supply and the controllable switch according to the voltage across the DC power supply and the voltage across the capacitor.

[0013] According to an embodiment of the present invention, the DC switching power supply includes an AC power supply and a rectifier circuit, wherein the AC power supply is connected to an input end of the rectifier circuit, and an output end of the rectifier circuit is connected to the capacitor.

[0014] According to an embodiment of the present invention, the rectifier circuit is a bridge rectifier circuit.

[0015] According to one embodiment of the present invention, the bridge rectifier circuit includes four IGBT tubes, wherein the controller is respectively connected to the control ends of the four IGBT tubes to control the voltage at the output end of the DC switching power supply.

[0016] According to an embodiment of the present invention, the unidirectional conducting unit comprises a diode, a cathode of the diode is connected to the positive electrode of the DC power supply, and an anode of the diode is connected to the other end of the capacitor.

[0017] According to an embodiment of the present invention, the DC power supply is a capacitor or a rechargeable battery.

[0018] According to an embodiment of the present invention, the controllable switch is a contactor, a circuit breaker or a relay.

[0019] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of a charging circuit in the related art;

[0021] Figure 2 is a schematic structural diagram of a charging circuit according to a first embodiment of the present invention;

[0022] Figure 3 is a schematic structural diagram of a charging circuit according to a second embodiment of the present invention;

[0023] Figure 4 is a schematic structural diagram of a charging circuit according to a third embodiment of the present invention;

[0024] Figure 5 4 is a schematic diagram of the structure of a charging circuit according to a fourth embodiment of the present invention. DETAILED DESCRIPTION

[0025] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0026] The charging circuit according to the embodiment of the present invention will be described below with reference to the accompanying drawings.

[0027] Figure 2 is a schematic diagram of the structure of a charging circuit according to an embodiment of the present invention. Figure 2 As shown, the charging circuit includes a capacitor C, a DC power supply 10, a unidirectional conduction unit 30 and a DC switching power supply 20.

[0028] Among them, the negative electrode of the DC power supply 10 is connected to one end of the capacitor C; the output end of the unidirectional conductive unit 30 is connected to the positive electrode of the DC power supply 10, and the input end of the unidirectional conductive unit 30 is connected to the other end of the capacitor C; the DC switching power supply 20 is connected in parallel with the capacitor C, and the DC switching power supply 20 is used to charge the DC power supply 10.

[0029] In this embodiment, when the DC switching power supply 20 and / or the capacitor C are discharged, the input end to the output end of the unidirectional conduction unit 30 is connected, and when the DC power supply 10 is discharged, the output end to the input end of the unidirectional conduction unit 30 is cut off. The DC power supply 10 can be a capacitor or a rechargeable battery.

[0030] The charging circuit has a unidirectional conduction unit connected in series between the capacitor and the positive electrode of the DC power supply, the input end of the unidirectional conduction unit is connected to the capacitor, and the output end is connected to the positive electrode of the DC power supply. The reverse cutoff function of the unidirectional conduction unit is utilized to prevent the DC power supply from pouring into the capacitor, thus avoiding the impact caused by the large voltage difference at both ends of the capacitor, preventing the capacitor from bursting or other components from being damaged. The circuit is simple and reliable, ensuring the simplicity and efficiency of the DC power supply charging control, while improving the economic benefits.

[0031] In one embodiment of the present invention, Figure 3 As shown, the charging circuit may further include a controller 40, which is connected to the DC switching power supply 20, and is used to control the DC switching power supply 20 to adjust the output voltage.

[0032] Furthermore, if Figure 4 As shown, the charging circuit further includes a controllable switch K, which is connected in series with the unidirectional conducting unit 30. The controllable switch K may be, but is not limited to, a contactor, a circuit breaker or a relay.

[0033] In this embodiment, the controller 40 is also connected to the controllable switch K, and the controller 40 is used to control the closing and opening of the controllable switch K.

[0034] Furthermore, if Figure 5 As shown, the charging circuit may further include: a first voltage sampling circuit 50 and a second voltage sampling circuit 60. The first voltage sampling circuit 50 is connected in parallel with the DC power supply 10, and the first voltage sampling circuit 50 is used to collect the voltage across the DC power supply 10; the second voltage sampling circuit 60 is connected in parallel with the capacitor C, and the second voltage sampling circuit 60 is used to collect the voltage across the capacitor C.

[0035] In this embodiment, the controller 40 is also connected to the first voltage sampling circuit 50 and the second voltage sampling circuit 60 respectively, and the controller 40 is used to control the DC switching power supply 20 and the controllable switch K according to the voltage across the DC power supply 10 and the voltage across the capacitor C.

[0036] See also Figure 5 The DC switching power supply 20 includes an AC power supply AC and a rectifier circuit (such as a bridge rectifier circuit), wherein the bridge rectifier circuit is composed of multiple ( Figure 5 The schematic diagram shows a DC switching power supply 20 composed of 4 IGBTs (Insulated Gate Bipolar Transistors), and a controller 40 is connected to the control end of each IGBT tube to control the voltage at the output end of the DC switching power supply 20 by turning the IGBT tube on and off.

[0037] In one embodiment of the present invention, Figure 5As shown, the unidirectional conducting unit 30 may include a diode D, a cathode of the diode D is connected to the positive electrode of the DC power supply 10, and an anode of the diode D is connected to the other end of the capacitor C.

[0038] For ease of understanding, the following Figure 5 The example shown describes the charging circuit in detail.

[0039] like Figure 5 As shown, the output end of the DC switching power supply 20 is connected in parallel with the capacitor C, the second voltage sampling circuit 60 is connected in parallel at both ends of the capacitor C, the positive electrode of the capacitor C is connected to the anode of the unidirectional conductive unit 30, the cathode of the unidirectional conductive unit 30 is connected to one end of the controllable switch K, the other end of the controllable switch K is connected to the positive electrode of the DC power supply 10, the negative electrode of the DC power supply 10 is connected to the negative electrode of the capacitor C, and the first voltage sampling circuit 50 is connected in parallel at both ends of the DC power supply 10.

[0040] The specific working process of the charging circuit is as follows:

[0041] After the DC switching power supply 20 is started, the capacitor C starts to charge, and the first voltage sampling circuit 50 and the second voltage sampling circuit 60 start to work, respectively collecting the voltage across the DC power supply 10 and the voltage across the capacitor C, and then comparing them.

[0042] If the voltage across capacitor C is less than or equal to the voltage across DC power supply 10 in the initial state, the electric energy of DC power supply 10 will not be injected into capacitor C due to the unidirectional conductivity of diode D. At this time, controller 40 can directly control controllable switch K to close, and there will be no impact on capacitor C, and the whole circuit is in a relatively stable state. Then, controller 40 controls DC switching power supply 20 to increase the output voltage and control the output current according to the voltage at the output end of DC switching power supply 20 (i.e., the voltage across capacitor C) and the voltage across DC power supply 10, so as to charge DC power supply 10.

[0043] If the voltage across capacitor C is greater than the voltage across DC power supply 10 in the initial state, controller 40 can control DC switching power supply 20 to adjust the output voltage so that the voltage across capacitor C is less than or equal to the voltage across DC power supply 10, and then control controllable switch K to close. Due to the unidirectional conductivity of diode D, the electric energy of DC power supply 10 will not be injected into capacitor C, that is, there will be no impact on capacitor C, and the whole circuit is in a relatively stable state. Then, controller 40 increases the output voltage and controls the output current according to the voltage at the output end of DC switching power supply 20 and the voltage across DC power supply 10, so as to charge DC power supply 10.

[0044] In summary, compared with Figure 1The prior art shown in the figure, the charging circuit of the present invention adopts a circuit in which a controllable switch and a diode are connected in series, and the structural design is simpler, the control method is also relatively simple, and the cost is lower, the volume is smaller, the reliability is higher, and better economic and space benefits can be achieved.

[0045] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0046] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0047] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0048] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0049] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0050] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A charging circuit, comprising a capacitor, characterized in that: Also includes: A direct current power supply, wherein a negative electrode of the direct current power supply is connected to one end of the capacitor; A unidirectional conductive unit, wherein the output end of the unidirectional conductive unit is connected to the positive electrode of the DC power supply, and the input end of the unidirectional conductive unit is connected to the other end of the capacitor; A DC switching power supply, the DC switching power supply is connected in parallel with the capacitor, and the DC switching power supply is used to charge the DC power supply; Also includes: A controller, the controller is connected to the DC switching power supply, and the controller is used to control the DC switching power supply to adjust the output voltage; Also includes: A controllable switch, the controllable switch being connected in series with the unidirectional conducting unit; Wherein, the controller is also connected to the controllable switch, and the controller is used to control the closing and opening of the controllable switch; Also includes: a first voltage sampling circuit, the first voltage sampling circuit being connected in parallel with the DC power supply, and the first voltage sampling circuit being used to collect voltages at both ends of the DC power supply; a second voltage sampling circuit, the second voltage sampling circuit being connected in parallel with the capacitor, and the second voltage sampling circuit being used to collect the voltage across the capacitor; The controller is also connected to the first voltage sampling circuit and the second voltage sampling circuit respectively, and the controller is used to control the DC switching power supply and the controllable switch according to the voltage across the DC power supply and the voltage across the capacitor; After the DC switching power supply is started, the capacitor starts to charge, and the first voltage sampling circuit and the second voltage sampling circuit start to work to respectively collect the voltage across the DC power supply and the voltage across the capacitor; If in the initial state, the voltage across the capacitor is less than or equal to the voltage across the DC power supply, the controller directly controls the controllable switch to close, and the controller controls the DC switching power supply to increase the output voltage and control the output current according to the voltage at the output end of the DC switching power supply and the voltage across the DC power supply, so as to charge the DC power supply; If in the initial state, the voltage across the capacitor is greater than the voltage across the DC power supply, the controller controls the DC switching power supply to adjust the output voltage so that the voltage across the capacitor is less than or equal to the voltage across the DC power supply, and then controls the controllable switch to close. The controller increases the output voltage and controls the output current according to the voltage at the output end of the DC switching power supply and the voltage across the DC power supply to charge the DC power supply.

2. The charging circuit according to claim 1, characterized in that: The DC switching power supply includes an AC power supply and a rectifier circuit, wherein the AC power supply is connected to an input end of the rectifier circuit, and an output end of the rectifier circuit is connected to the capacitor.

3. The charging circuit according to claim 2, characterized in that: The rectifier circuit adopts a bridge rectifier circuit.

4. The charging circuit according to claim 3, characterized in that: The bridge rectifier circuit includes four IGBT tubes, wherein the controller is connected to the control ends of the four IGBT tubes respectively to control the voltage at the output end of the DC switching power supply.

5. The charging circuit according to claim 1, characterized in that: The unidirectional conducting unit comprises a diode, a cathode of the diode is connected to the positive electrode of the DC power supply, and an anode of the diode is connected to the other end of the capacitor.

6. The charging circuit according to claim 1, characterized in that: The DC power source is a capacitor or a rechargeable battery.

7. The charging circuit according to claim 1, characterized in that: The controllable switch is a contactor, a circuit breaker or a relay.

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