An intrinsically safe uninterruptible power supply topology and its implementation method

Abstract

The present invention discloses an intrinsically safe uninterruptible power supply topology and implementation method, which can solve the technical problems of low efficiency, large loss and high temperature rise of existing intrinsically safe power supplies. It includes an input unit and a discharge circuit located on the primary side of the transformer, an output unit and a charging circuit located on the secondary side of the transformer, and the output unit is output to the intrinsically safe power supply through a safety barrier circuit; the input unit is connected to the AC power supply, and the input unit side is also connected to a power failure detection circuit for detecting whether the AC power supply is powered off; the charging circuit and the discharge circuit are both connected to a backup battery, and the backup battery is also connected to a voltage detection circuit; the input unit, the charging circuit and the discharge circuit respectively control the on and off of their respective circuit loops through a switch control circuit. The present invention can switch to different working modes under different power supply states, so that energy transfer only needs one conversion, achieving the purpose of efficient conversion of isolated power supply.

Description

Technical Field

[0001] The invention relates to the field of explosion-proof intrinsically safe power supplies, in particular to an intrinsically safe uninterruptible power supply topology and an implementation method thereof. Background Art

[0002] With the diversification and complexity of underground electrical equipment, the requirements for intrinsically safe power supplies are becoming higher and higher, such as higher isolation voltage, higher conversion efficiency, uninterruptible power supply, etc. The existing intrinsically safe power supplies for realizing the above functions have the disadvantages of low efficiency, high loss, high temperature rise, etc. In view of this, the applicant proposes an intrinsically safe uninterruptible power supply topology and implementation method. Summary of the invention

[0003] The purpose of the present invention is to provide an intrinsically safe uninterruptible power supply topology and implementation method, which can solve the technical problems of low efficiency, large loss and high temperature rise of existing intrinsically safe power supplies.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] An intrinsically safe uninterruptible power supply topology includes an input unit and a discharge circuit located on the primary side of a transformer, an output unit and a charging circuit located on the secondary side of the transformer, wherein the output unit outputs to an intrinsically safe power supply through a safety barrier circuit; the input unit is connected to an AC power supply, and a power-off detection circuit for detecting whether the AC power supply is powered off is also connected to the input unit side; the charging circuit and the discharge circuit are both connected to a backup battery, and a voltage detection circuit is also connected to the backup battery; according to the detection results of the power-off detection circuit and the voltage detection circuit, the input unit, the charging circuit and the discharge circuit respectively control the on and off of their respective circuit loops through a switch control circuit.

[0006] As an improved solution of the present invention, in order to realize the AC rectification and high-frequency modulation functions and complete the primary side function of the AC / DC power supply, the input unit includes a rectifier bridge D1 connected to the AC power supply, and a first capacitor C1 is connected in parallel to the rectifier bridge D1, a first end of the first capacitor C1 is connected to a first end of a first switch S1, a second end of the first switch S1 is connected to a first end of a first winding L1, a second end of the first winding L1 is connected to a drain of a first field effect transistor Q1, and a source of the first field effect transistor Q1 is connected to a second end of the first capacitor C1.

[0007] As an improved solution of the present invention, in order to enable the output unit to complete the secondary side functions of the AC / DC power supply in the normal mode and the DC / DC power supply in the backup mode, the output unit includes at least one output circuit.

[0008] As an improved solution of the present invention, in order to enable the output unit to complete the secondary side functions of the AC / DC power supply in normal mode and the DC / DC power supply in backup mode, the output unit includes a first output circuit that outputs an 18V DC voltage and a second output circuit that outputs a 12V DC voltage, the first output circuit includes a second winding L2, the first end of the second winding L2 is connected to the anode of the second diode D2, the cathode of the second diode D2 is connected to the first end of the second capacitor C2, and the second end of the second capacitor C2 is connected to the second end of the second winding L2; the second output circuit includes a third winding L3, the first end of the third winding L3 is connected to the anode of the third diode D3, the cathode of the third diode D3 is connected to the first end of the third capacitor C3, and the second end of the third capacitor C3 is connected to the second end of the third winding L3; the second capacitor C2 and the third capacitor C3 are respectively connected in parallel with the safety barrier circuit, and the safety barrier circuit outputs to the intrinsically safe power supply.

[0009] As an improved solution of the present invention, in order to realize charging of the backup battery, the charging circuit includes a fourth winding L4, a first end of the fourth winding L4 is connected to the anode of the fourth diode D4, a cathode of the fourth diode D4 is connected to the first end of the second switch S2, a second end of the second switch S2 is connected to the first end of the fourth capacitor C4 and the positive electrode of the backup battery, and a second end of the fourth capacitor C4 is respectively connected to the second end of the fourth winding L4 and the negative electrode of the backup battery.

[0010] As an improved solution of the present invention, in order to realize the discharge of the backup battery and complete the primary side function of the DC / DC power supply in the backup mode, the discharge circuit includes a fifth winding L5, a first end of the fifth winding L5 is connected in series with the third switch S3, and a second end is connected to the drain of the second field effect transistor Q2, and the source of the second field effect transistor Q2 and the third switch S3 are respectively connected to the positive and negative electrodes of the backup battery.

[0011] A method for implementing an intrinsically safe uninterruptible power supply topology comprises the steps of:

[0012] S1: The input unit is connected to the AC power supply, the switch control unit controls the first switch S1 to close, the second switch S2 and the third switch S3 to disconnect, and the power failure detection circuit detects whether the AC power supply is powered off. When the AC power supply is not powered off, the intrinsically safe power supply enters the normal mode;

[0013] S2: When the power failure detection circuit detects that the AC power fails, the switch control unit controls the first switch S1 and the second switch S2 to be disconnected and the third switch S3 to be closed, and the intrinsically safe power supply enters the backup mode;

[0014] S3: The voltage detection circuit detects whether the backup battery is under-voltage. When the backup battery is in an under-voltage state, the switch control circuit controls the first switch S1 and the second switch S2 to close, and the third switch S3 to open, and the intrinsically safe power supply enters the charging mode.

[0015] As an improved solution of the present invention, in step S2, when the power-off detection circuit detects that the AC power supply is no longer in a power-off state, the switch control circuit controls the on and off of each switch, and the intrinsically safe power supply changes from the backup mode to the normal mode.

[0016] As an improved solution of the present invention, in step S3, when the backup battery is not in an undervoltage state, the switch control circuit controls the on and off of each switch, and the intrinsically safe power supply changes from the charging mode to the normal mode.

[0017] As an improved solution of the present invention, when the intrinsically safe power supply is in the charging mode, the power-off detection circuit detects that the AC power supply is powered off, the switch control circuit controls the first switch S1 and the second switch S2 to be disconnected, and the third switch S3 to be closed, and the intrinsically safe power supply enters the backup mode; when the power-off detection circuit detects that the AC power supply is no longer in the power-off state, the intrinsically safe power supply changes from the backup mode to the charging mode.

[0018] An intrinsically safe uninterruptible power supply topology and implementation method of the present invention, on the basis of taking into account the requirements of input and output isolation, multi-channel intrinsically safe output and uninterruptible power supply of the intrinsically safe power supply, through redesigning the power supply topology, realizes that energy transfer from input unit to output unit, from input unit to charging circuit, from charging circuit to discharge circuit and from discharge circuit to output unit only needs one conversion, avoids the disadvantages of low efficiency, large loss and temperature rise caused by multi-stage series connection of power supplies, thereby achieving the purpose of efficient conversion of isolated power supply.

[0019] Beneficial effects of the present invention:

[0020] The present invention adopts power state detection and mode conversion control technology, that is, switching to different working modes under different power state, realizing energy transfer from input unit to output unit, from input unit to charging circuit, from charging circuit to discharge circuit and from discharge circuit to output unit with only one conversion, avoiding the disadvantages of low efficiency, large loss and temperature rise caused by multi-stage series connection of power supply, and achieving the purpose of efficient conversion of isolated power supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Shown is an overall schematic diagram of the intrinsically safe uninterruptible power supply of the present invention;

[0022] Figure 2 Shown is a topological schematic diagram of an intrinsically safe uninterruptible power supply of the present invention;

[0023] Figure 3Display as Figure 2 Normal mode equivalent circuit diagram;

[0024] Figure 4 Display as Figure 2 Schematic diagram of the equivalent circuit of the charging mode;

[0025] Figure 5 Display as Figure 2 Schematic diagram of the backup mode equivalent circuit;

[0026] Figure 6 Shown is a schematic diagram of the mode conversion of the intrinsically safe uninterruptible power supply of the present invention;

[0027] Figure 7 Display as Figure 6 Schematic diagram of specific steps for switching between normal mode and charging mode;

[0028] Figure 8 Display as Figure 6 Schematic diagram of the specific steps of switching between normal mode and backup mode;

[0029] Fig. 9 Display as Figure 6 Schematic diagram of the specific steps of switching between charging mode and backup mode.

[0030] Explanation of component numbers: C1 first capacitor; C2 second capacitor; C3 third capacitor; C4 fourth capacitor; D1 rectifier bridge; D2 second diode; D3 third diode; D4 fourth diode; L1 first winding; L2 second winding; L3 third winding; L4 fourth winding; L5 fifth winding; Q1 first field effect transistor; Q2 second field effect transistor; S1 first switch; S2 second switch; S3 third switch. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] Example 1, see Figure 1, an intrinsically safe uninterruptible power supply topology, including an input unit and a discharge circuit located on the primary side of a transformer, an output unit and a charging circuit located on the secondary side of the transformer, the output unit outputs to an intrinsically safe power supply (intrinsically safe uninterruptible power supply) through a safety barrier circuit; the input unit is connected to an AC power supply, and a power-off detection circuit for detecting whether the AC power supply is powered off is also connected to the input unit side; the charging circuit and the discharge circuit are both connected to a backup battery, and a voltage detection circuit is also connected to the backup battery; according to the detection results of the power-off detection circuit and the voltage detection circuit, the input unit, the charging circuit and the discharge circuit respectively control the on and off of their respective circuit loops through a switch control circuit.

[0033] In this embodiment, the power failure detection circuit is used to detect whether the AC power is lost, which serves as a judgment condition for whether to switch to the backup mode. When the AC power is detected to be normal, the input unit circuit switch is closed, the charging circuit and the discharge circuit circuit switches are disconnected, and the AC power supply provides power to the output unit; when the AC power is detected to be lost, the switch control circuit controls the discharge circuit to be closed, and the backup battery is used to provide backup power to the output unit.

[0034] In this embodiment, the voltage detection circuit is used to detect the battery power as a basis for starting and stopping the charging circuit. When the AC power supply is normal and the voltage detection circuit detects that the backup battery is undervoltage, the input unit circuit switch and the charging circuit circuit switch are closed, and the AC power supply charges the backup battery.

[0035] like Figure 2 As shown, the input unit includes a rectifier bridge D1 connected to an AC power source, a first capacitor C1 is connected in parallel to the rectifier bridge D1, a first end of the first capacitor C1 is connected to a first end of a first switch S1, a second end of the first switch S1 is connected to a first end of a first winding L1, a second end of the first winding L1 is connected to a drain of a first field effect transistor Q1, and a source of the first field effect transistor Q1 is connected to a second end of the first capacitor C1. The input unit is connected to an AC power source to realize AC rectification and high-frequency modulation functions, and complete the primary side function of an AC / DC power source.

[0036] In this embodiment, the output unit includes at least one output circuit, and in this embodiment preferably includes a first output circuit and a second output circuit, the first output circuit outputs an 18V DC voltage, and the second output circuit outputs a 12V DC voltage.

[0037] The first output circuit includes a second winding L2, a first end of the second winding L2 is connected to the anode of the second diode D2, a cathode of the second diode D2 is connected to the first end of the second capacitor C2, and a second end of the second capacitor C2 is connected to the second end of the second winding L2; the second output circuit includes a third winding L3, a first end of the third winding L3 is connected to the anode of the third diode D3, a cathode of the third diode D3 is connected to the first end of the third capacitor C3, and a second end of the third capacitor C3 is connected to the second end of the third winding L3; the second capacitor C2 and the third capacitor C3 are respectively connected in parallel with the safety barrier circuit, and the safety barrier circuit is output to the intrinsically safe power supply. The output unit is used to complete the secondary side functions of the AC / DC power supply in normal mode and the DC / DC power supply in backup mode.

[0038] The charging circuit includes a fourth winding L4, a first end of the fourth winding L4 is connected to an anode of a fourth diode D4, a cathode of the fourth diode D4 is connected to a first end of a second switch S2, a second end of the second switch S2 is connected to a first end of a fourth capacitor C4 and a positive electrode of a backup battery, and a second end of the fourth capacitor C4 is connected to a second end of the fourth winding L4 and a negative electrode of the backup battery, respectively. The charging circuit is used to realize a charging function of the backup battery.

[0039] The discharge circuit includes a fifth winding L5, a first end of the fifth winding L5 is connected in series with the third switch S3, a second end is connected to the drain of the second field effect transistor Q2, and the source of the second field effect transistor Q2 and the third switch S3 are respectively connected to the positive and negative electrodes of the backup battery. The discharge circuit is used to realize the discharge function of the backup battery and complete the primary side function of the DC / DC power supply in the backup mode; the backup battery is used to store electric energy and provide electric energy to the output unit when the AC power fails.

[0040] See also Figure 3 , shown as a normal mode equivalent circuit diagram, as Figure 3 As shown, when the AC input voltage is normal, the normal mode is achieved by closing the first switch S1 and opening the second switch S2 and the third switch S3.

[0041] See also Figure 4 , shown as a schematic diagram of the equivalent circuit of the charging mode, as Figure 4 As shown, when the battery is under-voltage, the charging mode is realized by closing the first switch S1 and the second switch S2 and opening the third switch S3.

[0042] See also Figure 5 , shown as a schematic diagram of the backup mode equivalent circuit, as Figure 5 As shown, when the AC input loses power, the backup mode is implemented by closing the third switch S3 and opening the first switch S1 and the second switch S2.

[0043] See also Figure 6, a method for realizing an intrinsically safe uninterruptible power supply, including: conversion steps and conditions between normal mode and charging mode, conversion steps and conditions between normal mode and backup mode, and conversion steps and conditions between charging mode and backup mode.

[0044] Example 2, please refer to Figure 7 , showing a schematic diagram of specific steps for switching between normal mode and charging mode, including the following steps:

[0045] S1: The input unit is connected to the AC power supply, the first switch S1 is closed by default, and before the switch control circuit is intervened, it enters the normal mode by default. As long as the AC power input voltage is within the supported voltage range, the intrinsically safe power supply can start working. At this time, the intrinsically safe power supply works as an AC / DC power supply, and the output unit outputs 18V and 12V DC voltages respectively;

[0046] S2: After the intrinsically safe power supply enters the normal mode, the voltage detection circuit starts working immediately. If it is detected that the backup battery is low in power or under voltage, the switch control circuit closes the first switch S1 and the second switch S2 and opens the third switch S3, so that the intrinsically safe power supply enters the charging mode; if the battery is not low in power, it continues to maintain the normal mode;

[0047] S3. After the intrinsically safe power supply is in charging mode, the voltage detection circuit continues to work. If it is detected that the backup battery is fully charged, the switch control circuit controls to disconnect the second switch S2, so that the intrinsically safe power supply returns to normal mode.

[0048] Example 3, please refer to Figure 8 , showing a schematic diagram of specific steps for switching between normal mode and backup mode, including the following steps:

[0049] S1: The input unit is connected to the AC power supply, the first switch S1 is closed by default, and before the switch control circuit is intervened, it enters the normal mode by default. As long as the AC power input voltage is within the supported voltage range, the intrinsically safe power supply can start working. At this time, the intrinsically safe power supply works as an AC / DC power supply, and the output unit outputs 18V and 12V DC voltages respectively;

[0050] S2: After the intrinsically safe power supply enters the normal mode, the power failure detection circuit starts working immediately. If the AC power failure is detected, the switch control circuit closes the third switch S3 and disconnects the first switch S1 and the second switch S2, so that the intrinsically safe power supply enters the backup mode; if the AC power failure is detected, the normal mode is maintained;

[0051] S3: After the intrinsically safe power supply is in the backup mode, the AC power failure detection circuit continues to work. If it is detected that the AC power supply is restored, the switch control circuit controls the third switch S3 to be disconnected and the first switch S1 to be closed, so that the intrinsically safe power supply returns to the normal mode.

[0052] Example 4, please refer to Fig. 9 , showing a schematic diagram of the specific steps of switching between charging mode and backup mode, including the following steps:

[0053] S1: As the voltage detection circuit detects that the backup battery is low on power, the switch control circuit closes the first switch S1 and the second switch S2 and opens the third switch S3, causing the intrinsically safe power supply to enter the charging mode;

[0054] S2: After the intrinsically safe power supply is in the charging mode, if the power failure detection circuit detects that the AC input is powered off, the switch control circuit controls the closing of the third switch S3 and the disconnection of the first switch S1 and the second switch S2, so that the intrinsically safe power supply enters the backup mode; if it is detected that the AC power supply is not powered off, the charging mode is maintained;

[0055] S3: After the intrinsically safe power supply is in backup mode, it works as a DC / DC power supply to convert the backup battery voltage into 18V and 12V DC voltage outputs.

[0056] The present invention adopts power state detection and mode conversion control technology, that is, switching to different working modes under different power state, realizing energy transfer from input unit to output unit, from input unit to charging circuit, from charging circuit to discharge circuit and from discharge circuit to output unit with only one conversion, avoiding the disadvantages of low efficiency, large loss and temperature rise caused by multi-stage series connection of power supply, and achieving the purpose of efficient conversion of isolated power supply.

[0057] In the description of the present invention, it should be noted that relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0058] In the description of the present invention, it is also necessary to explain that the orientations or positional relationships indicated by the terms "upper", "lower", "inside", "outside", etc. are based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the inventive product is usually placed when used. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0059] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "disposed" and "connected" 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 it can be an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0060] Although this specification is described according to implementation modes, not every implementation mode includes only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

[0061] Therefore, the above description is only a preferred embodiment of the present application and is not intended to limit the scope of implementation of the present application; that is, all equivalent changes made according to the scope of the claims of the present application are within the protection scope of the claims of the present application.

Claims

1. An intrinsically safe uninterruptible power supply topology, characterized in that: It includes an input unit and a discharge circuit located on the primary side of the transformer, an output unit and a charging circuit located on the secondary side of the transformer; The output unit outputs to the intrinsically safe power supply through the safety barrier circuit; The input unit is connected to an AC power supply, and a power failure detection circuit for detecting whether the AC power supply is powered off is also connected to the input unit side; The charging circuit and the discharging circuit are both connected to the backup battery, and the backup battery is also connected to a voltage detection circuit; According to the detection results of the power-off detection circuit and the voltage detection circuit, the input unit, the charging circuit and the discharging circuit respectively control the on and off of their respective circuit loops through the switch control circuit; The input unit includes a rectifier bridge D1 connected to an AC power source, a first capacitor C1 is connected in parallel to the rectifier bridge D1, a first end of the first capacitor C1 is connected to a first end of a first switch S1, a second end of the first switch S1 is connected to a first end of a first winding L1, a second end of the first winding L1 is connected to a drain of a first field effect transistor Q1, and a source of the first field effect transistor Q1 is connected to a second end of the first capacitor C1; The output unit includes a first output circuit outputting a 18V DC voltage and a second output circuit outputting a 12V DC voltage, the first output circuit includes a second winding L2, a first end of the second winding L2 is connected to an anode of a second diode D2, a cathode of the second diode D2 is connected to a first end of a second capacitor C2, and a second end of the second capacitor C2 is connected to a second end of the second winding L2; the second output circuit includes a third winding L3, a first end of the third winding L3 is connected to an anode of a third diode D3, a cathode of the third diode D3 is connected to a first end of a third capacitor C3, and a second end of the third capacitor C3 is connected to a second end of the third winding L3; the second capacitor C2 and the third capacitor C3 are respectively connected in parallel with a safety gate circuit, and the safety gate circuit is output to an intrinsically safe power supply; The charging circuit includes a fourth winding L4, a first end of the fourth winding L4 is connected to an anode of a fourth diode D4, a cathode of the fourth diode D4 is connected to a first end of a second switch S2, a second end of the second switch S2 is connected to a first end of a fourth capacitor C4 and a positive electrode of a backup battery, and a second end of the fourth capacitor C4 is connected to a second end of the fourth winding L4 and a negative electrode of the backup battery, respectively; The discharge circuit includes a fifth winding L5, a first end of which is connected in series with a third switch S3, a second end of which is connected to a drain of a second field effect transistor Q2, and a source of the second field effect transistor Q2 and the third switch S3 are respectively connected to the positive and negative electrodes of the backup battery.

2. The intrinsically safe uninterruptible power supply topology according to claim 1, characterized in that: The output unit includes at least one output circuit.

3. A method for implementing an intrinsically safe uninterruptible power supply topology, based on the intrinsically safe uninterruptible power supply topology described in any one of claims 1-2, characterized in that: The following steps are involved: S1: The input unit is connected to the AC power supply, the switch control unit controls the first switch S1 to close, the second switch S2 and the third switch S3 to disconnect, and the power failure detection circuit detects whether the AC power supply is powered off. When the AC power supply is not powered off, the intrinsically safe power supply enters the normal mode; S2: When the power failure detection circuit detects that the AC power fails, the switch control unit controls the first switch S1 and the second switch S2 to be disconnected and the third switch S3 to be closed, and the intrinsically safe power supply enters the backup mode; S3: The voltage detection circuit detects whether the backup battery is under-voltage. When the backup battery is in an under-voltage state, the switch control circuit controls the first switch S1 and the second switch S2 to close, and the third switch S3 to open, and the intrinsically safe power supply enters the charging mode.

4. The method for implementing an intrinsically safe uninterruptible power supply topology according to claim 3, characterized in that: In step S2, when the power-off detection circuit detects that the AC power supply is no longer in a power-off state, the switch control circuit controls the on and off of each switch, and the intrinsically safe power supply changes from the backup mode to the normal mode.

5. A method for implementing an intrinsically safe uninterruptible power supply topology according to claim 3 or 4, characterized in that: In step S3, when the backup battery is not in an undervoltage state, the switch control circuit controls the on and off of each switch, and the intrinsically safe power supply changes from the charging mode to the normal mode.

6. The method for implementing an intrinsically safe uninterruptible power supply topology according to claim 5, characterized in that: When the intrinsically safe power supply is in the charging mode, the power-off detection circuit detects that the AC power supply is powered off, and the switch control circuit controls the first switch S1 and the second switch S2 to be disconnected and the third switch S3 to be closed, and the intrinsically safe power supply enters the backup mode; when the power-off detection circuit detects that the AC power supply is no longer in the power-off state, the intrinsically safe power supply changes from the backup mode to the charging mode.

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