Multi-power-supply loop power supply circuit and electrical system

Abstract

The present invention discloses a multi-power-supply loop power supply circuit and an electrical system. The multi-power-supply loop power supply circuit includes: an AC load circuit, a DC load circuit, an AC power supply for supplying power to the AC load circuit, and a DC power supply for supplying power to the DC load circuit. It further includes a transfer circuit connecting the AC load circuit and the DC load circuit. When the AC power supply fails, the transfer circuit converts the direct current output by the DC power supply into alternating current and supplies power to the AC load circuit; and / or when the DC load circuit fails, the transfer circuit converts the alternating current output by the AC power supply into direct current and supplies power to the DC load circuit. Compared with the prior art, the present invention can enhance the stability of the power supply while reducing the number of backup power supplies.

Description

Technical Field

[0001] The present invention relates to an electrical system, in particular to a multi-power-supply-loop power supply circuit and an electrical system. Background Art

[0002] Please refer to Figure 1 , in the design of an electrical system, if the power supply is provided by a single loop, when the power supply of this loop fails or is under maintenance, the entire system will be paralyzed and unable to supply power normally. Therefore, it is necessary to introduce multiple loop inlets for power supply to improve the reliability and stability of the power supply. In addition, there are multiple power supplies in the electrical system, and each power supply supplies power to the corresponding power supply type. If the reliability and stability are to be improved and the types of the same category of power supplies are increased, then multiple backup power supplies need to be connected, and the investment and cost will be very high.

[0003] If the different power supplies directly adopt the mutual switching method and use technologies such as voltage transformation for control and power supply, the stability and reliability of the power supply can be improved, and the equipment, the installation space required by the equipment, the maintenance cost, and the floor area can be reduced.

[0004] The patent with the publication number of CN104410150A is a new continuous power supply type server power supply design method for realizing the AC and DC switching. Its characteristics are that one power supply interface is connected to the AC mains, and the other interface is connected to the direct current to form a backup for the power supply line; a mini switching module will be added after the two power supply interfaces to realize the AC / DC switching; when the power supply is working normally, the AC mains is used as the main line for power supply, and the direct current is used as the backup circuit for power supply; once the AC mains is cut off, the switching module will switch the power supply interface from AC to DC within 16 ms and continue to supply power with the direct current. This patent cannot solve the problems of multiple loops and equipment with multiple different power supply specifications.

[0005] Therefore, how to design a multi-power-supply-loop power supply circuit and an electrical system that can be applicable to multiple loops and equipment with multiple different power supply specifications while improving the stability and reliability of the multi-power-supply is a technical problem that the industry urgently needs to solve. Summary of the Invention

[0006] Aiming at the problem in the prior art that it cannot be applicable to multiple loops and equipment with multiple different power supply specifications, the present invention proposes a multi-power-supply-loop power supply circuit and an electrical system.

[0007] The technical solution of the present invention is to propose a multi-power-supply-loop power supply circuit, including: an AC load circuit, a DC load circuit, an AC power supply for supplying power to the AC load circuit, and a DC power supply for supplying power to the DC load circuit, and further including a transfer circuit connecting the AC load circuit and the DC load circuit;

[0008] When the AC power supply fails, the transfer circuit converts the direct current output by the DC power supply into alternating current and supplies power to the AC load circuit;

[0009] And / or when the DC load circuit fails, the transfer circuit converts the alternating current output by the AC power supply into direct current and supplies power to the DC load circuit.

[0010] Furthermore, a switch QF1 is connected in series between the AC power supply and the AC load circuit; a switch QF2 is connected in series between the DC power supply and the DC load circuit;

[0011] When the switch QF1 is closed, the AC power supply supplies power to the AC load circuit; when the switch QF2 is closed, the DC power supply supplies power to the DC load circuit.

[0012] Furthermore, the transfer circuit includes a switch QF3, a switch QF4, and a bidirectional converter AC / DC. One end of the switch QF3 is connected between the switch QF1 and the AC load circuit, and the other end is connected to the bidirectional converter AC / DC. The other end of the bidirectional converter AC / DC is connected to the switch QF4, and the other end of the switch QF4 is connected between the DC load circuit and the switch QF2.

[0013] Furthermore, the bidirectional converter AC / DC is started only when the switches QF3 and QF4 are closed.

[0014] Furthermore, a node A is provided between the AC power supply and the switch QF1, a node B is provided between the DC power supply and the switch QF2, a node C is provided between the switch QF3 connecting the switch QF1 and the AC load circuit, and a node D is provided between the switch QF4 connecting the switch QF2 and the DC load circuit. Each node is provided with a detection device for detecting current and / or voltage.

[0015] Furthermore, in the state where both the switch QF1 and the switch QF2 are closed:

[0016] When the voltages of nodes A and C are zero, the voltages of nodes B and D are not zero, and the current values of nodes A, B, C, and D are all less than the preset value, disconnect QF1, close the switches QF3 and QF4;

[0017] And / or when the voltages of nodes A and C are zero, the voltages of nodes B and D are not zero, and the current value of node B reaches the preset value, and the current values of nodes A, C, and D are all less than the preset value, disconnect QF1 and issue a warning to remind the staff to repair the DC load circuit and the DC power supply;

[0018] And / or when the voltage of node C is zero and the voltages of nodes A, B, and D are not zero, a warning is issued to remind the staff to repair switch QF1;

[0019] And / or when the voltages of nodes B and D are zero, the voltages of nodes A and C are not zero, and the current values of nodes A, B, C, and D are all less than the preset value, disconnect switch QF2, close switch QF3, and switch QF4;

[0020] And / or when the voltages of nodes B and D are zero, the voltages of nodes A and C are not zero, the current value of node A reaches the preset value, and the current values of nodes B, C, and D are all less than the preset value, disconnect switch QF2 and issue a warning to remind the staff to repair the AC load circuit and the AC power supply;

[0021] And / or when the voltage of node D is zero and the voltages of nodes A, B, and C are not zero, a warning is issued to remind the staff to repair switch QF2.

[0022] Furthermore, the preset value is the current protection value of the multi-power-supply loop power supply circuit.

[0023] Furthermore, when switch QF1, switch QF3, and switch QF4 are closed and switch QF2 is open, the bidirectional converter is started, and the alternating current flowing out of the AC power supply is converted into direct current to supply power to the DC load circuit;

[0024] And / or when switch QF2, switch QF3, and switch QF4 are closed and switch QF1 is open, the bidirectional converter is started, and the direct current flowing out of the DC power supply is converted into alternating current to supply power to the AC load circuit.

[0025] Furthermore, when switches QF1, QF2, QF3, and QF4 are all closed:

[0026] When the voltages of nodes A, B, C, and D are not zero, the current of node A reaches the preset value, and the currents of nodes B, C, and D are all less than the preset value, start the auxiliary power supply mode of the bidirectional converter AC / DC to provide auxiliary power supply to the AC load circuit;

[0027] And / or when the voltages of nodes A, B, C, and C are not zero, the current of node B reaches the preset value, and the currents of nodes A, C, and D are all less than the preset value, start the auxiliary power supply mode of the bidirectional converter AC / DC to provide auxiliary power supply to the DC load circuit.

[0028] The present invention also provides an electrical system, and the electrical system adopts the above multi-power-supply loop power supply circuit.

[0029] Compared with the prior art, the present invention has at least the following beneficial effects:

[0030] 1. By switching the power supply, the use of backup power can be reduced, saving costs.

[0031] 2. Power supply switching with two or more power supply specifications can be applied to devices with different power supply specifications.

[0032] 3. The AC load module and the DC load module can be assembled with multiple loads, which can be applied to the problem of multiple-loop devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the following-described drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0034] Figure 1 FIG. 16 is a schematic structural diagram of single-power and dual-power power supplies in the prior art;

[0035] Figure 2 FIG. 20 is a schematic structural diagram of the multi-power-loop power supply circuit of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0036] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the following further details the present invention with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0037] Therefore, a feature pointed out in this specification will be used to illustrate one feature of one embodiment of the present invention, rather than implying that each embodiment of the present invention must have the illustrated feature. In addition, it should be noted that this specification describes many features. Although some features can be combined to show possible system designs, these features can also be used in other combinations not explicitly described. Therefore, unless otherwise stated, the illustrated combinations are not intended to be limiting.

[0038] The principle and structure of the present invention will be described in detail below with reference to the drawings and embodiments.

[0039] Please refer to Figure 2, the present invention provides a multi - power - loop power - supply circuit, which includes an AC load circuit, a DC load circuit, an AC power supply connected to the AC load circuit, a DC power supply connected to the DC load circuit, and a transfer circuit connecting the AC load circuit and the DC load circuit. Among them, the transfer circuit is used to transfer the current of one circuit to the faulty circuit and supply power to it when a circuit fails. Specifically, when the AC power supply fails, the transfer circuit converts the direct current output by the DC power supply into alternating current and supplies power to the AC load circuit. When the DC load circuit fails, the transfer circuit converts the alternating current output by the AC power supply into direct current and supplies power to the DC load circuit.

[0040] Specifically, a switch QF1 is connected in series between the AC load circuit and the AC power supply, and a switch QF2 is connected in series between the DC load circuit and the DC power supply. When the switch QF1 is closed, the AC power supply supplies power to the AC load circuit. When the switch QF2 is closed, the DC power supply supplies power to the DC load circuit.

[0041] The transfer circuit includes a bidirectional converter AC / DC, a switch QF3, and a switch QF4. One end of the switch QF3 is connected between the switch QF1 and the AC load circuit, and the other end is connected to the bidirectional converter AC / DC. The other end of the bidirectional converter AC / DC is connected to the switch QF4, and the other end of the switch QF4 is connected between the switch QF2 and the DC load circuit.

[0042] Among them, the bidirectional converter starts only when the switch QF3 and the switch QF4 are closed at the same time. When the AC power supply fails, the switch QF1 is opened, and the switches QF2, QF3, and QF4 are closed. The bidirectional converter starts and converts the direct current flowing out of the DC power supply into alternating current to supply power to the AC load circuit. When the DC power supply fails, the switch QF2 is opened, and the switches QF1, QF3, and QF4 are closed. The bidirectional converter starts and converts the alternating current output by the AC power supply into direct current and supplies power to the DC load circuit.

[0043] A node A is provided between the AC power supply and the switch QF1, a node B is provided between the DC power supply and the switch QF2, a node C is provided between the switch QF3 connecting the switch QF1 and the AC load circuit, and a node D is provided between the switch QF4 connecting the switch QF2 and the DC load circuit. Devices for detecting current and / or voltage are provided at each node.

[0044] Specifically, in the state where both the switch QF1 and the switch QF2 are closed:

[0045] When the voltages of nodes A and C are zero, the voltages of nodes B and D are not zero, and the currents of nodes A, B, C, and D are all less than the preset value, the switch QF1 is opened, and the switches QF2, QF3, and QF4 are closed.

[0046] At this time, it can be judged that the power supply of the circuit at point A is abnormal. It may be that the substation or line supplying power to this part is abnormal, resulting in no power supply for this part of the circuit. After disconnecting switch QF1 and closing switches QF2, QF3, and QF4, the bidirectional converter AC / DC starts. The current flowing out of the DC power supply can flow into the bidirectional converter AC / DC. After receiving the current flowing out of the DC power supply, the bidirectional converter converts it into alternating current and supplies power to the AC load circuit.

[0047] When the voltages of nodes A and C are zero, the voltages of nodes B and D are not zero, and the current value of node B reaches the preset value, while the current values of nodes A, C, and D are all less than the preset value, disconnect switch QF1 and issue a warning to remind the staff to repair the AC load circuit and the AC power supply.

[0048] At this time, it is judged that the power supply of circuit A is abnormal. It may be that the substation or line supplying power to this part is abnormal, resulting in no power supply for this part of the circuit. The bidirectional converter AC / DC needs to be started after being confirmed by the staff. At this time, since the current at node B reaches the preset value, if the bidirectional converter is started again, a protection action will be executed, otherwise the entire circuit will be burned out. It is necessary to remind the maintenance personnel to confirm before starting the bidirectional converter AC / DC.

[0049] When the voltage of node C is zero and the voltages of nodes A, B, and D are not zero, issue a warning to remind the staff to repair switch QF1.

[0050] At this time, it is judged that switch QF1 is abnormal, or there is a problem with the circuit of this loop, or a short circuit of the equipment below point C causes QF1 to trip, and it needs to be detected and maintained.

[0051] When the voltages of nodes B and D are zero, the voltages of nodes A and C are not zero, and the current values of nodes A, B, C, and D are all less than the preset value, disconnect switch QF2 and close switches QF1, QF3, and QF4.

[0052] At this time, it is judged that the power supply of the circuit at point B is abnormal. It may be that the substation or line supplying power to this part is abnormal, resulting in no power supply for this part of the circuit. After disconnecting switch QF2 and closing switches QF1, QF3, and QF4, the bidirectional converter AC / DC starts. The current flowing out of the AC power supply can flow into the bidirectional converter AC / DC. After receiving the current flowing out of the AC power supply, the bidirectional converter converts it into direct current and supplies power to the DC load circuit.

[0053] When the voltages of nodes B and D are zero, the voltages of nodes A and C are not zero, and the current value of node A reaches the preset value, while the current values of nodes B, C, and D are all less than the preset value, disconnect switch QF2 and issue a warning to remind the staff to repair the DC load circuit and the DC power supply.

[0054] At this time, it is judged that the power supply of Circuit B is abnormal. It may be that the substation or line supplying power to this part is abnormal, resulting in no power supply for this part of the circuit. The bidirectional converter AC / DC needs to be started after confirmation by the staff. At this time, since the current at Node A reaches the preset value, if the bidirectional converter is started again, the protection action will be executed, otherwise the entire circuit will be burned out. It is necessary to remind the maintenance personnel to confirm before starting the bidirectional converter AC / DC.

[0055] When the voltage at Node D is zero and the voltages at Nodes A, B, and C are not zero, a warning is issued to remind the staff to repair Switch QF2.

[0056] At this time, it is judged that Switch QF2 is abnormal, or there is a problem with the circuit of this loop, or the equipment below Point D is short-circuited, causing QF2 to trip, and it needs to be detected and maintained.

[0057] Among them, the preset value is the current protection value of the multi-power-supply loop power supply circuit, or it can also be set to be slightly less than the protection value.

[0058] When switches QF1, QF2, QF3, and QF4 are all closed, when the voltages at Nodes A, B, C, and D are not zero, and the current at Node A reaches the preset value, and the currents at Nodes B, C, and D are all less than the preset value, start the auxiliary power supply mode of the bidirectional converter AC / DC to provide auxiliary power supply for the AC load circuit;

[0059] At this time, it is judged that the power required in the circuit has increased. At this time, the current in the circuit is already close to the protection value. If equipment is put into operation at this time, it is very likely that the protection action will be executed. By turning on the auxiliary power supply mode of the converter, the increased equipment power is provided by the converter. The converter can bear a part of the power (current), and the power (current) at Point A will not increase any more, and no protection action will occur.

[0060] When the voltages at Nodes A, B, C, and D are not zero, and the current at Node B reaches the preset value, and the currents at Nodes A, C, and D are all less than the preset value, start the auxiliary power supply mode of the bidirectional converter AC / DC to provide auxiliary power supply for the DC load circuit.

[0061] At this time, the current in the circuit is already close to the protection value. If equipment is put into operation at this time, it is very likely that the protection action will occur. By turning on the auxiliary power supply mode of the converter, the increased equipment power is provided by the converter. The converter can bear a part of the power (current), and the power (current) at Point B will not increase any more, and no protection action will occur.

[0062] The above description is the control strategy and control method for 2 power supplies, and it is also suitable for more loops with 3 or more loops expanded pairwise.

[0063] The present invention also provides an electrical system, which adopts the above-mentioned multi-power supply loop power supply circuit.

[0064] Compared with the prior art, the present invention does not need to add a standby power supply in each loop to prevent power failure. When a power failure occurs in the circuit, it can directly supply power through the power supply in the second loop, saving the use of the standby power supply and reducing the cost. At the same time, the two power supply specifications can be different and can be applicable to different specifications of equipment. The DC load module and the AC load module can be connected to multiple devices and can be applicable to multiple device loops.

[0065] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A multi-power-supply loop power supply circuit, comprising: An AC load circuit, a DC load circuit, an AC power supply for supplying power to the AC load circuit, and a DC power supply for supplying power to the DC load circuit, characterized in that: it further includes a transfer circuit connecting the AC load circuit and the DC load circuit; When the AC power supply fails, the transfer circuit converts the direct current output by the DC power supply into alternating current and supplies power to the AC load circuit; and / or when the DC load circuit fails, the transfer circuit converts the alternating current output by the AC power supply into direct current and supplies power to the DC load circuit; A switch QF1 is connected in series between the AC power supply and the AC load circuit; a switch QF2 is connected in series between the DC power supply and the DC load circuit; When the switch QF1 is closed, the AC power supply supplies power to the AC load circuit; when the switch QF2 is closed, the DC power supply supplies power to the DC load circuit; The transfer circuit includes a switch QF3, a switch QF4, and a bidirectional converter AC / DC. One end of the switch QF3 is connected between the switch QF1 and the AC load circuit, and the other end is connected to the bidirectional converter AC / DC. The other end of the bidirectional converter AC / DC is connected to the switch QF4, and the other end of the switch QF4 is connected between the DC load circuit and the switch QF2; A node A is provided between the AC power supply and the switch QF1, a node B is provided between the DC power supply and the switch QF2, a node C is provided between the switch QF3 connecting the switch QF1 and the AC load circuit, and a node D is provided between the switch QF4 connecting the switch QF2 and the DC load circuit. Each node is provided with a detection device for detecting current and / or voltage; In the state where both the switch QF1 and the switch QF2 are closed: When the voltages of nodes A and C are zero, the voltages of nodes B and D are not zero, and the current values of nodes A, B, C, and D are all less than the preset value, disconnect QF1, close the switches QF3 and QF4; and / or when the voltages of nodes A and C are zero, the voltages of nodes B and D are not zero, and the current value of node B reaches the preset value, and the current values of nodes A, C, and D are all less than the preset value, disconnect QF1 and issue a warning to remind the staff to repair the DC load circuit and the DC power supply; and / or when the voltage of node C is zero and the voltages of nodes A, B, and D are not zero, issue a warning to remind the staff to repair the switch QF1; and / or when the voltages of nodes B and D are zero, the voltages of nodes A and C are not zero, and the current values of nodes A, B, C, and D are all less than the preset value, disconnect the switch QF2, close the switches QF3 and QF4; and / or when the voltages of nodes B and D are zero, the voltages of nodes A and C are not zero, and the current value of node A reaches the preset value, and the current values of nodes B, C, and D are all less than the preset value, disconnect the switch QF2 and issue a warning to remind the staff to repair the AC load circuit and the AC power supply; and / or when the voltage of node D is zero and the voltages of nodes A, B, and C are not zero, issue a warning to remind the staff to repair the switch QF2; The bidirectional converter AC / DC starts only when the switches QF3 and QF4 are closed.

2. The multi-power-supply loop power supply circuit according to claim 1, characterized in that The preset value is the current protection value of the multi-power supply loop power supply circuit.

3. The multi-power-supply loop power supply circuit according to claim 1, characterized in that, When the switch QF1, switches QF3 and QF4 are closed and the switch QF2 is open, the bidirectional converter starts and converts the alternating current flowing out of the AC power supply into direct current to supply power to the DC load circuit; and / or when the switches QF2, QF3, and QF4 are closed and the switch QF1 is open, the bidirectional converter starts and converts the direct current flowing out of the DC power supply into alternating current to supply power to the AC load circuit.

4. The multi-power-supply loop power supply circuit according to claim 1, characterized in that, In the case where the switches QF1, QF2, QF3, and QF4 are all closed: When the voltages of nodes A, B, C, and D are not zero, and the current of node A reaches the preset value while the currents of nodes B, C, and D are all less than the preset value, the auxiliary power supply mode of the bidirectional converter AC / DC is started to provide auxiliary power supply to the AC load circuit; and / or when the voltages of nodes A, B, C, and C are not zero, and the current of node B reaches the preset value while the currents of nodes A, C, and D are all less than the preset value, the auxiliary power supply mode of the bidirectional converter AC / DC is started to provide auxiliary power supply to the DC load circuit.

5. An electrical system, characterized in that, The electrical system adopts the multi-power supply loop power supply circuit described in any one of claims 1 to 4.

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