Ring network power supply system and fault detection method and device thereof

Abstract

The present disclosure relates to a ring network power supply system and a fault detection method, device and computer-readable storage medium thereof. The ring network power supply system comprises: a bus ring; a plurality of power supplies connected to the bus ring and arranged in parallel, wherein the portion of the bus ring between two adjacent power supplies is a power supply section; a normally closed switch connected in series on each power supply section; and a controller for determining that a ground fault occurs on the side of the power supply section away from the normally closed switch and issuing a first alarm message when the normally closed switch on the power supply section is switched from a closed state to an open state and the load connected to the power supply section is switched from a normal working state to a stopped working state.

Description

Technical Field

[0001] The present disclosure relates to the technical field of ring network power supply, and in particular to a ring network power supply system and a fault detection method, device and computer-readable storage medium thereof. Background Art

[0002] Grid planning in power grid planning has a significant impact on the high-quality, safe and economical operation of the power system, and scientific and effective planning schemes are its foundation.

[0003] The ring network power supply system refers to a ring network formed by connecting power sources and loads through power lines. When a fault occurs in any section of the line in the ring network, the faulty section is isolated through a switch device, so that the normal power supply to other loads will not be affected. The ring network power supply can not only reduce voltage loss and power loss, but also improve the reliability of power supply operation.

[0004] When a section of the line in the ring network power supply system fails, how to accurately and quickly locate the faulty section is a technical problem that needs to be solved urgently. Summary of the invention

[0005] The embodiments of the present disclosure provide a ring network power supply system and a fault detection method, device and computer-readable storage medium thereof, so as to accurately and quickly locate the line section where the fault occurs and improve the efficiency of fault repair.

[0006] According to one aspect of an embodiment of the present disclosure, a ring network power supply system is provided, including:

[0007] Busbar ring;

[0008] Multiple power supplies connected to the bus ring and arranged in parallel, the part of the bus ring between two adjacent power supplies is a power supply section;

[0009] Normally closed switches connected in series on each power supply section;

[0010] The controller is used to determine that a ground fault occurs on the side of the power supply section away from the normally closed switch and issue a first alarm message when the normally closed switch on the power supply section is switched from a closed state to an open state and the load connected to the power supply section is switched from a normal working state to a stopped working state.

[0011] According to another aspect of an embodiment of the present disclosure, a fault detection method for a ring network power supply system is provided, comprising:

[0012] The normally closed switch on the control power supply section is disconnected;

[0013] Obtaining working status information of a load connected to the power supply segment before and after the normally closed switch is disconnected, wherein the working status information includes whether the load is in a normal working state or the load is in a stopped working state;

[0014] When the load is in a normal working state before the normally closed switch is disconnected and is in a stopped working state after the normally closed switch is disconnected, it is determined that a ground fault occurs on the side of the power supply section away from the normally closed switch and a first alarm message is issued.

[0015] According to another aspect of the embodiments of the present disclosure, there is provided a fault detection device for a ring network power supply system, comprising:

[0016] A switch control unit, used to control the normally closed switch on the power supply section to open;

[0017] An information acquisition unit, used to acquire working state information of a load connected to the power supply segment before and after the normally closed switch is disconnected, wherein the working state information includes whether the load is in a normal working state or the load is in a stopped working state;

[0018] The judgment unit is used to judge that a ground fault occurs on the side of the power supply section away from the normally closed switch and issue a first alarm message when the load is in a normal working state before the normally closed switch is disconnected and is in a stopped working state after the normally closed switch is disconnected.

[0019] According to another aspect of the embodiments of the present disclosure, there is provided a fault detection device for a ring network power supply system, comprising:

[0020] A memory; and a processor coupled to the memory, the processor being configured to execute the fault detection method described in any of the foregoing technical solutions based on instructions stored in the memory.

[0021] According to another aspect of the embodiments of the present disclosure, a computer-readable storage medium is provided, on which a computer program is stored. When the program is executed by a processor, the fault detection method described in any of the aforementioned technical solutions is implemented.

[0022] By adopting the technical solutions of the aforementioned embodiments of the present disclosure, the line section where the fault occurs can be accurately and quickly located, thereby improving the efficiency of fault repair.

[0023] Other features and advantages of the present disclosure will become apparent from the following detailed description of embodiments of the present disclosure with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings, which constitute a part of the specification, illustrate embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0025] The present disclosure may be more clearly understood from the following detailed description with reference to the accompanying drawings, in which:

[0026] Figure 1 A schematic diagram of a ring network power supply system according to an embodiment of the present disclosure;

[0027] Figure 2 A schematic diagram of a ring network power supply system according to another embodiment of the present disclosure;

[0028] Figure 3 This is a flow chart of a fault detection method for a ring network power supply system according to an embodiment of the present disclosure;

[0029] Figure 4 This is a flow chart of insulation impedance fault detection in another embodiment of the present disclosure;

[0030] Figure 5 A block diagram of a fault detection device for a ring network power supply system according to an embodiment of the present disclosure;

[0031] Figure 6 It is a block diagram of a fault detection device for a ring network power supply system according to another embodiment of the present disclosure;

[0032] Figure 7 A block diagram of a computer system according to an embodiment of the present disclosure.

[0033] It should be understood that the size of each part shown in the accompanying drawings is not drawn according to the actual proportional relationship. In addition, the same or similar reference numerals represent the same or similar components. DETAILED DESCRIPTION

[0034] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The description of the exemplary embodiments is merely illustrative and is in no way intended to limit the present disclosure and its application or use. The present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to make the present disclosure thorough and complete and to fully express the scope of the present disclosure to those skilled in the art. It should be noted that unless otherwise specifically stated, the relative arrangement of the components and steps described in these embodiments should be interpreted as being merely exemplary and not as a limitation.

[0035] All terms (including technical terms or scientific terms) used in the present disclosure have the same meanings as those understood by ordinary technicians in the field to which the present disclosure belongs, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries, such as general dictionaries, should be interpreted as having meanings consistent with their meanings in the context of the relevant technology, and should not be interpreted in an idealized or extremely formal sense, unless explicitly defined herein.

[0036] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0037] At present, when a section of the line in the ring network power supply system fails, technicians are unable to accurately and quickly locate the faulty section, which leads to maintenance delays and affects the efficiency of resuming operation of the faulty section.

[0038] The embodiments of the present disclosure provide a ring network power supply system and a fault detection method, device and computer-readable storage medium thereof, so as to accurately and quickly locate the line section where the fault occurs and improve the efficiency of fault repair.

[0039] like Figure 1 As shown, some embodiments of the present disclosure provide a ring network power supply system, including:

[0040] Busbar ring 10;

[0041] A plurality of power supplies 12 connected to the bus ring 10 and arranged in parallel, wherein the portion of the bus ring 10 between two adjacent power supplies 12 is a power supply section 100;

[0042] A normally closed switch 14 connected in series on each power supply section 100;

[0043] The controller 16 is used to determine that a ground fault occurs on the side of the power supply section 100 away from the normally closed switch 14 (such as the AB section in the figure) and issue a first alarm message when the normally closed switch 14 on the power supply section 100 is switched from a closed state to an open state and the load 50 connected to the power supply section 100 is switched from a normal working state to a stopped working state.

[0044] Furthermore, the controller 16 is also used to determine that a ground fault occurs on the other side of the load 50 (such as the AC section in the figure) of the power supply section 100 and issue a second alarm message when the normally closed switch 14 on the power supply section 100 is closed and the load 50 connected to the power supply section 100 is in a stopped working state.

[0045] In the embodiment of the present disclosure, the ring network power supply system may be an AC ring network power supply system or a DC ring network power supply system. Figure 1As shown, in this embodiment, the ring network power supply system is a DC ring network power supply system, and the power supply 12 includes a power grid 122, a photovoltaic module 124 and a converter 120. Among them, the converter 120 is a bidirectional converter, including a DC / DC conversion module (a DC / DC conversion module, which is used to convert electric energy of one voltage value into electric energy of another voltage value in a DC circuit) and an AC / DC conversion module (an AC / DC conversion module, which is used to convert AC power into DC power). When the light intensity can meet the power supply demand, the DC power output by the photovoltaic module 124 is transmitted to the bus ring 10 through the DC / DC conversion module of the converter 120. When the light intensity is not enough to meet the power supply demand, the AC power output by the power grid 122 is converted into DC power through the AC / DC conversion module of the converter 120 and then transmitted to the bus ring 10. In addition, according to a certain control strategy, the power grid 122 and the photovoltaic module 124 can also simultaneously transmit DC power to the bus ring 10 through the converter 120.

[0046] It is worth mentioning that in other embodiments of the present disclosure, the power source 12 may not include the photovoltaic module 124, but only the power grid 122 outputs direct current to the bus ring 10 via the converter 120. Alternatively, the power source 12 does not include the power grid 122, and only the photovoltaic module 124 outputs direct current to the bus ring 10 via the converter 14. The specific form of the power source 12 is selected according to the power supply demand and application scenario of the load 50.

[0047] In the embodiment of the present disclosure, the specific type of the normally closed switch 14 is not limited, for example, it can be a contactor or a relay, wherein the relay can be a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) type relay, an IGBT (Insulated Gate Bipolar Transistor) type relay, or a GTO (Gate Turn-Off thyristor) type relay, etc.

[0048] Based on the characteristics of ring network power supply, when the ring network power supply system is working normally, when the normally closed switch 14 of any power supply section 100 of the bus ring 10 is disconnected, if there is no ground fault in the power supply section 100, the power supply 12 can still supply power to the load 50 from the side of the load 50 away from the normally closed switch 14, and the load 50 can still work normally.

[0049] like Figure 1As shown, in the embodiment of the present disclosure, when the load 50 is in a normal working state before the normally closed switch 14 is disconnected, but is in a stopped working state after the normally closed switch 14 is disconnected, it can be determined that a ground fault occurs on the side of the power supply section 100 away from the normally closed switch 14, affecting the power output of the power supply 12 to the load 50. After determining that a ground fault occurs in the part of the power supply section 100, the controller 16 issues a first alarm message, and the first alarm message includes, for example, a location code and fault content of the fault section, so as to remind the system maintenance personnel to promptly repair the fault section.

[0050] When the normally closed switch 14 on the power supply section 100 is closed and the load 50 connected to the power supply section 100 is in a stopped working state, it can be determined that a ground fault occurs on the other side of the load 50 of the power supply section 100, affecting the power output of the power supply 12 to the load 50. After determining that a ground fault occurs in the part of the power supply section 100, the controller 16 issues a second alarm message, and the second alarm message includes, for example, a location code of the fault section and the fault content, so as to remind the system maintenance personnel to promptly repair the fault section.

[0051] Therefore, by adopting the design of the ring network power supply system of the embodiment of the present disclosure, the line section where the grounding fault occurs in the bus ring can be accurately and quickly located, thereby improving the efficiency of fault repair.

[0052] like Figure 2 As shown, in some embodiments of the present disclosure, the ring network power supply system also includes: an insulation impedance detection circuit 18 connected to the power supply section 100, the insulation impedance detection circuit 18 includes a first branch and a second branch connected in parallel and grounded, the first branch includes a first resistor R1 and a first switch S1 connected in series, and the second branch includes a second resistor R2 and a second switch S2 connected in series; and a voltage detection device 20, which is used to detect the voltage of the positive line 101 of the power supply section 100 to the ground and the voltage of the negative line 102 of the power supply section 100 to the ground.

[0053] Under normal working conditions, the insulation resistance of the positive line 101 and the negative line 102 of the power supply section 100 should reach the megohm level. However, as the line ages, its insulation surface may fall off, and the metal wire is exposed to the air and corroded and oxidized, and the insulation resistance decreases. If not handled in time, it is likely to cause the wire to break or discharge to the ground, and eventually develop into a ground fault.

[0054] In the embodiment of the present disclosure, the insulation impedance detection circuit 18 can be used to detect the insulation impedance value of the positive line 101 and the insulation impedance value of the negative line 102 of the power supply segment 100 .

[0055] Specifically, the controller 16 is used to close the first switch S1 and open the second switch S2 at a first moment, and to close the second switch S2 and open the first switch S1 at a second moment, when the normally closed switch 14 corresponding to the power supply section 100 is disconnected and the load 50 is working normally; obtain the insulation resistance value of the positive line 101 and the insulation resistance value of the negative line 102 according to the resistance value of the first resistor R1, the resistance value of the second resistor R2, the first voltage to ground of the positive line 101 and the first voltage to ground of the negative line 102 at a first moment, and the second voltage to ground of the positive line 101 and the second voltage to ground of the negative line 102 at a second moment; when the insulation resistance value of the positive line 101 is less than a set first threshold value, a first warning message is issued; when the insulation resistance value of the negative line 102 is less than a set second threshold value, a second warning message is issued.

[0056] When the normally closed switch 14 corresponding to the power supply section 100 is disconnected, if the load 50 works normally, the first switch S1 is closed and the second switch S2 is opened at the first moment, and after the circuit is stable, the voltage detection device 20 detects the ground voltage of the positive line 101 and the ground voltage of the negative line 102 of the power supply section 100. At this time, the resistance value of the first resistor R1, the resistance value of the second resistor R2, the first ground voltage of the positive line 101 and the first ground voltage of the negative line 102 at the first moment, and the insulation resistance value of the positive line 101 and the insulation resistance value of the negative line 102 meet:

[0057]

[0058] Among them, R + is the insulation resistance value of the positive line 101, R - is the insulation resistance value of the negative line 102, R1 is the resistance value of the first resistor R1, R2 is the resistance value of the second resistor R2, and U 1+ is the first ground voltage of the positive line 101, U 1- is the first ground voltage of the negative line 102 .

[0059] Then, the normally closed switch 14 corresponding to the power supply segment 100 is maintained open, the first switch S1 is opened and the second switch S2 is closed at the second moment, and after the circuit is stabilized, the voltage detection device 20 detects the ground voltage of the positive line 101 and the ground voltage of the negative line 102 of the power supply segment 100. At this time, the resistance value of the first resistor R1, the resistance value of the second resistor R2, the second ground voltage of the positive line 101 and the second ground voltage of the negative line 102 at the second moment, and the insulation resistance value of the positive line 101 and the insulation resistance value of the negative line 102 meet:

[0060]

[0061] Among them, U 2+ is the second ground voltage of the positive line 101, U2- is the second ground voltage of the negative line 102 .

[0062] Combining formula (1) and formula (2) we can get:

[0063]

[0064] Therefore, in one embodiment of the present disclosure, the insulation resistance value of the positive line 101 and the insulation resistance value of the negative line 102 can be obtained according to the above formula (III).

[0065] Through the design scheme of this embodiment, it is possible to quickly determine whether a serious insulation impedance drop occurs in the power supply section, thereby improving the efficiency of fault repair and ensuring the stable and reliable operation of the ring network power supply system.

[0066] In another embodiment of the present disclosure, the maintenance personnel can also manually disconnect the normally closed switch 14 corresponding to the power supply section 100. If the load 50 works normally, the first switch S1 is closed and the second switch S2 is disconnected at the first moment, and the second switch S2 is closed and the first switch S1 is disconnected at the second moment. Then, according to the above formula (III), the insulation impedance value of the positive line 101 and the insulation impedance value of the negative line 102 are obtained. When the insulation impedance value of the positive line 101 is less than the set first threshold value, it is determined that the insulation impedance of the positive line 101 has dropped more seriously. When the insulation impedance value of the negative line 102 is less than the set second threshold value, it is determined that the insulation impedance of the negative line 102 has dropped more seriously.

[0067] In some embodiments of the present disclosure, the controller 16 is used to perform ground fault and insulation impedance detection on each power supply segment 100 in sequence according to a set order. For example, the above-mentioned ground fault and insulation impedance detection is performed on each power supply segment 100 in sequence in a clockwise direction or a counterclockwise direction of the power supply ring 10 in the figure. The controller 16 can perform ground fault and insulation impedance detection on the power supply ring 10 at a set frequency (for example, once every 24 hours). The controller 16 can also start the above-mentioned ground fault and insulation impedance detection after receiving the detection start command input by the maintenance personnel. When the current power supply segment 100 is detected, the power supply of the load 50 by the other power supply segments 100 is not affected.

[0068] In the disclosed embodiment, the controller 16 can output the first alarm information and the second alarm information of the ground fault, the first warning information and the second warning information of the serious insulation impedance drop to the control platform of the ring network power supply system, and the control platform sends the alarm information or the warning information in at least one media form (such as sound, text or video, etc.). The control platform can be, for example, a related APP installed in the mobile phone of the maintenance personnel.

[0069] In the disclosed embodiment, the controller 16 is further used to control the switch devices (not shown in the figure) at both ends of the faulty power supply section to disconnect when at least one of the first alarm information, the second alarm information, the first warning information and the second warning information is issued, thereby isolating the faulty power supply section. After the maintenance personnel complete the maintenance, they reconnect the power supply section and restore the power supply of the power supply section, thereby achieving the purpose of reducing the power outage scope and reducing the load power outage time.

[0070] like Figure 3 As shown, the embodiment of the present disclosure further provides a fault detection method applied to the aforementioned ring network power supply system, and the method includes the following steps S301 to S302.

[0071] In step S301, the normally closed switch on the power supply section is controlled to be disconnected;

[0072] In step S302, the working state information of the load connected to the power supply segment before and after the normally closed switch is disconnected is obtained, and the working state information includes whether the load is in a normal working state or the load is in a stopped working state;

[0073] In step S303, when the load is in a normal working state before the normally closed switch is disconnected and is in a stopped working state after the normally closed switch is disconnected, it is determined that a ground fault occurs on the side of the power supply section away from the normally closed switch and a first alarm message is issued.

[0074] In some embodiments, the fault detection method further includes: when the normally closed switch on the power supply segment is closed and the load connected to the power supply segment is in a stopped working state, determining that a ground fault occurs on the other side of the load in the power supply segment and issuing a second alarm message.

[0075] In some embodiments, the ring network power supply system further includes: an insulation impedance detection circuit connected to the power supply segment, the insulation impedance detection circuit includes a first branch and a second branch connected in parallel and grounded, the first branch includes a first resistor and a first switch connected in series, and the second branch includes a second resistor and a second switch connected in series. Figure 4 As shown, the fault detection method may further include the following steps S401 to S403.

[0076] In step S401, when the normally closed switch corresponding to the power supply segment is disconnected, the load is working normally, the first switch is closed, and the second switch is disconnected, the first voltage to ground of the positive line of the power supply segment and the first voltage to ground of the negative line are obtained, as well as when the normally closed switch corresponding to the power supply segment is disconnected, the load is working normally, the first switch is disconnected, and the second switch is closed, the second voltage to ground of the positive line of the power supply segment and the second voltage to ground of the negative line are obtained.

[0077] In step S402, the insulation resistance value of the positive line and the insulation resistance value of the negative line are obtained according to the resistance value of the first resistor, the resistance value of the second resistor, the first voltage of the positive line to ground and the first voltage of the negative line to ground at the first moment, and the second voltage of the positive line to ground and the second voltage of the negative line to ground at the second moment.

[0078] In step S403, when the insulation resistance value of the positive line is less than a set first threshold, a first warning message is issued, and when the insulation resistance value of the negative line is less than a set second threshold, a second warning message is issued.

[0079] In some embodiments, the insulation resistance value of the positive line and the insulation resistance value of the negative line are obtained according to the following functional relationship:

[0080]

[0081] Among them, R + is the insulation resistance value of the positive line, R - is the insulation resistance value of the negative line, R1 is the resistance value of the first resistor, R2 is the resistance value of the second resistor, U 1+ is the first voltage of the positive line to ground, U 1- is the first voltage of the negative line to ground, U 2+ is the second voltage of the positive line to ground, U 2- is the second ground voltage of the negative line.

[0082] By adopting the fault detection method of the above embodiment of the present disclosure, the line section where the bus ring fails can be accurately and quickly located, thereby improving the efficiency of fault repair and ensuring the stable and reliable operation of the ring network power supply system. In a further embodiment, it is also possible to quickly determine whether a serious insulation impedance drop occurs in the power supply section, thereby further ensuring the stable and reliable operation of the ring network power supply system.

[0083] like Figure 5 As shown, the embodiment of the present disclosure also provides a fault detection device applied to the aforementioned ring network power supply system, including:

[0084] A switch control unit 501, used to control the normally closed switch on the power supply section to open;

[0085] An information acquisition unit 503 is used to acquire working state information of a load connected to the power supply segment before and after the normally closed switch is disconnected, the working state information including whether the load is in a normal working state or the load is in a stopped working state;

[0086] The judgment unit 505 is used to determine that a ground fault occurs on the side of the power supply section away from the normally closed switch and issue a first alarm message when the load is in a normal working state before the normally closed switch is disconnected and is in a stopped working state after the normally closed switch is disconnected.

[0087] Similarly, by using the fault detection device of the above embodiment of the present disclosure, the line section where the bus ring fault occurs can be accurately and quickly located, thereby improving the efficiency of fault repair and ensuring the stable and reliable operation of the ring network power supply system.

[0088] like Figure 6 As shown, some embodiments of the present disclosure also provide a fault detection device for a ring network power supply system, comprising: a memory 61 and a processor 62 coupled to the memory 61, wherein the processor 62 is configured to execute a fault detection method as described in any of the foregoing embodiments based on instructions stored in the memory 61.

[0089] It should be understood that each step in the aforementioned fault detection method can be implemented by a processor, and can be implemented by any means of software, hardware, firmware or a combination thereof.

[0090] In addition to the above-mentioned fault detection method and device, the embodiments of the present disclosure may also be in the form of a computer program product implemented on one or more non-volatile storage media containing computer program instructions. Therefore, some embodiments of the present disclosure also provide a computer-readable storage medium on which a computer program is stored, and when the program is executed by a processor, a fault detection method as described in any of the above-mentioned technical solutions is implemented.

[0091] Figure 7 A schematic diagram of a computer system according to some embodiments of the present disclosure is shown.

[0092] like Figure 7 As shown, the computer system can be expressed in the form of a general-purpose computing device, and the computer system can be used to implement the fault detection method of the above embodiment. The computer system includes a memory 71, a processor 72 and a bus 70 connecting different system components.

[0093] The memory 71 may include, for example, a system memory, a non-volatile storage medium, etc. The system memory may store, for example, an operating system, an application program, a boot loader, and other programs. The system memory may include a volatile storage medium, such as a random access memory (RAM) and / or a cache memory. The non-volatile storage medium may store, for example, instructions for executing the corresponding embodiment of the above-mentioned fault detection method. The non-volatile storage medium includes, but is not limited to, a disk memory, an optical memory, a flash memory, etc.

[0094] The processor 72 can be implemented by a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gates or transistors, etc. Discrete hardware components. Accordingly, each module such as the judgment module and the determination module can be implemented by a central processing unit (CPU) running instructions in a memory that execute corresponding steps, or can be implemented by a dedicated circuit that executes corresponding steps.

[0095] The bus 70 may use any of a variety of bus architectures, including, but not limited to, an Industry Standard Architecture (ISA) bus, a Micro Channel Architecture (MCA) bus, and a Peripheral Component Interconnect (PCI) bus.

[0096] The computer system may further include an input / output interface 73, a network interface 74, a storage interface 75, etc. The input / output interface 73, the network interface 74, the storage interface 75, the memory 71, and the processor 72 may be connected via a bus 70. The input / output interface 73 may provide a connection interface for input / output devices such as a display, a mouse, and a keyboard. The network interface 74 may provide a connection interface for various networked devices. The storage interface 75 may provide a connection interface for external storage devices such as a floppy disk, a USB flash drive, and an SD card.

[0097] So far, various embodiments of the present disclosure have been described in detail. In order to avoid obscuring the concept of the present disclosure, some details known in the art are not described. Based on the above description, those skilled in the art can fully understand how to implement the technical solution disclosed here.

[0098] Although some specific embodiments of the present disclosure have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present disclosure. It should be understood by those skilled in the art that the above embodiments may be modified or some technical features may be replaced by equivalents without departing from the scope and spirit of the present disclosure. The scope of the present disclosure is defined by the appended claims.

Claims

1. A ring network power supply system, comprising: Busbar ring; Multiple power supplies connected to the bus ring and arranged in parallel, the part of the bus ring between two adjacent power supplies is a power supply section; Normally closed switches connected in series on each power supply section; The controller is used to determine that a ground fault occurs on the side of the power supply section away from the normally closed switch and issue a first alarm message when the normally closed switch on the power supply section is switched from a closed state to an open state and the load connected to the power supply section is switched from a normal working state to a stopped working state.

2. The ring network power supply system according to claim 1, wherein: The controller is used to determine that a ground fault occurs on the other side of the load in the power supply section and issue a second alarm message when the normally closed switch on the power supply section is closed and the load connected to the power supply section is in a stopped working state.

3. The ring network power supply system according to claim 1 or 2, further comprising: An insulation impedance detection circuit connected to the power supply section, the insulation impedance detection circuit comprising a first branch and a second branch connected in parallel and grounded, the first branch comprising a first resistor and a first switch connected in series, and the second branch comprising a second resistor and a second switch connected in series; as well as The voltage detection device is used to detect the voltage of the positive line of the power supply section to the ground and the voltage of the negative line of the power supply section to the ground.

4. The ring network power supply system according to claim 3, wherein: A controller, used for closing the first switch and opening the second switch at a first moment, and closing the second switch and opening the first switch at a second moment, when the normally closed switch corresponding to the power supply section is disconnected and the load is working normally; obtaining the insulation impedance value of the positive line and the insulation impedance value of the negative line according to the resistance value of the first resistor, the resistance value of the second resistor, the first voltage to ground of the positive line and the first voltage to ground of the negative line at the first moment, and the second voltage to ground of the positive line and the second voltage to ground of the negative line at the second moment; issuing a first warning message when the insulation impedance value of the positive line is less than a set first threshold value; issuing a second warning message when the insulation impedance value of the negative line is less than a set second threshold value.

5. The ring network power supply system according to claim 4, wherein: The controller is used to detect ground faults and insulation impedance of each power supply section in turn according to a set order.

6. The ring network power supply system according to claim 1, wherein: Normally closed switches include contactors or relays.

7. The ring network power supply system according to claim 1, wherein: The power supply includes a power grid and a converter, and the power grid transmits direct current to the bus ring through the converter; and / or The power source includes photovoltaic modules, which transmit direct current to the bus ring through the converter.

8. A fault detection method for a ring network power supply system, comprising: The normally closed switch on the control power supply section is disconnected; Obtaining working status information of a load connected to the power supply segment before and after the normally closed switch is disconnected, wherein the working status information includes whether the load is in a normal working state or the load is in a stopped working state; When the load is in a normal working state before the normally closed switch is disconnected and is in a stopped working state after the normally closed switch is disconnected, it is determined that a ground fault occurs on the side of the power supply section away from the normally closed switch and a first alarm message is issued.

9. The fault detection method according to claim 8, further comprising: When the normally closed switch on the power supply section is closed and the load connected to the power supply section is in a stopped working state, it is determined that a ground fault occurs in the power supply section on the other side of the load and a second alarm message is issued.

10. The fault detection method according to claim 8 or 9, wherein: The ring network power supply system also includes: an insulation impedance detection circuit connected to the power supply section, the insulation impedance detection circuit includes a first branch and a second branch connected in parallel and grounded, the first branch includes a first resistor and a first switch connected in series, and the second branch includes a second resistor and a second switch connected in series; The fault detection method further includes: Obtaining a first voltage to ground of the positive line and a first voltage to ground of the negative line of the power supply segment when the normally closed switch corresponding to the power supply segment is disconnected, the load works normally, the first switch is closed, and the second switch is disconnected, and obtaining a second voltage to ground of the positive line and a second voltage to ground of the negative line of the power supply segment when the normally closed switch corresponding to the power supply segment is disconnected, the load works normally, the first switch is disconnected, and the second switch is closed; Obtaining an insulation resistance value of the positive line and an insulation resistance value of the negative line according to a resistance value of the first resistor, a resistance value of the second resistor, a first voltage to ground of the positive line and a first voltage to ground of the negative line at a first moment, and a second voltage to ground of the positive line and a second voltage to ground of the negative line at a second moment; When the insulation resistance value of the positive line is less than a set first threshold value, a first warning message is issued; When the insulation resistance value of the negative line is less than a set second threshold, a second warning message is issued.

11. The fault detection method according to claim 10, wherein: The insulation resistance value of the positive line and the insulation resistance value of the negative line are obtained according to the following functional relationship: Among them, R + is the insulation resistance value of the positive line, R - is the insulation resistance value of the negative line, R1 is the resistance value of the first resistor, R2 is the resistance value of the second resistor, U 1+ is the first voltage of the positive line to ground, U 1- is the first voltage of the negative line to ground, U 2+ is the second voltage of the positive line to ground, U 2- is the second ground voltage of the negative line.

12. A fault detection device for a ring network power supply system, comprising: A switch control unit, used to control the normally closed switch on the power supply section to open; An information acquisition unit, used to acquire working state information of a load connected to the power supply segment before and after the normally closed switch is disconnected, wherein the working state information includes whether the load is in a normal working state or the load is in a stopped working state; The judgment unit is used to judge that a ground fault occurs on the side of the power supply section away from the normally closed switch and issue a first alarm message when the load is in a normal working state before the normally closed switch is disconnected and is in a stopped working state after the normally closed switch is disconnected.

13. A fault detection device for a ring network power supply system, comprising: Memory; and A processor coupled to the memory, wherein the processor is configured to execute the fault detection method according to any one of claims 8 to 11 based on instructions stored in the memory.

14. A computer-readable storage medium having a computer program stored thereon, wherein when the program is executed by a processor, the fault detection method according to any one of claims 8 to 11 is implemented.

Images