Class switching method and device for direct-current power supply system

Abstract

The invention discloses a category switching method and device for a direct-current power supply system. The method comprises the following steps: acquiring an operation category and state information of the direct-current power supply system; determining a switching category of the direct-current power supply system according to the operation category; and switching the type of the direct-current power supply system according to the switching type and the state information. The category switching method provided by the invention can be operated without power failure, realizes simultaneous detection of grounding fault and other information of new and old power supply direct current systems, and greatly shortens the fault searching and eliminating time.

Description

Technical Field

[0001] The present invention relates to the technical field of direct current power supply system control, and in particular to a category switching method and device for a direct current power supply system. Background Art

[0002] The DC power supply system of a substation is an important component of the secondary system of the substation. It is the basis for the normal operation and correct action of relay protection, safety automatic devices and automation equipment. If an abnormality or accident occurs in the DC power supply system, the relay protection or safety device may refuse to operate at the least, or even cause major equipment damage or the entire substation to stop, causing heavy losses to power grid companies and the national economy.

[0003] The function of the insulation monitoring device is to monitor the insulation level of the entire DC power supply network, and to find the grounded feeder branch when grounding occurs, so that maintenance personnel can quickly find and eliminate the grounding point. During the transition period between the old and new DC systems, the DC busbars at both ends of the new and old systems are operated in parallel, and only the insulation monitoring device of the old screen busbar is kept in operation. The new busbar insulation monitoring device must wait until the charger screen and battery of the new DC system are all accepted and in place before it can be put into operation. As a result, when DC grounding occurs in the operational branch of the new DC system, the old DC system will not be able to identify the grounded branch, which brings great difficulties to the on-site DC grounding fault investigation. The current practice is to apply for the withdrawal of the insulation monitoring device and its balancing bridge of the old DC system first, and then put the insulation monitoring device and its balancing bridge of the new DC system into operation; for old substations, the withdrawal and insertion of the old balancing bridge involves disassembly and wiring, which is troublesome and time-consuming. Summary of the invention

[0004] The present invention provides a method and device for switching the category of a DC power supply system. By autonomously judging and automatically switching the versions of the new and old DC power supply systems of a substation, the technical problem of low efficiency caused by the inability of the old DC system to identify the grounded branch when a DC grounding occurs in the commissioning branch of the new DC system during the transformation, or the inability of the new DC system to identify the grounded branch when the old DC system is grounded, is solved.

[0005] According to a first aspect of the present invention, there is provided a class switching method for a DC power supply system, comprising:

[0006] Obtain the operation category and status information of the DC power supply system;

[0007] Determining a switching category of the DC power supply system according to the operation category;

[0008] The category of the DC power supply system is switched according to the switching category and the status information.

[0009] Optionally, determining the switching category of the DC power supply system according to the operation category includes:

[0010] When the operation category is the first DC system, the switching category is the second DC system;

[0011] When the operation category is the second DC system, the switching category is the first DC system.

[0012] Optionally, switching the category of the DC power supply system according to the switching category and the state information includes:

[0013] When the state information satisfies a first preset condition, the first DC system is switched to the second DC system or the second DC system is switched to the first DC system.

[0014] Optionally, the first preset condition includes that the positive and negative voltages to ground of the DC power supply system fluctuate beyond a first threshold range, the duration of time that the DC power supply system is in the first DC system or the second DC system exceeds a second threshold, or the positive and negative voltages to ground of the DC power supply system are in an unbalanced state;

[0015] The unbalanced state includes that the difference between the positive voltage and the negative voltage of the DC power supply system is greater than or equal to a third threshold.

[0016] Optionally, before obtaining the operation category and status information of the DC power supply system, including:

[0017] Selecting a switching mode of the current DC power supply system;

[0018] The category of the DC power supply system is switched according to the switching mode; wherein the switching module includes manual switching or automatic switching.

[0019] Optionally, switching the category of the DC power supply system according to the switching mode includes:

[0020] When the switching mode is automatic switching, obtaining the operation category and status information of the DC power supply system; determining the switching category of the DC power supply system according to the operation category; switching the category of the DC power supply system according to the switching category and the status information;

[0021] When the switching mode is manual switching, the type of the DC power supply system is switched according to a user instruction.

[0022] Optionally, when the switching mode is manual switching, after the category of the DC power supply system is switched, the following steps are performed:

[0023] Obtaining positive and negative voltages to ground of the DC power supply system;

[0024] An alarm is sent to the DC power supply system according to the positive and negative voltages to ground.

[0025] Optionally, sending an alarm to the DC power supply system according to the positive and negative voltages to ground includes:

[0026] When the positive and negative voltages to ground are in a balanced state, continue to detect the positive and negative voltages to ground of the DC power supply system;

[0027] When the positive and negative voltages to ground are in an unbalanced state, an alarm message is issued; wherein, the balanced state includes that the difference between the positive voltage and the negative voltage is less than a third threshold; the unbalanced state includes that the difference between the positive voltage and the negative voltage is greater than or equal to a second threshold.

[0028] According to a second aspect of the present invention, a category switching device for a DC power supply system is provided, the category switching device comprising a detection module, a control module and a switching module; the output end of the detection module is connected to the first input end of the control module; the output end of the switching module is connected to the second input end of the control module;

[0029] The detection module is used to obtain the operation category and status information of the DC power supply system;

[0030] The control module is used to determine the switching category of the DC power supply system according to the operation category;

[0031] The switching module is used to switch the category of the DC power supply system according to the switching category and the state information.

[0032] Optionally, the category switching device further includes a display module;

[0033] The output end of the display module is connected to the third input end of the control module, and the display module is used to display the positive and negative voltages to ground and the category switching result of the DC power supply system.

[0034] The present invention discloses a method and device for switching the category of a DC power supply system, including: obtaining the operation category and status information of the DC power supply system; determining the switching category of the DC power supply system according to the operation category; and switching the category of the DC power supply system according to the switching category and status information. The present invention provides a method and device for switching the category of a DC power supply system, which automatically switches the new and old DC power supply systems of a substation through autonomous judgment, thereby solving the technical problem of low efficiency caused by the DC grounding of the commissioning branch of the new DC system during the transformation period, or the grounding of the old DC system and the inability of the new DC system to identify the grounding branch.

[0035] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0037] Figure 1 is a flow chart of a method for switching categories of a DC power supply system provided by an embodiment of the present invention;

[0038] Figure 2 is a flow chart of another method for switching categories of a DC power supply system provided by an embodiment of the present invention;

[0039] Figure 3 is a flow chart of another method for switching categories of a DC power supply system provided by an embodiment of the present invention;

[0040] Figure 4 is a flow chart of another method for switching categories of a DC power supply system provided by an embodiment of the present invention;

[0041] Figure 5 is a flow chart of another method for switching categories of a DC power supply system provided by an embodiment of the present invention;

[0042] Figure 6 is a flow chart of another method for switching categories of a DC power supply system provided by an embodiment of the present invention;

[0043] Figure 7 is a flow chart of another method for switching categories of a DC power supply system provided by an embodiment of the present invention;

[0044] Figure 8 is a block diagram of a category switching device for a DC power supply system provided by an embodiment of the present invention;

[0045] Fig. 9 is a schematic diagram of a category switching device for a DC power supply system provided by an embodiment of the present invention;

[0046] Fig.10 is a circuit design diagram of a power supply in a DC power supply system provided by an embodiment of the present invention;

[0047] Fig.11 is a schematic diagram of a switching module in a DC power supply system provided by an embodiment of the present invention;

[0048] Fig.12 is a block diagram of another type switching device of a DC power supply system provided by an embodiment of the present invention;

[0049] Fig.13 This is a user interface design diagram of a category switching device for a DC power supply system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0050] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings 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 should fall within the scope of protection of the present invention.

[0051] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices. It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps recorded in the present invention can be executed in parallel, can be executed sequentially, or can be executed in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document is not limited here.

[0052] Figure 1 is a flow chart of a method for switching a category of a DC power supply system provided by an embodiment of the present invention, with reference to Figure 1 , an embodiment of the present invention provides a category switching method for a DC power supply system, comprising:

[0053] S1. Obtain the operation category and status information of the DC power supply system.

[0054] Among them, the DC power supply system is an important part of the substation secondary system and the basis for the normal operation and correct action of relay protection, safety automatic devices and automation equipment.

[0055] Specifically, in the daily work of the substation, the DC power supply system is divided into an old DC power supply system and a new DC power supply system. The DC busbars at both ends of the old and new DC power supply systems operate in parallel. The current operation category of the DC power supply system is obtained, that is, whether the current operation category of the DC power supply system is the old version or the new version is determined. At the same time, the status information of the DC power supply system is obtained, and the status information includes DC voltage information and operation time information.

[0056] S2. Determine the switching category of the DC power supply system according to the operation category.

[0057] Specifically, after the operation category of the DC power supply system is determined in the above step S1, the category to which the DC power supply system needs to be switched is determined according to the current operation category.

[0058] S3. Switch the category of the DC power supply system according to the switching category and status information.

[0059] Specifically, the DC power supply system is switched according to the category and state information of the DC power supply system to be switched determined in the above steps S1 and S2.

[0060] The category switching method of the DC power supply system provided in the embodiment of the present invention automatically switches the new and old DC power supply systems of the substation through autonomous judgment, thereby solving the technical problem of low efficiency caused by the inability of the old DC system to identify the grounded branch when DC grounding occurs in the operating branch of the new DC system during the transformation, or the inability of the new DC system to identify the grounded branch when the old DC system is grounded.

[0061] Based on the above embodiment, the embodiment of the present invention further refines the determination of the switching category of the DC power supply system according to the operation category. Figure 2 : is a flow chart of another category switching method of a DC power supply system provided by an embodiment of the present invention. The category switching method provided by an embodiment of the present invention includes:

[0062] S21. Obtain operation category and status information of the DC power supply system.

[0063] S22. When the operation category is the first DC system, the switching category is the second DC system.

[0064] Specifically, when the operation category of the DC power supply system determined in step S21 is the first DC system, the first DC system currently operated by the DC power supply system is switched to the second DC system.

[0065] S23. When the operation category is the second DC system, the switching category is the first DC system.

[0066] Specifically, when the operating category of the DC power supply system determined by the above step S21 is the second DC system, the second DC system currently operated by the DC power supply system is switched to the first DC system; exemplarily, the first DC system is the old DC power supply system, and the second DC system is the new DC power supply system.

[0067] S24. Switch the category of the DC power supply system according to the switching category and the status information.

[0068] Based on the above embodiment, the embodiment of the present invention further refines the switching of the category of the DC power supply system according to the switching category and the state information. Figure 3 : is a flow chart of another category switching method of a DC power supply system provided by an embodiment of the present invention. The category switching method provided by an embodiment of the present invention includes:

[0069] S31. Obtain operation category and status information of the DC power supply system.

[0070] S32: When the running version is the first DC system, the switching category is the second DC system.

[0071] S33. When the operation category is the second DC system, the switching category is the first DC system.

[0072] S34: Analyze the status information and the first preset condition.

[0073] The state information acquired in the above step S31 is compared and analyzed with the first preset condition. When the state information meets the first preset condition, step S35 is executed; when the state information does not meet the first preset condition, step S36 is executed.

[0074] S35. When the state information satisfies a first preset condition, the first DC system is switched to the second DC system or the second DC system is switched to the first DC system.

[0075] Specifically, the status information of the DC power supply system includes DC voltage information and operating time information, etc. When the status information of the DC power supply system meets the first preset condition, the first DC system is switched to the second DC system or the second DC system is switched to the first DC system. That is to say, when the status information of the DC power supply system meets the first preset condition, the first DC system is automatically switched to the second DC system or the second DC system is automatically switched to the first DC system. Exemplarily, the current version of the DC power supply system is the old DC power supply system, and the old DC power supply system is switched to the new DC power supply system, or the current version of the DC power supply system is the new DC power supply system, and the new DC power supply system is switched to the old DC power supply system.

[0076] S36: When the status information does not meet the first preset condition, maintain the current category of the DC power supply system.

[0077] Specifically, when the status information of the DC power supply system acquired in the above step S31 does not meet the first preset condition, the current operation category of the DC power supply system is maintained. Exemplarily, when the status information of the DC power supply system does not meet the first preset condition, the new DC power supply system is maintained, or when the status information of the DC power supply system does not meet the first preset condition, the old DC power supply system is maintained.

[0078] Optionally, the first preset condition includes that the positive and negative voltages to ground of the DC power supply system fluctuate beyond a first threshold range, the time for which the DC power supply system is in the first DC system or the second DC system exceeds a second threshold, or the positive and negative voltages to ground of the DC power supply system are in an unbalanced state; wherein the unbalanced state includes that the difference between the positive voltage and the negative voltage of the DC power supply system is greater than or equal to a third threshold.

[0079] Specifically, the positive and negative voltage fluctuations to the ground of the DC power supply system are detected. Exemplarily, the first threshold range is plus or minus 10% of the bus voltage. If the bus voltage is 220V, the first threshold range is 198V-242V; the time when the DC power supply system is in the first DC system or the second DC system exceeds the second threshold. Exemplarily, the time when the DC power supply system is in the new DC power supply system or the time when the DC power supply system is in the old DC power supply system exceeds 30 minutes; or the positive and negative voltages to the ground of the DC power supply system are in an unbalanced state, and the unbalanced state means that the difference between the positive voltage and the negative voltage is greater than or equal to the third threshold, where the third threshold can be 20V. Exemplarily, if the bus voltage is 110V, the unbalanced state is that the positive voltage is 65V and the negative voltage is 45V, then it is determined that the DC power supply system is in an unbalanced state at this time.

[0080] Figure 4 is a flow chart of another method for switching the category of a DC power supply system provided by an embodiment of the present invention, referring to Figure 4 , optionally, before obtaining the operation category and status information of the DC power supply system, including:

[0081] S41, selecting a switching mode of the current DC power supply system.

[0082] Specifically, the switching method of the DC power supply system provided in the embodiment of the present invention is divided into automatic switching and manual switching, that is, the switching mode is divided into automatic switching mode and manual switching mode, and the switching mode of the current DC power supply system is selected.

[0083] S42. Switch the category of the DC power supply system according to the switching mode; wherein the switching module includes manual switching or automatic switching.

[0084] Specifically, the category of the DC power supply system is switched according to the switching mode determined in the above step S41. For example, if the current switching mode of the DC power supply system is manual switching, the category of the DC power supply system is switched according to the manual switching mode; if the current switching mode of the DC power supply system is automatic switching, the category of the DC power supply system is switched according to the automatic switching mode.

[0085] S43. Obtain the operation category and status information of the DC power supply system.

[0086] S44. Determine a switching category of the DC power supply system according to the operation category.

[0087] S45. Switch the category of the DC power supply system according to the switching category and the status information.

[0088] Figure 5 is a flow chart of another method for switching the category of a DC power supply system provided by an embodiment of the present invention, referring to Figure 5 , the switching method includes:

[0089] S51, selecting a switching mode of the current DC power supply system.

[0090] S52: Switch the type of the DC power supply system according to the switching mode.

[0091] Optionally, after the category of the DC power supply system is switched according to the switching mode, the following steps are included:

[0092] S53, when the switching mode is automatic switching, obtaining the operation category and status information of the DC power supply system; determining the switching category of the DC power supply system according to the operation category; and switching the category of the DC power supply system according to the switching category and status information.

[0093] Specifically, when the switching mode of the DC power supply system is determined to be the automatic switching mode, the following steps are executed in sequence: Figure 1 Steps shown.

[0094] S54: When the switching mode is manual switching, the type of the DC power supply system is switched according to a user instruction.

[0095] Specifically, when the switching mode of the DC power supply system is determined to be the manual switching mode, the category of the DC power supply system is switched according to a user instruction.

[0096] Figure 6 is a flow chart of another method for switching the category of a DC power supply system provided by an embodiment of the present invention, referring to Figure 6 , the switching method includes:

[0097] S61. Select a switching mode of the current DC power supply system.

[0098] S62: Switch the type of the DC power supply system according to the switching mode.

[0099] When the switching mode of the DC power supply system is automatic switching, step S63 is executed; when the switching mode of the DC power supply system is manual switching, step S64 is executed.

[0100] S63. When the switching mode is automatic switching, obtain the operation category and status information of the DC power supply system; determine the switching category of the DC power supply system according to the operation category; and switch the category of the DC power supply system according to the switching category and status information.

[0101] S64: When the switching mode is manual switching, the type of the DC power supply system is switched according to user instructions.

[0102] Optionally, when the switching mode is manual switching, after the category of the DC power supply system is switched, it includes:

[0103] S65. Obtain the positive and negative voltages to ground of the DC power supply system.

[0104] Specifically, the positive and negative voltages to ground of the DC power supply system are obtained.

[0105] S66. Send an alarm to the DC power supply system based on the positive and negative voltages to ground.

[0106] Specifically, it is determined whether the DC power supply system issues an alarm based on the positive and negative voltages to ground obtained in step S65.

[0107] Figure 7 is a flow chart of another method for switching the category of a DC power supply system provided by an embodiment of the present invention, referring to Figure 7 , the switching method includes:

[0108] S71. Select a switching mode of the current DC power supply system.

[0109] S72. Switch the category of the DC power supply system according to the switching mode.

[0110] When the switching mode of the DC power supply system is automatic switching, step S73 is executed; when the switching mode of the DC power supply system is manual switching, step S74 is executed.

[0111] S73. When the switching mode is automatic switching, obtain the operation category and status information of the DC power supply system; determine the switching category of the DC power supply system according to the operation category; and switch the category of the DC power supply system according to the switching category and status information.

[0112] S74: When the switching mode is manual switching, the type of the DC power supply system is switched according to user instructions.

[0113] S75. Obtain the positive and negative voltages to ground of the DC power supply system.

[0114] S76. When the positive and negative voltages to ground are in a balanced state, continue to detect the positive and negative voltages to ground of the DC power supply system.

[0115] Specifically, when the positive and negative voltages to the ground of the DC power supply system are in a balanced state, the current operating category of the DC power supply system is maintained, and the positive and negative voltages to the ground of the DC power supply system continue to be detected. Exemplarily, the balanced state refers to when the bus voltage is 110V, the positive voltage is 55V, and the negative voltage is 55V.

[0116] S77. When the positive and negative voltages to the ground are in an unbalanced state, an alarm message is issued.

[0117] Specifically, when the positive and negative voltages to the ground of the DC power supply system are in an unbalanced state, an alarm message is issued, and the alarm message can be a buzzer alarm, a light alarm, etc., which is not limited in the embodiment of the present invention. Among them, the balanced state includes that the difference between the positive voltage and the negative voltage is less than the third threshold value. For example, the balanced state means that if the bus voltage is 110V, the positive voltage is 55V, and the negative voltage is 55V; the unbalanced state includes that the difference between the positive voltage and the negative voltage is greater than or equal to the second threshold value. For example, the unbalanced state means that if the bus voltage is 110V, the positive voltage is 65V, and the negative voltage is 45V.

[0118] According to the same concept of the present invention, Figure 8 is a block diagram of a category switching device for a DC power supply system provided by an embodiment of the present invention, with reference to Figure 8 , an embodiment of the present invention provides a category switching device for a DC power supply system, the category switching device comprising a detection module 1, a control module 2 and a switching module 3; the output end of the detection module 1 is connected to the first input end of the control module 2, and the output end of the switching module 3 is connected to the second input end of the control module 2;

[0119] The detection module 1 is used to obtain the operation category and status information of the DC power supply system;

[0120] The control module 2 is used to determine the switching category of the DC power supply system according to the operation category;

[0121] The switching module 3 is used to switch the category of the DC power supply system according to the switching category and state information.

[0122] Fig. 9 is a schematic diagram of a category switching device for a DC power supply system provided by an embodiment of the present invention, with reference to Fig. 9 The working principle of the category switching device of the DC power supply system is to switch between the old and new DC systems using the program-controlled switch QK through the control of the single-chip microcomputer. When the program-controlled switch QK is closed at point b, the DC power supply system operates in the old DC power supply system. At this time, the insulation monitoring device of the old DC power supply system can monitor the insulation fault of the old DC power supply system. Once an insulation fault occurs in the new DC power supply system, the operator only needs to press the switching button of the device, the program-controlled switch QK will be closed at point a, and the balancing bridge will switch from the old DC power supply system to the new DC power supply system, thereby realizing the detection and selection of the faulty feeder of the new DC power supply system.

[0123] Fig.10 is a circuit design diagram of a power supply in a DC power supply system provided by an embodiment of the present invention, with reference to Fig.10 , the output end of the diode D1 is connected to the first pin of the chip U4, the second pin of the chip U4 is connected to the voltage terminal VCC, the third pin of the chip U4 is connected to the first end of the inductor L1, the second end of the inductor L1 is connected to the first end of the capacitor C1, and the second end of the capacitor C1 is grounded GND. The power supply is the basis for the stable operation of the switching device of the DC power supply system, and its design must ensure the stability and reliability of the power supply. This device adopts a switching power supply with a wide voltage input, which can adapt to the voltage fluctuation range of the DC power supply system in different substations. At the same time, the power supply module also has over-current, over-voltage, under-voltage and other protection functions to ensure that the power supply can be quickly cut off under abnormal circumstances to avoid damage to the device. The circuit design is as follows Fig.10 shown.

[0124] Fig.11 is a schematic diagram of a switching module in a DC power supply system provided by an embodiment of the present invention, with reference to Fig.11 The switching module is the key module to realize the switching between the old and new DC power supply systems. The switching device of the DC power supply system has a low P2.4 level at the beginning. At this time, the potential difference between the base and emitter of transistor Q1 is less than 0.7V, transistor Q1 is cut off, relay U7 does not work, and is in a normally closed state. The switching device cuts into the old DC power supply system; when P2.4 is high, the potential difference between the base and emitter of transistor Q1 exceeds 0.7V. At this time, relay U7 is energized, and the device cuts into the new DC power supply system. The diode D2 connected in parallel on the coil of relay U7 is a current storage diode. Its function is to form a circuit to release the energy in the relay coil at the moment when transistor Q1 is cut off, so as to avoid the reverse peak voltage from breaking through the transistor.

[0125] A category switching device for a DC power supply system provided in an embodiment of the present invention can achieve the same technical effect as a category switching method for a DC power supply system provided in the above-mentioned embodiment of the invention, which will not be described in detail here.

[0126] Fig.12is a block diagram of another type switching device of a DC power supply system provided by an embodiment of the present invention, referring to Fig.12 , Optionally, the category switching device further includes a display module 4;

[0127] The output end of the display module 4 is connected to the third input end of the control module 2 , and the display module 4 is used to display the positive and negative voltages to ground and the category switching result of the DC power supply system.

[0128] Specifically, the display module 4 may be a display screen for displaying status information and switching results of the current DC power supply system.

[0129] Fig.13 This is a user interface design diagram of a category switching device of a DC power supply system provided by an embodiment of the present invention, with reference to Fig.13 .

[0130] Specifically, the user interface (UI) of the category switching device of the DC power supply system provided by the embodiment of the present invention is as follows: Fig.13 As shown, the main interface of the category switching device can display the positive and negative ground voltages of the DC power supply system, and whether the current DC power supply system is running with the new system or the old system, so that the operation and maintenance personnel can quickly view it. The interface design is simple and clear. Click Manual Setting to manually select the balancing bridge operation and the new / old DC system, which can be quickly switched to meet the actual needs of rapid maintenance for on-site troubleshooting. Click Automatic Setting to set the switching conditions according to actual needs. The system defaults to control the balancing bridge to switch into the old / new DC power supply system when the system voltage fluctuation reaches 10% of the bus voltage or the balancing bridge has been running in the new / old device for 30 minutes.

[0131] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for class switching of a DC power supply system, characterized in that: include: Obtain the operation category and status information of the DC power supply system; Determining a switching category of the DC power supply system according to the operation category; The category of the DC power supply system is switched according to the switching category and the status information.

2. The method for switching the category of a DC power supply system according to claim 1, characterized in that: Determining a switching category of the DC power supply system according to the operation category includes: When the operation category is the first DC system, the switching category is the second DC system; When the operation category is the second DC system, the switching category is the first DC system.

3. The method for switching the category of a DC power supply system according to claim 2, characterized in that: Switching the category of the DC power supply system according to the switching category and the state information includes: When the state information satisfies a first preset condition, the first DC system is switched to the second DC system or the second DC system is switched to the first DC system.

4. The method for switching the category of a DC power supply system according to claim 3, characterized in that: The first preset condition includes that the positive and negative voltages to ground of the DC power supply system fluctuate beyond a first threshold range, the duration of the DC power supply system being in the first DC system or the second DC system exceeds a second threshold, or the positive and negative voltages to ground of the DC power supply system are in an unbalanced state; The unbalanced state includes that the difference between the positive voltage and the negative voltage of the DC power supply system is greater than or equal to a third threshold.

5. The method for switching the category of a DC power supply system according to claim 1, characterized in that: Before obtaining the operating category and status information of the DC power system, include: Selecting a switching mode of the current DC power supply system; The category of the DC power supply system is switched according to the switching mode; wherein the switching module includes manual switching or automatic switching.

6. The method for switching the category of a DC power supply system according to claim 5, characterized in that: Switching the category of the DC power supply system according to the switching mode includes: When the switching mode is automatic switching, obtaining the operation category and status information of the DC power supply system; determining the switching category of the DC power supply system according to the operation category; switching the category of the DC power supply system according to the switching category and the status information; When the switching mode is manual switching, the type of the DC power supply system is switched according to a user instruction.

7. The method for switching the category of a DC power supply system according to claim 6, characterized in that: When the switching mode is manual switching, after the type of the DC power supply system is switched, the following steps are performed: Obtaining positive and negative voltages to ground of the DC power supply system; An alarm is sent to the DC power supply system according to the positive and negative voltages to ground.

8. The method for switching the category of a DC power supply system according to claim 7, characterized in that: Providing an alarm to the DC power supply system according to the positive and negative voltages to ground, including: When the positive and negative voltages to ground are in a balanced state, continue to detect the positive and negative voltages to ground of the DC power supply system; When the positive and negative voltages to ground are in an unbalanced state, an alarm message is issued; wherein, the balanced state includes that the difference between the positive voltage and the negative voltage is less than a third threshold; the unbalanced state includes that the difference between the positive voltage and the negative voltage is greater than or equal to a second threshold.

9. A category switching device for a DC power supply system, characterized in that: The category switching device comprises a detection module, a control module and a switching module; the output end of the detection module is connected to the first input end of the control module; the output end of the switching module is connected to the second input end of the control module; The detection module is used to obtain the operation category and status information of the DC power supply system; The control module is used to determine the switching category of the DC power supply system according to the operation category; The switching module is used to switch the category of the DC power supply system according to the switching category and the state information.

10. The category switching device of a DC power supply system according to claim 9, characterized in that: The category switching device also includes a display module; The output end of the display module is connected to the third input end of the control module, and the display module is used to display the positive and negative voltages to ground and the category switching result of the DC power supply system.

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