0.4kv hand-in-hand mutual power supply system
By using a three-phase four-wire air circuit breaker and disconnector to connect two independent transformers in a 0.4kV low-voltage power system, the problem of rapid power restoration in the event of transformer failure in the 0.4kV low-voltage power system is solved, achieving economical and efficient load user switching and wide applicability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHANXI HONGNENG INTELLIGENT ELECTRICAL CO LTD
- Filing Date
- 2026-03-17
- Publication Date
- 2026-06-05
AI Technical Summary
In the existing technology, the 0.4KV low-voltage power supply system lacks an effective dual power supply scheme, which leads to long-term power outages when the transformer fails. In addition, the existing medium-voltage power distribution line equipment is complex and costly, making it difficult to be widely used in residential power supply.
The integrated switch for distribution areas A and B is connected by a three-phase four-wire air circuit breaker and a disconnecting switch. The two independent transformers serve as loads for each other in case of a fault, enabling rapid switching of load users, simplifying power distribution wiring, and making it widely applicable.
It enables rapid power restoration of 0.4KV low-voltage power systems in the event of transformer failure, reducing power outage time, lowering equipment complexity and cost, and has a wide range of applications, making it economical and efficient.
Smart Images
Figure CN122159251A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of power line operation safety technology, specifically to a 0.4KV hand-in-hand mutual power supply system. Background Technology
[0002] Electricity is an indispensable resource in people's lives. Households need electricity, public facilities need electricity, and almost everything is inseparable from electricity. People are enjoying the many benefits that electricity brings. However, because these benefits are so great, and things often have two sides, the impact of a power outage is immeasurable. A sudden power outage can affect household electricity use, rendering appliances unusable and impacting basic living needs such as cooking, heating, and lighting. It can also affect important facilities such as traffic signals, elevators, and hospital equipment, increasing safety risks, restricting communication, and disrupting daily activities and work.
[0003] As a crucial component of the power system, the wiring method of the distribution network directly affects the reliability and economy of power supply. Among the many wiring methods, the dual-source "daily tandem" ring network connection has attracted much attention due to its unique advantages. This wiring method not only improves the stability of power supply but also facilitates rapid power restoration in the event of a fault, thereby ensuring the continuous and reliable operation of the power system.
[0004] Currently, there are 10KV and 6KV power supply systems available on the market, but there are no reports on 0.4KV residential power supply.
[0005] For example, patent number CN110323833A, entitled "A Smart Interconnection Structure for Dual Power Supply Lines in a 10kV Line," and patent number CN112865077A, entitled "A Locking Method for a Plant Power System Switch in a Locking Method," disclose patents for 10kV and 6kV medium-voltage distribution lines, respectively. These patents are not applicable to 0.4kV low-voltage lines. Furthermore, according to the disclosed content, medium-voltage distribution lines primarily involve point-to-point power distribution regulation. For instance, patent number CN112865077A, entitled "A Locking Method for a Plant Power System Switch in a Locking Method," distributes power to two generating units. The electrical range is relatively narrow. According to publicly available information, patent number CN110323833A, entitled "A 10kV Line Dual Power Supply Hand-in-Hand Intelligent Communication Structure," although capable of remote control, requires more basic equipment, increasing the overall control difficulty and consequently raising promotion costs and construction costs. Similarly, patent number CN112865077A, entitled "A Hand-in-Hand Plant Power System Switch Interlocking Method," is mainly used for the power supply of 6kV units in the plant area. It utilizes a hand-in-hand method to provide backup power to each other. Two sets of high-voltage transformers (T1), 6kV working incoming line switches (61AN), 6kV IA section busbars, 6kV IA section busbar voltage transformers (TV1), and 6kV backup incoming line switches (61AE) are used to control 380V Unit 1 and 380V Unit 2, respectively. Although this simplifies the basic equipment and can provide backup power to the two units, the equipment is cumbersome to use, and the application cost is correspondingly higher. Summary of the Invention
[0006] In view of the above-mentioned defects or deficiencies in the prior art, it is desirable to provide a 0.4KV daisy-chain power supply system.
[0007] The first objective of this invention is to provide a power distribution wiring method for 0.4KV low-voltage electricity users in the system, thereby reducing the long waiting time for power restoration caused by equipment failures such as transformers, facilitating immediate power restoration, and enabling rapid entry into equipment maintenance mode.
[0008] The second objective of this invention is to provide a simple, effective, and low-cost power distribution wiring method to ensure smooth power supply, expand the scope of application, and significantly improve the economic efficiency compared to diesel generator connection methods.
[0009] According to the technical solution provided in the embodiments of this application, a 0.4KV interconnected power supply system includes an A-zone integrated switch and a B-zone integrated switch connected by an air circuit breaker. The A-zone integrated switch and the B-zone integrated switch are respectively connected to the power grid through a JP integrated distribution box and a transformer. The load output of the A-zone integrated switch and the B-zone integrated switch is supplied to users. Under normal power supply conditions, the air circuit breaker is in the open position, and the A-zone integrated switch and the B-zone integrated switch supply users are supplied through transformers. Under abnormal power supply conditions, the air circuit breaker is in the closed position, and the two independent transformers connected to the A-zone integrated switch and the B-zone integrated switch supply users are supplied to each other.
[0010] Preferably, the two independent transformers connected to the integrated switch of area A and the integrated switch of area B can be sourced from the same power supply or from two different power supply sources, so as to achieve the independence of power supply for different areas.
[0011] Preferably, both the integrated switch for area A and the integrated switch for area B are three-phase four-wire disconnect switches.
[0012] Preferably, the air circuit breaker is a three-phase four-wire air switch.
[0013] Preferably, the incoming and outgoing terminals of the air circuit breaker are connected to the moving contact side of the integrated switch in area A and the integrated switch in area B, respectively, to facilitate the connection of mutual power supply lines.
[0014] Preferably, the stationary contact sides of both the integrated switch in area A and the integrated switch in area B are connected to a phase detection device and a phase indicator light for rapid detection of phase comparison results.
[0015] In summary, the beneficial effects of this application are as follows: This invention has the following advantages:
[0016] 1. This invention utilizes a three-phase four-wire air circuit breaker, disconnecting switch, and the connection of two independent power supply systems to enable the load users in the two independent power supply systems to serve as temporary loads for each other, preventing long-term power outages due to faults, while facilitating rapid repair and restoration of power supply to faulty lines.
[0017] 2. This invention utilizes simpler power distribution lines and cheaper power distribution switches to ensure smooth power supply for residents. It can also be matched with various types of transformers for power distribution, making it more widely applicable and providing the possibility for large-scale promotion and use. Attached Figure Description
[0018] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:
[0019] Figure 1This is a schematic diagram of the power distribution wiring of the entire system of the present invention;
[0020] Figure 2 This is a schematic diagram showing the connection of the integrated switch for area A, the integrated switch for area B, and the three-phase four-wire switch of the air circuit breaker in this invention.
[0021] The diagram labels are as follows: T1, T2 – Transformers; JP1, JP2 – JP Integrated Distribution Box; QS A – Integrated Switch for Area A; QS B – Integrated Switch for Area B; QF – Air Circuit Breaker. Detailed Implementation
[0022] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.
[0023] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.
[0024] like Figure 1 As shown, the 10KV or 6KV power grid is independently connected to the stationary contact side of the integrated switch QSA in area A and the integrated switch QS B in area B through two transformers T1 and T2, respectively. The moving contact side of the integrated switch QS A in area A and the integrated switch QS B in area B is connected through an air circuit breaker QF. The moving contact side of the integrated switch QS A in area A and the integrated switch QS B in area B outputs the load to the user.
[0025] like Figure 2 As shown in the diagram, the moving contact sides of the integrated switch QS A in area A and the integrated switch QS B in area B are connected by a daisy-chain air circuit breaker QF. The stationary contact sides of the integrated switch QS A in area A and the integrated switch QS B in area B are both connected to a phase detection switch, a phase detector, and a phase indicator light to detect the phase verification results.
[0026] Due to the combined effects of various factors such as application scenarios, voltage conversion requirements, load characteristics, environmental adaptability, technological advancements, and material selection, 0.4kV transformers used for residential electricity supply vary in model, capacity, impedance voltage, and connection group designation. To verify its adaptability, this solution includes the following experiments. The phase difference is represented by measuring the potential difference using a voltmeter method, and the phase difference can be calculated using the voltage difference conversion formula.
[0027] Example 1
[0028] When using transformers T1 and T2 with identical model, capacity, impedance voltage, and connection group designation, and connecting them to the power supply of integrated switch QSA in area A and integrated switch QSB in area B, the air circuit breaker QF is in the open position. At this time, using the phase detection switch (closed position), the phase detection device, and the phase indicator light, the phase difference is checked. When the phase difference is at its minimum or off, the phase verification result is obtained. When the corresponding indicator light illuminates and displays a numerical value, it indicates that the phase is out of phase; the operator should replace the phase. After the phase is determined, the phase confirmation device is deactivated.
[0029] When testing QS AA to QS BB, the two testing endpoints of the phase detector are placed on the lines of QS AA and QSB-B, respectively.
[0030] Table 1. Phase comparison results when transformers T1 and T2 have the same model, capacity, impedance voltage, and connection group number.
[0031]
[0032] As can be seen from Table 1, when the two transformers have the same model, capacity, impedance voltage, and connection group number, the measured phase comparison results are very ideal and perfectly match the results in the textbook.
[0033] Example 2
[0034] When using transformers T1 and T2, which are different in model, capacity, impedance voltage, and connection group designation, and connecting them to the power supply of integrated switch QSA in area A and integrated switch QSB in area B, the air circuit breaker QF is in the open position. At this time, the phase difference is detected using a phase detection switch (closed position), a phase detection device, and a phase indicator light—that is, the phase verification result. When the corresponding indicator light illuminates, it indicates that the phase is out of phase; the operator should replace the phase. After the phase is determined, the phase verification device is deactivated.
[0035] The T1 and T2 transformers use models S9-M-200 and S13-M-400 respectively. The table below shows the measured results.
[0036] Table 2. Phase comparison results for transformers T1 and T2 when their model, capacity, impedance voltage, and connection group number are all different.
[0037]
[0038] As can be seen from Table 2, the voltage differences between QS AA and QS BA, QS AB and QS BB, QS AC and QS BC, and QS AN and QSB-N are all within the acceptable range. This indicates that even after using transformers with different models, capacities, impedance voltages, and connection group numbers, this power distribution line can still achieve safe power distribution.
[0039] Example 3
[0040] When using transformers T1 and T2 of the same model but different capacity, reactance voltage, and connection group standard, and connecting them to the power supply of integrated switch QSA in area A and integrated switch QSB in area B, the air circuit breaker QF is in the open position. At this time, the phase difference is detected using the phase detection switch (closed position), the phase detector, and the phase indicator light—that is, the phase verification result. When the corresponding indicator light is lit, it indicates that the phase is out of phase; the operator should replace the phase. After the phase is determined, the phase confirmation device is exited.
[0041] The T1 and T2 transformers use models SBH15-M-200 and SH15-M-400 respectively. The table below shows the measured results.
[0042] Table 3. Phase comparison results for transformers T1 and T2 with different models, capacities, and impedance voltages, but the same connection group designation.
[0043]
[0044] As can be seen from Table 3, the phase comparison results of transformers with different models, capacities, and impedance voltages but the same connection group number used in the power distribution lines of this scheme are within the qualified range.
[0045] In summary, the 0.4kV interconnected power supply system of this scheme can achieve phase comparison results within the qualified range regardless of whether transformers of the same model, capacity, impedance voltage, and connection group number are used; transformers of different models, capacity, impedance voltage, and connection group number are used; or transformers of different models, capacity, and impedance voltage but the same connection group number are used for power distribution. This indicates that the application scope of this scheme for interconnected power supply systems for residential electricity consumption is quite wide.
[0046] Operating principle:
[0047] When the integrated switch of area A supplies power to A1, A2...An, and the integrated switch of area B supplies power to B1, B2...Bn, and all are in normal operation, the air circuit breaker QF, the integrated switch of area A QS A, and the integrated switch of area B QS B are all in the open position. The integrated switch of area A QS A and the integrated switch of area B QS B supply power to the users normally through the transformer.
[0048] When the T1 transformer connected to the integrated switch of area A fails, the air circuit breaker and integrated switch QS A of area A will be in the closed position, and integrated switch QS B of area B will be in the open position. At this time, users A1, A2...An will be connected to the T2 transformer, that is, the T2 transformer will simultaneously load users A1, A2...An and users B1, B2...Bn.
[0049] Similarly, when the T2 transformer connected to the B area integrated switch fails, the air circuit breaker and the B area integrated switch QS B will be in the closed position, and the A area integrated switch QS A will be in the open position. At this time, users B1, B2...Bn will be connected to the T1 transformer, that is, the T1 transformer will simultaneously load users A1, A2...An and users B1, B2...Bn.
[0050] This system enables power distribution lines to serve as loads for each other's users, thereby reducing power outage time for residents and preventing disruption to their lives.
[0051] The above description is merely a preferred embodiment of this application and an explanation of the technical principles and solutions employed. Furthermore, the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features with similar functions disclosed in this application.
Claims
1. A 0.4KV daisy-chain interconnected power supply system, characterized in that: include, The integrated switchgear A (QS A) and integrated switchgear B (QS B) are connected via air circuit breakers (QF). Integrated switchgear A (QS A) and integrated switchgear B (QS B) are connected to the power grid via integrated distribution boxes (JP1, JP2) and transformers (T1, T2), respectively. The load output of integrated switchgear A (QS A) and integrated switchgear B (QS B) is supplied to users. Under normal conditions, the air circuit breaker (QF) of each power supply system is in the open position, and the integrated switch of area A (QS A) and integrated switch of area B (QS B) are connected to the transformer load users respectively; In the abnormal state of the power supply system, the air circuit breaker (QF) is in the closed position, and the two independent transformers (T1 and T2) connected to the integrated switch of area A (QS A) and integrated switch of area B (QS B) are the loads of each other's output users.
2. The 0.4KV daisy-chain interconnected power supply system according to claim 1, characterized in that: The two independent transformers (T1, T2) connected to the integrated switch of area A (QS A) and integrated switch of area B (QS B) can be sourced from the same power supply or from two different power supplies.
3. A 0.4KV daisy-chain power supply system according to claim 2, characterized in that: Both the integrated switch for transformer substation A (QS A) and the integrated switch for transformer substation B (QS B) are three-phase four-wire disconnect switches.
4. A 0.4KV daisy-chain power supply system according to claim 3, characterized in that: The air circuit breaker (QF) is a three-phase four-wire air switch.
5. A 0.4KV daisy-chain interconnected power supply system according to claim 4, characterized in that: The incoming and outgoing terminals of the air circuit breaker (QF) are connected to the moving contact side of the integrated switch for area A (QS A) and the integrated switch for area B (QS B), respectively.
6. A 0.4KV daisy-chain power supply system according to claim 1, characterized in that: Both the stationary contact side of the integrated switch in area A (QS A) and the integrated switch in area B (QS B) are connected to a phase detection device and a phase indicator light for rapid detection of phase comparison results.