A kind of anti-crossing power distribution system

Abstract

The present application discloses an anti-crossing distribution system, which relates to the technical field of segmented protection of line systems, including a main bus and a branch bus, a distribution cabinet is connected to the branch bus, an incoming line circuit breaker is connected to the main bus, an anti-crossing circuit breaker is connected between the main bus and the branch bus, the rated current of the anti-crossing circuit breaker is less than the short-circuit current of the distribution cabinet, and the current redundancy of the anti-crossing circuit breaker is less than the current redundancy of the incoming line circuit breaker. The present application connects an anti-crossing circuit breaker between the main bus and the branch bus, and when a short circuit occurs in the distribution cabinet on the current branch bus, the anti-crossing circuit breaker is disconnected before the incoming line circuit breaker, thereby avoiding the impact on other distribution cabinets caused by the disconnection of the incoming line circuit breaker.

Description

Technical Field

[0001] The present application relates to the technical field of segment protection of line systems, and in particular to an anti-crossing distribution system. Background Art

[0002] In industrial production, equipment needs to be connected to a power source to work properly. Since there are many devices in the factory, the busbar is currently used for power supply. After multiple distribution cabinets are connected to the main busbar at the same time, the power needs of multiple devices can be met at the same time.

[0003] Figure 1 This is a schematic diagram of an existing power distribution system. The main bus in the figure is connected to multiple branch busbars at the same time. Some of the branch busbars are connected to motor protectors, contactors, circuit breakers and distribution cabinets, and other branch busbars are connected to reactive power compensation devices and reactive power compensation controllers. The power supply of the main busbar is provided by a transformer, and an incoming circuit breaker is connected between the transformer and the main busbar.

[0004] However, the distribution cabinets and equipment in the above-mentioned distribution system may suffer short-circuit faults during operation. The current during short circuit is very large, usually reaching several times the normal operating current. The branch bus and the main bus of the existing distribution system are directly connected. When a short-circuit fault occurs, the incoming circuit breaker will be disconnected, causing all branch busbars to lose power, seriously affecting the normal progress of industrial production. Utility Model Content

[0005] The embodiment of the present application provides an anti-crossing power distribution system to solve the problem in the prior art that when a short circuit occurs in a power distribution cabinet, the incoming circuit breaker on the main bus is disconnected, causing power outages in all branch buses.

[0006] An embodiment of the present application provides an anti-crossing distribution system, including a main bus and a branch bus, a distribution cabinet is connected to the branch bus, an incoming line circuit breaker is connected to the main bus, an anti-crossing circuit breaker is connected between the main bus and the branch bus, the rated current of the anti-crossing circuit breaker is less than the short-circuit current of the distribution cabinet, and the current redundancy of the anti-crossing circuit breaker is less than the current redundancy of the incoming line circuit breaker.

[0007] In a possible implementation, a motor protector, a contactor, and a circuit breaker switch are also connected to the branch bus.

[0008] In a possible implementation manner, a transformer is further connected to the main bus.

[0009] In a possible implementation, a reactive power compensation controller and a reactive power compensation device are also connected to the main bus.

[0010] In a possible implementation, the anti-crossing circuit breaker is a molded case circuit breaker.

[0011] In a possible implementation, the anti-crossing circuit breaker is an electrically operated circuit breaker.

[0012] The anti-crossing distribution system in this application has the following advantages:

[0013] An anti-crossing circuit breaker is connected between the main bus and the branch bus. When a short circuit occurs in the distribution cabinet on the current branch bus, the anti-crossing circuit breaker is disconnected before the incoming circuit breaker, avoiding the impact on other distribution cabinets caused by the disconnection of the incoming circuit breaker. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0015] Figure 1 It is a schematic diagram of the composition of the power distribution system in the prior art;

[0016] Figure 2 A schematic diagram of the composition of the anti-crossing distribution system provided in an embodiment of the present application.

[0017] Explanation of the accompanying figures: 1. Motor protector; 2. Contactor; 3. Circuit breaker switch; 4. Distribution cabinet; 5. Incoming circuit breaker; 6. Reactive power compensation controller; 7. Transformer; 8. Reactive power compensation device; 9. Anti-crossing circuit breaker. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0019] Figure 2 Schematic diagram of the composition of the anti-crossing distribution system provided in the embodiment of the present application. The embodiment of the present application provides an anti-crossing distribution system, including a main bus and a branch bus, a distribution cabinet 4 is connected to the branch bus, and an incoming circuit breaker 5 is connected to the main bus, characterized in that an anti-crossing circuit breaker 9 is connected between the main bus and the branch bus, the rated current of the anti-crossing circuit breaker 9 is less than the short-circuit current of the distribution cabinet 4, and the current redundancy of the anti-crossing circuit breaker 9 is less than the current redundancy of the incoming circuit breaker 5.

[0020] For example, a transformer 7 is also connected to the main bus, and the incoming circuit breaker 5 is connected between the transformer 7 and the connection point between the main bus and the branch bus. The transformer 7 converts the external input voltage into 0.4KV and supplies it to the distribution cabinet 4 on each branch bus through the main bus, thereby ensuring the normal operation of the equipment on each branch bus.

[0021] The rated current of the anti-crossing circuit breaker 9 is less than the short-circuit current of the distribution cabinet 4 but greater than the normal working current of the distribution cabinet 4. For example, the normal working current of the distribution cabinet 4 is 100A and the short-circuit current is 300A. Therefore, the anti-crossing circuit breaker 9 with a rated current of 250A can be selected. Under normal working conditions, since the normal working current of the distribution cabinet 4 is less than the rated current of the anti-crossing circuit breaker 9, the distribution cabinet 4 will work normally. When a short-circuit fault occurs in the distribution cabinet 4, the current on the branch bus will increase sharply and the maximum will become 300A. At this time, the current exceeds the rated current of the anti-crossing circuit breaker 9, and the anti-crossing circuit breaker 9 will be disconnected immediately to prevent the distribution cabinet 4 from being damaged due to the short circuit.

[0022] For the incoming circuit breaker 5, when the main bus is connected to 6 branch buses, and each branch bus is connected to an anti-crossing circuit breaker 9 with a rated current of 250A, the normal working current of the distribution cabinet 4 on each branch bus is still 100A, and the short-circuit current is 300A. At this time, an incoming circuit breaker 5 with a rated current of 900A can be selected. When the distribution cabinets 4 on each branch bus are working normally, the current of the main bus is 600A, so the current redundancy of the incoming circuit breaker 5 is 300A, and the current redundancy of the anti-crossing circuit breaker 9 is 150A. When a short circuit occurs in the distribution cabinet 4 on any branch bus, the current on the main bus will instantly reach 800A. This instantaneous current is still less than the rated current 900A of the incoming circuit breaker 5. Therefore, the incoming circuit breaker 5 will not be disconnected. However, the instantaneous current 300A on the corresponding branch bus exceeds the rated current 250A of the anti-crossing circuit breaker 9. Therefore, the anti-crossing circuit breaker 9 will be disconnected, achieving the effect of the branch bus being disconnected before the main bus, avoiding the problem of the overall power outage of the main bus caused by a short circuit of the branch bus.

[0023] It should be understood that in addition to the distribution cabinet 4, the branch bus is also connected to equipment such as motors, and these devices and the distribution cabinet 4 are connected in series on the branch bus. Therefore, the current of the equipment, the current of the distribution cabinet 4 and the current of the branch bus are the same. The anti-crossing circuit breaker 9 is used to monitor the current of the branch bus. Regardless of whether a short circuit occurs in the distribution cabinet 4 or the equipment, as long as the current on the branch bus exceeds the rated current of the anti-crossing circuit breaker 9, the anti-crossing circuit breaker 9 will be disconnected.

[0024] Furthermore, the branch bus is also connected with a motor protector 1, a contactor 2 and a circuit breaker switch 3. In the case where a motor device is connected to the branch bus, the motor protector 1 and the contactor 2 need to be connected to the branch bus, and they are connected in the order of anti-crossing circuit breaker 9, power distribution cabinet 4, circuit breaker switch 3, contactor 2 and motor protector 1 in the direction away from the connection point between the main bus and the branch bus. Figure 2 There is also a situation where no motor equipment is connected to the branch bus. In this case, only the distribution cabinet 4 and the circuit breaker switch 3 can be connected to the branch bus, and other equipment can be connected according to actual needs.

[0025] Furthermore, a reactive compensation controller 6 and a reactive compensation device 8 are also connected to the main bus. The reactive compensation controller 6 and the reactive compensation device 8 can be connected to a separate branch bus to perform reactive compensation on the power provided by the main bus. The reactive compensation device 8 in the present application can use a plurality of sub-devices connected in parallel, which are connected in parallel to the branch bus and then connected in series with the reactive compensation controller, and finally connected to the main bus.

[0026] Furthermore, the anti-crossing circuit breaker 9 adopts a molded case circuit breaker, and can adopt an electrically operated circuit breaker. The molded case circuit breaker is a circuit breaker that uses plastic as a shell or an internal insulator, and realizes disconnection in a short-circuit state under the control of a thermal magnetic release or an electronic release.

[0027] The electrically operated circuit breaker has an opening and closing motor inside the circuit breaker, and a normally open opening button and closing button on the outer casing. When manual opening or closing operations are required, the corresponding button can be pressed to achieve the opening or closing control of the circuit breaker through the opening and closing motor, without the need to perform opening and closing operations by turning the switch.

[0028] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0029] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. An anti-crossing power distribution system, comprising a main bus and a branch bus, wherein the branch bus is connected to a power distribution cabinet (4), and the main bus is connected to an incoming circuit breaker (5), characterized in that: An anti-crossing circuit breaker (9) is connected between the main bus and the branch bus, the rated current of the anti-crossing circuit breaker (9) is less than the short-circuit current of the distribution cabinet (4), and the current redundancy of the anti-crossing circuit breaker (9) is less than the current redundancy of the incoming line circuit breaker (5).

2. The anti-crossing distribution system according to claim 1, characterized in that: The branch bus is also connected to a motor protector (1), a contactor (2) and a circuit breaker switch (3).

3. The anti-crossing distribution system according to claim 1, characterized in that: The main busbar is also connected to a transformer (7).

4. The anti-crossing distribution system according to claim 1, characterized in that: The main bus is also connected to a reactive power compensation controller (6) and a reactive power compensation device (8).

5. The anti-crossing distribution system according to claim 1, characterized in that: The anti-crossing circuit breaker (9) is a molded case circuit breaker.

6. The anti-crossing power distribution system according to claim 1, characterized in that: The anti-crossing circuit breaker (9) is an electrically operated circuit breaker.

Images