Power distribution multi-power-supply interlocking system based on PLC system

Abstract

The utility model discloses a power distribution multi-power interlocking system based on a PLC system. The system comprises a power supply module I, a power supply module II, a circuit breaker module I, a circuit breaker module II, a bus coupler cabinet, a 10 kV I section bus, a 10 kV II section bus and a PLC system, the 10 kV I section bus is connected with the power supply module I through the circuit breaker module I, the 10 kV II section bus is connected with the power supply module II through the circuit breaker module II, the 10 kV I section bus and the 10 kV II section bus are connected through the bus coupler cabinet, and the PLC system is connected with the power supply module II through the bus coupler cabinet. The 10 kV I section bus and the bus coupler cabinet are connected through the first circuit breaker module, and the PLC system is connected with the first circuit breaker module and the second circuit breaker module. According to the utility model, the reliability of the power distribution multi-power interlocking system can be improved, the anti-interference capability is strong, and the use is flexible.

Description

Technical Field

[0001] The utility model relates to the field of power distribution multi-power supply interlocking system design, in particular to a power distribution multi-power supply interlocking system based on a PLC system. Background Art

[0002] In the 10kV power distribution system, in order to improve the reliability of power supply, there are three or even multiple power supplies in the same distribution room as backup for each other. If used improperly (control circuit failure or human error), it will cause serious accidents. Therefore, the safety interlock of switching between multiple power supplies is particularly important. The traditional practice is to use relay interlocking. The problem is that the multi-power interlocking will encounter insufficient auxiliary contacts of high-voltage circuit breakers, complex interlocking circuits, low reliability, difficult construction and maintenance, and even the interlocking function cannot be realized. When a fault occurs, there are many electrical nodes and the status is not intuitive, which makes troubleshooting complicated and time-consuming. In addition, the control circuit needs to be checked with power on, which poses a safety hazard. Utility Model Content

[0003] The utility model aims to provide a power distribution multi-power supply interlocking system based on a PLC system, which can improve the reliability, anti-interference ability and flexible use of the power distribution multi-power supply interlocking system.

[0004] To achieve the above purpose, the utility model provides the following solutions:

[0005] A power distribution multi-power interlocking system based on a PLC system comprises: a power module 1, a power module 2, a circuit breaker module 1, a circuit breaker module 2, a bus coupling cabinet, a 10kV I section bus, a 10kV II section bus and a PLC system, wherein the 10kV I section bus is connected to the power module 1 through the circuit breaker module 1, the 10kV II section bus is connected to the power module 2 through the circuit breaker module 2, the 10kV I section bus and the 10kV II section bus are connected through the bus coupling cabinet, the 10kV I section bus and the bus coupling cabinet are connected through the circuit breaker module 1, and the PLC system is connected to the circuit breaker module 1 and the circuit breaker module 2, respectively.

[0006] Optionally, the power module 1 and the power module 2 are from different transformers.

[0007] Optionally, the basic principle of power supply operation of the PLC system-based power distribution multi-power interlocking system is: it is strictly forbidden to close two power circuit breakers under the same section of the bus at the same time, and the bus tie circuit breaker cannot be closed in priority over the power circuit breaker.

[0008] Optionally, the power module 1 includes 1# power supply and 3# power supply, the power module 2 includes 2# power supply and 4# power supply, the circuit breaker module 1 includes 1#QF, 3#QF and 5#QF, and the circuit breaker module 2 includes 2#QF and 4#QF, wherein 1#QF, 2#QF, 3#QF and 4#QF are power circuit breakers, 5#QF is a bus tie circuit breaker, the 1# power supply, 3# power supply and bus tie cabinet are connected to the 10kVⅠ section bus through 1#QF, 3#QF and 5#QF respectively, and the 2# power supply and 4# power supply are connected to the 10kVⅡ section bus through 2#QF and 4#QF respectively.

[0009] Optionally, the PLC system includes a main controller and an expansion module, wherein the model of the main controller is EASY719-AC-RC, and the model of the expansion module is EASY618-AC-RE.

[0010] Optionally, the PLC system is provided with a liquid crystal display screen.

[0011] Optionally, the PLC system uses 12 input points + 12 extended input points, and uses 6 output points + 6 extended output points.

[0012] Optionally, the PLC system is directly arranged in the high-voltage cabinet.

[0013] Optionally, both the input point and the output point of the PLC system pass through an intermediate relay.

[0014] Optionally, the PLC system and the intermediate relay power supply both use 220V AC power.

[0015] According to the specific embodiments provided by the utility model, the utility model discloses the following technical effects:

[0016] The utility model provides a power distribution multi-power interlocking system based on a PLC system. The system includes: power module 1, power module 2, circuit breaker module 1, circuit breaker module 2, bus coupling cabinet, 10kV I bus, 10kV II bus and PLC system, 10kV I bus is connected to power module 1 through circuit breaker module 1, 10kV II bus is connected to power module 2 through circuit breaker module 2, 10kV I bus and 10kV II bus are connected through bus coupling cabinet, 10kV I bus and bus coupling cabinet are connected through circuit breaker module 1, and PLC system is respectively connected to circuit breaker module 1 and circuit breaker module 2. The utility model can improve the reliability, anti-interference ability and flexible use of the power distribution multi-power interlocking system. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0018] Figure 1 This is a schematic diagram of the structure of a power distribution multi-power interlocking system based on a PLC system in the utility model. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0020] The utility model aims to provide a power distribution multi-power supply interlocking system based on a PLC system, which can improve the reliability, anti-interference ability and flexible use of the power distribution multi-power supply interlocking system.

[0021] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0022] The utility model provides a power distribution multi-power interlocking system based on a PLC system, the system comprises: a power module 1, a power module 2, a circuit breaker module 1, a circuit breaker module 2, a bus coupling cabinet, a 10kV I bus section, a 10kV II bus section and a PLC system, the 10kV I bus section is connected to the power module 1 through the circuit breaker module 1, the 10kV II bus section is connected to the power module 2 through the circuit breaker module 2, the 10kV I bus section and the 10kV II bus section are connected through the bus coupling cabinet, the 10kV I bus section and the bus coupling cabinet are connected through the circuit breaker module 1, the PLC system is respectively connected to the circuit breaker module 1 and the circuit breaker module 2, and the PLC does not control the opening and closing of the circuit breaker module 1 and the circuit breaker module 2. The PLC only controls the closing locking coil of the circuit breaker, that is, whether closing is allowed. If the locking electromagnet of the circuit breaker is not energized, closing is impossible. The opening and closing of the circuit breaker module is determined by the relay protection and operation mode. The PLC only participates in the interlocking of circuit breaker module 1 and circuit breaker module 2 to determine whether the circuit breaker is allowed to close. For example, if the 1#QF circuit breaker in section I is in the closed state, the 3#QF circuit breaker in the same section cannot be closed because the locking electromagnet on the 3#QF circuit breaker is de-energized by the PLC control, so 3#QF cannot be closed. The opening and closing of the circuit breaker is controlled by the operation demand and relay protection.

[0023] The present invention utilizes the characteristics of high reliability, strong anti-interference ability and flexible use of the PLC system to replace the relay interlock. Figure 1 This is a schematic diagram of the structure of the power distribution multi-power interlocking system based on the PLC system of the utility model. Figure 1 As shown in the figure, taking four-power interlocking as an example, the implementation process is explained:

[0024] The power module 1 and the power module 2 are from different transformers. The basic principle of the power supply operation of the multi-power interlocking system based on the PLC system is: it is strictly forbidden to close the two power circuit breakers under the same section of the bus at the same time, and the bus tie circuit breaker cannot be closed first before the power circuit breaker. The circuit breaker is not interlocked in the test position. In addition, there are 10 operating modes for multi-power operation:

[0025] Serial number Power operation mode 1# Power supply 2# Power Supply 3# Power supply 4# Power supply 5# mother link 1 1# and 2# power supply are operated in sections combine combine point point point 2 1# and 4# power supply are operated in sections combine point point combine point 3 2# and 3# power supplies are operated in sections point combine combine point point 4 3# and 4# power supplies are operated in sections point point combine combine point 5 1# power supply with whole station combine point point point combine 6 2# power supply with whole station point combine point point combine 7 3# power supply with whole station point point combine point combine 8 4# power supply with full station point point point combine combine 9 1# and 2# power supply closed loop operation combine combine point point combine 10 Before power supply to the entire station point point point point Prohibition of

[0026] The power module 1 includes 1# power supply and 3# power supply, the power module 2 includes 2# power supply and 4# power supply, the circuit breaker module 1 includes 1#QF, 3#QF and 5#QF, the circuit breaker module 2 includes 2#QF and 4#QF, wherein 1#QF, 2#QF, 3#QF and 4#QF are power circuit breakers, 5#QF is a bus tie circuit breaker, the 1# power supply, 3# power supply and bus tie cabinet are connected to the 10kVⅠ section bus through 1#QF, 3#QF and 5#QF respectively, and the 2# power supply and 4# power supply are connected to the 10kVⅡ section bus through 2#QF and 4#QF respectively.

[0027] The input and output points of the PLC system are all through the intermediate relay, which is specially set up. Its main function is isolation and elimination of electromagnetic interference. This intermediate relay has a manual forced pull-in function, and the signal can be manually forced when manual confirmation is allowed.

[0028] The PLC system includes a main controller and an expansion module. The model of the main controller is EASY719-AC-RC, and the model of the expansion module is EASY618-AC-RE. The PLC system is equipped with an LCD display. The PLC system uses 12 input points + 12 extended input points, and 6 output points + 6 extended output points. The PLC system is directly set in the high-voltage cabinet. The input and output points of the PLC system are all passed through the intermediate relay. The power supply of the PLC system and the intermediate relay is 220V AC.

[0029] Figure 1 The 10kV I busbar and the 10kV II busbar are connected through the bus coupling cabinet. The 1# power supply to the 4# power supply come from different transformers, that is, different power supplies. Among them, the 1# power supply and the 2# power supply are on the 10kV I busbar and the 10kV II busbar respectively, and the loop can be closed after the 5#QF circuit breaker of the bus coupling cabinet is closed. The opening and closing of the remaining 3# power supply and 4# power supply must comply with the logic in the above table, that is, the 1# power supply and the 3# power supply on the 10kV I busbar are strictly prohibited from being closed at the same time. The 2# power supply and the 4# power supply on the 10kV II busbar cannot be closed at the same time.

[0030] The operation of 1# power supply - 4# power supply and main coupling cabinet is controlled by five circuit breakers 1#QF-5#QF. If there is no interlocking between the five circuit breakers, that is, 3#QF can also be closed after 1#QF is closed, serious accidents will occur.

[0031] The function of the PLC system is to use the position (maintenance position, working position) signal and the open and closed status of each circuit breaker as the input point DⅠ of the PLC, and the power control point of the locking electromagnet of each circuit breaker as the output point DO of the PLC. Through the PLC and the interlocking relationship of each circuit breaker, the programming logic determines whether the output control circuit breaker is allowed to close.

[0032] The above functions are realized by PLC system control, and its outstanding advantages are described from the following three aspects:

[0033] 1. High safety and reliability

[0034] The EASY719+ expansion module PLC has: 24 DⅠ points, 12 DO points, the normally open, normally closed and operating modes (segmented and closed) of the auxiliary contacts of each power circuit breaker are used as DⅠ points, the closing lock (allowed closing) of 1#-5# circuit breakers are used as 5 DO points, and the passive contacts of the output intermediate relay are connected in series to the closing lock circuit, which is only used to judge the closing conditions (closing lock) and does not participate in the protection tripping, closing and other controls, so that the advantages of PLC can be brought into play in the multi-power interlocking conditions, and does not participate in the relay protection (completed by the integrated protector), avoiding the wrong opening or closing caused by PLC, with high reliability and clear functions;

[0035] In the program, the open and closed states of the circuit breaker are correctly judged simultaneously by using two input points, the normally open point and the normally closed point, to avoid misjudgment caused by electromagnetic interference; if the circuit breaker is not in the maintenance position, it is defined as the working position, and the interlocking conditions are more stringent.

[0036] The PLC power supply and DⅠ\DO point power supply are both AC: 220V, no DC power supply is required, and the power consumption is relatively small (0.1kW). They can be taken from the DC panel inverter power supply (UPS) in the station. In the event of a power failure in the entire station, the PLC can still work normally, ensuring that the interlocking function is always effective;

[0037] The PLC DⅠ\DO points are all isolated through intermediate relays to avoid electromagnetic interference and ensure reliability from the hardware perspective. At the same time, relays with test functions are selected to manually allow closing of the circuit breaker as an emergency measure when the PLC loses power and is manually confirmed to be safe.

[0038] 2. Strong operability during construction

[0039] 1. Use a compact PLC system with a small size, which can be directly installed in the high-voltage cabinet, without the need for a dedicated PLC system cabinet, and is easy to install. At the same time, it reduces the number and distance of control lines, has a simple control principle, is easy to wire and debug, and has strong practicality for transformation;

[0040] 2. Both the PLC system and the intermediate relay power supply adopt AC: 220V, no special power supply is required, saving space and reducing failure points;

[0041] 3. The PLC system has its own display screen, which displays the DⅠ\DO point status and program. The control program input does not require a host computer, which is convenient for debugging, maintenance and troubleshooting.

[0042] 3. High cost performance and strong economy

[0043] 1. The cost of all components (PLC + intermediate relay + auxiliary materials) is less than 3,000 yuan. Since the interlocking control circuit is simple to construct, the overall cost is lower than the relay interlocking;

[0044] 2. No special power module is required in the PLC control system, and other components are almost maintenance-free, with reliable operation and low maintenance.

[0045] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the system disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0046] This article uses specific examples to illustrate the principles and implementation methods of the utility model. The above examples are only used to help understand the method and core ideas of the utility model. At the same time, for those skilled in the art, according to the ideas of the utility model, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the utility model.

Claims

1. A power distribution multi-power interlocking system based on a PLC system, characterized in that: The power distribution multi-power interlocking system based on the PLC system includes: power module 1, power module 2, circuit breaker module 1, circuit breaker module 2, bus coupling cabinet, 10kV I section bus, 10kV II section bus and PLC system, the 10kV I section bus is connected to the power module 1 through the circuit breaker module 1, the 10kV II section bus is connected to the power module 2 through the circuit breaker module 2, the 10kV I section bus and the 10kV II section bus are connected through the bus coupling cabinet, the 10kV I section bus and the bus coupling cabinet are connected through the circuit breaker module 1, and the PLC system is connected to the circuit breaker module 1 and the circuit breaker module 2 respectively.

2. The power distribution multi-power interlocking system based on the PLC system according to claim 1 is characterized in that: The power module 1 and the power module 2 are both from different transformers.

3. The power distribution multi-power interlocking system based on the PLC system according to claim 1 is characterized in that: The basic principle of power supply operation of the PLC-based power distribution multi-power interlocking system is: it is strictly forbidden to close the two power circuit breakers under the same section of the bus at the same time, and the bus tie circuit breaker cannot be closed in priority to the power circuit breaker.

4. The power distribution multi-power interlocking system based on the PLC system according to claim 3 is characterized in that: The power module 1 includes 1# power supply and 3# power supply, the power module 2 includes 2# power supply and 4# power supply, the circuit breaker module 1 includes 1#QF, 3#QF and 5#QF, and the circuit breaker module 2 includes 2#QF and 4#QF, wherein 1#QF, 2#QF, 3#QF and 4#QF are power circuit breakers, 5#QF is a bus tie circuit breaker, the 1# power supply, 3# power supply and bus tie cabinet are connected to the 10kVⅠ section bus through 1#QF, 3#QF and 5#QF respectively, and the 2# power supply and 4# power supply are connected to the 10kVⅡ section bus through 2#QF and 4#QF respectively.

5. The power distribution multi-power interlocking system based on the PLC system according to claim 1 is characterized in that: The PLC system includes a main controller and an expansion module, wherein the model of the main controller is EASY719-AC-RC, and the model of the expansion module is EASY618-AC-RE.

6. The power distribution multi-power interlocking system based on the PLC system according to claim 1 is characterized in that: The PLC system is provided with a liquid crystal display screen.

7. The power distribution multi-power interlocking system based on the PLC system according to claim 1 is characterized in that: The PLC system adopts 12 input points + 12 extended input points, and adopts 6 output points + 6 extended output points.

8. The power distribution multi-power interlocking system based on the PLC system according to claim 1 is characterized in that: The PLC system is directly arranged in the high-voltage cabinet.

9. The power distribution multi-power interlocking system based on the PLC system according to claim 1 is characterized in that: The input point and output point of the PLC system are both passed through the intermediate relay.

10. The power distribution multi-power interlocking system based on the PLC system according to claim 9 is characterized in that: The PLC system and the intermediate relay power supplies both use 220V AC.

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