Dual-purpose and one-standby electrical switching cabinet for high-voltage frequency converter

Abstract

The utility model discloses a dual-purpose and one-standby electrical switching cabinet for a high-voltage frequency converter. The dual-purpose and one-standby electrical switching cabinet comprises a first wire inlet cabinet, a second wire inlet cabinet, a first switching cabinet, an inverter group and a second switching cabinet, the first wire inlet cabinet is connected with the first switching cabinet; the second wire inlet cabinet is connected with the first switching cabinet; the output side of the first switching cabinet is connected with the inverter group; the output side of the inverter group is connected with the second switching cabinet; the output side of the second switching cabinet is connected with the first dust removal fan and the second dust removal fan. According to the utility model, by adopting a dual-purpose and one-standby electrical switching scheme, when one frequency converter breaks down, the frequency converter can be rapidly switched to the standby frequency converter, so that the continuous operation of the dust removal system is ensured, and the reliability and the stability of the system are improved.

Description

Technical Field

[0001] This utility model belongs to the field of electrical technology, specifically relating to an electrical switching cabinet for a high-voltage frequency converter with two-in-one standby operation. Background Technology

[0002] With the development of the steel industry and the continuous advancement of converter steelmaking technology, the converter dry dust removal system, as a key component, plays a vital role in improving steelmaking efficiency and reducing environmental pollution. However, the application of high-voltage frequency converters in traditional converter dry dust removal systems faces several challenges. For example, a failure in a single frequency converter often leads to the inability of the dust removal system to operate normally, thereby affecting the continuity and stability of the entire steelmaking process. Furthermore, traditional electrical switching devices may suffer from low switching efficiency and complex operation, making it difficult to meet the demands of modern industrial production for high efficiency, reliability, and safety.

[0003] To address the aforementioned issues, existing solutions on the market often suffer from drawbacks such as high cost and difficult maintenance. Therefore, developing a high-efficiency, reliable, and easy-to-maintain high-voltage frequency converter electrical switching device is of great significance for improving the overall performance of converter dry dust removal systems. Utility Model Content

[0004] In view of this, the main purpose of this utility model is to provide an electrical switching cabinet for dual-use and standby high-voltage frequency converters.

[0005] To achieve the above objectives, the technical solution of this utility model is implemented as follows:

[0006] A high-voltage frequency converter dual-use and one-standby electrical switching cabinet includes: a first incoming line cabinet, a second incoming line cabinet, a first switching cabinet, an inverter group, and a second switching cabinet;

[0007] The first incoming line cabinet is connected to the first switching cabinet;

[0008] The second incoming line cabinet is connected to the first switching cabinet;

[0009] The output side of the first switching cabinet is connected to the inverter group;

[0010] The output side of each inverter group is connected to the second switching cabinet;

[0011] The output side of the second switching cabinet is connected to the first dust removal fan and the second dust removal fan, respectively.

[0012] Preferably, the inverter group includes a first inverter, a second inverter, and a third inverter;

[0013] The output side of the first switching cabinet is connected to the first frequency converter, the second frequency converter, and the third frequency converter, respectively;

[0014] The output sides of the first, second, and third frequency converters are all connected to the second switching cabinet.

[0015] Preferably, the first switching cabinet includes a first double-throw disconnect switch QS1 and a second double-throw disconnect switch QS2;

[0016] The input side of the first double-throw disconnector QS1 is connected to the first incoming line cabinet, and the output side is connected to the first frequency converter and the second frequency converter.

[0017] The input side of the second double-throw disconnector QS2 is connected to the second incoming line cabinet, and the output side is connected to the second frequency converter and the third frequency converter.

[0018] Preferably, the second switching cabinet includes a third double-throw disconnect switch QS3 and a fourth double-throw disconnect switch QS4;

[0019] The input side of the third double-throw isolating switch QS3 is connected to the first frequency converter and the second frequency converter, and the output side is connected to the first dust removal fan.

[0020] The input side of the fourth double-throw disconnector QS4 is connected to the second and third frequency converters, and the output side is connected to the second dust removal fan.

[0021] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0022] This invention employs a dual-use, one-standby electrical switching scheme. When one frequency converter fails, it can quickly switch to the standby frequency converter, ensuring continuous operation of the dust removal system and improving system reliability and stability. Through a rationally designed electrical switching cabinet structure and switching logic, this invention simplifies and speeds up switching operations, reducing the workload and difficulty for operators. By using high-performance frequency converters and an optimized electrical switching scheme, this invention enhances the overall performance of the dust removal system, including dust removal efficiency and energy consumption. Attached Figure Description

[0023] The accompanying drawings, which are included to provide a further understanding of the present invention and form part of this invention, illustrate exemplary embodiments of the present invention and, together with their description, serve to explain the present invention and do not constitute an undue limitation thereof. In the drawings:

[0024] Figure 1 This utility model provides an electrical structure diagram of a high-voltage frequency converter dual-use and standby electrical switching cabinet.

[0025] Figure 2 This utility model provides a schematic diagram of the control principle of a high-voltage frequency converter dual-use and one-standby electrical switching cabinet. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0027] In the accompanying drawings of this embodiment, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that the terms "upper", "lower", "left", "right", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0028] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, article, or apparatus that includes that element.

[0029] This utility model embodiment provides an electrical switching cabinet for a high-voltage frequency converter with dual-use and one-standby configuration, such as... Figure 1 As shown, it includes: first incoming line cabinet 1, second incoming line cabinet 2, first switching cabinet 3, inverter group 4, and second switching cabinet 5;

[0030] The first incoming line cabinet 1 is connected to the first switching cabinet and is used to provide the first power input.

[0031] The second incoming line cabinet 2 is connected to the first switching cabinet and is used to provide a second power input;

[0032] The first power supply and the second power supply provide reliable power supply for the electrical switching cabinet.

[0033] The output side of the first switching cabinet 3 is connected to the inverter group 4;

[0034] The output side of each inverter group 4 is connected to the second switching cabinet 5;

[0035] The output side of the second switching cabinet 5 is connected to the first dust removal fan 6 and the second dust removal fan 7 respectively, and is used to switch the output of the inverter group 4 to the corresponding dust removal fan to realize the power supply control of the dust removal fan.

[0036] This invention employs a dual-use, one-standby electrical switching scheme. When one frequency converter fails, it can quickly switch to the standby frequency converter, ensuring continuous operation of the dust removal system and improving system reliability and stability. Through a rationally designed electrical switching cabinet structure and switching logic, this invention simplifies and speeds up switching operations, reducing the workload and difficulty for operators. By using high-performance frequency converters and an optimized electrical switching scheme, this invention enhances the overall performance of the dust removal system, including dust removal efficiency and energy consumption.

[0037] This utility model incorporates multiple safety protection measures in the electrical switching cabinet, such as a mechanical electromagnetic lock device, a live display, and an electromagnetic lock control circuit, which effectively prevent misoperation and equipment damage, and improve the safety of the system.

[0038] The first incoming line cabinet 1 is also equipped with a first circuit breaker DL1, and the first incoming line cabinet 1 is also equipped with a second circuit breaker DL2.

[0039] The inverter group 4 includes a first frequency converter 41, a second frequency converter 42, and a third frequency converter 43;

[0040] The output side of the first switching cabinet 3 is connected to the first frequency converter 41, the second frequency converter 42, and the third frequency converter 43 respectively;

[0041] The output sides of the first frequency converter 41, the second frequency converter 42, and the third frequency converter 43 are all connected to the second switching cabinet.

[0042] The output side of the first switching cabinet 3 is connected to these three frequency converters respectively to realize power distribution and switching.

[0043] The first switching cabinet 3 includes a first double-throw disconnect switch QS1 and a second double-throw disconnect switch QS2;

[0044] The input side of the first double-throw disconnect switch QS1 is connected to the first incoming line cabinet 1, and the output side is connected to the first frequency converter 41 and the second frequency converter 42;

[0045] The input side of the second double-throw disconnector QS2 is connected to the second incoming line cabinet 2, and the output side is connected to the second frequency converter 42 and the third frequency converter 43.

[0046] The first dual-throw disconnect switch QS1 and the second dual-throw disconnect switch QS2 are used to switch the input power supply to different frequency converters.

[0047] QS1 and QS2 are double-throw isolating switches. QS1 and QS2 are isolating switches on the power frequency input side of the frequency converter. The second position of QS1 and the first position of QS2 are equipped with mechanical electromagnetic lock devices. It is strictly forbidden to close the second position of QS1 and the first position of QS2 at the same time.

[0048] The second switching cabinet 5 includes a third double-throw disconnect switch QS3 and a fourth double-throw disconnect switch QS4;

[0049] The input side of the third double-throw isolating switch QS3 is connected to the first frequency converter 41 and the second frequency converter 42, and the output side is connected to the first dust removal fan 6.

[0050] The input side of the fourth double-throw disconnector QS4 is connected to the second frequency converter 42 and the third frequency converter 43, and the output side is connected to the second dust removal fan 7.

[0051] The third double-throw disconnect switch QS3 and the fourth double-throw disconnect switch QS4 are used to switch the output of the frequency converter to different dust removal fans.

[0052] QS3 and QS4 are double-throw disconnect switches, serving as disconnect switches for the inverter's frequency converter output side. Mechanical electromagnetic devices are installed at position II of QS3 and position I of QS4; simultaneous closure of positions II of QS3 and I of QS4 is strictly prohibited.

[0053] The working process of this utility model:

[0054] Normal operating state: QS1 is switched to position I, QS3 is switched to position I, and the motor of the first dust collector fan 6 is driven by the first frequency converter 41. QS2 is switched to position II, QS4 is switched to position II, and the motor of the second dust collector fan 7 is driven by the third frequency converter 43.

[0055] Under normal operating conditions, when the first frequency converter 41 fails, the second frequency converter 42 is manually switched to drive the motor of the first dust removal fan 6.

[0056] It also includes the DLK control circuit for the cabinet door electromagnetic lock;

[0057] like Figure 2 As shown, the control circuit of the cabinet door electromagnetic lock DLK connects the normally closed contacts of the energized display DXN and the normally closed contacts of positions I and II of the double-throw disconnect switches QS1, QS2, QS3, and QS4 in series. When the cabinet is energized, the energized display lights up, and the normally closed contacts open, de-energizing the electromagnetic lock coil and keeping the lock in the locked state, preventing the cabinet door from opening. When the double-throw disconnect switches QS1, QS2, QS3, and QS4 are in positions I and II, their normally closed contacts open, de-energizing the electromagnetic lock coil and keeping the lock in the locked state, preventing the cabinet door from opening. This prevents accidental entry into the energized compartment.

[0058] The control principle of the electromagnetic lock on the cabinet door in the second switching cabinet 5 is the same as that in the first switching cabinet 3, except that the number of live indicators at the incoming line end has changed from 2 to 3.

[0059] The control circuit of the cabinet door electromagnetic lock DLK connects the normally closed contacts of the live display DXN and the normally closed contacts of positions I and II of QS1, QS2, QS3, and QS4 in series.

[0060] When the first switching cabinet 3 and the second switching cabinet 5 are energized, the energization indicator lights up, and the normally closed contact opens, so the electromagnetic lock coil is not energized and the electromagnetic lock is in the locked state, preventing the cabinet door from being opened. When QS1, QS2, QS3, and QS4 are in positions I and II, their normally closed contacts open, so the electromagnetic lock coil is not energized and the electromagnetic lock is in the locked state, preventing the cabinet door from being opened, thus preventing accidental entry into the energized compartment. The control principle of the electromagnetic locks for the other cabinet doors is the same.

[0061] It also includes the control circuit for the electromagnetic mechanism lock SLK2;

[0062] Taking the control circuit of the electromagnetic mechanism lock SLK2 at position II of QS1 as an example: the electromagnetic mechanism lock SLK2 is connected in series with the normally closed contact of the energized display DXN1 and the normally closed contact of the double-throw disconnector QS2 at position I. When the power frequency input side of QS1 is energized, the energized display lights up, and the normally closed contact opens, so the electromagnetic mechanism lock coil is not energized, and the electromagnetic mechanism lock is in the locked state, preventing the disconnector switch from being operated while energized; at the same time, when the double-throw disconnector QS2 is in position I, its normally closed contact opens, the electromagnetic lock coil is not energized, and the electromagnetic lock is in the locked state, preventing the positions II of QS1 and I of QS2 from closing simultaneously.

[0063] The electromagnetic mechanism lock control principle in the second switching cabinet 5 is the same as that in the first switching cabinet 3, except that the normally closed contact of the energized display on the output side of the third frequency converter is connected in series in the control circuit of each electromagnetic mechanism lock.

[0064] The control circuit of the electromagnetic mechanism lock SLK2 in position II of QS1 is connected in series with the normally closed contact of the energized display DXN1 and the normally closed contact of position I of QS2. When the power frequency input side of QS1 is energized, the energized display lights up, and the normally closed contact opens, de-energizing the electromagnetic mechanism lock coil and keeping the electromagnetic mechanism lock in the locked state to prevent energized operation of the isolating switch. Simultaneously, when the double-throw isolating switch QS2 is in position I, its normally closed contact opens, de-energizing the electromagnetic lock coil and keeping the electromagnetic lock in the locked state to prevent simultaneous closure of positions II of QS1 and I of QS2. The control principle of the remaining electromagnetic mechanism locks is the same.

[0065] Door control switches are installed on the doors of the first switching cabinet 3 and the second switching cabinet 5. The normally open contact of the door control switch of the first switching cabinet 3 is extended by a series intermediate relay. The normally open contact after the extension by the intermediate relay is used to connect to the protection trip input of the upper-level high-voltage switchgear. When the upper-level high-voltage switchgear is energized, if the cabinet door of the switching cabinet is opened due to human error, the upper-level high-voltage switchgear can be forcibly tripped through this normally open contact, thereby protecting the personal safety of the operators. At the same time, the normally closed contact of the door control switch after the extension by the intermediate relay is connected to the working position closing interlocking circuit of the upper-level high-voltage switchgear, ensuring that the upper-level high-voltage switchgear can only be closed in the working position when the cabinet door of the switching cabinet is closed.

[0066] The door control switch extension signal of the second switching cabinet 5 is sent to the terminal block. If the high-voltage frequency converter has a related interlocking function, it is convenient to directly connect to the high-voltage frequency converter in the future.

[0067] The interlocking signals (allow closing, fault tripping, and closing signals) between the standby second frequency converter 42 and the upper-level high-voltage switchgear are extended within the first switching cabinet 3. Simultaneously, the normally open contacts of positions I and II of the double-throw disconnectors QS1 and QS2, as well as the interlocking signal of the standby second frequency converter 42, are connected to the upper-level high-voltage switchgear 1AH and 2AH, respectively, for switching the interlocking signals between the standby second frequency converter 42 and the upper-level high-voltage switchgear. For example, if QS1 is switched to position II and QS3 is switched to position II, and the motor of the first dust collector fan 6 is driven by the standby second frequency converter 42, the relevant interlocking signal only needs to be connected in series with the normally open contact of position II of QS3 to achieve the switching of the interlocking signals between the standby high-voltage frequency converter and the upper-level high-voltage switchgear.

[0068] Condensation controllers and electric heaters are installed in the first switching cabinet 3 and the second switching cabinet 5. The operating environment of the switchgear has humidity requirements; when the humidity exceeds the required value, the heating device is activated. The heating device is mainly used for dehumidification. In areas with high humidity, condensation may occur on the wiring inside the distribution cabinet; the function of the heating device is to prevent condensation.

[0069] Lighting equipment is installed in the cable compartments of the first switching cabinet 3 and the second switching cabinet 5. The lighting equipment is connected in series with the normally open contact of the cabinet door limit switch. When the cabinet door of the switching cabinet cable compartment is opened, the lighting equipment is automatically turned on, which facilitates maintenance and other operations.

[0070] The switching operation sequence is as follows:

[0071] Disconnect the power supply circuit breaker DL1, switch QS1 to position II, switch QS3 to position II, and close the power supply circuit breaker DL1. The motor of the first dust removal fan 6 will be driven by the second frequency converter 42.

[0072] Under normal operating conditions, when the third frequency converter 43 fails, the second frequency converter 42 is manually switched to drive the motor of the second dust removal fan 7.

[0073] The switching operation sequence is as follows:

[0074] Disconnect power circuit breaker DL2, switch QS2 to position I, switch QS4 to position I, and close power circuit breaker DL2. The second frequency converter 42 drives the motor of the second dust removal fan 7 to run.

[0075] When circuit breaker DL1 or DL2 is closed, it is strictly forbidden to operate disconnecting switches QS1, QS2, QS3, and QS4.

[0076] like Figure 2 As shown, the first switching cabinet 3 and the second switching cabinet 5 are equipped with door control switches to prevent the cabinet doors from being opened while the switching cabinets are energized.

[0077] Door control switches are installed on the doors of the first switching cabinet 3 and the second switching cabinet 5. The normally open contact of the door control switch of the first switching cabinet 3 is extended through a series intermediate relay. The extended normally open contact is connected in series to the protection trip input of the upper-level high-voltage switchgear. When the upper-level high-voltage switchgear is energized, if the cabinet door of the switching cabinet is opened due to human error, the upper-level high-voltage switchgear can be forcibly tripped through this normally open contact, thereby protecting the personal safety of the operators. At the same time, the normally closed contact of the door control switch, after being extended through the intermediate relay, is connected in series to the working position closing interlocking circuit of the upper-level high-voltage switchgear, ensuring that the upper-level high-voltage switchgear can only be closed in the working position when the cabinet door of the switching cabinet is closed. The extended signal of the door control switch of the second switching cabinet 5 is sent to the terminal block. If the high-voltage frequency converter has relevant interlocking functions, it is convenient to directly connect the high-voltage frequency converter in the future.

[0078] Switching of interlocking signals between the standby high-voltage frequency converter and the upstream high-voltage switchgear.

[0079] The interlocking signals (allow closing, fault tripping, and closing signals) between the standby No. 3 high-voltage frequency converter 3VFD and the upstream high-voltage switchgear are extended in the first switching cabinet 3. Simultaneously, the normally open contacts of positions I and II of the double-throw disconnectors QS1 and QS2, as well as the interlocking signal of the standby No. 3 high-voltage frequency converter 3VFD, are connected to the upstream high-voltage switchgear 1AH and 2AH respectively for switching the interlocking signals between the standby No. 3 high-voltage frequency converter 3VFD and the upstream high-voltage switchgear. For example, if QS1 is switched to position II and QS3 is switched to position II, and the standby No. 3 high-voltage frequency converter 1VFD drives the No. 1 dust collector fan motor, the relevant interlocking signal only needs to be connected in series with the normally open contact of position II of QS3 to achieve the switching of the interlocking signals between the standby high-voltage frequency converter and the upstream high-voltage switchgear.

[0080] The first switching cabinet 3 and the second switching cabinet 5 are equipped with condensation controllers and electric heaters to prevent condensation from occurring inside the switching cabinets.

[0081] Condensation controllers and electric heaters are installed in the first switching cabinet 3 and the second switching cabinet 5. The operating environment of the switchgear has humidity requirements; when the humidity exceeds the required value, the heating device is activated. The heating device is mainly used for dehumidification. In areas with high humidity, condensation may occur on the wiring inside the distribution cabinet; the function of the heating device is to prevent condensation.

[0082] Lighting equipment is installed in the cable compartments of the first switching cabinet 3 and the second switching cabinet 5.

[0083] Lighting equipment is installed in the cable compartments of the first switching cabinet 3 and the second switching cabinet 5. The lighting equipment is connected in series with the normally open contact of the cabinet door limit switch. When the cabinet door of the switching cabinet cable compartment is opened, the lighting equipment is automatically turned on, which facilitates maintenance and other operations.

[0084] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the scope of protection of the present utility model.

Claims

1. A high-voltage frequency converter dual-use, one-standby electrical switching cabinet for use in a converter dry dust removal system, characterized in that, include: First incoming line cabinet 1, second incoming line cabinet 2, first switching cabinet 3, inverter group 4, second switching cabinet 5; The first incoming line cabinet 1 is connected to the first switching cabinet 3; The second incoming line cabinet 2 is connected to the first switching cabinet 3; The output side of the first switching cabinet 3 is connected to the inverter group 4; The output side of each inverter group 4 is connected to the second switching cabinet 5; The output side of the second switching cabinet 5 is connected to the first dust removal fan 6 and the second dust removal fan 7 respectively.

2. The high-voltage frequency converter dual-use and one-standby electrical switching cabinet according to claim 1, characterized in that, The inverter group 4 includes a first frequency converter 41, a second frequency converter 42, and a third frequency converter 43; The output side of the first switching cabinet 3 is connected to the first frequency converter 41, the second frequency converter 42, and the third frequency converter 43 respectively; The output sides of the first frequency converter 41, the second frequency converter 42, and the third frequency converter 43 are all connected to the second switching cabinet.

3. The high-voltage frequency converter dual-use, one-standby electrical switching cabinet according to claim 1 or 2, characterized in that, The first switching cabinet 3 includes a first double-throw disconnect switch QS1 and a second double-throw disconnect switch QS2; The input side of the first double-throw disconnect switch QS1 is connected to the first incoming line cabinet 1, and the output side is connected to the first frequency converter 41 and the second frequency converter 42; The input side of the second double-throw disconnector QS2 is connected to the second incoming line cabinet 2, and the output side is connected to the second frequency converter 42 and the third frequency converter 43.

4. The high-voltage frequency converter dual-use and one-standby electrical switching cabinet according to claim 3, characterized in that, The second switching cabinet 5 includes a third double-throw disconnect switch QS3 and a fourth double-throw disconnect switch QS4; The input side of the third double-throw disconnector QS3 is connected to the first frequency converter 41 and the second frequency converter 42, and the output side is connected to the first dust removal fan 6. The input side of the fourth double-throw disconnector QS4 is connected to the second frequency converter 42 and the third frequency converter 43, and the output side is connected to the second dust removal fan 7.

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