Frequency converter cabinet with low-voltage drawer

Abstract

A frequency converter cabinet with a low-voltage drawer comprises a cabinet body, a frequency converter chamber used for accommodating a frequency converter is arranged below the cabinet body, and a frequency converter drawer and a plurality of drawer cabinets are arranged on the upper side of the frequency converter chamber. According to the utility model, the drawer cabinet with a relatively high separation form can be used for installing the drawer and also can be used for installing the frequency converter; the advantages of a drawer cabinet are fully utilized, and a main protection switch and a control circuit for supplying power to the frequency converter are designed in the form of a special drawer; the frequency converter is mounted in an independent compartment; according to the scheme, a secondary control device and a primary high-power device can be strictly separated from the frequency converter and are physically isolated; a series of problems of low separation form or no separation form of a traditional frequency converter fixed cabinet body, low safety protection, easy electric shock of installation and maintenance personnel, personal casualties and the like can be solved; and the drawer cabinet has the advantages of convenience, quick repair and maintenance and the like.

Description

Technical Field

[0001] The utility model relates to the field of power distribution cabinets, in particular to a frequency converter cabinet with a low-voltage drawer. Background Art

[0002] In the low-voltage distribution board, the low-voltage cabinet is divided into three types according to the partition type and operation method: fixed partition cabinet, drawer cabinet, and fixed cabinet. The structure of the inverter cabinet has always been designed and manufactured in the form of a fixed cabinet. Because the fixed cabinet has the following advantages: simple cabinet type, easy installation, no internal partition compartments, all components are installed in one cabinet compartment, no partition type, so the price is cheap and it is deeply loved by economical users such as large heavy industries and small counties.

[0003] Because of the large number of components inside a general inverter cabinet, fixed inverter cabinets also have their disadvantages. For example, their simple structure places inverters of different circuits, high-power primary wiring devices, and secondary control components in one compartment of the cabinet. This means there is no strict separation or physical isolation. Therefore, there is no safe separation type and protection level. When wiring or testing the secondary control components in the cabinet, it is easy to touch the high-voltage, high-power primary components, resulting in serious electric shock and personal injury accidents, causing immeasurable property losses to the national economy.

[0004] With the improvement of the national economy, people have also realized the importance of power distribution safety. For first-tier cities and users with high requirements for protection against electric shock, fixed inverter cabinets can no longer meet the requirements of separation type and corresponding protection against electric shock. Utility Model Content

[0005] In order to solve the above problems, the present technical solution provides a frequency converter cabinet with a low-voltage drawer.

[0006] To achieve the above purpose, the technical solution is as follows:

[0007] A frequency converter cabinet with a low-voltage drawer comprises a cabinet body, a frequency converter chamber for accommodating the frequency converter is provided below the cabinet body, a frequency converter drawer is provided on the upper side of the frequency converter chamber, and multiple drawer cabinets.

[0008] In some embodiments, the inverter cabinet is provided with a circuit part:

[0009] Power busbar, used to receive voltage;

[0010] A primary plug-in CJD is connected to the power busbar and is turned on when the inverter drawer is inserted into the cabinet;

[0011] The circuit breaker QF3 has its upper end connected to the primary plug-in CJD, and its lower end connected to the contactor KM1 and the main contactor KM respectively;

[0012] Thermal overload relay KH, one end of which is connected to the contactor KM1, and the other end of which is connected to the cooling fan of the exhaust fan through the primary plug CJD2;

[0013] The frequency converter VSD has one end connected to the main contactor KM via the primary plug-in CJD1, and the other end connected to the high-power load smoke exhaust fan.

[0014] In some embodiments, a plurality of openings are provided at the bottom of the cabinet.

[0015] The beneficial effects of this application are:

[0016] The present application is to transform a drawer cabinet with a high partition form into a cabinet type that can be installed with both drawers and inverters while maintaining the original partition form Form 3b. The advantages of the drawer cabinet are fully utilized, and the main protection switch and control circuit for powering the inverter are designed in the form of dedicated drawers. The inverter is installed in a separate compartment. This solution can strictly separate and physically isolate secondary control devices and primary high-power devices from the inverter. It can also solve a series of problems of traditional fixed inverter cabinets with low or no partition form, low safety protection, and easy risk of electric shock and personal injury to installation and maintenance personnel. The advantages of the drawer cabinet are convenient and fast to repair and maintain. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments.

[0018] Figure 1 This is a schematic diagram of the structure of the embodiment of the utility model Figure 1 ;

[0019] Figure 2 This is a schematic diagram of the structure of the embodiment of the utility model Figure 2 ;

[0020] Figure 3 This is an electrical schematic diagram of a frequency conversion cabinet according to an embodiment of the present utility model;

[0021] Figure 4 This is a layout diagram of a frequency conversion cabinet according to an embodiment of the present utility model. DETAILED DESCRIPTION

[0022] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0023] Please refer to Figure 1-4 As shown, a frequency converter cabinet with a low-voltage drawer includes a cabinet body, a frequency converter room for accommodating the frequency converter is provided below the cabinet body, a frequency converter drawer is provided on the upper side of the frequency converter room, and multiple drawer cabinets.

[0024] In this embodiment, the inverter cabinet is provided with a circuit part:

[0025] Power busbar, used to receive voltage;

[0026] A primary plug-in CJD is connected to the power busbar and is turned on when the inverter drawer is inserted into the cabinet;

[0027] The circuit breaker QF3 has its upper end connected to the primary plug-in CJD, and its lower end connected to the contactor KM1 and the main contactor KM respectively;

[0028] Thermal overload relay KH, one end of which is connected to the contactor KM1, and the other end of which is connected to the cooling fan of the exhaust fan through the primary plug CJD2;

[0029] The frequency converter VSD has one end connected to the main contactor KM via the primary plug-in CJD1, and the other end connected to the high-power load smoke exhaust fan.

[0030] In this embodiment, a plurality of openings are provided on the bottom of the cabinet.

[0031] The details of this plan are as follows:

[0032] It is generally divided into the following two parts: structural parts and electrical parts;

[0033] 1. The low-voltage cabinet frame is assembled from columns and beams, and then assembled with four left and right cover plates, a rear door panel, a front lower door panel, mounting brackets, insulating busbar clamps, partitions inside the cabinet, drawers in the front of the cabinet, and a frequency converter compartment to form a standard low-voltage cabinet with a width of 800 mm, a depth of 1000 mm, and a height of 2200 mm.

[0034] The partition with ventilation holes divides the interior of the cabinet from top to bottom into the busbar room at the top of the cabinet, the drawer compartment at the front of the cabinet, and the dedicated inverter compartment. The height of the drawer compartment is determined by the size of the switch installed in the drawer. The switches in this analysis plan are all small current molded case circuit breakers of 160A and below, so the height of the drawer compartment is 200mm. However, the drawer unit that provides protection for the inverter needs to install three primary plug-ins, so it is changed to 400mm high. The main purpose is to ensure that there is enough space for the installation of circuit breakers and related components on the feeder circuit. Each drawer compartment is equipped with guide rails on both sides, along which the drawer can move forward and backward. A handle for operating the internal switch is installed on the front door panel of the drawer. The handle can be rotated to different positions and works together with the drawer's interlocking mechanism to lock the drawer in different positions (withdrawal, isolation, test, and working) to prevent misoperation of the low-voltage cabinet. The drawer contains the feeder main switch, main contactor, thermal relay, primary and secondary dynamic plug-ins (i.e., conductive docking dynamic and static plug-ins) on the drawer, and related secondary control components on the feeder circuit, etc.

[0035] Conventional plug-in modules require one secondary plug-in and two primary plug-ins. However, the drawer for the main protection switch circuit that powers the inverter is unique in this design, housing three primary plug-ins. The inverter's exhaust fan, the corresponding fan circuit for cooling it, and all secondary control circuits are housed in this 400mm-high drawer. The inverter connected to the rear end of this drawer is housed separately in the inverter compartment at the bottom of the cabinet.

[0036] This variable frequency power distribution cabinet features cable entry and exit holes at the top and bottom, fitted with rubber rings for cable protection. Behind the drawer compartments, a sealed busbar channel is located for the installation of vertical busbars. Busbar clamps are installed in the channel to secure the three-phase vertical busbars. These three-phase vertical busbars connect to the horizontal main power busbar at the top of the cabinet, which in turn connects to the primary connectors in each drawer, providing power to each drawer.

[0037] 2. Regarding electrical components, the main primary power supply circuit is explained in detail. Regarding secondary control, the connections are made according to the schematic diagram shown in the figure, so that the inverter can smoothly control the start and stop of the high-power fan and control the heat dissipation fan to cool the high-power fan.

[0038] The partition form of the standard low-voltage drawer cabinet can reach Form 3b or even Form 4b. Because the main busbars and vertical busbars in a drawer cabinet are sealed into separate compartments with partitions, and each feeder circuit is also strictly separated by a single drawer, each compartment is isolated from the others. This cabinet fully utilizes the advantages of the drawer cabinet's high partitioning structure, placing the inverter's primary power supply circuit and secondary control relay in separate, isolated drawers. The power supply path is as follows: the horizontal main busbar connects to the vertical copper busbar at the rear of the cabinet drawer, then passes through the primary connector CJD on the incoming line to the upper end of the main circuit breaker QF3. After passing through QF3, the power is split into two paths. One path passes through the main contactor KM and then to the primary connector CJD1 on the outgoing line. The power is then sent out of the drawer and connected to the inverter VSD in the inverter room, where it powers the high-power smoke exhaust fan. The other path passes through contactor KM1 and then to the thermal overload relay KH. After passing through KH, it reaches the primary connector CJD2 on the outgoing line to power the cooling fan. Because this circuit is special, with one input and two outputs, an additional primary plug-in CJD2 is installed on the output side compared to conventional drawers with one input and one output. Therefore, the drawer height is changed to 400mm. Because high-power motors in industry require cooling fans, one circuit has two loads and requires two feeders. This solution cleverly solves this problem by adding a plug-in to one drawer.

[0039] This cabinet has a total of 3 drawers and 1 inverter room. The top two drawers are regular independent circuits with one input and one output; the third drawer is a special drawer that provides protection and power supply for the inverter; this cabinet can appropriately increase drawers and inverters according to the user's on-site needs; the overall structure of the cabinet is similar.

[0040] The technical effect of this solution is

[0041] First, the traditional drawer cabinet is structurally modified, and the main switches of each feeder circuit are placed in separate drawer units to separate them from each other. The main switch of the inverter circuit is also in the form of a drawer unit, which improves the separation form of the inverter cabinet and can meet the requirements of Form 3b, reducing the risk of electric shock in the inverter cabinet and improving the safety performance and electric shock protection requirements of the inverter cabinet during maintenance.

[0042] Secondly, the main switch and control components of the inverter circuit are installed in a 400mm high drawer, and the inverter is placed in a separate compartment in the lower half of the cabinet. The maintenance of each component not only improves safety but also greatly shortens the maintenance time. For example, if the main switch of the inverter is damaged, just pull out the entire drawer and keep it away from the live parts. After maintenance, replace the new device and then insert it into the original position to restore power supply. There is no need to shut down the entire cabinet or even the entire power room. If the inverter is damaged, just disconnect the main switch in the drawer, and the rear inverter compartment will be de-energized. After the inverter is repaired or replaced, just turn the operating handle on the drawer to the closed position to restore power supply. This solution is not only convenient and efficient, but also fast and safer.

[0043] Third, the traditional fixed inverter cabinet only installs the inverter circuit and generally does not install other feeder circuits; this inverter cabinet with low-voltage drawers, in addition to installing the inverter, can also install the main switches of other feeder circuits, increasing the installation capacity of the cabinet and making full use of the effective space of the cabinet. Moreover, each circuit is independent of each other in the form of a drawer, and when one of the circuits fails, they will not interfere with each other.

[0044] The above description is only a preferred embodiment of the present application and is not intended to limit the scope of implementation of the present application. Other embodiments whose principles and basic structures are the same or similar to those of the present application are within the scope of protection of the present application.

Claims

1. A frequency converter cabinet with a low-voltage drawer, characterized in that: It comprises a cabinet body, a frequency converter room for accommodating a frequency converter is provided at the bottom of the cabinet body, a frequency converter drawer is provided on the upper side of the frequency converter room, and a plurality of drawer cabinets; The inverter cabinet is provided with a circuit part: Power busbar, used to receive voltage; A primary plug-in CJD is connected to the power busbar and is turned on when the inverter drawer is inserted into the cabinet; The circuit breaker QF3 has its upper end connected to the primary plug-in CJD, and its lower end connected to the contactor KM1 and the main contactor KM respectively; Thermal overload relay KH, one end of which is connected to the contactor KM1, and the other end of which is connected to the cooling fan of the exhaust fan through the primary plug CJD2; The frequency converter VSD has one end connected to the main contactor KM via the primary plug-in CJD1, and the other end connected to the high-power load smoke exhaust fan.

2. The frequency converter cabinet with a low-voltage drawer according to claim 1, characterized in that: The bottom of the cabinet is provided with a plurality of openings.

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