CN111277116A

CN111277116A - Frequency converter

Info

Publication number: CN111277116A
Application number: CN202010187227.7A
Authority: CN
Inventors: 王存; 覃秋敏; 郑军志
Original assignee: ZHEJIANG HECHUAN TECHNOLOGY CO LTD
Current assignee: ZHEJIANG HECHUAN TECHNOLOGY CO LTD
Priority date: 2020-03-17
Filing date: 2020-03-17
Publication date: 2020-06-12
Anticipated expiration: 2040-03-17
Also published as: CN111277116B; WO2021184465A1

Abstract

The invention discloses a frequency converter, which comprises a shell and a circuit board arranged in the shell; the circuit board is provided with a circuit copper exposing end and a grounding copper exposing end which are mutually disconnected, wherein the circuit copper exposing end is electrically connected with the circuit board electromagnetic interference suppression circuit; the shell is provided with a movable conductive connecting piece, the conductive connecting piece penetrates through the shell, and the conductive area can be moved to be connected or disconnected with the copper exposing end of the circuit and the copper exposing end of the grounding circuit at the same time. Therefore, the movable conductive connecting piece is arranged between the grounding end and the circuit end in the frequency converter provided by the application, so that the communication between the circuit in the frequency converter and the grounding end can be controlled through the conductive connecting piece, and then the frequency converter can be grounded or ungrounded according to the requirements of the application environment in practical application, so that the better application performance of the frequency converter is achieved.

Description

Frequency converter

Technical Field

The invention relates to the field of frequency converters, in particular to a frequency converter.

Background

A Variable-frequency Drive (VFD) is a power control device that applies frequency conversion technology and microelectronic technology to control an ac motor by changing the frequency of a working power supply of the motor. The frequency converter mainly comprises a rectifying unit (alternating current to direct current), a filtering unit, an inverting unit (direct current to alternating current), a braking unit, a driving unit, a detection unit micro-processing unit and the like. The frequency converter adjusts the voltage and frequency of an output power supply by switching on and off an internal IGBT, provides the required power supply voltage according to the actual requirement of the motor, and further achieves the purposes of energy saving and speed regulation. With the continuous improvement of the industrial automation degree, the frequency converter is also widely applied.

Because a large number of power electromagnetic elements exist in the frequency converter, the frequency converter is subjected to increasingly serious electromagnetic interference when being applied to various industrial control systems, and a corresponding anti-interference design technology becomes more and more important. Grounding a circuit network in a frequency converter is one of important means for suppressing electromagnetic interference and improving electromagnetic compatibility of electronic equipment. The correct grounding can not only make the system effectively inhibit the external interference, but also reduce the interference of the device itself to the outside.

Disclosure of Invention

The invention aims to provide a frequency converter, which solves the problem that the frequency converter has different requirements on grounding in different application environments.

In order to solve the technical problem, the invention provides a frequency converter, which comprises a shell and a circuit board arranged in the shell;

the circuit board is provided with a circuit copper exposing end and a grounding copper exposing end which are mutually disconnected, wherein the circuit copper exposing end is electrically connected with a circuit used for shielding electromagnetic interference on the circuit board; the shell is provided with a movable conductive connecting piece, the conductive connecting piece penetrates through the shell, and a conductive area of the conductive connecting piece can be moved to be connected or disconnected with the circuit copper exposing end and the grounding copper exposing end at the same time.

In an alternative embodiment of the present application, the housing is provided with a jack; the conductive connecting piece comprises an insulating substrate and a metal layer arranged on the insulating substrate; the conductive connecting piece is arranged in the jack in a pluggable mode, so that the metal layer can be connected with or disconnected from the circuit copper exposing end and the grounding copper exposing end at the same time.

In an optional embodiment of the present application, a locking structure is further disposed at positions of the circuit copper exposing end and the grounding copper exposing end on the circuit board, and when the conductive connecting member is communicated with the circuit copper exposing end and the grounding copper exposing end, the locking structure locks the conductive connecting member and the circuit board.

In an alternative embodiment of the present application, the locking structure comprises an electroless plated screw hole and a screw disposed between the circuit exposed copper end and the ground exposed copper end; the end part of the insulating substrate of the conductive connecting piece, which is provided with the metal layer, is a U-shaped end part; the screw can run through the screw hole with U type tip locking electrically conductive connecting piece with the circuit board.

In an alternative embodiment of the present application, an end of the conductive connection facing away from the metal layer is provided with a snap ring.

In an alternative embodiment of the present application, the metal layer is a gold plating layer.

The invention provides a frequency converter, which comprises a shell and a circuit board arranged in the shell; the circuit board is provided with a circuit copper exposing end and a grounding copper exposing end which are mutually disconnected, wherein the circuit copper exposing end is electrically connected with the circuit board electromagnetic interference suppression circuit; the shell is provided with a movable conductive connecting piece, the conductive connecting piece penetrates through the shell, and the conductive area can be moved to be connected or disconnected with the copper exposing end of the circuit and the copper exposing end of the grounding circuit at the same time.

According to the practical application environment research of the frequency converter, the circuit in the frequency converter is not suitable for grounding in all environments, and the problem of anti-electromagnetic interference is solved. However, the circuits in the conventional frequency converters are grounded, which affects the performance of the frequency converters in some application environments. Therefore, the movable conductive connecting piece is arranged between the grounding end and the circuit end in the frequency converter provided by the application, so that the communication between the circuit in the frequency converter and the grounding end can be controlled through the conductive connecting piece, and then the frequency converter can be grounded or ungrounded according to the requirements of the application environment in practical application, so that the better application performance of the frequency converter is achieved.

Drawings

In order to more clearly illustrate the embodiments or technical solutions of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained based on these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a frequency converter according to an embodiment of the present application;

fig. 2 is a schematic diagram of a circuit board of a frequency converter provided in an embodiment of the present application;

fig. 3 is a schematic structural diagram of a conductive connection component according to an embodiment of the present disclosure;

fig. 4 is a partial schematic diagram of an interior of a frequency converter according to an embodiment of the present application.

Detailed Description

The core of the invention is to provide a frequency converter, which can select whether to ground or not to ground a circuit in the frequency converter according to the practical application environment of the frequency converter, thereby ensuring the working performance of the frequency converter to the maximum extent.

In order that those skilled in the art will better understand the disclosure, the invention will be described in further detail with reference to the accompanying drawings and specific embodiments. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The frequency converter is a common electrical device, and because the number of electronic circuit devices contained in the frequency converter is large, the frequency converter inevitably receives electromagnetic interference in the environment during use, and further influences the normal operation of the frequency converter. In order to eliminate electromagnetic interference in the environment, a grounding circuit specially used for solving the problem of electromagnetic compatibility in the frequency converter is arranged in the conventional frequency converter, and related circuits which can generate electromagnetic interference in a circuit board are grounded through the grounding circuit, so that the grounding protection effect on the circuit board is further realized.

In practical applications, however, not all application environments are suitable for grounding the circuit on the circuit board for the frequency converter. For example, in an application environment where one end of a single phase in a three-phase power grid is grounded, an angular point of a triangle in the three-phase power grid connected in a triangle is grounded, a midpoint in the three-phase power grid is grounded, and a three-phase power source is not stably grounded to a neutral power source connected to the power grid, the three-phase power source is not suitable for grounding a circuit in a circuit board of the frequency converter, and if the circuit in the circuit board is grounded, a potential difference is caused, and the working performance of the frequency converter is affected. And if the circuit in the circuit board is not grounded, the circuit board is seriously interfered by electromagnetism in other power grid environments, and the normal work is influenced. And for the frequency converter, whether the circuit in the circuit board needs to be grounded or not can be determined by connecting the frequency converter into an actual power grid for testing.

In order to avoid electromagnetic interference, a circuit board in the conventional frequency converter is generally grounded, and the power grid environment which is not suitable for the circuit to be grounded cannot be considered, so that the working performance of the frequency converter is reduced.

Therefore, the frequency converter is provided, whether the circuit in the circuit board in the frequency converter is grounded can be adjusted and controlled, and therefore in practical application, a user can control and adjust the frequency converter according to the actual power grid requirement, and the use performance of the frequency converter is improved.

As shown in fig. 1 and fig. 2, fig. 1 is a schematic structural diagram of a frequency converter provided in an embodiment of the present application, and fig. 2 is a schematic structural diagram of a circuit board of the frequency converter provided in the embodiment of the present application, where the frequency converter includes a circuit board 2 and a housing 1;

a circuit copper exposing end 21 and a grounding copper exposing end 22 which are mutually disconnected are arranged on the circuit board 2, wherein the circuit copper exposing end 21 is electrically connected with a circuit for shielding electromagnetic interference on the circuit board 2; the shell 1 is provided with a movable conductive connecting piece 11, the conductive connecting piece 11 penetrates through the shell 1, and a conductive area of the conductive connecting piece can be moved to be connected with or disconnected with the circuit exposed copper end 21 and the grounding exposed copper end 22 at the same time.

As shown in fig. 1, the frequency converter encapsulates a circuit board 2 and other electronic components inside a housing 1, and a circuit exposed copper terminal 21 and a grounding exposed copper terminal 22 are disposed on the circuit board 2, wherein the circuit exposed copper terminal 21 is connected to a circuit for shielding electromagnetic interference on the circuit board 2, and obviously, the grounding exposed copper terminal 22 is also electrically connected to a ground terminal. When the circuit copper exposing end 21 and the grounding copper exposing end 22 are mutually communicated, the circuit for shielding electromagnetic interference on the circuit board 2 can be grounded; when the circuit exposed copper terminal 21 and the grounding exposed copper terminal 22 are disconnected from each other, the circuit for shielding electromagnetic interference on the circuit board 2 is also disconnected from the grounding terminal.

In this embodiment, a conductive connecting member is disposed on the casing 1 of the frequency converter, one end of the conductive connecting member 11 extends to the inside of the casing, the other end extends to the outside of the casing, and the positions of the circuit copper exposing end 21 and the grounding copper exposing end 22 on the circuit board 2 are opposite to the position of the conductive connecting member 11 disposed on the casing 1, and the conductive connecting member 11 is movably disposed on the casing 1. In practical application, a user can control the conductive connecting piece 11 from the outside of the housing 1 to enable the conductive connecting piece 11 to move towards the circuit copper exposing end 21 and the grounding copper exposing end 22 on the circuit board 2 until the circuit copper exposing end 21 and the grounding copper exposing end 22 are in mutual contact with the conductive connecting piece 11, and the circuit copper exposing end 21 and the grounding copper exposing end 22 can be conducted with each other; conversely, the user can also pull the conductive connecting piece 11 out of the shell 1, so that the conductive connecting piece 11 moves to disconnect the circuit exposed copper end 21 and the grounding exposed copper end 22, that is, the disconnection between the circuit exposed copper end 21 and the grounding exposed copper end 22 can be realized, thus achieving the purpose of controllable and adjustable grounding of the circuit for shielding electromagnetic interference on the circuit board 2 in the frequency converter, greatly increasing the application performance of the frequency converter in different power grid environments, and being beneficial to the wide application of the frequency converter.

To sum up, the converter that provides in this application through set up two dew copper endpoints of disconnection between shielding electromagnetic interference's circuit and earthing terminal to disconnection and switch-on between two dew copper endpoints, the electrically conductive connecting piece of accessible control, whether make the circuit ground connection in the converter can adjust according to the application demand, and then strengthen the adaptability of converter to the environment, improve the application property of converter.

The technical solutions in the present application will be described in more detail with specific examples. As shown in fig. 3, fig. 3 is a schematic structural diagram of a conductive connection component provided in an embodiment of the present application, and in another optional embodiment of the present application, the conductive connection component may further include:

the shell 1 is provided with a jack 10;

the conductive connection member 11 includes an insulating substrate 110 and a metal layer 111 disposed on the insulating substrate 110;

the conductive connector 11 is removably disposed in the jack 10 such that the metal layer 111 can be connected to or disconnected from the circuit exposed copper terminals 21 and the ground exposed copper terminals 22 simultaneously.

Specifically, the conductive connecting piece 11 in this application is a plug-in board structure, and the housing 1 of the frequency converter is provided with a jack 10 matched with the conductive connecting piece 11 in shape structure.

The conductive connecting member 11 is composed of two parts, one part is a non-conductive insulating substrate 110, the insulating substrate 110 can be made of plastic and other materials, and the other part is a conductive metal layer 111, and can be a gold plating layer; the gold has good antioxidation.

The end of the conductive connector 11 provided with the metal layer 111 can be plugged into a circuit board through the jack 10 on the housing 1. When the surface of the conductive connecting piece 11 and the circuit board 2 which are attached to each other is the surface of the insulating substrate 110 provided with the metal layer 111, the metal layer 111 can be connected with the circuit copper exposing end 21 and the grounding copper exposing end 22; when the surface of the conductive connecting member 11 and the circuit board 2 is bonded to each other without the metal layer 111 on the insulating substrate 110, even if the conductive connecting member 11 is bonded to both the circuit exposed copper terminal 21 and the ground exposed copper terminal 22, both terminals cannot be connected. Therefore, in practical application, when the conductive connector 11 is inserted into the jack 10, whether the surface of the attached circuit board 2 is the metal layer 111 or the insulating substrate 110 can be adjusted to adjust the circuit grounding and the circuit non-grounding of the circuit board 2. Meanwhile, the conductive connecting piece 11 can be inserted into the jack 10 of the shell 1 no matter whether the circuit copper exposing end 21 and the grounding copper exposing end 22 are connected or not connected, and the problem that the conductive connecting piece 11 with a small structure is lost due to the fact that the conductive connecting piece 11 is placed everywhere after being pulled out can be well avoided.

Further, in another optional embodiment of the present application, the method may further include:

the positions of the circuit copper exposing end 21 and the grounding copper exposing end 22 on the circuit board 2 are also provided with locking structures, and when the conductive connecting piece 11 is communicated with the circuit copper exposing end 21 and the grounding copper exposing end 22, the locking structures lock the conductive connecting piece 11 and the circuit copper exposing end 21 and the grounding copper exposing end 22 on the circuit board 2.

Considering that the circuit exposed copper terminals 21 and the grounding exposed copper terminals 22 on the circuit board 2 are only a thin copper metal film layer on the circuit board 2, and the metal layer 111 on the insulating substrate 110 is only attached to the copper metal film layer by inserting the conductive connecting member 11 into the insertion hole, the attachment connection is not too tight, which further causes poor contact. Therefore, in the embodiment, a locking structure is further disposed on the circuit board 2, so that when the conductive connecting member 11 is connected to the circuit exposed copper end 21 and the grounding exposed copper end 22, the metal layer 111 on the conductive connecting member 11 can be tightly pressed on the circuit exposed copper end 21 and the grounding exposed copper end 22.

Specifically, as shown in fig. 4, fig. 4 is a partial schematic diagram of the inside of the frequency converter provided in the embodiment of the present application. Fig. 4 is a schematic partial structural diagram of a case of the frequency converter with a portion removed and related to a position of the conductive connecting member, and with reference to fig. 1 to 3, the locking structure in this embodiment may specifically include:

an electroless plated screw hole 23 and a screw provided between the circuit exposed copper end 21 and the grounding exposed copper end 22;

the end of the insulating substrate 110 of the conductive connection member 11 on which the metal layer 111 is provided is a U-shaped end;

a screw may be inserted through the screw hole 23 and the U-shaped end portion to lock the conductive connector 11 and the circuit board 2.

Referring to fig. 1 to 4, in the present embodiment, the conductive connecting member 11 and the circuit board 2 are fastened by screws, and the screw holes 23 between the U-shaped end of the conductive connecting member 11 and the circuit exposed copper ends 21 and the grounding exposed copper ends 22 on the circuit board 2 are used for accommodating screws to pass through.

In addition, as can be seen from fig. 1, the casing of the frequency converter is not a casing of a closed structure, and the upper side of the circuit board 2 where the grounding copper exposed end 22 and the circuit copper exposed end 21 are arranged is not closed by the casing 1, so that a screwdriver can be inserted from the notch of the casing 1 to unscrew or tighten a screw each time the conductive connecting piece needs to be adjusted.

Of course, the locking structure in this application can also set up the structure similar to the spring plate etc. for electrically conductive connecting piece can be pressed tightly on circuit board 2 with electrically conductive connecting piece 11 after inserting from the jack, but this kind of mode will cause the frequent and electrically conductive connecting piece 11 friction of structure such as spring plate etc. certainly, accelerate the wearing and tearing of electrically conductive connecting piece 11, consequently, adopt screw locking to be a more optional embodiment.

Optionally, in another specific embodiment of the present application, the method may further include:

the end of the conductive connection 11 facing away from the metal layer 111 is provided with a retaining ring 112.

As mentioned above, the structure of the conductive connecting part is relatively small, so that the user is difficult to operate when manually plugging and unplugging the conductive connecting part 11 from the jack, and therefore, in the present application, the retaining ring 112 is disposed at the end of the conductive connecting part 11 extending out of the housing 1, so that the user can conveniently use the finger to buckle the retaining ring 112 to plug and unplug the conductive connecting part 11, thereby facilitating the user operation.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Furthermore, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include elements inherent in the list. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element. In addition, parts of the above technical solutions provided in the embodiments of the present application, which are consistent with the implementation principles of corresponding technical solutions in the prior art, are not described in detail so as to avoid redundant description.

The principles and embodiments of the present invention are explained herein using specific examples, which are presented only to assist in understanding the method and its core concepts. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.

Claims

1. The frequency converter is characterized by comprising a shell and a circuit board arranged in the shell;

2. The frequency converter according to claim 1, wherein the housing is provided with a jack; the conductive connecting piece comprises an insulating substrate and a metal layer arranged on the insulating substrate; the conductive connecting piece is arranged in the jack in a pluggable mode, so that the metal layer can be connected with or disconnected from the circuit copper exposing end and the grounding copper exposing end at the same time.

3. The frequency converter according to claim 2, wherein the circuit copper exposing end and the grounding copper exposing end on the circuit board are further provided with locking structures, and when the conductive connecting piece is communicated with the circuit copper exposing end and the grounding copper exposing end, the locking structures lock the conductive connecting piece and the circuit board.

4. The frequency converter of claim 3, wherein said locking structure comprises an unplated screw hole and a screw disposed between said circuit exposed copper end and said ground exposed copper end; the end part of the insulating substrate of the conductive connecting piece, which is provided with the metal layer, is a U-shaped end part; the screw can run through the screw hole with U type tip locking electrically conductive connecting piece with the circuit board.

5. The frequency converter according to claim 2, characterized in that an end of the conductive connection piece facing away from the metal layer is provided with a snap ring.

6. A frequency conversion device according to any of claims 2 to 5, characterized in that the metal layer is a gold plating.