阅读说明：本技术 电荷泄放电路、变流器、离心机组及电器 (Charge leakage circuit, converter, centrifugal unit and electric appliance ) 是由 党培育 姜颖异 黄猛 黄颂儒 徐志国 于 2020-10-13 设计创作，主要内容包括：本申请涉及一种电荷泄放电路、变流器、离心机组及电器,电荷泄放电路包括开关电源以及与开关电源串联的接触器；开关电源和接触器并联在待泄放电荷的母线电容的两端。本申请可以在接触器闭合时可以安全泄放母线残余电荷,同时降低设备内部的温度,不限制设备的启动频率,增加了设备的安全性能。(The application relates to a charge relief circuit, a converter, a centrifugal unit and an electric appliance, wherein the charge relief circuit comprises a switch power supply and a contactor connected with the switch power supply in series; the switch power supply and the contactor are connected in parallel at two ends of a bus capacitor to be discharged with charges. This application can be when contactor is closed can the bus residual charge of safely releasing, reduces the inside temperature of equipment simultaneously, does not restrict the starting frequency of equipment, has increased the security performance of equipment.)

1. A charge bleed circuit, comprising:

the switching power supply and the contactor are connected with the switching power supply in series;

the switch power supply and the contactor are connected in parallel at two ends of a bus capacitor to be discharged with charges.

2. The charge bleed circuit of claim 1, wherein the switching power supply and the contactor are connected in series between a bus bar, the contactor including a normally closed contact,

one end of the switch power supply is connected with the normally closed contact, and the other end of the switch power supply is connected with the bus.

3. The charge bleed circuit of claim 1 or 2, wherein the contactor is an ac contactor.

4. The charge bleed circuit of claim 1 or 2, wherein the switching power supply is a direct current switching power supply.

5. A current transformer, comprising: a bus section; the bus section includes:

the charge bleeding circuit of any of claims 1-4.

6. The converter according to claim 5, wherein the bus section further comprises:

two buses and a bus capacitor;

the charge leakage circuit and the bus capacitor are connected between the two buses in parallel.

7. The converter according to claim 5, further comprising:

a rectifying part and an inverting part;

the bus section is connected in series between the rectifying section and the inverting section.

8. The converter according to claim 5, further comprising:

and the controller is connected with the charge release circuit and is powered by the switching power supply when the normally closed contact of the contactor is closed.

9. The converter according to claim 8, wherein the controller is specifically configured to:

when the power supply grid of the converter fails, whether a switch and a relay in the converter are abnormal or not is detected, the abnormality is prompted when the converter is started next time, and the converter is started again after the abnormality is cleared.

10. A centrifuge assembly, comprising:

a current transformer as claimed in any one of claims 5 to 9.

11. An electrical appliance, comprising: a centrifuge assembly according to claim 10.

Technical Field

The application belongs to the technical field of converters, and particularly relates to a charge leakage circuit, a converter, a centrifugal unit and an electric appliance.

Background

When the converter works, a high voltage is established on a direct current bus, when the converter stops, a large amount of residual charges exist on the bus, and if the charges cannot be discharged quickly, potential safety hazards exist. The main topology of the converter for the high-power variable-frequency centrifugal unit generally adopts an 'alternating current-direct current-alternating current' structure, namely, the input is alternating current, direct current potential is established through a rectifier module, and then the direct current is converted into proper alternating current through an inverter module. The rectification module is connected with the inversion module through a direct current bus, and a large capacitor is connected to the direct current bus for energy storage. The current scheme for discharging the residual charge of the direct current bus is to directly access a discharging resistor at two ends of the direct current bus or indirectly access the discharging resistor through a normally closed contact of a contactor to realize the function, and the two schemes use the discharging resistor to consume electric energy. Therefore, the waste of residual charges can be caused, when the bleeder resistor consumes electric energy, the electric energy is converted into heat energy, the internal temperature of the converter can be increased, and particularly, after the converter is stopped, the converter is restarted for debugging or overhauling work is carried out in a short time, the converter is easy to break down and potential safety hazards are increased due to high temperature in the equipment cabinet.

Disclosure of Invention

For overcoming traditional bleeder circuit at least to a certain extent and adopting bleeder resistor to consume the electric energy, cause the waste of residual charge to bleeder resistor is when consuming the electric energy, and the electric energy converts heat energy into, can make the inside temperature of converter rise, especially when the converter shuts down the back, when the short time starts again, higher temperature in the equipment cupboard increases the problem of potential safety hazard, this application provides a charge bleeder circuit, converter, centrifugal unit and electrical apparatus.

In a first aspect, the present application provides a charge bleed circuit comprising:

the switching power supply and the contactor are connected with the switching power supply in series;

the switch power supply and the contactor are connected in parallel at two ends of a bus capacitor to be discharged with charges.

Further, the switching power supply and the contactor are connected in series between the bus bars, the contactor comprises a normally closed contact,

one end of the switch power supply is connected with the normally closed contact, and the other end of the switch power supply is connected with the bus.

Further, the contactor is an alternating current contactor.

Further, the switching power supply is a direct current switching power supply.

In a second aspect, the present application provides a current transformer comprising:

a bus section; the bus section includes:

a charge bleed circuit as claimed in any one of the first aspect.

Further, the bus section further includes:

two buses and a bus capacitor;

the charge leakage circuit and the bus capacitor are connected between the two buses in parallel.

Further, the method also comprises the following steps:

a rectifying part and an inverting part;

the bus section is connected in series between the rectifying section and the inverting section.

Further, the method also comprises the following steps:

and the controller is connected with the charge release circuit and is powered by the switching power supply when the normally closed contact of the contactor is closed.

Further, the controller is specifically configured to:

when the power supply grid of the converter fails, whether a switch and a relay in the converter are abnormal or not is detected, the abnormality is prompted when the converter is started next time, and the converter is started again after the abnormality is cleared.

In a third aspect, the present application provides a centrifuge assembly comprising:

the current transformer of any one of the second aspect.

In a fourth aspect, the present application provides an electrical appliance comprising:

a centrifuge assembly according to the third aspect.

The technical scheme provided by the embodiment of the application can have the following beneficial effects:

the embodiment of the invention provides a charge release circuit, a converter, a centrifugal unit and an electric appliance, wherein the charge release circuit comprises a switch power supply and a contactor connected with the switch power supply in series; the switch power supply and the contactor are connected in parallel at two ends of a bus capacitor to be subjected to charge discharging, so that residual charge of the bus can be safely discharged when the contactor is closed, the temperature inside the equipment is reduced, the starting frequency of the equipment is not limited, and the safety performance of the equipment is improved.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and together with the description, serve to explain the principles of the application.

Fig. 1 is a schematic structural diagram of a charge bleeding circuit according to an embodiment of the present application.

Fig. 2 is a schematic structural diagram of a direct access bleeder resistor scheme according to an embodiment of the present application.

Fig. 3 is a schematic structural diagram of an indirect access bleeder resistor scheme according to an embodiment of the present application.

Fig. 4 is a schematic structural diagram of a current transformer according to an embodiment of the present application.

Fig. 5 is a flowchart illustrating a state determination of various switches and relays according to an embodiment of the present disclosure.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the technical solutions of the present application will be described in detail below. It is to be understood that the embodiments described are only a few embodiments of the present application and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the examples given herein without making any creative effort, shall fall within the protection scope of the present application.

Fig. 1 is a schematic structural diagram of a charge draining circuit according to an embodiment of the present application, and as shown in fig. 1, the charge draining circuit includes:

a switching power supply 1 and a contactor 2 connected in series with the switching power supply;

the switch power supply 1 and the contactor 2 are connected in parallel at two ends of a bus 3 capacitor to be discharged with charges.

In some embodiments, the switching power supply 1 and the contactor 2 are connected in series between the bus bars 3, the contactor 2 includes a normally closed contact, and one end of the switching power supply 1 is connected to the normally closed contact and the other end is connected to the bus bar 3.

In some embodiments, the contactor 2 is an ac contactor.

In some embodiments, the switching power supply 1 is a dc switching power supply.

The traditional scheme for discharging the residual charge of the direct current bus is to directly switch in a discharging resistor at two ends of the direct current bus (as shown in fig. 2) or indirectly switch in the discharging resistor through a normally closed contact of a contactor (as shown in fig. 3) to realize the function, and both schemes use the discharging resistor to consume electric energy. Therefore, the waste of residual charges can be caused, when the bleeder resistor consumes electric energy, the electric energy is converted into heat energy, the internal temperature of the converter can be increased, and particularly, after the converter is stopped, the converter is restarted for debugging or overhauling work is carried out in a short time, the converter is easy to break down and potential safety hazards are increased due to high temperature in the equipment cabinet.

In the embodiment, a coil in the alternating current contactor is supplied with power through a power grid, when the converter works normally, the coil of the alternating current contactor is electrified, a normally closed contact K1 of the alternating current contactor is disconnected, and a residual charge discharging circuit of a direct current bus is disconnected;

when the power grid is powered off, the coil of the alternating current contactor is powered off, the normally closed contact K1 of the contactor is closed, and the charge discharging circuit forms a complete path to realize charge discharging.

In this embodiment, the charge discharging circuit includes a switching power supply and a contactor connected in series with the switching power supply; the switch power supply and the contactor are connected in parallel at two ends of a bus capacitor to be subjected to charge discharging, so that residual charge of the bus can be safely discharged when the contactor is closed, the temperature inside the equipment is reduced, the starting frequency of the equipment is not limited, and the safety performance of the equipment is improved.

Fig. 4 is a schematic structural diagram of a current transformer according to an embodiment of the present application, and as shown in fig. 4, the current transformer includes:

a bus section 41; the bus section includes:

such as the charge bleed circuit in the embodiments described above.

The bus section 41 further includes:

two buses and a bus capacitor;

the charge leakage circuit and the bus capacitor are connected in parallel between the two buses.

The converter further includes:

a rectifying portion 42 and an inverting portion 43;

the bus section 41 is connected in series between the rectifying section 42 and the inverting section 43.

In some embodiments, further comprising:

and a controller (not shown in the figure) connected with the charge leakage circuit and powered by the switching power supply when the normally closed contact of the contactor is closed. The controller is specifically configured to:

when the power supply grid of the converter fails, whether a switch and a relay in the converter are abnormal or not is detected, the abnormality is prompted when the converter is started next time, and the converter is started again after the abnormality is cleared. The state determination flow of each switch and relay is shown in fig. 5.

The coil of the alternating current contactor is powered through a power grid, when the converter works normally, the coil of the contactor is powered on, a normally closed contact K1 of the contactor is disconnected, and a residual charge leakage circuit of a direct current bus is disconnected; when the power failure of the power grid occurs, the coil of the alternating current contactor is powered off, the normally closed contact K1 of the contactor is closed, the residual charge leakage circuit of the direct current bus is connected, meanwhile, the direct current switch power supply starts working and provides power for the controller, the controller detects that no voltage exists on the power grid side at the moment, and the time of the shutdown event is recorded.

The controller judges whether the converter is abnormal or not by judging the power grid power failure condition, and the power grid power failure is divided into two conditions:

the first condition is that a power grid fails, and the judgment method comprises the following steps:

when the controller does not send the closing command of the opening coil to the electric operating mechanism, the power grid is powered off, and the main circuit breaker is turned off by the undervoltage release.

The first condition is that the controller sends a breaking instruction to the electric operating mechanism, and the main breaker is turned off by closing the opening coil.

After the power failure of the power grid, the controller starts to detect the switch states of the switches and the relays, compares the preset switch states, judges whether the switches and the relays are damaged or are in a non-initialization state, records and compares the judged information, and waits for the next startup. If an abnormal condition occurs, the controller can report that the switch or relay switch state at the corresponding position is abnormal when the converter is started next time, and a user needs to go to fault clearing and clear firstly to enable the converter to be started normally.

In this embodiment, the converter includes a bus portion, and the bus portion includes a charge bleeding circuit, adopts direct current switching power supply to carry out residual charge bleeding, consumes the residual charge of bus capacitor through direct current switching power supply. In addition, the direct-current switch power supply also supplies power to the controller, so that the state parameter record of the converter after the power grid fault and some control strategies such as generating a power failure log can be realized, and the safety of the converter is protected.

This embodiment provides a centrifuge group, includes: such as the current transformer in the above embodiment.

The present embodiment provides an electric appliance, including: such as the centrifuge assemblies described in the above embodiments.

It is understood that the same or similar parts in the above embodiments may be mutually referred to, and the same or similar parts in other embodiments may be referred to for the content which is not described in detail in some embodiments.

It should be noted that, in the description of the present application, the terms "first", "second", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. Further, in the description of the present application, the meaning of "a plurality" means at least two unless otherwise specified.

Any process or method descriptions in flow charts or otherwise described herein may be understood as representing modules, segments, or portions of code which include one or more executable instructions for implementing specific logical functions or steps of the process, and the scope of the preferred embodiments of the present application includes other implementations in which functions may be executed out of order from that shown or discussed, including substantially concurrently or in reverse order, depending on the functionality involved, as would be understood by those reasonably skilled in the art of the present application.

It should be understood that portions of the present application may be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, the various steps or methods may be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, any one or combination of the following techniques, which are known in the art, may be used: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application specific integrated circuit having an appropriate combinational logic gate circuit, a Programmable Gate Array (PGA), a Field Programmable Gate Array (FPGA), or the like.

It will be understood by those skilled in the art that all or part of the steps carried by the method for implementing the above embodiments may be implemented by hardware related to instructions of a program, which may be stored in a computer readable storage medium, and when the program is executed, the program includes one or a combination of the steps of the method embodiments.

In addition, functional units in the embodiments of the present application may be integrated into one processing module, or each unit may exist alone physically, or two or more units are integrated into one module. The integrated module can be realized in a hardware mode, and can also be realized in a software functional module mode. The integrated module, if implemented in the form of a software functional module and sold or used as a stand-alone product, may also be stored in a computer readable storage medium.

The storage medium mentioned above may be a read-only memory, a magnetic or optical disk, etc.

In the description herein, reference to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the application. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although embodiments of the present application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present application, and that variations, modifications, substitutions and alterations may be made to the above embodiments by those of ordinary skill in the art within the scope of the present application.

It should be noted that the present invention is not limited to the above-mentioned preferred embodiments, and those skilled in the art can obtain other products in various forms without departing from the spirit of the present invention, but any changes in shape or structure can be made within the scope of the present invention with the same or similar technical solutions as those of the present invention.