CN217282722U - Three-phase incoming line circuit of frequency converter, frequency conversion circuit and frequency converter - Google Patents
Three-phase incoming line circuit of frequency converter, frequency conversion circuit and frequency converter Download PDFInfo
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- CN217282722U CN217282722U CN202221563102.0U CN202221563102U CN217282722U CN 217282722 U CN217282722 U CN 217282722U CN 202221563102 U CN202221563102 U CN 202221563102U CN 217282722 U CN217282722 U CN 217282722U
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Abstract
The utility model discloses a converter three-phase inlet wire circuit, inverter circuit and converter. Wherein, converter three-phase inlet wire circuit is applied to the converter, and the converter includes inverter circuit, and inverter circuit includes a plurality of three-phase rectifier circuit, direct current bus and a plurality of inverter circuit, and converter three-phase inlet wire circuit includes: the input ends of the three-phase incoming line branch circuits are respectively connected with the three-phase alternating current ends, and the output ends of the three-phase incoming line branch circuits are connected with the input ends of the three-phase rectifying circuits in a one-to-one correspondence mode. Each three-phase incoming line branch circuit comprises a three-phase main switch circuit and a pre-charging switch circuit, the input end of the three-phase main switch circuit is connected with a three-phase alternating current end, the output end of the three-phase main switch circuit is connected with the input end of a three-phase rectification circuit, the first end of the pre-charging switch circuit is connected with the three-phase alternating current end, and the second end of the pre-charging switch circuit is connected with the input end of the three-phase rectification circuit. The utility model provides high reliability and stability of converter work.
Description
Technical Field
The utility model relates to an electrical technology field, in particular to converter three-phase inlet wire circuit, inverter circuit and converter.
Background
Along with the high-speed development of economy, the demand of the market for energy conservation of products is increased, and the market demand of frequency converters is greatly stimulated. Meanwhile, more and more customers have higher and higher requirements on the reliability of the functional loop in the cabinet of the finished-cabinet frequency converter.
At present, in a frequency converter, in order to meet the use requirement, a plurality of inlet wire main switch circuits are arranged on an alternating current inlet wire side, however, a pre-charging loop is usually arranged on one inlet wire main switch circuit, once the only pre-charging loop is damaged or fails, main switches on all inlet wire main switch circuits cannot be closed, the frequency converter cannot be used, and the working reliability and stability of the frequency converter are reduced.
SUMMERY OF THE UTILITY MODEL
The utility model aims at providing a converter three-phase inlet wire circuit, inverter circuit and converter aims at improving reliability and the stability of converter work.
In order to achieve the above object, the utility model provides a converter three-phase incoming line circuit is applied to the converter, the converter includes inverter circuit, inverter circuit includes a plurality of three-phase rectifier circuit, direct current generating line and a plurality of inverter circuit, and is a plurality of three-phase rectifier circuit's output, a plurality of inverter circuit's input respectively with direct current generating line electricity is connected, converter three-phase incoming line circuit includes:
the input ends of the three-phase inlet branch circuits are respectively connected with a three-phase alternating current end, and the output ends of the three-phase inlet branch circuits are connected with the input ends of the three-phase rectifying circuits in a one-to-one correspondence manner;
each said three phase incoming line leg comprising:
the input end of the three-phase main switch circuit is connected with the three-phase alternating current end, the output end of the three-phase main switch circuit is connected with the input end of the three-phase rectifying circuit, and the controlled end of the three-phase main switch circuit is used for accessing a main switch signal; the three-phase main switching circuit is used for being in an open state or a closed state according to the main switching signal;
a first end of the pre-charging switch loop is connected with the three-phase alternating current end, and a second end of the pre-charging switch loop is connected with the input end of the three-phase rectifying circuit; and the pre-charging switch loop is used for conducting a path between the three-phase alternating current end and the input end of the three-phase rectifying circuit when the pre-charging switch loop is in a closed state, so that the voltage of the direct current bus is increased.
Optionally, the input ends of the three-phase rectification circuit include a first input end, a second input end and a third input end; the three-phase alternating current end comprises a first cross current end, a second cross current end and a third cross current end; the three-phase main switch circuit comprises a three-phase main switch, and the three-phase main switch is provided with a first input end, a second input end, a third input end, a first output end, a second output end and a third output end;
the first input end of the three-phase main switch is connected with the first cross current end, and the first output end of the three-phase main switch is connected with the first input end of the three-phase rectification circuit;
a second input end of the three-phase main switch is connected with the second phase alternating current end, and a second output end of the three-phase main switch is connected with a second input end of the three-phase rectification circuit;
the first input end of the three-phase main switch is connected with the third alternating-current end, and the third output end of the three-phase main switch is connected with the third input end of the three-phase rectifying circuit;
the controlled end of the three-phase main switch is used for accessing a main switch signal and is in a closed state according to the main switch signal so as to conduct a path between a first input end and a first output end of the three-phase main switch, a path between a second input end and a second output end of the three-phase main switch and a path between a third input end and a third output end of the three-phase main switch; alternatively, the first and second electrodes may be,
and the three-phase main switch is in an open state to disconnect a path between a first input end and a first output end of the three-phase main switch, a path between a second input end and a second output end of the three-phase main switch and a path between a third input end and a third output end of the three-phase main switch.
Optionally, the pre-charge switch circuit includes: the three-phase switching-on/off switch, the first resistor, the second resistor and the third resistor;
the three-phase switching-on and switching-off switch is provided with a first input end, a second input end, a third input end, a first output end, a second output end and a third output end, the first input end of the three-phase switching-on and switching-off switch is connected with the first cross current end, the second input end of the three-phase switching-on and switching-off switch is connected with the second phase alternating current end, the third input end of the three-phase switching-on and switching-off switch is connected with the third phase alternating current end, the first output end of the three-phase switching-on and switching-off switch is connected with the first input end of the three-phase rectifying circuit through the first resistor, the second output end of the three-phase switching-on and switching-off switch is connected with the second input end of the three-phase rectifying circuit through the second resistor, and the third output end of the three-phase switching-on and switching-off switch is connected with the second input end of the three-phase rectifying circuit through the third resistor;
and the three-phase switching-on and switching-off switch is used for switching on or switching off a path between the first cross current terminal and the first input terminal of the three-phase rectification circuit, switching on or switching off a path between the second cross current terminal and the second input terminal of the three-phase rectification circuit and switching on or switching off a path between the third cross current terminal and the third input terminal of the three-phase rectification circuit when triggered by a user.
Optionally, the pre-charging switch circuit further includes a three-phase auxiliary switch, where the three-phase auxiliary switch has a controlled end, a first input end, a second input end, a third input end, a first output end, a second output end, and a third output end, the first input end of the three-phase auxiliary switch is connected with the first output end of the three-phase opening and closing switch, the second input end of the three-phase auxiliary switch is connected with the second output end of the three-phase opening and closing switch, the third input end of the three-phase auxiliary switch is connected with the third output end of the three-phase opening and closing switch, the first output end of the three-phase auxiliary switch is connected with the first end of the first resistor, the second output end of the three-phase auxiliary switch is connected with the first end of the second resistor, and the third output end of the three-phase auxiliary switch is connected with the first end of the third resistor;
the controlled end of the three-phase auxiliary switch is used for accessing an auxiliary switch closing signal or an auxiliary switch opening signal;
the three-phase auxiliary switch is used for conducting a path between a first input end and a first output end of the three-phase auxiliary switch, a path between a second input end and a second output end of the three-phase auxiliary switch and a path between a third input end and a third output end of the three-phase auxiliary switch when receiving the auxiliary switch closing signal;
the three-phase auxiliary switch is used for disconnecting a path between a first input end and a first output end of the three-phase auxiliary switch, a path between a second input end and a second output end of the three-phase auxiliary switch and a path between a third input end and a third output end of the three-phase auxiliary switch when the auxiliary switch opening signal is received.
Optionally, the three-phase auxiliary switch is a contactor.
The utility model also provides a frequency conversion circuit, include:
a plurality of three-phase rectification circuits;
a direct current bus;
a plurality of inverter circuits; and the number of the first and second groups,
a frequency converter three-phase incoming line circuit as described in any of the above;
the output ends of the three-phase rectification circuits and the input ends of the inverter circuits are respectively electrically connected with the direct current bus.
Optionally, the frequency conversion circuit further includes:
the starting and stopping trigger component is used for outputting a corresponding starting signal or a corresponding stopping signal when triggered by a user;
the voltage detection circuit is electrically connected with the direct current bus and is used for detecting the voltage of the direct current bus and outputting a corresponding voltage detection signal;
the main controller is respectively and electrically connected with the start-stop trigger assembly, the voltage detection circuit and the plurality of pre-charging switch loops;
the main controller is also provided with a plurality of main switch control pins which are respectively connected with the controlled ends of the three-phase main switch circuits;
the main controller is used for outputting an auxiliary switch closing signal to the plurality of pre-charging switch loops when receiving the starting signal;
the main controller is further configured to output a corresponding main switching signal to the three-phase main switching circuit corresponding to the start signal when it is determined that the voltage of the dc bus reaches a preset start voltage according to the voltage detection signal, so that the corresponding three-phase main switching circuit is in a closed state, and output an auxiliary switch opening signal to the plurality of pre-charge switching circuits;
and the main controller is further used for outputting a corresponding main switching signal to the three-phase main switching circuit corresponding to the stop signal when receiving the stop signal, so that the corresponding three-phase main switching circuit is in an open state.
Optionally, the start-stop triggering component is a key array, and the key array is configured to output the corresponding start signal or the corresponding stop signal when triggered by the user.
Optionally, the start-stop triggering component is a touchable screen, and the touchable screen is configured to output the corresponding start signal or stop signal when triggered by a user.
The utility model also provides a converter, include as above-mentioned arbitrary inverter circuit.
The utility model discloses converter three-phase inlet wire circuit includes a plurality of three-phase inlet wire branch circuits, and is a plurality of the input of three-phase inlet wire branch circuit is connected with the three-phase AC end respectively, and is a plurality of the output and a plurality of three-phase inlet wire branch circuit three-phase rectifier circuit's input one-to-one is connected. Each three-phase incoming line branch circuit comprises a three-phase main switch circuit and a pre-charging switch circuit, and the pre-charging switch circuit is used for conducting a path between the three-phase alternating current end and the input end of the three-phase rectification circuit when the pre-charging switch circuit is in a closed state, so that the voltage of the direct-current bus is increased. So, when the converter is opened to actual need, if the pre-charge switch return circuit trouble on a certain or a plurality of three-phase inlet wire branch road leads to can't be closed, as long as there is the pre-charge switch return circuit on a three-phase inlet wire branch road normal, this normal pre-charge switch return circuit is after closed so, just can make the voltage of direct current generating line rise normally to make the converter can normally control three-phase main switch circuit in follow-up start-up process and be in the closed condition, the utility model discloses an all be provided with the pre-charge switch return circuit in every three-phase inlet wire branch road, realized the redundant design to the pre-charge switch return circuit, improved reliability and the stability of converter work effectively.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the technical solutions in the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings can be obtained according to the structures shown in the drawings without creative efforts for those skilled in the art.
Fig. 1 is a schematic block diagram of an embodiment of a three-phase incoming line branch of the present invention;
fig. 2 is a specific circuit schematic diagram of a three-phase incoming line branch according to an embodiment of the present invention;
fig. 3 is a specific circuit diagram of a three-phase incoming line branch according to another embodiment of the present invention;
fig. 4 is a specific circuit diagram of an embodiment of the frequency conversion circuit of the present invention.
The reference numbers indicate:
| reference numerals | Name (R) | Reference numerals | Name (R) |
| 10 | Three-phase |
11 | Three-phase |
| 12 | |
20 | Three- |
| 30 | |
40 | |
| 50 | |
60 | |
| 70 | Start-stop trigger assembly |
The purpose of the present invention is to provide a novel and improved method and apparatus for operating a computer.
Detailed Description
The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.
It should be noted that, if directional indications (such as up, down, left, right, front, and back) are involved in the embodiments of the present invention, the directional indications are only used for explaining the relative position relationship between the components in a specific posture (as shown in the drawings), the motion condition, and the like, and if the specific posture is changed, the directional indication is changed accordingly.
In addition, if there is a description of designing "first", "second", etc. in the embodiments of the present invention, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defining "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions in the embodiments may be combined with each other, but it must be based on the realization of those skilled in the art, and when the technical solutions are contradictory to each other or cannot be realized, such a combination should not be considered to exist, and is no longer within the protection scope of the present invention.
It should be understood that in the frequency converter, in order to meet the requirement of use, a plurality of incoming line main switch circuits are arranged on the alternating current incoming line side. When the frequency converter needs to be started, in order to prevent the main switch from being closed, the three-phase alternating voltage directly impacts the subsequent circuit, so that devices in the subsequent circuit, such as capacitors, are broken down. Generally, a pre-charging circuit is arranged in an incoming line main switch circuit, and before starting, the pre-charging circuit is closed to gradually increase the voltage on the dc bus, and when the voltage on the dc bus is higher than a preset starting voltage, the main switch is controlled to be closed. However, a pre-charging circuit is often arranged on only one incoming line main switch circuit in the frequency converter, and once the only pre-charging circuit is damaged or fails, the main switches on all incoming line main switch circuits cannot be closed, so that the frequency converter cannot be used, and the working reliability and stability of the frequency converter are reduced.
Therefore, the utility model provides a converter three-phase inlet wire circuit is applied to converter, converter include inverter circuit, and inverter circuit includes a plurality of three-phase rectifier circuit 20, direct current bus 30 and a plurality of inverter circuit 40, and a plurality of three-phase rectifier circuit 20's output, a plurality of inverter circuit 40's input are connected with direct current bus 30 electricity respectively.
Referring to fig. 1, in an embodiment of the present invention, a three-phase incoming line circuit of a frequency converter includes:
the three-phase incoming line circuit comprises a plurality of three-phase incoming line branch circuits 10, wherein the input ends of the three-phase incoming line branch circuits 10 are respectively connected with a three-phase alternating current end, and the output ends of the three-phase incoming line branch circuits 10 are correspondingly connected with the input ends of a plurality of three-phase rectifying circuits 20 one by one;
each three-phase incoming branch 10 comprises:
the input end of the three-phase main switch circuit 11 is connected with a three-phase alternating current end, the output end of the three-phase main switch circuit 11 is connected with the input end of the three-phase rectifying circuit 20, and the controlled end of the three-phase main switch circuit 11 is used for accessing a main switch signal; the three-phase main switch circuit 11 is used for being in an open state or a closed state according to a main switch signal;
a pre-charging switch circuit 12, wherein a first end of the pre-charging switch circuit 12 is connected with a three-phase alternating current end, and a second end of the pre-charging switch circuit 12 is connected with an input end of a three-phase rectification circuit 20; the pre-charge switch circuit 12 is used to open a path between the three-phase current-intersecting terminal and the input terminal of the three-phase rectification circuit 20 when in a closed state, so as to raise the voltage of the dc bus 30.
In this embodiment, the three-phase ac terminal includes a first ac terminal, a second ac terminal, and a third ac terminal, a three-phase ac transformer may be disposed in the frequency converter, and an output side winding of the transformer is connected to the three-phase ac terminal, and is configured to perform voltage conversion on a three-phase voltage externally connected to the frequency converter, and then output the three-phase voltage through the three-phase ac terminal. In the inverter circuit, a main controller may be provided for electrically connecting with the controlled terminal of the three-phase main switch circuit 11, and the main controller may output a main switch signal to the controlled terminal of the three-phase main switch circuit 11 to control the three-phase main switch circuit 11 to be in an open or closed state. For example, the main switch signal includes a main switch opening signal and a main switch closing signal, and the main controller may output the main switch opening signal to the controlled terminal of the three-phase main switch circuit 11 to control the three-phase main switch circuit 11 to be in the open state. The main controller may also output a main switch closing signal to the controlled terminal of the three-phase main switch circuit 11 to control the three-phase main switch circuit 11 to be in an open state. Optionally, the three-phase main switch circuit 11 may be implemented by a contactor, and the main controller may output a corresponding main switch signal to control the contactor to be in an open or closed state, for example, the main controller outputs a high level signal to control the contactor to be in a closed state, and at this time, a path between the three-phase ac terminal and the three-phase rectifier circuit 20 is conducted; optionally, the three-phase main switch circuit 11 may also be implemented by a circuit breaker, and the main controller may also output a corresponding main switch signal to control the circuit breaker to be in an open or closed state.
In this embodiment, optionally, the pre-charging switch circuit 12 may be implemented by using a manual opening/closing switch and a resistive load connected in series with the manual opening/closing switch, and a user may manually control the corresponding preset switch circuit to be in a closed state or an open state, and when the user pulls the manual opening/closing switch to make the manual opening/closing switch in the closed state, the three-phase ac terminal can be electrically connected to the input terminal of the three-phase rectifier circuit 20 through the pre-charging switch circuit 12. In practical application, when a user needs to start the frequency converter, the manual opening and closing switch is pulled firstly to enable the frequency converter to be in a closed state, at this time, an electric connection path is established between the three-phase AC end and the three-phase rectifying circuit 20, three-phase AC output by the three-phase AC end enters the three-phase rectifying circuit 20 through the manual opening and closing switch and the resistive load, and the three-phase AC is rectified by the three-phase rectifying circuit 20 and then is output to the DC bus 30, so that the voltage of the DC bus 30 is gradually increased. Optionally, the pre-charge switch loop 12 may also be implemented by using an electrically controlled on-off switch and a resistive load connected in series with the electrically controlled on-off switch, when the frequency converter is started, a user may trigger an external trigger component to output a corresponding trigger signal to the main controller in the frequency conversion circuit of the above embodiment, so that the main controller controls the electrically controlled on-off switch to be in a closed state, and like the above embodiment, the voltage of the dc bus 30 is gradually increased, so that the frequency converter can normally control the three-phase main switch circuit 11 to be in the closed state in a subsequent starting process. It is understood that in practical applications, the plurality of pre-charging switch circuits 12 in the plurality of three-phase incoming branches 10 may be controlled in a linkage manner or may be controlled individually. Therefore, when the frequency converter needs to be started actually, if the pre-charging switch circuit 12 on one or more three-phase incoming line branches 10 fails to close due to a fault, as long as one pre-charging switch circuit 12 on one three-phase incoming line branch 10 is normal, the voltage of the direct-current bus 30 can be raised normally after the normal pre-charging switch circuit 12 is closed, so that the frequency converter can normally control the three-phase main switch circuit 11 to be in a closed state in a subsequent starting process, and the situation that the frequency converter cannot be started normally due to the fact that only one pre-charging switch circuit 12 is damaged and cannot be closed due to the fact that only one pre-charging switch circuit 12 is arranged cannot occur can be avoided, and the working reliability and stability of the frequency converter are effectively improved.
The utility model discloses converter three-phase inlet wire circuit includes a plurality of three-phase inlet wire branch roads 10, and a plurality of three-phase inlet wire branch roads 10's input is connected with the three-phase interchange end respectively, and a plurality of three-phase inlet wire branch roads 10's output is connected with a plurality of three-phase rectifier circuit 20's input one-to-one. Each three-phase incoming line branch 10 includes a three-phase main switch circuit 11 and a pre-charging switch circuit 12, and the pre-charging switch circuit 12 is configured to conduct a path between a three-phase current-intersecting end and an input end of the three-phase rectification circuit 20 when the three-phase incoming line branch is in a closed state, so as to raise a voltage of the dc bus 30. So, when the converter is opened to actual need, if the preliminary filling switch return circuit 12 trouble on a certain or a plurality of three-phase inlet wire branch road 10 leads to can't be closed, as long as there is preliminary filling switch return circuit 12 on a three-phase inlet wire branch road 10 normal, this normal preliminary filling switch return circuit 12 is in the closed back so, just can make direct current bus 30's voltage normally rise to make the converter normally control three-phase main switch circuit 11 and be in the closed state in follow-up start-up process, the utility model discloses an all be provided with preliminary filling switch return circuit 12 in every three-phase inlet wire branch road 10, realized the redundant design to preliminary filling switch return circuit 12, improved the reliability and the stability of converter work effectively.
Specifically, referring to fig. 2, in an embodiment of the present invention, the input terminal of the three-phase rectification circuit 20 includes a first input terminal, a second input terminal, and a third input terminal; the three-phase alternating current end comprises a first cross current end, a second cross current end and a third cross current end; the three-phase main switch QF1 circuit comprises a three-phase main switch QF1, wherein the three-phase main switch QF1 is provided with a first input end, a second input end, a third input end, a first output end, a second output end and a third output end;
a first input end of the three-phase main switch QF1 is connected with a first cross current end, and a first output end of the three-phase main switch QF1 is connected with a first input end of the three-phase rectifying circuit 20;
a second input end of the three-phase main switch QF1 is connected with a second phase alternating current end, and a second output end of the three-phase main switch QF1 is connected with a second input end of the three-phase rectifying circuit 20;
a first input end of the three-phase main switch QF1 is connected with a third phase alternating current end, and a third output end of the three-phase main switch QF1 is connected with a third input end of the three-phase rectifying circuit 20;
the controlled end of the three-phase main switch QF1 is used for accessing a main switch signal and is in a closed state according to the main switch signal so as to conduct a path between a first input end and a first output end of the three-phase main switch QF1, conduct a path between a second input end and a second output end of the three-phase main switch QF1 and conduct a path between a third input end and a third output end of the three-phase main switch QF 1; alternatively, the first and second electrodes may be,
in an open state to open the path between the first input and the first output of the three-phase main switch QF1, open the path between the second input and the second output of the three-phase main switch QF1, and open the path between the third input and the third output of the three-phase main switch QF 1.
The pre-charge switch circuit 12 includes: the three-phase switching-on and switching-off switch QS1, a first resistor R1, a second resistor R2 and a third resistor R3;
the three-phase switching-on and switching-off switch QS1 is provided with a first input end, a second input end, a third input end, a first output end, a second output end and a third output end, the first input end of the three-phase switching-on and switching-off switch QS1 is connected with the first cross current end, the second input end of the three-phase switching-on and switching-off switch QS1 is connected with the second phase alternating current end, the third input end of the three-phase switching-on and switching-off switch QS1 is connected with the third phase alternating current end, the first output end of the three-phase switching-on and switching-off switch QS1 is connected with the first input end of the three-phase rectifying circuit 20 through a first resistor, the second output end of the three-phase switching-on and switching-off switch QS1 is connected with the second input end of the three-phase rectifying circuit 20 through a second resistor, and the third output end of the three-phase switching-on and switching-off switch QS1 is connected with the second input end of the three-phase rectifying circuit 20 through a third resistor;
and a three-phase switching-on/off switch QS1, configured to, when triggered by a user, turn on or off a path between the first cross current terminal and the first input terminal of the three-phase rectification circuit 20, turn on or off a path between the second cross current terminal and the second input terminal of the three-phase rectification circuit 20, and turn on or off a path between the third cross current terminal and the third input terminal of the three-phase rectification circuit 20.
In the present embodiment, the controlled terminals QF1-KZ of the three-phase main switch QF1 can be electrically connected with the main controller in the inverter circuit in the above embodiments to be in a closed or open state according to the main switch signal output by the main controller. The three-phase opening and closing switch QS1 is controlled by a user manually, when the frequency converter needs to be started, the three-phase opening and closing switch QS1 can be controlled manually to be in a closed state, at the moment, the alternating current output by the first cross current end can enter the three-phase rectification circuit 20 through the three-phase opening and closing switch QS1 and the first resistor R1, and similarly, the alternating current output by the second phase alternating current end and the alternating current output by the third phase alternating current end can enter the three-phase rectification circuit 20 through the three-phase opening and closing switch QS1, the second resistor R2 or the third resistor R3 respectively, so that the three-phase rectification circuit 20 rectifies the three-phase alternating current output by the three-phase alternating current end and outputs direct current voltage to the direct current bus 30, and the voltage value of the direct current bus 30 is improved. It is understood that the three-phase closing and opening switches in the plurality of three-phase incoming line branches 10 may be set to be controlled in a linkage manner or controlled independently.
Further, the reliability and stability of the operation of the pre-charge switch circuit 12 can be improved by using a manual mechanical three-phase on-off switch.
In addition, in another embodiment, referring to fig. 3, the pre-charging switch loop 12 further includes a three-phase auxiliary switch KM1, the three-phase auxiliary switch KM1 has a controlled terminal, a first input terminal, a second input terminal, a third input terminal, a first output terminal, a second output terminal and a third output terminal, the first input terminal of the three-phase auxiliary switch KM1 is connected to the first output terminal of the three-phase switching-on/off switch, the second input terminal of the three-phase auxiliary switch KM1 is connected to the second output terminal of the three-phase switching-on/off switch, the third input terminal of the three-phase auxiliary switch KM1 is connected to the third output terminal of the three-phase switching-on/off switch, the first output terminal of the three-phase auxiliary switch KM1 is connected to the first terminal of the first resistor, the second output terminal of the three-phase auxiliary switch KM1 is connected to the first terminal of the second resistor, and the third output terminal of the three-phase auxiliary switch KM1 is connected to the first terminal of the third resistor;
the controlled end of the three-phase auxiliary switch KM1 is used for accessing an auxiliary switch closing signal or an auxiliary switch opening signal;
the three-phase auxiliary switch KM1 is used for conducting a path between a first input terminal and a first output terminal of the three-phase auxiliary switch KM1, a path between a second input terminal and a second output terminal of the three-phase auxiliary switch KM1 and a path between a third input terminal and a third output terminal of the three-phase auxiliary switch KM1 when receiving an auxiliary switch closing signal;
the three-phase sub-switch KM1 is used to disconnect a path between a first input terminal and a first output terminal of the three-phase sub-switch KM1, a path between a second input terminal and a second output terminal of the three-phase sub-switch KM1, and a path between a third input terminal and a third output terminal of the three-phase sub-switch KM1, when receiving a sub-switch opening signal.
In this embodiment, the three-phase sub switch KM1 may be implemented by a contactor, and the controlled terminal of the three-phase sub switch KM1 may also be electrically connected to the main controller in the above embodiment, so as to be in an open state or a closed state according to a sub switch opening signal or a sub switch closing signal transmitted from the main controller. The frequency conversion circuit can also be provided with a trigger component electrically connected with the main controller, when a user needs to start the frequency converter, the QS1 of the three-phase on-off switch can be manually controlled to be in a closed state, and the trigger component is touched, so that the main controller determines that the current frequency converter needs to be started, at the moment, the main controller can output an auxiliary switch closing signal to a controlled end KM-KZ of a three-phase auxiliary switch KM1 to control the three-phase auxiliary switch KM1 to be in a closed state, at the moment, the pre-charging switch loop 12 is in a closed state, and the voltage of the direct-current bus 30 gradually rises. When the main controller determines that the current main stream bus voltage reaches the pre-charging starting voltage, the main controller outputs an auxiliary switch opening signal to the controlled end KM-KZ of the three-phase auxiliary switch KM1, and outputs a corresponding main switch signal to the controlled end QF1-KZ of the three-phase main switch QF1, so that the three-phase main switch QF1 is in a closed state, the three-phase auxiliary switch KM1 is in an open state, the three-phase main switch circuit 11 is controlled to be in a closed state, and the pre-charging switch circuit 12 is controlled to be in an open state. Therefore, the situation that a user forgets to manually restore the three-phase opening and closing switch QS1 to the opening state again when the pre-charging is finished can be prevented, the stable work of the frequency converter after the frequency converter is started is guaranteed, and the working reliability of the frequency converter is improved.
It can be understood that the controlled ends of the three-phase secondary switches in the three-phase incoming line branches 10 may be electrically connected to the same pin of the main controller, so that the main controller controls all the three-phase secondary switches simultaneously, or electrically connected to the pins of the main controller one by one, so that the main controller controls all the three-phase secondary switches respectively.
Referring to fig. 1 and 4, the utility model also provides a frequency conversion circuit, include:
a plurality of three-phase rectification circuits 20;
a DC bus 30;
a plurality of inverter circuits 40; and (c) a second step of,
a frequency converter three-phase incoming line circuit as described in any of the above;
the output ends of the three-phase rectification circuits 20 and the input ends of the inverter circuits 40 are electrically connected to the dc bus 30, respectively.
In this embodiment, the three-phase rectification circuit 20 may be implemented by a plurality of rectification modules integrated by a switching tube and a rectification controller, and the inverter circuit 40 may be implemented by an inverter module integrated by a switching tube and an inverter control chip. The inverter circuit 40 may be a three-phase inverter circuit or a single-phase inverter circuit 40.
It is worth noting, because the utility model discloses inverter circuit has contained above-mentioned converter three-phase inlet wire circuit's whole embodiments, consequently the utility model discloses inverter circuit has above-mentioned converter three-phase inlet wire circuit's all beneficial effects, and it is no longer repeated here.
It should be understood that during the actual starting process of the frequency converter, when the voltage of the dc bus 30 of the frequency converter rises to the preset starting voltage, the main controller 60 in the frequency converter controls the three-phase main switch circuits 11 in all three-phase incoming branches 10 to be in the closed state. However, in the subsequent use process, although the dc bus 30 is connected to the plurality of inverter circuits 40, the loads at the user end do not need to start as many inverter circuits 40, however, at this time, all three-phase main switch circuits 11 at the incoming line end of the frequency converter are in the closed state, that is, the plurality of rectifier circuits are in the working state, so that the power that can be actually borne by the incoming line end of the frequency converter is far greater than the power that needs to be actually output, thereby causing waste.
In an embodiment of the present invention, referring to fig. 4, the frequency conversion circuit further includes:
the start-stop triggering component 70, the start-stop triggering component 70 is used for outputting a corresponding start signal or stop signal when triggered by a user;
the voltage detection circuit 50 is electrically connected with the direct current bus 30, and the voltage detection circuit 50 is used for detecting the voltage of the direct current bus 30 and outputting a corresponding voltage detection signal;
the main controller 60, the main controller 60 is electrically connected with the start-stop triggering assembly 70, the voltage detection circuit 50 and the plurality of pre-charge switch loops 12 respectively;
the main controller 60 further has a plurality of main switch control pins, which are respectively connected to the controlled terminals of the plurality of three-phase main switch circuits 11;
a main controller 60 for outputting a sub-switch closing signal to the plurality of pre-charge switch circuits 12 when receiving the start signal;
the main controller 60 is further configured to, when it is determined that the voltage of the dc bus 30 reaches the preset starting voltage according to the voltage detection signal, output a corresponding main switching signal to the three-phase main switching circuit 11 corresponding to the starting signal, so that the corresponding three-phase main switching circuit 11 is in a closed state, and output an auxiliary switch opening signal to the plurality of pre-charge switching circuits 12;
the main controller 60 is further configured to, upon receiving the stop signal, output a corresponding main switching signal to the three-phase main switching circuit 11 corresponding to the stop signal, so that the corresponding three-phase main switching circuit 11 is in an open state.
In the present embodiment, the main controller 60 may be implemented by an MCU (microprogrammed control unit), a DSP (Digital Signal processing chip), an FPGA (Field Programmable Gate Array), or the like. The controlled ends KM-KZ of the three-phase auxiliary switches in the plurality of pre-charging switch loops 12 are electrically connected with the same pin on the main controller 60; the plurality of main switch control pins are respectively connected to the controlled terminals of the plurality of three-phase main switch circuits 11, that is, the plurality of main switch control pins are respectively connected to the controlled terminals of the plurality of three-phase main switches.
In this embodiment, the start-stop triggering component 70 is optionally a key array, and the key array is configured to output a corresponding start signal or stop signal when triggered by a user. The key array may be formed by a plurality of self-locking keys, one end of each self-locking key is grounded, and the other end of each self-locking key is electrically connected to the pull-up circuit and a pin on the main controller 60. When a user presses any self-locking key, the two ends of the self-locking key can be conducted to the main controller 60 through low level signals, when the user presses the key which is in a self-locking state again, the key can rebound and the electric connection paths at the two ends of the key are disconnected, at the moment, the voltage of the end, connected with the upper pin of the main controller 60, of the self-locking key can be pulled up by the pull-up circuit to output high level signals, the low level signals can be starting signals, and the high level signals can be stopping signals. In practical application, different self-locking keys in the key array can represent different three-phase main switch circuits 11, for example, the current three-phase main switch circuit is divided into two, the key array is provided with 3 self-locking keys a \ B \ C, and when a user presses the self-locking key a, the main controller can control the three-phase main switch circuit a to be in a closed state when the voltage detection signal determines that the voltage of the direct-current bus reaches a preset starting voltage.
Optionally, start-stop triggering component 70 is a touch screen for outputting a corresponding start signal or stop signal when triggered by a user. The user can touch different touch functional areas on the touch screen, so that the touch screen outputs a corresponding start signal or stop signal to the main controller 60, so that the main controller 60 outputs a corresponding main switching signal to the three-phase main switching circuit 11 corresponding to the start signal when determining that the voltage of the dc bus 30 reaches a preset start voltage according to the voltage detection signal, so that the corresponding three-phase main switching circuit 11 is in a closed state, or outputs a corresponding main switching signal to the three-phase main switching circuit 11 corresponding to the stop signal, so that the corresponding three-phase main switching circuit 11 is in an open state.
In the present embodiment, the voltage detection circuit 50 may be implemented by using a hall voltage detection sensor, a resistance division detection circuit, a voltage detection chip, and other circuits.
Specifically, referring to fig. 4, the number of the three-phase incoming line branches 10 is two (three-phase incoming line branch 10A and three-phase incoming line branch 10B), and the main switch signal output by the main controller 60 controls the three-phase main switch to be closed when the main switch signal is a high level signal and controls the three-phase main switch to be opened when the main switch signal is a low level signal.
If the user only needs to control the three-phase incoming line branch 10A to be closed, and after the user manually controls the three-phase opening and closing switch QS1 to be in a closed state, the start-stop triggering assembly 70 may be triggered, so that the start-stop triggering assembly 70 outputs a corresponding starting signal. After receiving the start signal, the main controller 60 determines that the sub-switch closing signal is output to the controlled terminals KM-KZ of the plurality of pre-charging switch circuits 12 to close all the three-phase sub-switches as long as the three-phase incoming line branch 10A is controlled to be closed. At this time, only the three-phase on-off switch QS1 and the three-phase auxiliary switch KM1 are in a closed state, that is, only the three-phase rectification circuit 20 electrically connected to the three-phase incoming line branch 10A starts to operate, so that the voltage of the dc bus 30 rises. When the main controller 60 determines that the voltage of the dc bus 30 reaches the preset starting voltage according to the voltage detection signal output by the voltage detection circuit 50, it will output the sub-switch opening signal to the controlled terminals KM-KZ of the plurality of pre-charge switch circuits 12 to open all the three-phase sub-switches, and output a high level to the controlled terminals QF1-KZ of the three-phase main switch QF1 through only one pin, so that the three-phase main switch QF1 in the three-phase incoming line branch 10A is in a closed state. Therefore, in practical application, a user can select the number of the three-phase main switch circuits 11 which need to be in a closed state according to actual power requirements, so that unnecessary energy consumption of the frequency converter in the working process is avoided, and the energy conservation of the frequency converter is improved.
The utility model also provides a converter, including above-mentioned arbitrary inverter circuit.
It is worth noting, because the utility model discloses the converter has contained above-mentioned inverter circuit's whole embodiments, consequently the utility model discloses the converter has above-mentioned inverter circuit's all beneficial effects, and it is no longer repeated here.
The above is only the preferred embodiment of the present invention, not limiting the patent scope of the present invention, all of which are under the concept of the present invention, the equivalent structure transformation made by the contents of the specification and the drawings is utilized, or the direct or indirect application is included in other related technical fields in the patent protection scope of the present invention.
Claims (10)
1. The utility model provides a converter three-phase incoming line circuit, is applied to the converter, the converter includes frequency conversion circuit, frequency conversion circuit includes a plurality of three-phase rectifier circuit, direct current bus and a plurality of inverter circuit, and is a plurality of three-phase rectifier circuit's output, a plurality of inverter circuit's input respectively with the direct current bus electricity is connected, its characterized in that, converter three-phase incoming line circuit includes:
the input ends of the three-phase incoming line branches are respectively connected with a three-phase alternating current end, and the output ends of the three-phase incoming line branches are connected with the input ends of the three-phase rectifying circuits in a one-to-one correspondence manner;
each said three phase incoming line leg comprising:
the input end of the three-phase main switch circuit is connected with the three-phase alternating current end, the output end of the three-phase main switch circuit is connected with the input end of the three-phase rectifying circuit, and the controlled end of the three-phase main switch circuit is used for accessing a main switch signal; the three-phase main switching circuit is used for being in an open state or a closed state according to the main switching signal;
a first end of the pre-charging switch loop is connected with the three-phase alternating current end, and a second end of the pre-charging switch loop is connected with the input end of the three-phase rectifying circuit; and the pre-charging switch loop is used for conducting a path between the three-phase alternating current terminal and the input terminal of the three-phase rectification circuit when the pre-charging switch loop is in a closed state, so that the voltage of the direct current bus is increased.
2. The frequency converter three-phase incoming circuit of claim 1, wherein said three-phase rectifier circuit input terminals include a first input terminal, a second input terminal, and a third input terminal; the three-phase alternating current end comprises a first cross current end, a second cross current end and a third cross current end; the three-phase main switch circuit comprises a three-phase main switch, and the three-phase main switch is provided with a first input end, a second input end, a third input end, a first output end, a second output end and a third output end;
the first input end of the three-phase main switch is connected with the first cross current end, and the first output end of the three-phase main switch is connected with the first input end of the three-phase rectifying circuit;
a second input end of the three-phase main switch is connected with the second phase alternating current end, and a second output end of the three-phase main switch is connected with a second input end of the three-phase rectifying circuit;
the first input end of the three-phase main switch is connected with the third alternating-current end, and the third output end of the three-phase main switch is connected with the third input end of the three-phase rectifying circuit;
the controlled end of the three-phase main switch is used for accessing a main switch signal and is in a closed state according to the main switch signal so as to conduct a path between a first input end and a first output end of the three-phase main switch, a path between a second input end and a second output end of the three-phase main switch and a path between a third input end and a third output end of the three-phase main switch; alternatively, the first and second electrodes may be,
and the three-phase main switch is in an open state to disconnect a path between a first input end and a first output end of the three-phase main switch, a path between a second input end and a second output end of the three-phase main switch and a path between a third input end and a third output end of the three-phase main switch.
3. The inverter three-phase incoming circuit of claim 2, wherein the pre-charge switch circuit comprises: the three-phase switching-on and switching-off switch, the first resistor, the second resistor and the third resistor;
the three-phase opening and closing switch is provided with a first input end, a second input end, a third input end, a first output end, a second output end and a third output end, the first input end of the three-phase opening and closing switch is connected with the first cross current end, the second input end of the three-phase opening and closing switch is connected with the second phase alternating current end, the third input end of the three-phase opening and closing switch is connected with the third phase alternating current end, the first output end of the three-phase opening and closing switch is connected with the first input end of the three-phase rectifying circuit through the first resistor, the second output end of the three-phase opening and closing switch is connected with the second input end of the three-phase rectifying circuit through the second resistor, and the third output end of the three-phase opening and closing switch is connected with the second input end of the three-phase rectifying circuit through the third resistor;
and the three-phase switching-on and switching-off switch is used for switching on or switching off a path between the first cross current terminal and the first input terminal of the three-phase rectification circuit, switching on or switching off a path between the second cross current terminal and the second input terminal of the three-phase rectification circuit and switching on or switching off a path between the third cross current terminal and the third input terminal of the three-phase rectification circuit when triggered by a user.
4. The inverter three-phase incoming circuit of claim 3, wherein the pre-charge switch circuit further comprises three-phase auxiliary switches, the three-phase auxiliary switch is provided with a controlled end, a first input end, a second input end, a third input end, a first output end, a second output end and a third output end, the first input end of the three-phase auxiliary switch is connected with the first output end of the three-phase opening and closing switch, the second input end of the three-phase auxiliary switch is connected with the second output end of the three-phase opening and closing switch, the third input end of the three-phase auxiliary switch is connected with the third output end of the three-phase opening and closing switch, a first output end of the three-phase auxiliary switch is connected with a first end of the first resistor, a second output end of the three-phase auxiliary switch is connected with a first end of the second resistor, and a third output end of the three-phase auxiliary switch is connected with a first end of the third resistor;
the controlled end of the three-phase auxiliary switch is used for accessing an auxiliary switch closing signal or an auxiliary switch opening signal;
the three-phase auxiliary switch is used for conducting a path between a first input end and a first output end of the three-phase auxiliary switch, a path between a second input end and a second output end of the three-phase auxiliary switch and a path between a third input end and a third output end of the three-phase auxiliary switch when receiving the auxiliary switch closing signal;
the three-phase auxiliary switch is used for disconnecting a path between a first input end and a first output end of the three-phase auxiliary switch, a path between a second input end and a second output end of the three-phase auxiliary switch and a path between a third input end and a third output end of the three-phase auxiliary switch when the auxiliary switch opening signal is received.
5. The frequency converter three-phase incoming circuit of claim 4, characterized in that said three-phase secondary switch is a contactor.
6. A frequency conversion circuit, comprising:
a plurality of three-phase rectification circuits;
a direct current bus;
a plurality of inverter circuits; and (c) a second step of,
the frequency converter three-phase incoming line circuit of any one of claims 1 to 5;
the output ends of the three-phase rectification circuits and the input ends of the inverter circuits are respectively electrically connected with the direct current bus.
7. The frequency conversion circuit of claim 6, further comprising:
the starting and stopping triggering component is used for outputting a corresponding starting signal or a corresponding stopping signal when triggered by a user;
the voltage detection circuit is electrically connected with the direct current bus and is used for detecting the voltage of the direct current bus and outputting a corresponding voltage detection signal;
the main controller is respectively and electrically connected with the start-stop trigger assembly, the voltage detection circuit and the plurality of pre-charging switch loops;
the main controller is also provided with a plurality of main switch control pins which are respectively connected with the controlled ends of the three-phase main switch circuits;
the main controller is used for outputting an auxiliary switch closing signal to the plurality of pre-charging switch loops when receiving the starting signal;
the main controller is further configured to output a corresponding main switch signal to the three-phase main switch circuit corresponding to the start signal when it is determined that the voltage of the dc bus reaches a preset start voltage according to the voltage detection signal, so that the corresponding three-phase main switch circuit is in a closed state, and output an auxiliary switch opening signal to the plurality of pre-charge switch circuits;
and the main controller is further used for outputting a corresponding main switching signal to the three-phase main switching circuit corresponding to the stop signal when receiving the stop signal, so that the corresponding three-phase main switching circuit is in an open state.
8. The frequency conversion circuit according to claim 7, wherein the start-stop trigger component is a key array, and the key array is configured to output the corresponding start signal or the corresponding stop signal when triggered by the user.
9. The frequency conversion circuit of claim 7, wherein the start-stop trigger component is a touchable screen for outputting the corresponding start signal or stop signal when triggered by a user.
10. A frequency converter comprising a frequency conversion circuit according to any of claims 6-9.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202221563102.0U CN217282722U (en) | 2022-06-22 | 2022-06-22 | Three-phase incoming line circuit of frequency converter, frequency conversion circuit and frequency converter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202221563102.0U CN217282722U (en) | 2022-06-22 | 2022-06-22 | Three-phase incoming line circuit of frequency converter, frequency conversion circuit and frequency converter |
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| Publication Number | Publication Date |
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| CN217282722U true CN217282722U (en) | 2022-08-23 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN202221563102.0U Active CN217282722U (en) | 2022-06-22 | 2022-06-22 | Three-phase incoming line circuit of frequency converter, frequency conversion circuit and frequency converter |
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| Country | Link |
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| CN (1) | CN217282722U (en) |
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