CN217882964U

CN217882964U - Frequency conversion control system

Info

Publication number: CN217882964U
Application number: CN202221767320.6U
Authority: CN
Inventors: 李立平
Original assignee: Beijing Hekang Xinneng Frequency Conversion Technology Co ltd
Current assignee: Beijing Hekang Xinneng Frequency Conversion Technology Co ltd
Priority date: 2022-07-11
Filing date: 2022-07-11
Publication date: 2022-11-22
Anticipated expiration: 2032-07-11

Abstract

The utility model provides a frequency conversion control system, wherein, frequency conversion control system includes: the frequency converter comprises a frequency converter assembly, a first switch, a first contactor, a second contactor, a third contactor, a second switch, a third switch, a fourth contactor, a fifth contactor, a sixth contactor and a fourth switch. The utility model provides a frequency conversion control system utilizes first switch, first contactor, second switch, second contactor and third contactor to and third switch, fourth contactor, fourth switch, fifth contactor and sixth contactor, realizes the control to the different operating modes of first motor and second motor, need not to adopt PLC control, has reduced because of PLC's stability problem, the unstable problem of motor control that leads to, has promoted frequency conversion control system's stability.

Description

Frequency conversion control system

Technical Field

The utility model relates to a frequency conversion control system technical field particularly relates to a frequency conversion control system.

Background

In the related art, a dual-power-supply one-to-two automatic switching cabinet for a high-voltage frequency converter generally needs to add a Programmable Logic Controller (PLC) to realize control of each path, and the stability of the PLC is not controllable, which easily causes a problem that a motor cannot operate according to a predetermined mode.

SUMMERY OF THE UTILITY MODEL

The utility model discloses aim at solving or improving at least and adopt PLC control among the prior art one drags two converter control system, and one of the unstable technical problem of system that leads to.

Therefore, the utility model discloses an aspect provides a frequency conversion control system.

In view of this, according to the utility model discloses an aspect, the utility model provides a frequency conversion control system, include: a frequency converter assembly; the first system comprises a first circuit and a second circuit, the first circuit comprises a first switch and a first contactor which are connected in series, and the second circuit comprises a second contactor and a third contactor and a second switch which are connected in series; the second system comprises a third circuit and a fourth circuit, the third circuit comprises a third switch and a fourth contactor which are connected in series, and the fourth circuit comprises a fifth contactor, a sixth contactor and a fourth switch which are connected in series; the incoming line end of the first switch and the incoming line end of the second contactor form the incoming line end of the first system, the outgoing line end of the second contactor and the outgoing line end of the third contactor form the outgoing line end of the first system, the incoming line end of the third switch and the incoming line end of the fifth contactor form the incoming line end of the second system, and the outgoing line end of the sixth contactor and the outgoing line end of the fifth contactor form the outgoing line end of the second system.

The utility model provides a frequency conversion control system, including converter subassembly, first system and second system, the inlet wire end of first system and the inlet wire end of second system are used for a plurality of different power electricity respectively and are connected, and the leading-out terminal of first system and the leading-out terminal of second system are used for connecting different motors respectively. Specifically, the wire inlet end of the first system may be electrically connected to a first power source, the wire inlet end of the second system may be electrically connected to a second power source, the wire outlet end of the first system may be electrically connected to a first motor, and the wire outlet end of the second system may be electrically connected to a second motor.

And the frequency converter assembly is connected into the first system and the second system, so that the frequency conversion control of the two motors is realized through one frequency converter assembly.

The first system comprises a first circuit, the first circuit comprises a first switch and a first contactor, the first switch is connected with the first contactor in series, the first system further comprises a second circuit, the second circuit comprises a second contactor, a third contactor and a second switch, the third contactor is connected with the second switch in series, wherein the wire inlet end of the first switch and the wire inlet end of the second contactor form the wire inlet end of the first system, namely, the wire inlet end of the first switch and the wire inlet end of the second contactor are used for being electrically connected with a first power supply, the wire outlet end of the second switch and the wire outlet end of the first contactor are respectively connected to the frequency converter assembly, the wire outlet end of the second contactor and the wire outlet end of the third contactor form the wire outlet end of the first system, namely, the wire outlet end of the second contactor and the wire outlet end of the third contactor are used for being connected with the first motor.

The second system comprises a third circuit, the third circuit comprises a third switch and a fourth contactor, the third switch and the fourth contactor are connected in series, the second system further comprises a fourth circuit, the fourth circuit comprises a fifth contactor, a sixth contactor and a fourth contactor, the sixth contactor and the fourth contactor are connected in series, wherein the wire inlet end of the third switch and the wire inlet end of the fifth contactor form the wire inlet end of the second system, namely, the wire inlet end of the third switch and the wire inlet end of the fifth contactor are used for being electrically connected with a second power supply, the wire outlet end of the fourth switch and the wire outlet end of the fourth contactor are respectively connected to the frequency converter assembly, the wire outlet end of the fifth contactor and the wire outlet end of the sixth contactor form the wire outlet end of the second system, namely, the wire outlet end of the fifth contactor and the wire outlet end of the sixth contactor are used for being connected with a second motor.

Thereby utilize first switch, first contactor, second switch, second contactor and third contactor to and third switch, fourth contactor, fourth switch, fifth contactor and sixth contactor, realize the control to the different operating modes of first motor and second motor, need not to adopt PLC control, reduced because of PLC's stability problem, the unstable problem of motor control that leads to has promoted frequency conversion control system's stability.

Additionally, according to the utility model provides a frequency conversion control system among the above-mentioned technical scheme can also have following additional technical characteristics:

on the basis of the technical scheme, the second contactor and the third contactor are mechanically interlocked and electrically interlocked; the fifth and sixth contactors are mechanically interlocked and electrically interlocked.

In this technical scheme, second contactor and third contactor mechanical interlocking to, electric interlocking, and fifth contactor and sixth contactor mechanical interlocking, and, electric interlocking, and then for frequency conversion control system provides dual fail-safe, the control of power frequency and frequency conversion can only have a work, promotes frequency conversion control system's security and stability.

Specifically, if the frequency conversion control system outputs to the outside through the leading-out terminal of the second contactor, the frequency conversion control system enters into a first power frequency output mode, and the down converter component cannot supply power to the outside in this situation, so that the third contactor and the second contactor are mechanically interlocked and electrically interlocked, and the third contactor does not supply power to the outside.

If the variable frequency control system outputs to the outside through the wire outlet end of the third contactor, the variable frequency control system enters a first variable frequency output mode, and in this case, the second contactor cannot supply power to the outside, so that the third contactor and the second contactor are mechanically interlocked and electrically interlocked, and the second contactor does not supply power to the outside.

If the frequency conversion control system outputs to the outside through the wire outlet end of the fifth contactor, the frequency conversion control system enters a second power frequency output mode, and the down converter component cannot supply power to the outside under the condition, so that the sixth contactor is mechanically interlocked and electrically interlocked with the fifth contactor, and the sixth contactor does not supply power to the outside.

If the variable frequency control system outputs to the outside through the wire outlet end of the sixth contactor, the variable frequency control system enters a second variable frequency output mode, in this case, the fifth contactor cannot supply power to the outside, therefore, the sixth contactor and the fifth contactor are mechanically interlocked and electrically interlocked, and the fifth contactor does not supply power to the outside.

On the basis of any one of the above technical solutions, further, the third contactor and the sixth contactor are electrically interlocked.

In this technical scheme, third contactor and sixth contactor electric interlocking because first system and second system share the converter subassembly, consequently, the converter subassembly can't realize two sets of clear control logics simultaneously, and consequently, third contactor and sixth contactor electric interlocking promote frequency conversion control system's security and stability.

On the basis of any one of the above technical solutions, further, the method further includes: the frequency converter assembly comprises a high-voltage switch-on allowable extension relay; the variable-frequency control system comprises a first variable-frequency switching-on control loop and a second variable-frequency switching-on control loop, wherein in the first variable-frequency switching-on control loop, a normally-off point of a second input extension relay, a normally-off point of a second contactor, a normally-closed point parallel connection node of a first contactor and a normally-closed point parallel connection node of a third contactor, a normally-open point of a first switch, a normally-open point of a second switch and a normally-open point of a high-voltage switching-on allowable extension relay are connected in series; in the second variable-frequency switching-on control loop, a normally-off point of the first input extension relay, a normally-off point of the fifth contactor, a normally-closed point parallel node of the fourth contactor and the sixth contactor, a normally-on point of the third switch, a normally-on point of the fourth switch and a normally-on point of the high-voltage switching-on permission extension relay are connected in series.

In the technical scheme, the frequency conversion control system further comprises a first input extension relay and a second input extension relay, and the frequency converter assembly comprises a high-voltage switching-on allowable extension relay.

And the variable-frequency control system comprises two variable-frequency closing control loops, namely a first variable-frequency closing control loop and a second variable-frequency closing control loop.

The first variable-frequency switching-on control loop comprises a normally-closed point of a second switching-on extension relay, a normally-closed point of a second contactor, normally-closed point parallel nodes of a first contactor and a third contactor, a normally-open point of a first switch, a normally-open point of a second switch and a normally-open point of a high-voltage switching-on permission extension relay, wherein the normally-closed point of the second switching-on extension relay, the normally-closed point of the second contactor, the normally-closed point of the first contactor and the normally-open point of the third contactor are connected in series.

The second variable-frequency switching-on control loop comprises a normally-closed point of a first switching-on extension relay, a normally-closed point of a fifth contactor, a normally-closed point parallel node of a fourth contactor and a sixth contactor, a normally-open point of a third switch, a normally-open point of a fourth switch and a normally-open point of a high-voltage switching-on permission extension relay, wherein the normally-closed point of the first switching-on extension relay, the normally-closed point of the fifth contactor, the normally-closed point of the fourth contactor and the normally-open point of the high-voltage switching-on permission extension relay are connected in series.

And then can realize the frequency conversion output to the frequency conversion output of first system and second system through first frequency conversion combined floodgate control circuit and second frequency conversion combined floodgate control circuit to, both can not go on simultaneously, promote frequency conversion control system's stability and security.

On the basis of any one of the above technical solutions, further, the frequency conversion control system further includes: the automatic switching device comprises a first manual variable-frequency switching-on switch, a second manual variable-frequency switching-on switch, a first automatic variable-frequency switching-on switch and a second automatic variable-frequency switching-on switch; in the first variable-frequency switching-on control loop, a normally-open point of the first manual variable-frequency switching-on switch and a normally-open point of the first automatic variable-frequency switching-on switch are connected in parallel with a normally-closed point of the second input extended relay; in the second variable-frequency switching-on control loop, a normally-on point of the second manual variable-frequency switching-on switch and a normally-on point of the second automatic variable-frequency switching-on switch are connected in parallel with a normally-off point of the first input extension relay.

In the technical scheme, the variable frequency control system further comprises a first manual variable frequency closing switch, a second manual variable frequency closing switch, a first automatic variable frequency closing switch and a second automatic variable frequency closing switch.

Wherein, first frequency conversion combined floodgate control circuit includes that the second of series connection drops into the normally closed point of extension relay, the normally closed point of second contactor, the normally closed point parallel node of first contactor and third contactor, the normally open point of first switch, the normally open point of second switch and the normally open point that high-pressure combined floodgate allowed extension relay, and, the normally open point of first manual frequency conversion combined floodgate switch and the parallel node of the normally open point of first automatic frequency conversion combined floodgate switch, and the normally closed point of second input extension relay, the normally closed point of second contactor, the normally closed point parallel node of first contactor and third contactor, the normally open point of first switch, the normally open point of second switch and the normally open point that high-pressure combined floodgate allowed extension relay are in series connection together.

The second variable-frequency switching-on control loop comprises a normally-closed point of a first input extension relay, a normally-closed point of a fifth contactor, normally-closed point parallel nodes of a fourth contactor and a sixth contactor, a normally-open point of a third switch, a normally-open point of the fourth switch and a normally-open point of a high-voltage switching-on allowable extension relay, and the normally-open point of the first manual variable-frequency switching-on switch and the normally-open point of the first automatic variable-frequency switching-on switch are connected in parallel, and the normally-closed point of the second input extension relay, the normally-closed point of the second contactor, the normally-closed point parallel nodes of the first contactor and the third contactor, the normally-open point of the first switch, the normally-open point of the second switch and the normally-open point of the high-voltage switching-on allowable extension relay are connected in series.

On the basis of any one of the above technical solutions, further, the frequency conversion control system further includes: the first manual power frequency switch-on switch, the second manual power frequency switch-on switch, the first automatic power frequency switch-on switch and the second automatic power frequency switch-on switch; the frequency conversion control system comprises a first power frequency switching-on control loop and a second power frequency switching-on control loop, wherein in the first power frequency switching-on control loop, a parallel connection node of a normally-open point of a first manual power frequency switching-on switch and a normally-open point of a first automatic power frequency switching-on switch, a normally-closed point of a first contactor, a normally-closed point of a third contactor and a normally-closed point of a second contactor are connected in series; in the second power frequency switching-on control circuit, a parallel node of a normally-on point of the second manual power frequency switching-on switch and a normally-on point of the second automatic power frequency switching-on switch, a normally-off point of the fourth contactor, a normally-off point of the sixth contactor and a normally-off point of the fifth contactor are connected in series.

In this technical solution, the frequency conversion control system further includes: the automatic power frequency switching-on switch comprises a first manual power frequency switching-on switch, a second manual power frequency switching-on switch, a first automatic power frequency switching-on switch and a second automatic power frequency switching-on switch.

And the frequency conversion control system comprises two power frequency closing control loops, namely a first power frequency closing control loop and a second power frequency closing control loop.

The first power frequency switching-on control loop comprises a normally-on point of a first manual power frequency switching-on switch and a parallel node of a normally-on point of a first automatic power frequency switching-on switch which are connected in series, a normally-off point of a first contactor, a normally-off point of a third contactor and a normally-off point of a second contactor.

The second power frequency switching-on control loop comprises a normally-on point of a second manual power frequency switching-on switch and a parallel node of a normally-on point of a second automatic power frequency switching-on switch which are connected in series, a normally-off point of a fourth contactor, a normally-off point of a sixth contactor and a normally-off point of a fifth contactor.

And then through first manual power frequency closing switch, first automatic power frequency closing switch, first contactor, third contactor and second contactor to and manual power frequency closing switch of second, second automatic power frequency closing switch, fourth contactor, sixth contactor and fifth contactor, realize the power frequency output to first system and second system, and, promote frequency conversion control system's stability and security.

On the basis of any one of the above technical solutions, further, the frequency converter assembly further includes: in the second power frequency switching-on control loop, the normally-open point of the fault signal expansion relay, the normally-open point of the second manual power frequency switching-on switch and the normally-open point of the second automatic power frequency switching-on switch are connected in parallel.

In this technical solution, the frequency converter assembly further includes: and the fault signal extension relay is connected into the first power frequency switching-on control loop and the second power frequency switching-on control loop.

The first power frequency switching-on control loop comprises a normally-open point of a first manual power frequency switching-on switch, a normally-open point of a first automatic power frequency switching-on switch, a parallel node of a normally-open point of a fault signal expansion relay, a normally-closed point of a first contactor, a normally-closed point of a third contactor and a normally-closed point of a second contactor, wherein the normally-open point of the first manual power frequency switching-on switch and the normally-open point of the first automatic power frequency switching-on switch are connected in series.

The second power frequency switching-on control loop comprises a normally-open point of a second manual power frequency switching-on switch, a normally-open point of a second automatic power frequency switching-on switch, a parallel node of a normally-open point of a fault signal expansion relay, a normally-closed point of a fourth contactor, a normally-closed point of a sixth contactor and a normally-closed point of a fifth contactor, wherein the normally-open point of the second manual power frequency switching-on switch, the normally-open point of the second automatic power frequency switching-on switch, the parallel node of the normally-open point of the fault signal expansion relay, the normally-closed point of the fourth contactor, the normally-closed point of the sixth contactor and the normally-closed point of the fifth contactor are connected in series.

And, through fault signal extension relay, can be when converter subassembly trouble, automatic switch into power frequency control promotes frequency conversion control system's stability.

On the basis of any one of the above technical solutions, further, the method further includes: the frequency converter component comprises an operation signal expansion relay; the frequency conversion control system comprises a first brake control loop and a second brake control loop, in the first brake control loop, a normally-open point of a first manual brake control switch and a normally-open point of a first automatic brake control switch are connected in parallel to form a fifth circuit, a normally-open point of a first contactor and a normally-open point of a third contactor are connected in parallel to form a sixth circuit, a normally-closed point of an operation signal expansion relay and the sixth circuit are connected in series to form a seventh circuit, the seventh circuit and the normally-open point of a second contactor are connected in parallel to form an eighth circuit, and the fifth circuit and the eighth circuit are connected in series; in the second opening control loop, the normally-open point of the second manual opening control switch and the normally-open point of the second automatic opening control switch are connected in parallel to form a ninth circuit, the normally-open point of the fourth contactor and the normally-open point of the sixth contactor are connected in parallel to form a tenth circuit, the normally-closed point of the operation signal expansion relay and the tenth circuit are connected in series to form an eleventh circuit, the eleventh circuit and the normally-open point of the fifth contactor are connected in parallel to form a twelfth circuit, and the ninth circuit and the twelfth circuit are connected in series.

In this technical solution, the frequency conversion control system further includes: the frequency converter component comprises an operation signal extension relay.

And the frequency conversion control system comprises two brake-separating control loops, namely a first brake-separating control loop and a second brake-separating control loop.

Wherein, first separating brake control circuit is including the fifth circuit and the eighth circuit of series connection, wherein, the fifth circuit includes the normally open point of parallelly connected first manual separating brake control switch to and the normally open point of first automatic separating brake control switch, the eighth circuit includes the normally open point of parallelly connected seventh circuit and second contactor, the seventh circuit includes the normally closed point of the sixth circuit and the running signal extension relay of series connection, the sixth circuit includes the normally open point of first relay and the normally open point of third relay.

The second opening control loop comprises a ninth circuit and a twelfth circuit which are connected in series, wherein the ninth circuit comprises a normally open point of a second manual opening control switch which is connected in parallel, and a normally open point of a second automatic opening control switch, the twelfth circuit comprises a normally open point of an eleventh circuit and a normally open point of a fifth contactor which are connected in parallel, the eleventh circuit comprises a normally closed point of a tenth circuit and an operation signal expansion relay which are connected in series, and the tenth circuit comprises a normally open point of a fourth relay and a normally open point of a sixth relay.

And then through first manual separating brake control switch, second manual separating brake control switch, first automatic separating brake control switch and second automatic separating brake control switch, running signal extension relay and first contactor, second contactor, third contactor, fourth contactor, fifth contactor and sixth contactor, realize to first frequency conversion combined floodgate control circuit control, second frequency conversion combined floodgate control circuit control, the same separating brake control of first power frequency combined floodgate control circuit control and second power frequency combined floodgate control circuit control for the line of frequency conversion control system is more succinct.

On the basis of any one of the above technical solutions, further, the frequency converter assembly includes: the fault signal extension relay is connected in parallel with a normally open point of the first manual brake-separating control switch and a normally open point of the first automatic brake-separating control switch in the first brake-separating control loop; in the second brake-separating control loop, the normally-open point of the fault signal expansion relay, the normally-open point of the second manual brake-separating control switch and the normally-open point of the second automatic brake-separating control switch are connected in parallel.

In the technical scheme, the frequency converter assembly further comprises a fault signal extension relay, and the fault signal extension relay is connected into the first switching control loop and the second switching control loop.

Wherein, first separating brake control circuit is including the fifth circuit and the eighth circuit of series connection, wherein, the fifth circuit includes parallelly connected first manual separating brake control switch's normal open point, the normal open point of first automatic separating brake control switch and fault signal extension relay's normal open point, the eighth circuit includes the normal open point of parallelly connected seventh circuit and second contactor, the seventh circuit includes the normal close point of the sixth circuit and the operation signal extension relay of series connection, the sixth circuit includes the normal open point of first relay and the normal open point of third relay.

The second opening control loop comprises a ninth circuit and a twelfth circuit which are connected in series, wherein the ninth circuit comprises a normally-open point of a second manual opening control switch, a normally-open point of a second automatic opening control switch and a normally-open point of a fault signal extension relay which are connected in parallel, the twelfth circuit comprises a normally-open point of an eleventh circuit and a normally-open point of a fifth contactor which are connected in parallel, the eleventh circuit comprises a tenth circuit and a normally-closed point of an operation signal extension relay which are connected in series, and the tenth circuit comprises a normally-open point of a fourth relay and a normally-open point of a sixth relay.

Through the setting of fault signal extension relay, and then when the converter trouble, automatic separating brake promotes frequency conversion control system's stability and security.

On the basis of any one of the above technical solutions, further, the frequency conversion control system further includes: the first brake switch is electrically connected with the incoming line end of the first system; the second switch is electrically connected with the incoming line end of the second system.

In this technical solution, the frequency conversion control system further includes: two superior switches, namely a first shunt switch electrically connected with the inlet wire end of the first system and a second shunt switch electrically connected with the inlet wire end of the second system, thereby controlling the inlet electricity of the first system and the second system and improving the safety of the frequency conversion control system.

On the basis of any one of the above technical solutions, further, the method further includes: the first cabinet, at least part of the first system locates at the first cabinet; and at least part of the second system is arranged in the second cabinet.

In this solution, at least part of the first system is arranged in the first cabinet, thereby protecting the first system, and at least part of the second system is arranged in the second cabinet, thereby protecting the second system.

On the basis of any one of the above technical solutions, further, the method further includes: the first cabinet door state expansion relay is used for detecting the opening and closing state of the cabinet door of the first cabinet; the second cabinet door state expansion relay is used for detecting the cabinet door opening and closing state of the second cabinet; the normally open point of the first cabinet door state expansion relay is connected with the normally open point of the second cabinet door state expansion relay in parallel, and is electrically connected with the first shunt switch and the second shunt switch.

In this technical scheme, frequency conversion control system includes first cabinet door state extension relay and second cabinet door state extension relay, and first cabinet door state extension relay can detect the on-off state of the cabinet door of first cabinet, and second cabinet door state extension relay can detect the on-off state of the cabinet door of second cabinet to be suitable for the judgement to the state of the cabinet door of first cabinet and second cabinet.

And, the normal open point of first cabinet door state extension relay and the normal open point of second cabinet door state extension relay are parallelly connected, thereby be convenient for to higher level's switch, also be exactly the state of first cabinet and second cabinet of first separating brake switch and second separating brake switch feedback, and then can be when the cabinet door of first cabinet is in the state of opening, cut off higher level's switch, also be exactly first separating brake switch, thereby promote frequency conversion control system's security, and likewise, when the cabinet door of second cabinet is in the state of opening, cut off higher level's switch also is exactly the second separating brake switch, thereby promote frequency conversion control system's security.

On the basis of any one of the above technical solutions, further, the first disconnecting switch is a first circuit breaker; the second switch is a second breaker.

In this technical scheme, first separating brake switch is first circuit breaker to can pass through the switching on or open circuit of first separating brake switch, realize the control whether advance electric to first system, likewise, the second separating brake switch is the second circuit breaker, thereby can pass through the switching on or open circuit of second separating brake switch, realize the control whether advance electric to the second system.

On the basis of any one of the above technical solutions, further, the first switch is a first isolating switch; the second switch is a second isolating switch; the third switch is a third isolating switch; the fourth switch is a fourth isolating switch.

In the technical scheme, the first switch adopts a first isolating switch, the second switch adopts a second isolating switch, the third switch adopts a third isolating switch, and the fourth switch adopts a fourth isolating switch.

Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 is a schematic connection diagram of a frequency conversion control system according to an embodiment of the present invention;

fig. 2 shows a schematic connection relationship diagram of a first variable-frequency switching-on control loop in a variable-frequency control system according to an embodiment of the present invention;

fig. 3 is a schematic diagram illustrating a connection relationship between a second variable-frequency switching-on control loop in the variable-frequency control system according to an embodiment of the present invention;

fig. 4 shows a schematic diagram of a connection relationship of a first power frequency closing control loop in the variable frequency control system provided by an embodiment of the present invention;

fig. 5 shows a schematic diagram of a connection relationship of a second power frequency closing control loop in the variable frequency control system provided by an embodiment of the present invention;

fig. 6 is a schematic diagram illustrating a connection relationship between first switching control loops in a variable frequency control system according to an embodiment of the present invention;

fig. 7 is a schematic diagram illustrating a connection relationship between second shunt control loops in the variable frequency control system according to an embodiment of the present invention;

fig. 8 shows a schematic connection diagram of a cabinet door state detection circuit of a first cabinet in a frequency conversion control system according to an embodiment of the present invention;

fig. 9 is a schematic diagram illustrating a connection relationship of a cabinet door state detection circuit of a second cabinet in the frequency conversion control system according to an embodiment of the present invention;

fig. 10 is a schematic diagram illustrating a connection relationship between a first cabinet door state expansion relay and a second cabinet door state expansion relay in the variable frequency control system according to an embodiment of the present invention;

fig. 11 is a schematic diagram illustrating a connection relationship between a frequency converter and a fault signal extension relay in the frequency conversion control system according to an embodiment of the present invention;

fig. 12 is a schematic diagram illustrating a connection relationship between a frequency converter and an operation signal extension relay in the frequency conversion control system according to an embodiment of the present invention;

fig. 13 is a schematic diagram illustrating a connection relationship between a first contactor, a third contactor, and a first input extension relay in a variable frequency control system according to an embodiment of the present invention;

fig. 14 is a schematic diagram illustrating a connection relationship between a fourth contactor, a sixth contactor, and a second input extension relay in the variable frequency control system according to an embodiment of the present invention;

fig. 15 is a schematic diagram illustrating a connection relationship between a frequency converter and a high-voltage switching-on allowable extension relay in the frequency conversion control system according to an embodiment of the present invention;

fig. 16 shows a schematic connection diagram of the variable frequency control system, the first motor, and the second motor according to an embodiment of the present invention.

Wherein, the correspondence between the reference numbers and the part names in fig. 1 to 16 is:

100 variable frequency control system, 110 variable frequency drive assembly, 112 variable frequency drive, 114 first input extension relay, 116 second input extension relay, 118 high voltage closing enable extension relay, 120 run signal extension relay, 122 fault signal extension relay, 130 first system, 132 first circuit, 134 second circuit, 136 first switch, 138 first contactor, 140 second switch, 142 second contactor, 144 third contactor, 150 second system, 152 third circuit, 154 fourth circuit, 156 third switch, 158 fourth contactor, 160 fifth contactor, 162 fourth switch, 164 sixth contactor, 170 first variable frequency closing control loop, 172 first manual variable frequency closing switch, 174 first automatic variable frequency closing switch, 180 second variable frequency closing control loop, 182 second manual variable frequency closing switch, 184 second automatic variable frequency closing switch, 190 first closing control loop, 192 first manual power frequency closing switch, 194 first automatic power frequency closing switch, 200 second power frequency closing control loop, 202 second manual power frequency closing switch, 204 second automatic power frequency closing switch, 210 first switching control loop, 212 first manual switching control switch, 214 first automatic switching control switch, 220 second switching control loop, 222 second manual switching control switch, 224 second automatic switching control switch, 230 first switching switch, 240 second switching switch, 250 first cabinet, 260 second cabinet, 270 third cabinet, 280 fourth cabinet, 290 first cabinet door state expansion relay, 300 second cabinet door state expansion relay, 310 first stroke switch, 320 second stroke switch, 330 third stroke switch, 340 fourth stroke switch, 352 fifth circuit, 354 sixth circuit, 358 seventh circuit, 360 eighth circuit, 362 ninth circuit, 364 tenth circuit, 366 eleventh circuit, 368 twelfth circuit, 410 first motor, 420 second motor.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention more clearly understood, the present invention will be described in further detail with reference to the accompanying drawings and detailed description. It should be noted that the embodiments and features of the embodiments of the present application may be combined with each other without conflict.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, the present invention may be practiced in other ways than those specifically described herein, and therefore the scope of the present invention is not limited by the specific embodiments disclosed below.

A variable frequency control system 100 provided in accordance with some embodiments of the present invention is described below with reference to fig. 1-16.

As shown in fig. 1, the present invention provides a frequency conversion control system 100 for frequency conversion control of one driving two, wherein, the frequency conversion control system 100 includes a frequency converter assembly 110, a first system 130 and a second system 150, the frequency converter assembly 110 is connected to the first system 130 and the second system 150, and the first system 130 and the second system 150 share the frequency converter assembly 110.

The first system 130 includes a first circuit 132 and a second circuit 134, specifically, the first circuit 132 includes a first switch 136 and a first contactor 138, the first switch 136 and the first contactor 138 are connected in series, the second circuit 134 includes a second contactor 142, a third contactor 144 and a second switch 140, and the third contactor 144 and the second switch 140 are connected in series.

Furthermore, the outlet terminal of the first switch 136 is electrically connected to the inlet terminal of the first contactor 138, the outlet terminal of the first contactor 138 is electrically connected to the frequency converter assembly 110, the inlet terminal of the second switch 140 is electrically connected to the frequency converter assembly 110, the outlet terminal of the second switch 140 is electrically connected to the inlet terminal of the third contactor 144, and the outlet terminal of the second contactor 142 is electrically connected to the outlet terminal of the third contactor 144.

And the line inlet end of the first switch 136 and the line inlet end of the second contactor 142 are connected in parallel to be used as the line inlet end of the first system 130. The outlet of the second contactor 142 and the outlet of the third contactor 144 are connected in parallel as the outlet of the first system 130.

The second system 150 includes a third circuit 152 and a fourth circuit 154, specifically, the third circuit 152 includes a third switch 156 and a fourth contactor 158, the third switch 156 and the fourth contactor 158 are connected in series, the fourth circuit 154 includes a fifth contactor 160, a sixth contactor 164 and a fourth contactor 162, and the sixth contactor 164 and the fourth contactor 162 are connected in series.

Moreover, the outlet terminal of the third switch 156 is electrically connected to the inlet terminal of the fourth contactor 158, the outlet terminal of the fourth contactor 158 is electrically connected to the inverter assembly 110, the inlet terminal of the fourth switch 162 is electrically connected to the inverter assembly 110, the outlet terminal of the fourth switch 162 is electrically connected to the inlet terminal of the sixth contactor 164, and the outlet terminal of the fifth contactor 160 is electrically connected to the outlet terminal of the sixth contactor 164.

And the inlet end of the third switch 156 and the inlet end of the fifth contactor 160 are connected in parallel as the inlet end of the second system 150. The outlet terminal of the fifth contactor 160 and the outlet terminal of the sixth contactor 164 are connected in parallel as the outlet terminal of the second system 150.

The utility model provides a frequency conversion control system 100, including converter subassembly 110, first system 130 and second system 150, the inlet wire end of first system 130 and the inlet wire end of second system 150 are used for a plurality of different power electricity respectively to be connected, and the leading-out terminal of first system 130 and the leading-out terminal of second system 150 are used for connecting different motors respectively. Specifically, the inlet terminal of the first system 130 may be electrically connected to a first power source, the inlet terminal of the second system 150 may be electrically connected to a second power source, the outlet terminal of the first system 130 may be electrically connected to the first motor 410, and the outlet terminal of the second system 150 may be electrically connected to the second motor 420.

And, the frequency converter assembly 110 is connected to the first system 130 and the second system 150, so that the frequency conversion control of the two motors through one frequency converter assembly 110 is realized.

The first system 130 includes a first circuit 132, the first circuit 132 includes a first switch 136 and a first contactor 138, the first switch 136 and the first contactor 138 are connected in series, the first system 130 further includes a second circuit 134, the second circuit 134 includes a second contactor 142, a third contactor 144 and a second switch 140, the third contactor 144 and the second switch 140 are connected in series, wherein an incoming line end of the first switch 136 and an incoming line end of the second contactor 142 constitute an incoming line end of the first system 130, that is, an incoming line end of the first switch 136 and an incoming line end of the second contactor 142 are used for electrically connecting with a first power source, an incoming line end of the second switch 140 and an outgoing line end of the first contactor 138 are respectively connected to the frequency converter assembly 110, and an outgoing line end of the second contactor 142 and an outgoing line end of the third contactor 144 constitute an outgoing line end of the first system 130, that is, an outgoing line end of the second contactor 142 and an outgoing line end of the third contactor 144 are used for connecting with the first motor 410.

The second system 150 includes a third circuit 152, the third circuit 152 includes a third switch 156 and a fourth contactor 158, the third switch 156 and the fourth contactor 158 are connected in series, the second system 150 further includes a fourth circuit 154, the fourth circuit 154 includes a fifth contactor 160, a sixth contactor 164 and a fourth contactor 162, the sixth contactor 164 and the fourth contactor 162 are connected in series, wherein the incoming line terminal of the third switch 156 and the incoming line terminal of the fifth contactor 160 constitute the incoming line terminal of the second system 150, that is, the incoming line terminal of the third switch 156 and the incoming line terminal of the fifth contactor 160 are used for electrically connecting with a second power source, the incoming line terminal of the fourth switch 162 and the outgoing line terminal of the fourth contactor 158 are respectively connected to the inverter assembly 110, and the outgoing line terminal of the fifth contactor 160 and the outgoing line terminal of the sixth contactor 164 constitute the outgoing line terminal of the second system 150, that is, the outgoing line terminal of the fifth contactor 160 and the outgoing line terminal of the sixth contactor 164 are used for connecting with the second motor 420.

Therefore, the first switch 136, the first contactor 138, the second switch 140, the second contactor 142, the third contactor 144, the third switch 156, the fourth contactor 158, the fourth switch 162, the fifth contactor 160 and the sixth contactor 164 are utilized to control different working conditions of the first motor 410 and the second motor 420, PLC control is not needed, the problem of unstable motor control caused by the stability problem of PLC is reduced, and the stability of the variable frequency control system 100 is improved.

Specifically, the frequency converter assembly 110 includes a frequency converter 112.

As shown in fig. 1, as a possible embodiment of the present invention, further, there are a mechanical interlock and an electrical interlock between the second contactor 142 and the third contactor 144; the fifth and

sixth contacts

160 and 164 have a mechanical interlock and an electrical interlock therebetween.

In this embodiment, the second contactor 142 and the third contactor 144 are mechanically interlocked and electrically interlocked, and the fifth contactor 160 and the sixth contactor 164 are mechanically interlocked and electrically interlocked, so as to provide a double insurance for the variable frequency control system 100, and the control of the power frequency and the variable frequency can only be operated by one, thereby improving the safety and stability of the variable frequency control system 100.

Specifically, if the variable frequency control system 100 outputs to the outside through the outlet of the second contactor 142, the variable frequency control system 100 enters the first power frequency output mode, in which case the downconverter assembly 110 cannot supply power to the outside, and therefore, the third contactor 144 and the second contactor 142 are mechanically interlocked and electrically interlocked, and the third contactor 144 does not supply power to the outside.

If the variable frequency control system 100 outputs to the outside through the outlet terminal of the third contactor 144, the variable frequency control system 100 enters the first variable frequency output mode, in which case the second contactor 142 cannot supply power to the outside, and therefore, the third contactor 144 and the second contactor 142 are mechanically interlocked and electrically interlocked, and the second contactor 142 does not supply power to the outside.

If the frequency conversion control system 100 outputs to the outside through the outlet terminal of the fifth contactor 160, the frequency conversion control system 100 enters the second power frequency output mode, and in this case, the down converter assembly 110 cannot supply power to the outside, so that the sixth contactor 164 and the fifth contactor 160 are mechanically interlocked and electrically interlocked, and the sixth contactor 164 does not supply power to the outside.

If the variable frequency control system 100 outputs to the outside through the outlet terminal of the sixth contactor 164, the variable frequency control system 100 enters the second variable frequency output mode, in which case the fifth contactor 160 cannot supply power to the outside, and therefore, the sixth contactor 164 and the fifth contactor 160 are mechanically and electrically interlocked, and the fifth contactor 160 does not supply power to the outside.

That is, the contacts of the second contactor 142 and the third contactor 144 are electrically connected to each other to form an electrical interlock, and the movable cores of the third contactor 144 and the second contactor 142 are also connected by a link mechanism to form a mechanical interlock.

As a possible embodiment of the present invention, further, there is an electrical interlock between the third contactor 144 and the sixth contactor 164.

In this embodiment, the third contactor 144 and the sixth contactor 164 are electrically interlocked, and since the first system 130 and the second system 150 share the frequency converter assembly 110, the frequency converter assembly 110 cannot implement two clear sets of control logics simultaneously, and therefore, the third contactor 144 and the sixth contactor 164 are electrically interlocked, thereby improving the safety and stability of the variable frequency control system 100.

That is, the contacts of the third contactor 144 and the sixth contactor 164 are electrically connected to each other to form an electrical interlock.

As a possible embodiment of the present invention, further, as shown in fig. 13, the variable frequency control system 100 further includes a first input extension relay 114, the first input extension relay 114 is connected in series with the first contactor 138 and the third contactor 144, and then when the first contactor 138, the frequency converter assembly 110 and the third contactor 144 are turned on, the first input extension relay 114 is triggered.

As shown in fig. 14, the inverter control system 100 further includes a second input extension relay 116, and the second input extension relay 116 is connected in series with the fourth contactor 158 and the sixth contactor 164, and when the fourth contactor 158, the inverter assembly 110 and the sixth contactor 164 are turned on, the second input extension relay 116 is activated.

And, as shown in fig. 15, the frequency converter assembly 110 includes a frequency converter 112 and a high-voltage closing allowance extension relay 118, the frequency converter 112 and the high-voltage closing allowance extension relay 118 are electrically connected, and the high-voltage closing allowance signal of the frequency converter 112 triggers the high-voltage closing allowance extension relay 118.

And, as shown in fig. 2 and fig. 3, the variable-frequency control system 100 includes a first variable-frequency switching-on control loop 170 and a second variable-frequency switching-on control loop 180, and the two variable-frequency switching-on control loops, the first variable-frequency switching-on control loop 170 controls the first system 130, and the second variable-frequency switching-on control loop 180 controls the second system 150. Wherein, first frequency conversion combined floodgate control circuit 170 includes: the normally closed point of the second throw extension relay 116, the normally closed point of the second contactor 142, the normally closed point parallel node of the first contactor 138 and the third contactor 144, the normally open point of the first switch 136, the normally open point of the second switch 140, and the normally open point of the high-voltage closing allowance extension relay 118 are connected in series. The second variable-frequency switching-on control circuit 180 includes: the normally closed point of the first throw extension relay 114, the normally closed point of the fifth contactor 160, the normally closed point parallel node of the fourth contactor 158 and the sixth contactor 164, the normally open point of the third switch 156, the normally open point of the fourth switch 162, and the normally open point of the high-voltage closing allowance extension relay 118 are connected in series.

In this embodiment, the inverter assembly 110 includes a first throw extension relay 114, a second throw extension relay 116, and a high-voltage closing enable extension relay 118.

Furthermore, the variable-frequency control system 100 includes two variable-frequency switching-on control loops, namely a first variable-frequency switching-on control loop 170 and a second variable-frequency switching-on control loop 180.

As shown in fig. 2, the first variable-frequency closing control loop 170 includes a normally open point of the second input extension relay 116, a normally closed point of the second contactor 142, a normally closed point parallel node of the first contactor 138 and the third contactor 144, a normally open point of the first switch 136, a normally open point of the second switch 140, and a normally open point of the high-voltage closing allowance extension relay 118, which are connected in series.

That is, the condition that the first variable-frequency closing control circuit 170 is turned on requires that the normally closed point of the second input extension relay 116 is in a closed state, that is, the variable-frequency control system 100 does not perform the variable-frequency closing control of the second system 150. The normally closed point of the second contactor 142 is in a conducting state. The normally closed point of the first contactor 138 and/or the normally closed point of the third contactor 144 are in a conductive state. The normally open point of the first switch 136 is in a conductive state. The normally open point of the second switch 140 is in a conducting state. The high-voltage closing allows the normally open point of the extension relay 118 to be in a conducting state, that is, the high-voltage closing allows the extension relay 118 to allow a closing action. The first system 130 may then provide variable frequency control of the first motor 410 via the first power supply and inverter assembly 110.

As shown in fig. 3, the second variable-frequency closing control circuit 180 includes a normally closed point of the first input extension relay 114, a normally closed point of the fifth contactor 160, a normally closed point parallel node of the fourth contactor 158 and the sixth contactor 164, a normally open point of the third switch 156, a normally open point of the fourth switch 162, and a normally open point of the high-voltage closing allowance extension relay 118, which are connected in series.

That is, the condition that the second variable-frequency closing control loop 180 is turned on requires that the normally closed point of the first input extension relay 114 is in a conducting state, that is, the variable-frequency control system 100 does not perform the variable-frequency closing control of the first system 130. The normally closed point of the fifth contactor 160 is in a conducting state. The normally closed point of the fourth contactor 158 and/or the normally closed point of the sixth contactor 164 is in a conducting state. The normally open point of the third switch 156 is in a conducting state. The normally open point of the fourth switch 162 is in a conductive state. The normally open point of the high-voltage closing permission extension relay 118 is in a conducting state, that is, the high-voltage closing permission extension relay 118 allows a closing action. The second system 150 may then provide variable frequency control of the second motor 420 via the second power supply and inverter assembly 110.

Furthermore, the first variable-frequency switching-on control circuit 170 and the second variable-frequency switching-on control circuit 180 can realize variable-frequency output of the first system 130 and variable-frequency output of the second system 150, and the two can not be performed simultaneously, thereby improving the stability and safety of the variable-frequency control system 100.

As an embodiment of the present invention, further, as shown in fig. 2, the frequency conversion control system 100 further includes a first manual frequency conversion switch-on switch 172 and a first automatic frequency conversion switch-on switch 174, the first manual frequency conversion switch-on switch 172 is manually controlled by an operator, and the first automatic frequency conversion switch-on switch 174 is automatically controlled by an automation. Specifically, the first automatic variable frequency closing switch 174 is triggered by adopting a DCS (distributed Control System).

As shown in fig. 3, the variable-frequency control system 100 further includes a second manual variable-frequency closing switch 182 and a second automatic variable-frequency closing switch 184, wherein the second manual variable-frequency closing switch 182 is manually controlled by an operator, and the second automatic variable-frequency closing switch 184 is automatically controlled by an automation controller. Specifically, the second automatic variable frequency closing switch 184 is triggered by a DCS (distributed Control System).

And, the frequency converter assembly 110 includes a frequency converter 112 and a high-voltage switch-on allowance extension relay 118, the frequency converter 112 and the high-voltage switch-on allowance extension relay 118 are electrically connected, and the high-voltage switch-on allowance signal of the frequency converter 112 triggers the high-voltage switch-on allowance extension relay 118.

And, the variable frequency control system 100 includes a first variable frequency closing control loop 170 and a second variable frequency closing control loop 180, two variable frequency closing control loops. Wherein, first frequency conversion combined floodgate control circuit 170 includes: a normally closed point of the second input extension relay 116, a normally closed point of the second contactor 142, a normally closed point parallel node of the first contactor 138 and the third contactor 144, a normally open point of the first switch 136, a normally open point of the second switch 140, a normally open point of the high-voltage switching-on allowing extension relay 118, and a parallel node of a normally open point of the first manual variable-frequency switching-on switch 172 and a normally open point of the first automatic variable-frequency switching-on switch 174 which are connected in series. The second variable-frequency switching-on control circuit 180 includes: a normally closed point of the first input extension relay 114, a normally closed point of the fifth contactor 160, a normally closed point parallel node of the fourth contactor 158 and the sixth contactor 164, a normally open point of the third switch 156, a normally open point of the fourth switch 162, a normally open point of the high-voltage closing permission extension relay 118, and a parallel node of a normally open point of the second manual variable-frequency closing switch 182 and a normally open point of the second automatic variable-frequency closing switch 184, which are connected in series.

In this embodiment, the variable frequency control system 100 further includes a first manual variable frequency closing switch 172, a second manual variable frequency closing switch 182, a first automatic variable frequency closing switch 174, and a second automatic variable frequency closing switch 184.

The condition for the conduction of the first variable-frequency closing control loop 170 requires at least one of a normally open point of the first manual variable-frequency closing switch 172 and a normally open point of the first automatic variable-frequency closing switch 174 to be conducted, that is, the first manual variable-frequency closing switch 172 is triggered and/or the first automatic variable-frequency closing switch 174 is triggered. The normally closed point of the second input extension relay 116 is in a conducting state, that is, the variable frequency control system 100 does not perform the variable frequency closing control of the second system 150. The normally closed point of the second contactor 142 is in a conducting state. At least one of the normally closed point of the first contactor 138 and the normally closed point of the third contactor 144 is in a conductive state, and the second contactor 142 and the third contactor 144 are interlocked, so the second contactor 142 and the third contactor 144 are not simultaneously conductive. The normally open point of the first switch 136 is in a conductive state. The normally open point of the second switch 140 is in a conducting state. The normally open point of the high-voltage closing permission extension relay 118 is in a conducting state, that is, the high-voltage closing permission extension relay 118 allows a closing action. The first system 130 may then provide variable frequency control of the first motor 410 via the first power supply and inverter assembly 110.

The condition for the conduction of the second variable-frequency closing control loop 180 requires at least one of a normally open point of the second manual variable-frequency closing switch 182 and a normally open point of the second automatic variable-frequency closing switch 184 to be conducted, that is, the second manual variable-frequency closing switch 182 is triggered, and/or the second automatic variable-frequency closing switch 184 is triggered. The normally closed point of the first input extension relay 114 is in a conducting state, that is, the variable frequency control system 100 does not perform the variable frequency closing control of the first system 130. The normally closed point of the fifth contactor 160 is in a conductive state. At least one of the normally closed point of the fourth contactor 158 and the normally closed point of the sixth contactor 164 is in a conductive state since the fifth contactor 160 and the sixth contactor 164 are interlocked, the fifth contactor 160 and the sixth contactor 164 are not conductive at the same time. The normally open point of the third switch 156 is in a conducting state. The normally open point of the fourth switch 162 is in a conductive state. The high-voltage closing allows the normally open point of the extension relay 118 to be in a conducting state, that is, the high-voltage closing allows the extension relay 118 to allow a closing action. The second system 150 may then provide variable frequency control of the second motor 420 via the second power supply and frequency converter assembly 110.

As an embodiment of the utility model discloses a possible implementation, furtherly, as shown in fig. 4, frequency conversion control system 100 still includes first manual power frequency closing switch 192 and first automatic power frequency closing switch 194, and wherein, first manual power frequency closing switch 192 passes through operator manual control, and first automatic power frequency closing switch 194 is through automated control action by oneself.

Frequency conversion control system 100 includes first power frequency combined floodgate control circuit 190, and first power frequency combined floodgate control circuit 190 includes: a parallel node of a normally-open point of the first manual power frequency switching-on switch 192 and a normally-open point of the first automatic power frequency switching-on switch 194, a normally-closed point of the third contactor 144, a normally-closed point of the first contactor 138, and a normally-closed point of the second contactor 142, which are connected in series.

As shown in fig. 5, the variable frequency control system 100 further includes a second manual power-frequency closing switch 202 and a second automatic power-frequency closing switch 204, wherein the second manual power-frequency closing switch 202 is manually controlled by an operator, and the second automatic power-frequency closing switch 204 automatically operates by an automated control.

Frequency conversion control system 100 includes second power frequency combined floodgate control circuit 200, and second power frequency combined floodgate control circuit 200 includes: a parallel node of a normally-open point of the second manual power frequency closing switch 202 and a normally-open point of the second automatic power frequency closing switch 204, a normally-closed point of the fifth contactor 160, a normally-closed point of the fourth contactor 158 and a normally-closed point of the sixth contactor 164 which are connected in series.

In this embodiment, the variable frequency control system 100 further includes: a first manual power frequency switch-on switch 192, a second manual power frequency switch-on switch 202, a first automatic power frequency switch-on switch 194, and a second automatic power frequency switch-on switch 204.

Moreover, the variable frequency control system 100 includes two power frequency closing control loops, i.e., a first power frequency closing control loop 190 and a second power frequency closing control loop 200.

The condition that the first power frequency switching-on control circuit 190 is turned on needs at least one of a normally-on point of the first manual power frequency switching-on switch 192 and a normally-on point of the first automatic power frequency switching-on switch 194 to be turned on, that is, the first manual power frequency switching-on switch 192 is triggered, and/or the first automatic power frequency switching-on switch 194 is triggered. The normally closed point of the first contactor 138 is in a conducting state. The normally closed point of the third contactor 144 is in a conducting state. The normally closed point of the second contactor 142 is in a conducting state.

The condition for switching on the second power frequency switching-on control loop 200 requires at least one of a normally-on point of the second manual power frequency switching-on switch 202 and a normally-on point of the second automatic power frequency switching-on switch 204 to be switched on, that is, the second manual power frequency switching-on switch 202 is triggered, and/or the second automatic power frequency switching-on switch 204 is triggered. The normally closed point of the fourth contactor 158 is in a conducting state. The normally closed point of the sixth contactor 164 is in a conducting state. The normally closed point of the fifth contactor 160 is in a conducting state.

And then, the power frequency output of the first system 130 and the second system 150 is realized through the first manual power frequency switch-on switch 192, the first automatic power frequency switch-on switch 194, the first contactor 138, the third contactor 144, the second contactor 142, the second manual power frequency switch-on switch 202, the second automatic power frequency switch-on switch 204, the fourth contactor 158, the sixth contactor 164 and the fifth contactor 160, and the stability and the safety of the variable frequency control system 100 are improved.

As a possible embodiment of the present invention, furthermore, as shown in fig. 4, the frequency conversion control system 100 further includes a first manual power frequency switch-on switch 192 and a first automatic power frequency switch-on switch 194, as shown in fig. 11, the frequency converter assembly 110 includes a frequency converter 112 and a fault signal extension relay 122, after the fault signal of the frequency converter 112 is switched on, the fault signal extension relay 122 is triggered, wherein, the first manual power frequency switch-on switch 192 is manually controlled by an operator, the first automatic power frequency switch-on switch 194 automatically acts through automatic control, the frequency converter 112 is electrically connected with the fault signal extension relay 122, and the fault signal of the frequency converter 112 triggers the fault signal extension relay 122.

As shown in fig. 5, the variable frequency control system 100 further includes a second manual power frequency closing switch 202 and a second automatic power frequency closing switch 204, as shown in fig. 11, the frequency converter assembly 110 includes a frequency converter 112 and a fault signal extension relay 122, and after the fault signal of the frequency converter 112 is closed, the fault signal extension relay 122 is triggered, wherein the second manual power frequency closing switch 202 is manually controlled by an operator, the second automatic power frequency closing switch 204 automatically operates through automatic control, the frequency converter 112 is electrically connected with the fault signal extension relay 122, and the fault signal of the frequency converter 112 triggers the fault signal extension relay 122.

In this embodiment, the frequency converter assembly 110 further comprises: and the fault signal extension relay 122 are connected into the first power frequency switching-on control loop 190 and the second power frequency switching-on control loop 200.

As shown in fig. 4, the first power frequency switching-on control circuit 190 includes a normally open point of the first manual power frequency switching-on switch 192, a normally open point of the first automatic power frequency switching-on switch 194, a parallel node of a normally open point of the fault signal extension relay 122, a normally closed point of the third contactor 144, a normally closed point of the first contactor 138, and a normally closed point of the second contactor 142, which are connected in series.

That is, the condition that the first power frequency closing control loop 190 is turned on needs at least one of a normally-open point of the first manual power frequency closing switch 192, a normally-open point of the first automatic power frequency closing switch 194, and a normally-open point of the fault signal extension relay 122 to be turned on, that is, the first manual power frequency closing switch 192 is triggered, and/or the first automatic power frequency closing switch 194 is triggered, and/or the normally-open point of the fault signal extension relay 122 is in a conducting state, that is, the frequency converter assembly 110 fails, and is unable to perform variable frequency output. The normally closed point of the first contactor 138 is in a conducting state. The normally closed point of the third contactor 144 is in a conducting state. The normally closed point of the second contactor 142 is in a conducting state.

As shown in fig. 5, the second power frequency closing control loop 200 includes a parallel node of a normally open point of a second manual power frequency closing switch 202, a normally open point of a second automatic power frequency closing switch 204, and a normally open point of the fault signal extension relay 122, a normally closed point of the fifth contactor 160, a normally closed point of the fourth contactor 158, and a normally closed point of the sixth contactor 164, which are connected in series.

That is, the condition that the second power frequency closing control circuit 200 is turned on requires that at least one of the normally-open point of the second manual power frequency closing switch 202, the normally-open point of the second automatic power frequency closing switch 204, and the normally-open point of the fault signal extension relay 122 is turned on, that is, the second manual power frequency closing switch 202 is triggered, and/or the second automatic power frequency closing switch 204 is triggered, and/or the normally-open point of the fault signal extension relay 122 is in a conducting state, that is, the frequency converter assembly 110 fails, and thus, the frequency conversion output cannot be performed. The normally closed point of the fourth contactor 158 is in a conducting state. The normally closed point of the sixth contactor 164 is in a conducting state. The normally closed point of the fifth contactor 160 is in a conducting state.

And then, the power frequency output of the first system 130 and the second system 150 is realized through the first manual power frequency switch-on switch 192, the first automatic power frequency switch-on switch 194, the fault signal extension relay 122, the first contactor 138, the third contactor 144, the second contactor 142, the second manual power frequency switch-on switch 202, the second automatic power frequency switch-on switch 204, the fourth contactor 158, the sixth contactor 164 and the fifth contactor 160, and the stability and the safety of the frequency conversion control system 100 are improved.

Moreover, the fault signal extension relay 122 can automatically switch to power frequency control when the frequency converter assembly 110 has a fault, so that the stability of the frequency conversion control system 100 is improved.

As a possible embodiment of the present invention, further, as shown in fig. 6, the frequency conversion control system 100 further includes a first manual opening control switch 212 and a first automatic opening control switch 214, as shown in fig. 12, the frequency converter assembly 110 includes a frequency converter 112 and an operation signal extension relay 120, and after the operation signal of the frequency converter 112 is switched on, the operation signal extension relay 120 is triggered. The first manual opening control switch 212 is manually controlled by an operator, the first automatic opening control switch 214 automatically operates through automatic control, the frequency converter 112 is electrically connected with the operation signal extension relay 120, and the operation signal of the frequency converter 112 triggers the operation signal extension relay 120.

The variable frequency control system 100 comprises a first switching control loop 210, the first switching control loop 210 comprises a fifth circuit 352 and an eighth circuit 360 which are connected in series, wherein the fifth circuit 352 comprises a normally open point of a first manual switching control switch 212 and a normally open point of a first automatic switching control switch 214 which are connected in parallel, the eighth circuit 360 comprises a normally open point of a seventh circuit 358 and a second contactor 142 which are connected in parallel, the seventh circuit 358 comprises a normally closed point of a sixth circuit 354 and an operation signal extension relay 120 which are connected in series, and the sixth circuit 354 comprises a normally open point of a first contactor 138 and a normally open point of a third contactor 144 which are connected in parallel.

As shown in fig. 7, the variable frequency control system 100 further includes a second manual opening control switch 222 and a second automatic opening control switch 224, as shown in fig. 12, the frequency converter assembly 110 includes a frequency converter 112 and an operation signal extension relay 120, and the operation signal extension relay 120 is triggered after the operation signal of the frequency converter 112 is closed. The second manual opening control switch 222 is manually controlled by an operator, the second automatic opening control switch 224 automatically operates through automatic control, the frequency converter 112 is electrically connected with the operation signal extension relay 120, and the operation signal of the frequency converter 112 triggers the operation signal extension relay 120.

The second opening control loop 220 includes a ninth circuit 362 and a twelfth circuit 368 connected in series, wherein the ninth circuit 362 includes a normally open point of the second manual opening control switch 222 and a normally open point of the second automatic opening control switch 224 connected in parallel, the twelfth circuit 368 includes a normally open point of an eleventh circuit 366 and a fifth contactor 160 connected in parallel, the eleventh circuit 366 includes a normally closed point of the tenth circuit 364 and the operation signal extension relay 120 connected in series, and the tenth circuit 364 includes a normally open point of the fourth contactor 158 and a normally open point of the sixth contactor 164 connected in parallel.

In this embodiment, the variable frequency control system 100 further includes: the first manual opening control switch 212, the second manual opening control switch 222, the first automatic opening control switch 214 and the second automatic opening control switch 224, and the frequency converter assembly 110 includes the operation signal extension relay 120.

Furthermore, the variable frequency control system 100 includes two switching control loops, i.e. a first switching control loop 210 and a second switching control loop 220.

The condition that the first opening control loop 210 is turned on requires that at least one of a normally-open point of the first manual opening control switch 212 and a normally-open point of the first automatic opening control switch 214 is in a conducting state, that is, the first manual opening control switch 212 is triggered and/or the first automatic opening control switch 214 is triggered. The normally open point of the second contactor 142 is in a conducting state, that is, the variable frequency control system 100 is in a state controlled by the first power frequency closing control loop 190. Alternatively, at least one of the normally open point of the first contactor 138 and the normally open point of the third contactor 144 is in a conducting state, and the normally closed point of the operation signal extension relay 120 is in a conducting state, that is, the frequency converter assembly 110 is normally operated, that is, the normally open point of the first contactor 138 is in a conducting state, and/or the normally open point of the third contactor 144 is in a conducting state, and the normally closed point of the operation signal extension relay 120 is in a conducting state, that is, the variable frequency closing control system 100 is in control of the first variable frequency closing control loop 170.

The condition that the second opening control loop 220 is turned on requires that at least one of a normally-open point of the second manual opening control switch 222 and a normally-open point of the second automatic opening control switch 224 is in a conducting state, that is, the second manual opening control switch 222 is triggered and/or the second automatic opening control switch 224 is triggered. The normally open point of the fifth contactor 160 is in a conducting state, that is, the variable frequency control system 100 is in a state controlled by the second power frequency closing control loop 200. Alternatively, at least one of the normally open point of the fourth contactor 158 and the normally open point of the sixth contactor 164 is in a conducting state, and the normally closed point of the operation signal extension relay 120 is in a conducting state, that is, the frequency converter assembly 110 is normally operated, that is, the normally open point of the fourth contactor 158 is in a conducting state, and/or the normally open point of the sixth contactor 164 is in a conducting state, and the normally closed point of the operation signal extension relay 120 is in a conducting state, that is, the variable frequency closing control system 100 is in the control of the second variable frequency closing control loop 180.

Further, through the first manual opening control switch 212, the second manual opening control switch 222, the first automatic opening control switch 214, the second automatic opening control switch 224, the operation signal extension relay 120, the first contactor 138, the second contactor 142, the third contactor 144, the fourth contactor 158, the fifth contactor 160, and the sixth contactor 164, unified opening control controlled by the first variable-frequency closing control loop 170, the second variable-frequency closing control loop 180, the first power-frequency closing control loop 190, and the second power-frequency closing control loop 200 is realized, so that wiring of the variable-frequency control system 100 is simpler.

As a possible embodiment of the present invention, further, as shown in fig. 6, the variable frequency control system 100 further includes a first manual opening control switch 212 and a first automatic opening control switch 214, and the frequency converter assembly 110 includes a frequency converter 112 and a fault signal extension relay 122. The first manual opening control switch 212 is manually controlled by an operator, the first automatic opening control switch 214 automatically operates through automatic control, the frequency converter 112 is electrically connected with the fault signal extension relay 122, and the fault signal of the frequency converter 112 triggers the fault signal extension relay 122.

The variable frequency control system 100 comprises a first opening control loop 210, the first opening control loop 210 comprises a fifth circuit 352 and an eighth circuit 360 which are connected in series, wherein the fifth circuit 352 comprises a normally-open point of a first manual opening control switch 212, a normally-open point of a first automatic opening control switch 214 and a normally-open point of a fault signal extension relay 122 which are connected in parallel, the eighth circuit 360 comprises a seventh circuit 358 and a normally-open point of a second contactor 142 which are connected in parallel, the seventh circuit 358 comprises a sixth circuit 354 and a normally-closed point of an operation signal extension relay 120 which are connected in series, and the sixth circuit 354 comprises a normally-open point of a first contactor 138 and a normally-open point of a third contactor 144.

As shown in fig. 7, the variable frequency control system 100 further includes a second manual opening control switch 222 and a second automatic opening control switch 224, and the frequency converter assembly 110 includes the frequency converter 112 and the fault signal extension relay 122. The second manual opening control switch 222 is manually controlled by an operator, the second automatic opening control switch 224 is automatically controlled by automation, the frequency converter 112 is electrically connected with the fault signal extension relay 122, and the fault signal of the frequency converter 112 triggers the fault signal extension relay 122.

The second opening control loop 220 includes a ninth circuit 362 and a twelfth circuit 368 connected in series, wherein the ninth circuit 362 includes a normally open point of the second manual opening control switch 222, a normally open point of the second automatic opening control switch 224 and a normally open point of the fault signal extension relay 122 connected in parallel, the twelfth circuit 368 includes a normally open point of the eleventh circuit 366 and the fifth contactor 160 connected in parallel, the eleventh circuit 366 includes a normally closed point of the tenth circuit 364 and the operation signal extension relay 120 connected in series, and the tenth circuit 364 includes a normally open point of the fourth contactor 158 and a normally open point of the sixth contactor 164 connected in series.

In this embodiment, the frequency converter assembly 110 further comprises a fault signal propagation relay 122, the fault signal propagation relay 122 being switched into the first switching control loop 210 and the second switching control loop 220.

The condition that the first opening control loop 210 is turned on requires that at least one of a normally-open point of the first manual opening control switch 212, a normally-open point of the first automatic opening control switch 214, and a normally-open point of the fault signal extension relay 122 is in a conducting state, that is, the first manual opening control switch 212 is triggered and/or the first automatic opening control switch 214 is triggered and/or the frequency converter assembly 110 fails. The normally open point of the second contactor 142 is in a conductive state. Alternatively, at least one of the normally open point of the first contactor 138 and the normally open point of the third contactor 144 is in a conducting state, and the normally closed point of the operation signal extension relay 120 is in a conducting state, and/or the normally open point of the third contactor 144 is in a conducting state, and the normally closed point of the operation signal extension relay 120 is in a conducting state, that is, the variable frequency control system 100 is in the control of the first variable frequency closing control loop 170.

The condition that the second opening control loop 220 is turned on requires that at least one of a normally-open point of the second manual opening control switch 222, a normally-open point of the second automatic opening control switch 224 and a normally-open point of the fault signal extension relay 122 is in a conducting state, that is, the second manual opening control switch 222 is triggered and/or the second automatic opening control switch 224 is triggered and/or the frequency converter assembly 110 fails. The normally open point of the fifth contactor 160 is in a conductive state. Alternatively, at least one of the normally open point of the fourth contactor 158 and the normally open point of the sixth contactor 164 is in a conducting state, and the normally closed point of the operation signal extension relay 120 is in a conducting state, that is, the frequency converter assembly 110 is normally operated, that is, the normally open point of the fourth contactor 158 is in a conducting state, and/or the normally open point of the sixth contactor 164 is in a conducting state, and the normally closed point of the operation signal extension relay 120 is in a conducting state, that is, the variable frequency closing control system 100 is in the control of the second variable frequency closing control loop 180.

Through the setting of fault signal extension relay 122, and then when converter 112 broke down, automatic separating brake promoted the stability and the security of frequency conversion control system 100.

As a possible embodiment of the present invention, further, as shown in fig. 1, the frequency conversion control system 100 further includes: the first and second switch switches 230 and 240 are electrically connected, the outlet terminal of the first switch 230 is electrically connected to the inlet terminal of the first system 130, the outlet terminal of the second switch 240 is electrically connected to the inlet terminal of the second system 150, the inlet terminal of the first switch 230 is electrically connected to the power supply, and the inlet terminal of the second switch 240 is electrically connected to the power supply.

In this embodiment, the variable frequency control system 100 further includes: two upper switches, namely, a first shunt switch 230 electrically connected to the incoming line terminal of the first system 130, and a second shunt switch 240 electrically connected to the incoming line terminal of the second system 150, so as to control the incoming power of the first system 130 and the second system 150, thereby improving the safety of the variable frequency control system 100.

Specifically, the first breaking switch 230 is installed in the third cabinet 270 to protect the first breaking switch 230, and the second breaking switch 240 is installed in the fourth cabinet 280 to protect the second breaking switch 240.

As a possible embodiment of the present invention, further, as shown in fig. 1, the frequency conversion control system 100 further includes: a first cabinet 250 and a second cabinet 260, a part or all of the first system 130 being installed in the first cabinet 250, and a part or all of the second system 150 being installed in the second cabinet 260.

In this embodiment, part or all of the first system 130 is disposed in the first cabinet 250 to protect the first system 130, and part or all of the second system 150 is disposed in the second cabinet 260 to protect the second system 150.

Specifically, the first and

second cabinets

250 and 260 are bypass cabinets.

As a possible embodiment of the present invention, further, as shown in fig. 10, the variable frequency control system 100 further includes a first cabinet door state extension relay 290 and a second cabinet door state extension relay 300, wherein the first cabinet door state extension relay 290 switches states according to the cabinet door on-off state of the first cabinet 250, and the second cabinet door state extension relay 300 switches states according to the cabinet door on-off state of the second cabinet 260.

In this embodiment, the frequency converter assembly 110 includes a first cabinet door state expansion relay 290 and a second cabinet door state expansion relay 300, the first cabinet door state expansion relay 290 can detect the opening and closing state of the cabinet door of the first cabinet 250, and the second cabinet door state expansion relay 300 can detect the opening and closing state of the cabinet door of the second cabinet 260, so as to be suitable for determining the states of the cabinet doors of the first cabinet 250 and the second cabinet 260.

And, the normally open point of first cabinet door state extension relay 290 and the normally open point of second cabinet door state extension relay 300 are parallelly connected, thereby be convenient for to higher level's switch, namely first separating brake switch 230 and the state of second cabinet 260 of second separating brake switch 240 feedback, and then can be when the cabinet door of first cabinet 250 is in the open mode, cut off higher level's switch, namely first separating brake switch 230, thereby promote frequency conversion control system 100's security, likewise, when the cabinet door of second cabinet 260 is in the open mode, cut off higher level's switch also and be second separating brake switch 240, thereby promote frequency conversion control system 100's security.

As shown in fig. 8 and 9, the first cabinet 250 is provided with a first travel switch 310 and a second travel switch 320, and then the first travel switch 310 and the second travel switch 320 are triggered when the cabinet door of the first cabinet 250 is in a closed state and an open state, respectively, specifically, the first travel switch 310 and the second travel switch 320 are electrically connected to the first cabinet door state extension relay 290 in parallel, so that both the first travel switch 310 and the second travel switch 320 can trigger the first cabinet door state extension relay 290, and thus the opening and closing state of the cabinet door of the first cabinet 250 can be detected by the first cabinet door state extension relay 290.

Be provided with third travel switch 330 and fourth travel switch 340 on the second cabinet 260, and then be in the closed condition and open condition at the cabinet door of second cabinet 260 and trigger third travel switch 330 and fourth travel switch 340 respectively, specifically, third travel switch 330 and fourth travel switch 340 parallelly connected with second cabinet door state extension relay 300 electricity and connect, thereby third travel switch 330 and fourth travel switch 340 can both trigger second cabinet door state extension relay 300, thereby can detect the on-off state of second cabinet 260 cabinet door through second cabinet door state extension relay 300.

As a possible embodiment of the present invention, further, the first switch-off switch 230 employs a first circuit breaker; the second breaking switch 240 employs a second breaker.

In this embodiment, the first opening switch 230 is a first breaker, so that whether the first system 130 is powered on or off can be controlled by turning on or off the first opening switch 230, and similarly, the second opening switch 240 is a second breaker, so that whether the second system 150 is powered on or off can be controlled by turning on or off the second opening switch 240.

As a possible embodiment of the present invention, further, the first switch 136 employs a first isolation switch, the second switch 140 employs a second isolation switch, the third switch 156 employs a third isolation switch, and the fourth switch 162 employs a fourth isolation switch.

As shown in fig. 16, the first system 130 of the variable frequency control system 100 is electrically connected to a first motor 410, and the second system 150 of the variable frequency control system 100 is electrically connected to a second motor 420.

In the present application, the terms "first", "second", "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance; the term "plurality" means two or more unless expressly limited otherwise. The terms "mounted," "connected," "fixed," and the like are to be construed broadly, and for example, "connected" may be a fixed connection, a removable connection, or an integral connection; "coupled" may be direct or indirect through an intermediary. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

In the description of the present invention, it should be understood that the terms "upper", "lower", "left", "right", "front", "rear", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description of the present invention and simplification of description, but do not indicate or imply that the designated components or units must have a specific direction, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

In the description of the present specification, the description of the terms "one embodiment," "some embodiments," "specific embodiments," 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 invention. 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.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A variable frequency control system, comprising:

a frequency converter assembly;

the first system comprises a first circuit and a second circuit, wherein the first circuit comprises a first switch and a first contactor which are connected in series, and the second circuit comprises a second contactor and a third contactor and a second switch which are connected in series;

a second system comprising a third circuit and a fourth circuit, the third circuit comprising a third switch and a fourth contactor connected in series, the fourth circuit comprising a fifth contactor and a sixth contactor and a fourth switch connected in series;

wherein, the inlet wire end of converter subassembly with the outlet wire end of first contactor and the outlet wire end electricity of fourth contactor is connected, the outlet wire end of converter subassembly with the inlet wire end of second switch and the inlet wire end electricity of fourth switch is connected, the inlet wire end of first switch with the inlet wire end of second contactor forms the inlet wire end of first system, the outlet wire end of second contactor with the outlet wire end of third contactor forms the outlet wire end of first system, the inlet wire end of third switch with the inlet wire end of fifth contactor forms the inlet wire end of second system, the outlet wire end of sixth contactor with the outlet wire end of fifth contactor forms the outlet wire end of second system.

2. The variable frequency control system of claim 1,

the second and third contactors are mechanically and electrically interlocked;

the fifth contactor and the sixth contactor are mechanically interlocked and electrically interlocked.

3. The variable frequency control system of claim 2,

the third contactor and the sixth contactor are electrically interlocked.

4. The variable frequency control system according to any one of claims 1 to 3, further comprising:

the frequency converter assembly comprises a first input extension relay and a second input extension relay, wherein the frequency converter assembly comprises a high-voltage switch-on allowable extension relay;

the variable-frequency control system comprises a first variable-frequency switching-on control loop and a second variable-frequency switching-on control loop, wherein in the first variable-frequency switching-on control loop, a normally-closed point of the second input extension relay, a normally-closed point of the second contactor, a normally-closed point parallel node of the first contactor and the third contactor, a normally-open point of the first switch, a normally-open point of the second switch and a normally-open point of the high-voltage switching-on permission extension relay are connected in series; in the second variable-frequency switching-on control circuit, a normally-off point of the first input extension relay, a normally-off point of a fifth contactor, a normally-closed point parallel node of the fourth contactor and the sixth contactor, a normally-open point of a third switch, a normally-open point of a fourth switch, and a normally-open point of the high-voltage switching-on allowing extension relay are connected in series.

5. The variable frequency control system of claim 4, further comprising:

the automatic switching device comprises a first manual variable-frequency switching-on switch, a second manual variable-frequency switching-on switch, a first automatic variable-frequency switching-on switch and a second automatic variable-frequency switching-on switch;

in the first variable-frequency switching-on control loop, a normally open point of the first manual variable-frequency switching-on switch and a normally open point of the first automatic variable-frequency switching-on switch are connected in parallel with a normally closed point of the second input extended relay; in the second variable-frequency switching-on control loop, a normally open point of the second manual variable-frequency switching-on switch and a normally open point of the second automatic variable-frequency switching-on switch are connected in parallel with a normally closed point of the first input extension relay.

6. The variable frequency control system according to any one of claims 1 to 3, further comprising:

the first manual power frequency switch-on switch, the second manual power frequency switch-on switch, the first automatic power frequency switch-on switch and the second automatic power frequency switch-on switch;

the frequency conversion control system comprises a first power frequency switching-on control loop and a second power frequency switching-on control loop, wherein in the first power frequency switching-on control loop, a parallel connection node of a normally open point of the first manual power frequency switching-on switch and a normally open point of the first automatic power frequency switching-on switch, a normally closed point of the first contactor, a normally closed point of the third contactor and a normally closed point of the second contactor are connected in series; in the second power frequency switching-on control loop, a parallel connection node of a normally open point of the second manual power frequency switching-on switch and a normally open point of the second automatic power frequency switching-on switch, a normally closed point of the fourth contactor, a normally closed point of the sixth contactor and a normally closed point of the fifth contactor are connected in series.

7. The variable frequency control system of claim 6, wherein the frequency converter assembly further comprises:

the fault signal extension relay is characterized in that in the first power frequency closing control loop, a normally-open point of the fault signal extension relay, a normally-open point of the first manual power frequency closing switch and a normally-open point of the first automatic power frequency closing switch are connected in parallel, and in the second power frequency closing control loop, a normally-open point of the fault signal extension relay, a normally-open point of the second manual power frequency closing switch and a normally-open point of the second automatic power frequency closing switch are connected in parallel.

8. The variable frequency control system according to any one of claims 1 to 3, further comprising:

the frequency converter component comprises an operation signal expansion relay;

the variable frequency control system comprises a first switching control loop and a second switching control loop, in the first switching control loop, a normally open point of a first manual switching control switch and a normally open point of a first automatic switching control switch are connected in parallel to form a fifth circuit, a normally open point of a first contactor and a normally open point of a third contactor are connected in parallel to form a sixth circuit, a normally closed point of the operation signal expansion relay and the sixth circuit are connected in series to form a seventh circuit, a normally open point of the seventh circuit and a normally open point of the second contactor are connected in parallel to form an eighth circuit, and the fifth circuit and the eighth circuit are connected in series; in the second opening control loop, a normally open point of the second manual opening control switch and a normally open point of the second automatic opening control switch are connected in parallel to form a ninth circuit, a normally open point of the fourth contactor and a normally open point of the sixth contactor are connected in parallel to form a tenth circuit, a normally closed point of the operation signal expansion relay and the tenth circuit are connected in series to form an eleventh circuit, a normally open point of the eleventh circuit and a normally open point of the fifth contactor are connected in parallel to form a twelfth circuit, and the ninth circuit and the twelfth circuit are connected in series.

9. The variable frequency control system of claim 8, wherein the frequency converter assembly comprises:

the fault signal extension relay is connected in parallel with a normally open point of the first manual brake-separating control switch and a normally open point of the first automatic brake-separating control switch in the first brake-separating control loop; in the second brake-separating control loop, the normally-open point of the fault signal expansion relay, the normally-open point of the second manual brake-separating control switch and the normally-open point of the second automatic brake-separating control switch are connected in parallel.

10. The variable frequency control system according to any one of claims 1 to 3, further comprising:

the first brake switch is electrically connected with the incoming line end of the first system;

and the second switch-off switch is electrically connected with the incoming line terminal of the second system.

11. The variable frequency control system of claim 10, further comprising:

the first cabinet, at least part of the said first system locates the said first cabinet;

a second cabinet, at least a portion of the second system being disposed in the second cabinet.

12. The variable frequency control system of claim 11, further comprising:

the first cabinet door state expansion relay is used for detecting the cabinet door opening and closing state of the first cabinet;

the second cabinet door state expansion relay is used for detecting the cabinet door opening and closing state of the second cabinet;

the normally open point of the first cabinet door state expansion relay is connected with the normally open point of the second cabinet door state expansion relay in parallel, and is electrically connected with the first shunt switch and the second shunt switch.

13. The variable frequency control system of claim 10,

the first opening switch is a first breaker;

the second switch-off switch is a second circuit breaker.

14. The variable frequency control system according to any one of claims 1 to 3,

the first switch is a first isolating switch;

the second switch is a second isolating switch;

the third switch is a third isolating switch;

the fourth switch is a fourth isolating switch.