CN217656566U

CN217656566U - One-to-four non-reactor undisturbed switching device of cascade frequency converter

Info

Publication number: CN217656566U
Application number: CN202221725603.4U
Authority: CN
Inventors: 阮敬稳; 刘兴状; 张晓飞; 徐保帅; 林凡堂
Original assignee: Windsun Science and Technology Co Ltd
Current assignee: Windsun Science and Technology Co Ltd
Priority date: 2022-07-06
Filing date: 2022-07-06
Publication date: 2022-10-25
Anticipated expiration: 2032-07-06

Abstract

The utility model discloses a cascade converter one drags four does not have reactance ware undisturbed auto-change over device, including main converter, vice converter, 1# -4 # motor, the input of main, vice converter is connected to the alternating current network through isolator SQ1-1, SQ1-2 respectively, the output of main, vice converter is connected to the input of isolator SQ2-1, SQ2-2 respectively; the output ends of the isolation switches SQ2-1 and SQ2-2 are respectively connected with the power input ends of the motors 1# -4 # through the normally open points of the contactors KM 7-KM 10, and the power input ends of the motors 1# -4 # are respectively connected with an alternating current network through the normally open points of the contactors KM 1-KM 4. The utility model discloses a tandem type converter drags four no reactance ware undisturbed auto-change over device, when a converter breaks down, can utilize another converter to start, has realized the on-the-spot continuous operation of can not shutting down, has practiced thrift the quantity of converter, can effectively practice thrift the cost.

Description

One-to-four undisturbed switching device without reactance for cascade frequency converter

Technical Field

The utility model relates to a converter auto-change over device, more specifically the theory that says so especially relates to a tandem type converter drags four no reactance ware undisturbed auto-change over device.

Background

At present, the common site of the domestic high-voltage frequency converter is a machine type of one-to-one and one-to-two, the adaptability to site working conditions is limited, the complex conditions of field operation such as maintenance of the frequency converter and damage of a motor can not be met, and the problem of economic loss or unpredictability can be caused to the site which can not be shut down.

And the field adopts one-to-many technical performance. Although the investment cost of the frequency converter speed regulation starting is higher than that of the intelligent soft starting, the frequency conversion speed regulation starting has good static and dynamic performances during starting, the torque of the motor can be randomly regulated even under the condition of low speed, the motor can be started with constant torque, and the starting current can be limited below the rated current. The soft starter has current feedback, and can also adopt constant current starting, namely, the starting current is kept unchanged in the starting process until the motor approaches the synchronous rotating speed. In view of technical performance, the variable-frequency speed-regulating starting is suitable for loads with larger starting torque, generally in heavy-load occasions, such as reciprocating air compressors, centrifugal separators, conveyors with loads, crushers, spiral or rotary air compressors, centrifugal fans, centrifugal pumps, conveyors with no-load starting and various devices with no-load starting.

Disclosure of Invention

The utility model provides an overcome above-mentioned technical problem's shortcoming, provide a tandem type converter drags four no reactance ware undisturbed auto-change over device.

The utility model discloses a cascade converter drags four no reactance ware undisturbed auto-change over device, including main converter, vice converter, 1# motor, 2# motor, 3# motor and 4# motor, the input of main converter and the input of vice converter connect to the alternating current network through isolator SQ1-1 and isolator SQ1-2 respectively, the output of main converter and the output of vice converter connect to isolator SQ2-1 and the input of isolator SQ2-2 respectively; the method is characterized in that: the output ends of the isolating switch SQ2-1 and the isolating switch SQ2-2 are respectively connected with the power input ends of the 1# motor, the 2# motor, the 3# motor and the 4# motor through normally open points of a contactor KM7, a contactor KM8, a contactor KM9 and a contactor KM10, and the power input ends of the 1# motor, the 2# motor, the 3# motor and the 4# motor are respectively connected with an alternating current network through normally open points of a contactor KM1, a contactor KM2, a contactor KM3 and a contactor KM 4.

The utility model discloses a tandem type converter drags four no reactance ware undisturbed switching device, there are circuit breaker QF1, circuit breaker QF2, circuit breaker QF3 and circuit breaker QF4 on the circuit between contactor KM1, contactor KM2, contactor KM4 and the AC power grid respectively in series.

The utility model discloses a tandem type converter drags four no reactance ware undisturbed auto-change over device, the cluster has isolator QF5 on the circuit between isolator SQ1-1 and isolator SQ1-2 and the alternating current electric network, the cluster has earthing switch SQ1 between isolator QF 5's the output and the ground.

The utility model discloses a tandem type converter drags four no reactance ware undisturbed auto-change over device, isolator SQ1-1 and isolator SQ1-2 are a single-pole double-throw switch, isolator SQ2-1 and isolator SQ2-2 are a single-pole double-throw switch.

The beneficial effects of the utility model are that: the utility model discloses a cascade-type converter one drags four no reactance ware undisturbed auto-change over device, be provided with two converters (main, vice converter) between 4 motors that wait the frequency conversion to start and the alternating current electric wire netting, be provided with isolator between main, vice converter and alternating current electric wire netting and the motor input power, and it has the contactor to cluster between the input power of motor and the alternating current electric wire netting, thus, utilize arbitrary one converter in main converter and vice converter can realize the frequency conversion of arbitrary one in 4 motors to start, after the frequency conversion starts, through the contactor between disconnection converter and the motor input power, the contactor between closing motor and the alternating current power simultaneously, can accomplish the frequency conversion of motor and start, can realize the frequency conversion start of conveyer such as reciprocating air compressor machine, centrifugal separator, the conveyer of taking load, the breaker, spiral or such as rotary air compressor machine, centrifugal fan, centrifugal pump, the no-load starts; and when one frequency converter breaks down, the other frequency converter can be utilized to start, so that the continuous operation of a non-stop field is realized, the problem that the production situation is influenced due to the stop of equipment caused by the maintenance of the existing frequency converter is solved, and meanwhile, because the one frequency converter (the other standby frequency converter) is adopted to control the starting of 4 motors, the number of the frequency converters is saved, and the cost can be effectively saved.

Drawings

Fig. 1 is a circuit diagram of a disturbance-free switching device without reactors for four-to-one cascaded frequency converter according to the present invention.

In the figure: 1 is a main frequency converter, 2 is an auxiliary frequency converter, 3 is a 1# motor, 4 is a 2# motor, 5 is a 3# motor, and 6 is a 4# motor; QS1-1, QS1-2, QS2-1 and QS2-2 are isolating switches, KM 1-KM 4 and KM 7-KM 10 are contactors, QF 1-QF 5 are circuit breakers, and SQ1 is a grounding switch.

Detailed Description

The present invention will be further explained with reference to the accompanying drawings and examples.

As shown in fig. 1, the utility model discloses a cascade-type converter drags four circuit diagrams that do not have reactance ware undisturbed auto-change over device, it is by main converter 1, vice converter 2, 1

# motor

3, 2

# motor

4, 3

# motor

5, 4# motor 6 and alternating current network constitute, main converter 1 and vice converter 2 realize the frequency conversion start-up of 1# to 4# motor, one is commonly used in two converters, be used for controlling 1# to 4# motor and carry out the frequency conversion start-up, another stand-by (like vice converter 2), when frequency converter commonly used (like main converter 1) breaks down and needs maintenance or change, then utilize the frequency conversion start-up control that the reserve converter carried out 1# to 4# motor, in order to ensure the continuous operation on the scene that can not stop.

The input end of a main frequency converter 1 (such as a 1# frequency converter in the figure) is connected to the alternating current network through an isolating switch QS1-1, and the input end of an auxiliary frequency converter 2 (such as a 2# frequency converter in the figure) is connected to the alternating current network through an isolating switch QS 1-2; the output end of the main frequency converter 1 is connected with the input end of an isolating switch QS2-1, and the output end of the auxiliary frequency converter 2 is connected with the input end of the isolating switch QS 2-2. The isolating switches QS1-1 and QS1-2 adopt a single-pole double-throw switch, and the isolating switches QS2-1 and QS2-2 adopt a single-pole double-throw switch, so that when the single-pole double-throw switch is driven to be connected with the input end and the output end of the main frequency converter 1 to be closed, the main frequency converter 1 can be used for carrying out frequency conversion starting control on the motor; when the single-pole double-throw switch is driven to the contact point connected with the input end and the output end of the auxiliary frequency converter 2 to be closed, the auxiliary frequency converter 2 can be utilized to carry out frequency conversion starting control on the motor.

The output ends of the disconnecting switch SQ2-1 and the isolating switch SQ2-2 are respectively connected with the power input ends of the 1# motor, the 2# motor, the 3# motor and the 4# motor through normally open points of a contactor KM7, a contactor KM8, a contactor KM9 and a contactor KM10, so that the 1# motor, the 2# motor, the 3# motor and the 4# motor can be subjected to frequency conversion starting control by using the main frequency converter 1 or the auxiliary frequency converter 2. The power input ends of the 1# motor, the 2# motor, the 3# motor and the 4# motor are connected to the alternating current power grid through normally open points of a contactor KM1, a contactor KM2, a contactor KM3 and a contactor KM4 respectively, when the 1# motor, the 2# motor, the 3# motor and the 4# motor are subjected to frequency conversion starting by using a main frequency converter 1 or an auxiliary frequency converter 2, a loop between the corresponding motor and the alternating current power grid can be connected, and the alternating current power grid is used for supplying power to the motors at power frequency.

The circuit between the contactor KM1, the contactor KM2, the contactor KM3 and the contactor KM4 and the alternating current power grid is respectively connected with a breaker QF1, a breaker QF2, a breaker QF3 and a breaker QF4 in series. An isolating switch QF5 is connected in series on a line between the isolating switch SQ1-1 and the isolating switch SQ1-2 and the alternating current power grid, and a grounding switch SQ1 is connected in series between the output end of the isolating switch QF5 and the ground.

The utility model discloses a tandem type converter drags four no reactance ware undisturbed auto-change over device's working process as follows:

when the 1# frequency converter with the 1# motor operates, the isolating switches QS1-1 and QS2-1 are switched on, and the isolating switches QS1-2 and QS2-2 are switched off at the moment, so that the 2# frequency converter cannot operate. The operation of a 1# motor is selected and high-voltage electricity is sent, the contactor KM7 is automatically attracted, the 1# frequency converter is started at the moment, the 1# motor is subjected to frequency conversion starting, after the frequency converter operates to 50Hz, the master control monitors that the phases are consistent to perform undisturbed switching, the contactor KM1 is attracted, the KM7 is disconnected at the moment, and the 1# motor operates at power frequency.

When the 1# frequency converter with the 2# motor operates, an isolating switch QS1-1 and an isolating switch QS2-1 are closed; at the moment, the isolating switches QS1-2 and QS2-2 are all switched off, and the 2# frequency converter is ensured not to run. And (3) selecting a No. 2 motor to operate, sending high voltage to the motor, attracting a contactor KM8, and starting a No. 1 frequency converter at the moment. And (3) carrying out frequency conversion starting on the 2# motor, when the frequency converter runs to 50Hz, monitoring the phase consistency by the main control, carrying out undisturbed switching, carrying out suction of the contactor KM2, at the moment, disconnecting the KM8, and carrying out power frequency running on the 2# motor.

When the 1# frequency converter with the 3# motor operates, the isolating switch QS1-1 and QS2-1 are closed; at the moment, the isolating switches QS1-2 and QS2-2 are all switched off, and the 2# frequency converter is ensured not to run. And (3) selecting the motor to operate and sending high voltage power, attracting the contactor KM9, and starting the frequency converter 1 at the moment. And (3) carrying out frequency conversion starting on the motor 3# and carrying out undisturbed switching when the frequency converter runs to 50Hz and the master control monitors that the phases are consistent, carrying out suction of the contactor KM3, and at the moment, cutting off the KM9 and carrying out power frequency running on the motor 3 #.

When the 1# frequency converter with the 4# motor operates, an isolating switch QS1-1 and an isolating switch QS2-1 are closed; at the moment, the isolating switches QS1-2 and QS2-2 are all switched off, and the 2# frequency converter is ensured not to run. And (4) selecting the motor to operate and sending high voltage power, attracting the contactor KM10, and starting the frequency converter 1 at the moment. And (3) carrying out frequency conversion starting on the 4# motor, when the frequency converter runs to 50Hz, monitoring the phase consistency by the main control, carrying out undisturbed switching, carrying out suction of the contactor KM4, disconnecting the KM10 at the moment, and carrying out power frequency running on the 4# motor.

When the 1# frequency converter fails, the 2# frequency converter is started, and the process of starting the motor is similar to that of the 1# frequency converter.

Therefore, the invention discloses a one-to-four non-reactor undisturbed switching device of a cascade frequency converter, which comprises:

(1) The field starting equipment is used for one time, and any equipment can independently start four loads on the field. An operator can randomly select a starting sequence to start the load according to the field condition without relevant logic restriction, and a complex control system in the system can ensure the convenience of field operation and the safety and reliability of the field.

(2) The principle of one use and one standby is adopted, the single-pole double-throw switch is used for carrying out random selection, after the selection is finished, the standby frequency converter can be overhauled and maintained during one operation, the normal and reliable state of the standby frequency converter is ensured, and therefore the stable operation of the field load equipment is ensured.

(3) Any one motor can be started by the two devices at will, the starting sequence of the motor has no restriction condition, and the flexibility application of the field load is ensured according to the actual requirements of customers while the safety is ensured through logic judgment.

(4) The frequency converter equipment uses the undisturbed switching function without an electric reactor, and when any motor is selected, the current impact of the motor in the switching process of the frequency converter can be avoided, the field load equipment is protected, and the service life of the load equipment is prolonged.

(5) The design of one-driving-multiple main loops has strong replaceability, ensures the actual economic performance of a site while ensuring the use effect of the site, and optimizes the site experience of customers.

The utility model discloses a tandem type converter drags four no reactance ware undisturbed auto-change over device, cooperation automatic control system has effectively solved the great condition of air compressor machine starting process disturbance, and the field application shows that its ripe reliable being applied to high-pressure variable frequency speed control system drags the air compressor machine, can improve air compressor machine control degree of automation greatly, reduces the field maintenance volume, brings considerable benefit, is worth wideling popularize.

Claims

1. A disturbance-free switching device without an electric reactor and with four split cascaded frequency converters comprises a main frequency converter (1), an auxiliary frequency converter (2), a 1# motor (3), a 2# motor (4), a 3# motor (5) and a 4# motor (6), wherein the input end of the main frequency converter and the input end of the auxiliary frequency converter are respectively connected to an alternating current network through an isolating switch SQ1-1 and an isolating switch SQ1-2, and the output end of the main frequency converter and the output end of the auxiliary frequency converter are respectively connected to the input ends of the isolating switch SQ2-1 and the isolating switch SQ 2-2; the method is characterized in that: the output ends of the isolating switch SQ2-1 and the isolating switch SQ2-2 are respectively connected with the power input ends of the 1# motor, the 2# motor, the 3# motor and the 4# motor through normally open points of a contactor KM7, a contactor KM8, a contactor KM9 and a contactor KM10, and the power input ends of the 1# motor, the 2# motor, the 3# motor and the 4# motor are respectively connected with an alternating current network through normally open points of a contactor KM1, a contactor KM2, a contactor KM3 and a contactor KM 4.

2. The cascaded frequency converter one-to-four non-reactor undisturbed switching device of claim 1 wherein: and the circuit between the contactor KM1, the contactor KM2, the contactor KM3 and the contactor KM4 and the alternating current power grid is respectively connected with a breaker QF1, a breaker QF2, a breaker QF3 and a breaker QF4 in series.

3. The tandem-type frequency converter one-to-four undisturbed switching device of claim 1 or 2 wherein: an isolating switch QF5 is connected in series on a line between the isolating switch SQ1-1 and the isolating switch SQ1-2 and the alternating current power grid, and a grounding switch SQ1 is connected in series between the output end of the isolating switch QF5 and the ground.

4. The tandem-type frequency converter one-to-four undisturbed switching device of claim 1 or 2 wherein: the isolation switch SQ1-1 and the isolation switch SQ1-2 are single-pole double-throw switches, and the isolation switch SQ2-1 and the isolation switch SQ2-2 are single-pole double-throw switches.