CN114759758A - Long-stator linear motor stator segment parallel power supply connection circuit and switch switching method thereof - Google Patents

Abstract

The invention provides a long stator linear motor stator section parallel power supply connecting circuit and a switch switching method thereof, wherein a motor stator section is connected with a current transformer through a switch composed of a bidirectional thyristor, and neutral points of stator sections which are powered by the same current transformer and are sequentially electrified and deenergized are connected; when the rotor of the motor leaves a certain stator section, a turn-off signal is sent to the bidirectional thyristors of all phases connected with the stator section, and all phase switches of the same phase connected with the next stator section are sequentially turned on simultaneously according to the sequence of zero-crossing turn-off of each phase current; when one converter supplies power for a multi-section motor stator section or a plurality of converters supply power for different motor stator sections respectively, the circuit and the switching method have the advantages that the output current of the converter and the current in a feed cable are stable and have no sudden change in the power supply switching process of the stator section, the current is stable and has no distortion when a switch of the stator section is switched off, and the current has no impact when the switch of the stator section is switched on.

Description

Long-stator linear motor stator segment parallel power supply connection circuit and switch switching method thereof

Technical Field

The invention belongs to the field of motors, and particularly relates to a parallel power supply connecting circuit for a stator section of a long-stator linear motor and a switch switching method thereof.

Background

Compared with a rotating motor, the linear motor has the advantages of simple structure, high response speed and good tracking effect, and can be widely applied to the field of linear driving, such as a part ground test system of a high-speed carrying system of a maglev train, an electromagnetic propulsion acceleration system, a vehicle high-speed collision test system, aerospace and the like. Generally, linear motors are divided into a long armature linear motor and a short armature linear motor, the short armature linear motor is represented by a medium-low speed magnetic suspension train, direct current on the ground is transmitted to a vehicle through a bow net or a third rail, and voltage, current and frequency are converted to supply power to a vehicle-mounted armature so as to drive the train to run. The typical application of the long-armature linear motor is a high-speed magnetic suspension train system, such as a german TR series magnetic suspension train, a japanese superconducting magnetic suspension train and the like, wherein a long-armature stator is arranged on a track on the ground, alternating current output by a ground converter is fed into an armature winding through a switch, and the total length of the ground armature is the length of a train line track. The rotor of the long stator armature linear motor (arranged at the lower part of a train) is far shorter than the stator armature fixed on a track, if the stator is completely electrified, the proportion of an effective area is very small, the efficiency is very low, the power factor is very small, the requirement on the capacity of a power supply converter is high, and the manufacturing cost is high. The long stator of the motor with the armature is generally segmented when applied, and each segment is called a stator segment. The alternating current output by the ground converter passes through the feeder cable, the switch and then is fed into the stator segments. And supplying power to the stator sections near the motor rotor, and switching to supply power to the corresponding stator sections according to the moving process of the motor rotor when the rest stator sections do not supply power. Therefore, the system efficiency can be effectively improved, and the voltage and current levels of a single converter can be reduced.

At present, two common power supply modes of a linear motor stator section include a series power supply mode and a parallel power supply mode. The series power supply mode is that a plurality of armature windings of stator segments arranged along a line are connected in series through a switch and an intermediate bus and then connected into a power supply converter; when the rotor of the driving motor operates, the switch connected with the stator segments is controlled to be sequentially switched on or switched off, and the converter supplies power to the sequentially arranged stator segments in an alternate switching mode. And when the motor rotor is switched once, the stator section where the motor rotor leaves is powered off, and the stator section where the motor rotor is located or the stator section where the motor rotor is about to enter is powered on. The power supply mode of serially connecting the stator segments requires that the voltage grade of a converter system is very high, the voltage-resistant level of armature windings of the motor stators which are serially connected together, the voltage-resistant level of switches, the voltage-resistant level of feed cables and the like are very high, the number of used feed cables and switches is large, when one stator segment or one group of switches which are serially connected together breaks down, one stator segment is quit working, and the fault tolerance is poor. The document entitled "linear motor section power supply strategy taking current zero crossing into account" (zhangming yuan J university of navy, 2019,31(04):11-16) applies linear motors supplied by sections in series to a rapid electromagnetic drive system. The chinese invention patent CN 110912493 a "sectional power supply system for induction linear motor" proposes an improved series power supply connection mode, which reduces the number of switches by adding power supply bus bars.

The parallel power supply mode is that armature windings of a plurality of linear motor stator segments arranged along a line are directly connected to the output end of the converter through a switch, and the linear motor stator segments arranged in sequence are supplied with power in an alternating mode. In a parallel power supply mode, the voltage level of a single converter is low, and even if one stator section fails to be switched, the rest stator sections can still normally operate, so that the fault tolerance is high. Compared with series power supply, the power supply mode has the advantages of high power and high speed electromagnetic driving occasions.

The neutral point of a stator winding is independent in a common parallel power supply mode, a switch is generally composed of high-voltage and high-current thyristors, and a zero-crossing turn-off strategy can be adopted for parallel power supply. However, when one phase of current crosses zero and the phase is disconnected, the circuit changes, the waveform of the other phase of current changes, the current is distorted, and the current is not sequentially turned off according to the original turn-off sequence, so that the turn-off time is prolonged. When at least two phases are switched on, the circuit loop only has current, so that a one-phase circuit cannot be switched on independently, the current overshoot is increased, the current harmonic waves are increased, and the switching time of each phase circuit cannot be controlled independently, so that the current overshoot is reduced, and a large amount of harmonic waves generated in the switching process are reduced. Meanwhile, the requirements on the output voltage of the converter and the allowable current of a motor winding are high, and the system cost is high.

Disclosure of Invention

The invention aims to provide a stator section parallel power supply connection circuit of a long stator linear motor and a switch switching method thereof, and solves the problems that when a switch connected with a stator section of the stator section parallel power supply linear motor is switched, the current is distorted in the process of switching off the switch of a last certain section, the current has impact in the process of switching on the switch of a next certain section, and the current is interrupted in the process of switching power supply of the stator section.

In order to realize the purpose, the invention adopts the following scheme:

a kind of long stator linear motor stator section connects the power supply connecting circuit in parallel, it includes converter, linear motor stator section, linear motor mover, feed-in cable, diverter switch and connecting cable, divide the long stator linear motor stator armature into a plurality of linear motor stator sections, each linear motor stator section connects a series of diverter switches, then connect to the converter output end for supplying power of the linear motor stator section through the feed-in cable; when the linear motor stator section is powered, the linear motor stator section where the linear motor rotor is located and a change-over switch of the linear motor stator section where the linear motor rotor is about to enter are closed, and the converter supplies power for the linear motor stator sections; disconnecting the change-over switch of the linear motor stator section just left by the linear motor rotor and the linear motor stator section not entering, and not supplying power to the linear motor stator sections by the converter; when the length of the rotor of the linear motor is less than or equal to the length of the stator segment of one linear motor, at least two adjacent segments of the stator segments of the linear motor supply power simultaneously; when the length of the rotor of the linear motor is greater than one section of the stator section of the linear motor and less than or equal to the length of the stator section of the linear motor, at least three sections of continuous stator sections of the linear motor are supplied with power simultaneously; when the length of the rotor of the linear motor is greater than that of the two sections of linear motor stator sections and less than or equal to that of the three sections of linear motor stator sections, at least four continuous sections of linear motor stator sections are simultaneously powered, and the like.

Further, the long stator linear motor is a long stator armature linear asynchronous motor or a long stator armature linear synchronous motor.

Further, the long stator linear motor is a motor with a single-side structure form or a motor with a double-side structure form.

Furthermore, the linear motor stator sections simultaneously supplying power are connected to the output end of the same converter, or a plurality of linear motor stator sections simultaneously supplying power are connected to the output ends of two or more different converters.

Furthermore, neutral points of stator segments which are supplied with power by the same converter and are sequentially electrified and deenergized are connected, and the linear motor stator segments are sequentially numbered along the running direction, namely: under the condition that two adjacent linear motor stator sections supply power simultaneously, neutral points of the stator sections 1#, 3#, 5# · (2m1+1) # which are connected into the same converter in parallel are connected together, and neutral points of the stator sections 2#, 4#, 6# · (2m1+2) # which are connected into the same converter in parallel are connected together; under the condition that three continuous stator sections supply power simultaneously, neutral points of stator sections 1#, 4#, 7# · (3m1+1) # which are connected into the same converter in parallel are connected together, neutral points of stator sections 2#, 5#, 8# · (3m1+2) # which are connected into the same converter in parallel are connected together, and neutral points of stator sections 3#, 6#, 9# · (3m1+3) # which are connected into the same converter in parallel are connected together; under the condition that the four continuous stator sections supply power simultaneously, neutral points of the stator sections 1#, 5#, 9#, 10#, 4m1+2) which are connected in parallel into the same converter are connected together, neutral points of the stator sections 2#, 6#, 10#, 4m1+2) which are connected in parallel into the same converter are connected together, neutral points of the stator sections 3#, 7#, 11#, 4m1+3) which are connected in parallel into the same converter are connected together, neutral points of the stator sections 4#, 8#, 12#, 4m1+4) which are connected in parallel into the same converter are connected together, and the rest is repeated, wherein m1 is a natural number.

The invention also provides a switch switching method of the long stator linear motor stator section parallel power supply connection circuit, which determines the linear motor stator section to be supplied with power according to the position of the linear motor rotor, when the linear motor rotor moves, the converter alternately supplies power to the linear motor stator sections, when the linear motor rotor leaves a certain linear motor stator section, a turn-off signal is sent to each phase bidirectional thyristor connected with the linear motor stator section, and each phase switch connected with the next linear motor stator section is simultaneously and sequentially switched on according to the sequence of zero-crossing turn-off of each phase current to complete the switching.

The beneficial effects of the invention are: the invention provides a circuit connected with neutral points between stator sections of a linear motor connected in parallel under a power supply line of the same converter, which adopts a switching method of switching off the current of the previous stator section by zero crossing and simultaneously switching on the next stator section, thereby reducing the problems of current distortion in the process of switching off the previous stator section, current impact in the process of switching on the next stator section and current discontinuity in the whole switching process.

Drawings

FIG. 1 is a block power supply bilateral linear motor drive structure of the present invention;

FIG. 2 is a schematic diagram of a circuit for connecting two adjacent linear motor stator segments in parallel power supply by a single current transformer according to the present invention;

FIG. 3 is a schematic diagram of a circuit for connecting two current transformers according to the present invention to supply power to two adjacent linear motor stator segments in parallel;

FIG. 4 is a schematic diagram of a circuit for connecting a single current transformer to supply power to three adjacent linear motor stator segments in parallel;

FIG. 5 is a schematic diagram of a circuit for connecting three current transformers of the present invention to a parallel power supply for three adjacent linear motor stator segments;

FIG. 6 is a schematic diagram of a circuit for connecting two adjacent stator segments of a double three-phase linear motor with parallel power supplies of two converters according to the present invention;

FIG. 7 is a schematic view of a single stator segment current waveform of the present invention;

fig. 8 is a full-range current waveform diagram of the current transformer of the present invention.

In the figure, a 1 converter 1#, a 2 converter 2#, a 3 converter 3#, a 10 converter 1# output cable, a 11 converter 2# output cable, linear motor stator sections 1#, 2#, 3#, 4#, 5#, 6# … … m1# and 100 linear motor rotors 30, 31, 32, 33 and 34 are sequentially arranged in sequence, 35 … … n1 sequentially arranged feed cables, 40, 41, 42, 43, 44, 45 … … n2 sequentially arranged change-over switches, 50, 51, 52, 53, 54, 55 … … n3 sequentially arranged connecting cables, 60 middle point connecting cables of the stator segment 1, 60 'and 4, 62 middle point connecting cables of the stator segment 3, 61', and m, m1, n1, n2 and n3 are natural numbers.

Detailed Description

The invention is further described below with reference to the drawings and the detailed description, which are given for illustration only and do not limit the scope of the invention.

The structure diagram of the sectional power supply double-sided linear motor drive shown in fig. 1. Taking the example that the length of the linear motor mover 100 is smaller than that of one stator segment, since the linear motor mover 100 is coupled to two stator segments at most at the same time, the two stator segments need to be powered on at the same time to keep the coupling magnetic field between the linear motor stator segment and the linear motor mover 100 constant. The linear motor stator comprises a current transformer 1#1, a current transformer 2#2, linear motor stator sections 1#, 2#, 3#, 4#, 5#, 6# … … m1# 20, 21, 22, 23 … … m, a linear motor rotor 100, feed cables 30, 31, 32, 33 … … n1 which are arranged in sequence, change-over switches 40, 41, 42 and 43 … … n2 which are arranged in sequence and connecting cables 50, 51, 52 and 53 … … n3 which are arranged in sequence. A stator armature of a long stator linear motor is divided into a plurality of linear motor stator sections 20, 21, 22 and 23 … … m, each linear motor stator section is connected with a group of change-over switches, and then is connected to an output end of a current transformer for supplying power to the linear motor stator sections through a corresponding current transformer 1# output cable 10 and a corresponding current transformer 2# output cable 11, wherein m represents m1# of the linear motor stator sections. Preferably, the stator segments simultaneously supplying power can be connected to the output end of the same converter, and a plurality of stator segments simultaneously supplying power can be connected to two or more different converter output ends. When in power supply operation, the change-over switches of the stator section where the linear motor rotor is located and the stator section where the linear motor rotor is about to enter are closed, and the converter supplies power to the stator sections; the change-over switches of the stator segments just leaving and the stator segments not entering the linear motor rotor are switched off, and the current transformer does not supply power to the stator segments. The number of the power supply stator sections is determined according to the length relation between the linear motor rotor and the length of a single stator section. When the length of a rotor of the linear motor is smaller than or equal to the length of one stator segment, at least two adjacent stator segments supply power simultaneously; when the length of the rotor of the linear motor is greater than one section of stator segment and less than or equal to two sections of stator segments, at least three continuous sections of stator segments supply power simultaneously; when the length of the rotor of the linear motor is larger than the two-section stator segment and smaller than or equal to the three-section stator segment, at least four continuous sections of stator segments supply power simultaneously, and so on.

The method comprises the steps that a stator section to be powered is determined according to the position of a rotor of the linear motor, when the rotor of the linear motor alternately supplies power to a given subsection in the moving process of the rotor of the linear motor and the rotor of the linear motor leaves a certain stator section, a turn-off signal is sent to each phase bidirectional thyristor connected with the stator section, and each phase switch connected with the next stator section is sequentially turned on according to the sequence of zero-crossing turn-off of each phase current to complete switching.

It should be noted that, the relationship between the length of the linear motor rotor and the length of the linear motor stator segment may be determined according to the output voltage, current, frequency of the linear motor system converter and the operation speed of the motor rotor.

It should be understood that when multiple converters are connected in parallel for supplying power, the number of the multiple converters required is optional, for example, the length of a rotor of the linear motor is greater than one stator section length, and less than two stator section lengths, and the number of the stator sections is three, three converters can be selected to supply power to three stator sections at the same time, four converters can be selected to supply power to four stator sections at the same time, and the selection is performed according to actual requirements, and the neutral point connection mode between the stator sections is not changed.

Optionally, the parallel power supply connection circuit of the stator segments of the long-stator linear motor adopts a single converter for power supply, and the stator segments are all connected to 1 converter through a change-over switch. When two adjacent stator sections are simultaneously powered, neutral points of the stator sections 1#, 3#, 5# · (2m1+1) # are connected together through a midpoint connecting cable, and neutral points of the stator sections 2#, 4#, 6# · (2m1+2) # are connected together through a midpoint connecting cable; when three continuous stator sections are simultaneously powered, neutral points of the stator sections of 1#, 4#, 7# · (3m1+1) # are connected together through a midpoint connecting cable, neutral points of the stator sections of 2#, 5#, 8# · (3m1+2) # are connected together through a midpoint connecting cable, and neutral points of the stator sections of 3#, 6#, 9# · (3m1+3) # are connected through a midpoint connecting cable; when four continuous stator sections are simultaneously powered, neutral points of the stator sections of 1#, 5#, 9# (4m1+1) # are connected together through a midpoint connecting cable, neutral points of the stator sections of 2#, 6#, 10# (4m1+2) # are connected together through a midpoint connecting cable, neutral points of the stator sections of 3#, 7#, 11#, 4m1+3) # are connected through a midpoint connecting cable, neutral points of the stator sections of 4#, 8#, 12#, 4m1+4) # are connected together through a midpoint connecting cable, and m1 is a natural number and the like in sequence.

Optionally, the parallel power supply connection circuit for the stator segments of the long-stator linear motor is powered by multiple inverters, when two adjacent stator segments are powered simultaneously, two inverters are used for supplying power, the 1#, 3#, 5# · (2m1+1) # stator segments are all connected to the inverter 1# through respective switches, the neutral points of the 1#, 3#, 5# · (2m1+1) # stator segments are connected together through a midpoint connecting cable, the 2#, 4#, 6# · (2m1+2) # stator segments are all connected to the inverter 2# through respective switches, and the neutral points of the 2#, 4#, 6# · (2m1+2) # stator segments are connected together through a midpoint connecting cable; when three continuous stator sections are simultaneously powered, three converters are adopted to supply power, the stator sections 1#, 4#, 7# · (3m1+1) # are all connected to the converter 1#1 through respective change-over switches, neutral points of the stator sections 1#, 4#, 7# · (3m1+1) # are connected together through a midpoint connecting cable, the stator sections 2#, 5#, 8# · (3m1+2) # are all connected to a converter 2#2 through respective change-over switches, the neutral points of the stator segments 2#, 5#, 8# · (3m1+2) # are connected together through a midpoint connecting cable, the stator segments 3#, 6#, 9# · (3m1+3) # are all connected to the converter 3# through respective change-over switches, and connecting neutral points of the stator sections of the 3#, 6#, 9# · (3m1+3) # by neutral point connecting cables; when four continuous stator sections are simultaneously powered, four converters are adopted for power supply, the stator sections 1#, 5#, 9#, 4m1+1) # are all connected to the converter 1# through respective change-over switches, the neutral points of the stator sections 1#, 5#, 9#, 4m1+1) # are all connected together through neutral point connecting cables, the stator sections 2#, 6#, 10#, 4m1+2) # are all connected to the converter 2# through respective change-over switches, the neutral points of the stator sections 2#, 6#, 10#, 4m1+2) # are connected together through neutral point connecting cables, the stator sections 3#, 7#, 11#, 4m1+ 3)' are connected to all the converters 3# through respective change-over switches, and the stator sections 3#, 7, 11#, 4m 1# are connected to the neutral point connecting cables, the stator segments 4#, 8#, 12# · (4m1+4) # are all connected to the converter 4# through respective switches, and the neutral points of the stator segments 4#, 8#, 12# · (4m1+4) # are connected together through a midpoint connecting cable, m1 is a natural number, and so on.

Fig. 2 is a schematic diagram of a circuit for connecting two adjacent linear motor stator segments in parallel power supply by using a single current transformer according to the invention. The linear motor stator segments 20, 21, 22, 23 … … m are connected to the respective switches 40, 41, 42, 43 … … n2 through connecting cables 50, 51, 52, 53 … … n3, and the switches 40, 41, 42, 43 … … n2 are all connected to the output end of 1 converter 1#1 through feeder cables 30, 31, 32, 33 … … n 1. Under the condition that two adjacent linear motor stator sections are simultaneously powered, neutral points of the stator sections 1#, 3#, 5# · (2m1+1) # are connected together through neutral point connecting cables 160 of the stator sections, neutral points of the stator sections 2#, 4#, 6# · (2m1+2) # are connected together through neutral point connecting cables 361 of the stator sections, and m, m1, n1 and n2 are natural numbers.

Fig. 3 is a schematic diagram of a parallel power supply connection circuit for two adjacent converters to supply power to two adjacent stator segments of a linear motor, for a multi-converter power supply system, when two adjacent stator segments supply power simultaneously, two converters 1#1 and 2#2 are used for supplying power, the 1#, 3#, 5# · (2m1+1) # stator segments are connected to respective change-over switches 40, 42, … … (n2-1) through connecting cables 50, 52, … … (n3-1), the change-over switches 40, 42, … … (n2-1) are all connected to the converter 1#1 through feed-in cables 30, 32, … … (n1-1), and neutral points of the 1#, 3#, 5# · (2m1+1) # stator segments are connected together through a neutral point connecting cable 160 of the stator segments; 2#, 4#, 6# · (2m1+2) # stator segments are connected to respective change-over switches 41, 43, … … n2 through connecting cables 51, 53, … … n3, the change-over switches 41, 43, … … n2 are all connected to the converter # 22 through feeder cables 31, 33, … … n1, neutral points of the 2#, 4#, 6# · (2m1+2) # stator segments are connected together through a neutral point connecting cable 361 of the stator segments, and m1, n1, n2 and n3 are natural numbers.

Fig. 4 is a schematic diagram of a circuit for connecting three adjacent linear motor stator segments in parallel power supply by using a single current transformer. The linear motor stator segments 20, 21, 22, 23 … … m are connected to the respective switches 40, 41, 42, 43 … … n2 through connecting cables 50, 51, 52, 53 … … n3, and the switches 40, 41, 42, 43 … … n2 are all connected to the output end of 1 converter 1#1 through feeder cables 30, 31, 32, 33 … … n 1. Under the condition that three continuous stator sections supply power simultaneously, neutral points of the stator sections 1#, 4#, 7# · (3m1+1) # are connected together through neutral point connecting cables 160 of the stator sections, neutral points of the stator sections 2#, 5#, 8# · (3m1+2) # are connected together through neutral point connecting cables 361 of the stator sections, neutral points of the stator sections 3#, 6#, 9# · (3m1+3) # are connected through neutral point connecting cables 562 of the stator sections, and m, m1, n1 and n2 are natural numbers, and so on.

Fig. 5 is a schematic diagram of a circuit for connecting three current transformers of the invention to supply power to three adjacent linear motor stator segments in parallel. When three converters are used for supplying power, the 1#, 4#, 7# · (3m1+1) # stator segments are connected to respective change-over switches 40, 43, … … (n2-2) through connecting cables 50, 53, … … n3-2, the change-over switches 40, 43, … … (n2-2) are all connected to the converter 1#1 through feed-in cables 30, 33, … … (n1-2), and neutral points of the 1#, 4#, 7# · (3m1+1) # stator segments are connected together through a neutral point connecting cable 160 of the stator segments; connecting the stator segments 2#, 5#, 8# · (3m1+2) # to respective change-over switches 41, 44, … … (n2-1) through connecting cables 51, 54, … … (n3-1), wherein the change-over switches 41, 44, … … (n2-1) are all connected to the converter 2#2 through feeder cables 31, 34, … … (n1-1), and connecting neutral points of the stator segments 2#, 5#, 8# · (3m1+2) # together through a neutral point connecting cable 361 of the stator segments; the stator segments of 3#, 6#, 9# · (3m1+3) # are connected to respective change-over switches 42, 45, … … n2 through connecting cables 52, 55, … … n3, the change-over switches 42, 45, … … n25 are all connected to the converter 3#, the neutral points of the stator segments of 3#, 6#, 9# · (3m1+3) # are connected through neutral point connecting cables 562 of the stator segments, and m, m1, n1, n2 and n3 are natural numbers.

Optionally, in some embodiments, the linear electric machine may be a multiphase electric machine, such as a double three-phase electric machine, the neutral point connection circuit is shown in fig. 6, the neutral point connection manner of the stator section windings of the linear electric machine of the two current transformer parallel power supply connection circuits is that the current transformer 1# is powered by 1#, 3#, 5# · (2m1+1) # stator sections 20, 22, 24 … … (m-1), and the double neutral points of 1#, 3#, 5# · (2m1+1) # stator sections 20, 22, 24 … … (m-1) are respectively connected through neutral point connection cables 1, 260, 60' of the stator sections; the 2# converter 2 supplies power to the 2#, 4#, 6# · (2m1+2) # stator sections 21, 23 and 25 … … m, and double neutral points of the 2#, 4#, 6# · (2m1+2) # stator sections 21, 23 and 25 … … m are respectively connected through neutral point connecting cables 3, 461 and 61' of the stator sections, and m1 are natural numbers.

Alternatively, in some embodiments, the linear motor may be a long stator armature linear asynchronous motor, a long stator armature linear synchronous motor, or other forms of long stator armature linear motors. The long stator linear motor can be a motor with a single-side structure form, and can also be a motor with a double-side structure form.

FIG. 7 is a single stator segment current waveform, for a single stator segment current, when the single stator segment current is switched on, all phases are switched on in sequence according to a current phase sequence, and the current has no impact; when the switch-off is carried out, all phases are switched off in sequence according to the current phase sequence, and the current has no distortion.

Fig. 8 is a full-range current waveform diagram of the converter. For the current of the converter in the whole course, the current is not interrupted in the switching process, the current has no impact, and the current change trend is not influenced. The parallel power supply connecting circuit for the stator sections of the linear motor ensures that the current of the converter is not influenced by the switching of the sectional stator sections in the sectional parallel power supply system for the long-stator linear motor; for motor control, the current is continuous, so that the motor control is simpler.

Although illustrative embodiments of the present invention have been described above to facilitate the understanding of the present invention by those skilled in the art, it should be understood that the present invention is not limited to the scope of the embodiments, but various changes may be apparent to those skilled in the art, and it is intended that all inventive concepts utilizing the inventive concepts set forth herein be protected without departing from the spirit and scope of the present invention as defined and limited by the appended claims.

Claims (6)

1. A kind of long stator linear motor stator section connects the power supply connecting circuit in parallel, it includes converter, linear motor stator section, linear motor mover, feed-in cable, diverter switch and connecting cable, divide the long stator linear motor stator armature into a plurality of linear motor stator sections, each linear motor stator section connects a series of diverter switches, then connect to the converter output end for supplying power of linear motor stator section through the feed-in cable; when the linear motor stator section supplies power to operate, the linear motor stator section where the linear motor rotor is located and a change-over switch of the linear motor stator section where the linear motor rotor is about to enter are closed, and the converter supplies power to the linear motor stator sections; disconnecting the change-over switches of the linear motor stator sections which are just left by the linear motor rotor and the linear motor stator sections which are not entered by the linear motor rotor, wherein the current transformer does not supply power to the linear motor stator sections;

The linear motor is characterized in that when the length of a rotor of the linear motor is less than or equal to the length of a stator segment of the linear motor, at least two adjacent segments of stator segments of the linear motor supply power simultaneously; when the length of the rotor of the linear motor is greater than one section of the stator section of the linear motor and less than or equal to the length of the stator section of the linear motor, at least three sections of continuous stator sections of the linear motor are supplied with power simultaneously; when the length of the rotor of the linear motor is greater than that of the two sections of linear motor stator sections and less than or equal to that of the three sections of linear motor stator sections, at least four continuous sections of linear motor stator sections are simultaneously powered, and the like.

2. The long stator linear motor stator segment parallel power supply connection circuit of claim 1, wherein: the long stator linear motor is a long stator armature linear asynchronous motor or a long stator armature linear synchronous motor.

3. The long stator linear motor stator segment parallel power supply connection circuit of claim 1, wherein: the long stator linear motor is a motor with a unilateral structure form or a motor with a bilateral structure form.

4. The long stator linear motor stator segment parallel power supply connection circuit of claim 1, wherein: the linear motor stator segments which are supplied with power simultaneously or alternatively are connected to the output end of the same converter, or a plurality of linear motor stator segments which are supplied with power simultaneously or alternatively are connected to the output ends of two or more different converters.

5. The long stator linear motor stator segment parallel power supply connection circuit of claim 1, wherein: neutral points of stator segments which are powered by the same converter and are sequentially powered on and powered off are connected, namely neutral points of stator segments of two adjacent linear motors are connected together under the condition that the stator segments of two adjacent linear motors are powered simultaneously, neutral points of stator segments of 1#, 3#, 5#, 6#, 2m1+ 1# which are connected into the same converter in parallel are connected together, and neutral points of stator segments of 2#, 4#, 6#, 2m1+ 2# which are connected into the same converter in parallel are connected together; under the condition that three continuous stator sections supply power simultaneously, neutral points of stator sections 1#, 4#, 7# · (3m1+1) # which are connected into the same converter in parallel are connected together, neutral points of stator sections 2#, 5#, 8# · (3m1+2) # which are connected into the same converter in parallel are connected together, and neutral points of stator sections 3#, 6#, 9# · (3m1+3) # which are connected into the same converter in parallel are connected together; under the condition that the four continuous stator sections supply power simultaneously, neutral points of stator sections 1#, 5#, 9#, 10#, 4m1+2) which are connected in parallel into the same converter are connected together, neutral points of stator sections 2#, 6#, 10#, 4m1+2) which are connected in parallel into the same converter are connected together, neutral points of stator sections 3#, 7#, 11#, 4m1+3) which are connected in parallel into the same converter are connected together, neutral points of stator sections 4#, 8#, 12#, 4m1+4) which are connected in parallel into the same converter are connected together, and the rest is repeated, wherein m1 is a natural number.

6. The method for switching the switching of the circuit for connecting the parallel supply of stator segments of a long-stator linear motor according to any one of claims 1 to 5, wherein: the method comprises the steps of determining a linear motor stator section to be powered according to the position of a linear motor rotor, sending a turn-off signal to each phase bidirectional thyristor connected with the linear motor stator section when the linear motor rotor alternately supplies power to the linear motor stator section and leaves a certain linear motor stator section in the moving process of the linear motor rotor, and simultaneously sequentially turning on each phase switch connected with the next linear motor stator section according to the sequence of zero-crossing turn-off of each phase current to complete switching.

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