Low-impact modeling and switching method for segmented power supply of linear motors based on thyristors

Abstract

This invention belongs to the field of linear motor current modeling and switching control, specifically involving a thyristor-based method for low-impact modeling and switching of segmented power supply for linear motors. It aims to solve the problem that existing parallel segmented power supply methods for linear motors require external cables and suffer from high inrush current. The invention includes: firstly, establishing mathematical models for four states during the segmented power supply switching process: uncoupled, first parallel coupling, separate coupling, and second parallel coupling. Then, combining the parallel connection and zero-state response of the stator, it analyzes the impact of different voltage switching angles on the converter current, and performs state switching based on the mover position information and voltage phase angle. This invention achieves segmented power supply switching in a parallel power supply structure for linear motors without the need for external cables, reducing the inrush current caused by stator parallel connection and zero-state response in traditional switching methods.

Description

Technical Field

[0001] This invention belongs to the field of linear motor current modeling and switching control, and specifically relates to a low-impact modeling and switching method for segmented power supply of linear motors based on thyristors. Background Technology

[0002] Segmented power supply for long-stator linear motors has been widely used in applications requiring rapid acceleration and high thrust due to its high power factor and relatively small inverter capacity. Considering the large current and short switching time, two anti-parallel thyristors are selected as the switching switches for segmented power supply. Thyristors are semi-controlled devices with nonlinear characteristics, exhibiting zero-crossing turn-off. However, improper control during segmented power supply switching can generate inrush currents, leading to insufficient utilization of the converter capacity.

[0003] At present, segmented power supply is mainly divided into series power supply and parallel power supply according to different stator connection methods. For series structure, the air gap magnetic field and electromagnetic parameters remain unchanged when segmented power supply is switched. The control circuit is simple and the stator parallel connection will not generate a large inrush current. The disadvantage is that it requires a converter with a voltage capacity of several times. Some literatures connect the three stator segments in series and propose a method of switching based on two conditions: mover position information and current zero crossing point [1]. The switching process is divided into normal mode, parallel mode and misaligned mode, and different motor parameters are used for control. This method makes the stator parallel connection only occur in one of the series stators, which has little impact on the linear motor. However, it requires an inverter with a voltage capacity of 3 times and an additional power supply bus. Parallel power supply can improve the voltage utilization rate of the converter, but the motor parameters change when segmented power supply is switched and the stator parallel connection will cause a large current inrush of the linear motor. Another document discloses a modeling method for a linear induction motor based on segmented power supply of a virtual mover [2]. When the mover switches on different stators, different motor parameters are used to control it according to the degree of coupling between the stator and the mover, which solves the problem of thrust fluctuation during switching. However, this method focuses on the change of motor parameters during switching rather than the switching of stator windings.

[0004] The following documents are technical background information related to this invention:

[0005] [1] Zhang Mingyuan, Ma Weiming, Xu Xinghua, et al. A segmented power supply strategy for linear motors considering zero current crossing [J]. Proceedings of the CSEE, 2019.

[0006] [2] Xu Fei, Kong Ganlin, Zhang Mingyuan, et al., A modeling method for segmented power supply linear induction motor based on virtual mover, Linear Motor, 2020-10-13, CN112380670A. Summary of the Invention

[0007] To address the aforementioned problems in existing technologies, namely the need for external cables and high inrush current in parallel segmented power supply of existing linear motors, this invention provides a low-impact modeling method for segmented power supply of linear motors based on thyristors. The linear motor includes a stator n with A... n B n C n Phase, where n is the number of stators in the linear motor, characterized in that the modeling method includes:

[0008] Step S10: Based on the relative positions of the mover and stator after the linear motor starts, obtain the coupling state of the linear motor; the coupling state includes no coupling state, first parallel coupling state, separate coupling state and second parallel coupling state;

[0009] Step S20: When the linear motor starts and there is no mover covering it, the linear motor is in an uncoupled state, and a mathematical model of the uncoupled state is constructed.

[0010] When two phases of the three phases of the stator below the relative position of the mover of the linear motor are connected, the linear motor is in the first parallel coupling state, and a mathematical model of the first parallel coupling state is constructed.

[0011] When one of the three phases of the stator before the relative position of the mover of the linear motor is zero-crossing and turned off, the linear motor is in a separated coupling state, and a mathematical model of the separated coupling state is constructed.

[0012] When the remaining phase of the three phases of the next stator of the linear motor is turned on, the linear motor is in the second parallel coupling state, and a mathematical model of the second parallel coupling state is constructed.

[0013] In some preferred embodiments, the uncoupled state mathematical model is expressed as:

[0014]

[0015] Among them, i A i B i C Here, represents the three-phase current of the linear motor, U is the amplitude of the input voltage of the linear motor, ω is the angular frequency of the stator input voltage of the linear motor, and l is the three-phase current of the linear motor. ms Let t be the stator inductance of the linear motor, and t be the time variable.

[0016] In some preferred embodiments, the mathematical model of the first parallel coupling state is expressed as follows:

[0017]

[0018] Where t1 is the moment when the linear motor enters the first parallel coupling state, τ = l ms / R sR is the time constant. s This is the stator resistance of the linear motor.

[0019] In some preferred embodiments, the mathematical model of the separated coupling state is expressed as:

[0020]

[0021] In some preferred embodiments, the mathematical model of the second parallel coupling state is expressed as follows:

[0022]

[0023] Where t2 is the moment when the linear motor enters the second parallel coupling state.

[0024] In some preferred embodiments, the time t2 when the linear motor enters the second parallel coupling state is expressed as:

[0025] t2=π / (2ω)+t1

[0026] In another aspect, the present invention proposes a low-impact switching method for segmented power supply of a linear motor based on thyristors, the switching method comprising:

[0027] Step T10: When the ratio of the moving part of the linear motor to the stator is zero, the linear motor is in an uncoupled state. The switching angle of the parallel segmented power supply of the linear motor is obtained.

[0028] Step T20: Determine the value of the switching angle and execute:

[0029] If the switching angle is 0, the linear motor is switched from uncoupled to first parallel coupling to separate coupling to second parallel coupling to uncoupled state using the first switching method; if the switching angle is π / 3, the linear motor is switched from uncoupled to first parallel coupling to separate coupling to second parallel coupling to uncoupled state using the second switching method; if the switching angle is 2π / 3, the linear motor is switched from uncoupled to first parallel coupling to separate coupling to second parallel coupling to uncoupled state using the third switching method.

[0030] In some preferred embodiments, the first switching method is:

[0031] When the B and C phases of the next stator with the relative position of the mover are turned on, the linear motor enters the first parallel coupling state and maintains conduction π / 6;

[0032] When the relative position of the mover is such that the B phase of the stator before the zero crossing is turned off, the linear motor enters the separated coupling state and remains on π / 3;

[0033] When the moving part is in the relative position of the next stator, phase A of the linear motor enters the second parallel coupling state and remains in conduction for π / 3.

[0034] When the relative position of the mover is reversed, the A and C phases of the stator are turned off at zero crossing, and the linear motor enters a decoupled state, completing the state switching of the linear motor.

[0035] In some preferred embodiments, the second switching method is:

[0036] When the relative positions of the moving part and the next stator are connected, the linear motor enters the first parallel coupling state and maintains conduction π / 6;

[0037] When the relative position of the mover is such that the A phase of the stator before the zero crossing is turned off, the linear motor enters the separated coupling state and remains on π / 3;

[0038] When the C phase of the next stator relative to the moving part is turned on, the linear motor enters the second parallel coupling state and maintains conduction π / 3;

[0039] When the relative position of the mover is reversed, the A and B phases of the stator are turned off at zero crossing, and the linear motor enters a decoupled state, completing the state switching of the linear motor.

[0040] In some preferred embodiments, the third switching method is:

[0041] When the relative position of the mover is turned on, the A and C phases of the next stator are connected, and the linear motor enters the first parallel coupling state and maintains conduction π / 6;

[0042] When the relative position of the mover is such that the C phase of the stator before the zero crossing is turned off, the linear motor enters the separated coupling state and remains on π / 3;

[0043] When the B phase of the next stator relative to the moving part is turned on, the linear motor enters the second parallel coupling state and maintains conduction π / 3;

[0044] When the relative position of the mover is reversed, the A and B phases of the stator are turned off at zero crossing, and the linear motor enters a decoupled state, completing the state switching of the linear motor.

[0045] The beneficial effects of this invention are:

[0046] This invention presents a low-impact modeling and switching method for segmented power supply of linear motors based on thyristors. It realizes segmented power supply switching without external cables in the parallel power supply structure of linear motors, reducing the inrush current caused by stator parallel connection and zero-state response in traditional switching methods. Verified by the Matlab / Simulink simulation platform, the switching method of this invention reduces the current impact by 50% compared with the traditional switching method. Attached Figure Description

[0047] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0048] Figure 1 This is a diagram of the segmented power supply structure of a linear motor, representing an embodiment of the thyristor-based segmented power supply low-impact modeling method for linear motors according to the present invention.

[0049] Figure 2 This is a schematic diagram of the initial uncoupled state of an embodiment of the low-impact modeling method for segmented power supply of linear motors based on thyristors of the present invention;

[0050] Figure 3 This is a schematic diagram of the first parallel coupling state of an embodiment of the low-impact modeling method for segmented power supply of linear motor based on thyristors of the present invention;

[0051] Figure 4 This is a schematic diagram of the separated coupling state of an embodiment of the low-impact modeling method for segmented power supply of linear motor based on thyristors of the present invention;

[0052] Figure 5 This is a schematic diagram of the second parallel coupling state of an embodiment of the low-impact modeling method for segmented power supply of linear motor based on thyristors of the present invention;

[0053] Figure 6 This is a schematic diagram of returning to the uncoupled state in an embodiment of the low-impact modeling method for segmented power supply of linear motors based on thyristors of the present invention;

[0054] Figure 7 This invention relates to an embodiment of a thyristor-based linear motor segmented power supply low-impact modeling method, which examines the influence of different switching angles on converter current fluctuations under the steady-state condition of the first parallel coupling state.

[0055] Figure 8 This invention relates to an embodiment of a segmented power supply low-impact modeling method for linear motors based on thyristors, which examines the influence of different switching angles on the system during the zero-state response of the stator winding in the first parallel coupling state.

[0056] Figure 9 This invention relates to an embodiment of a thyristor-based method for segmented power supply low-impact modeling of linear motors, which describes the influence of different switching angles on converter current fluctuations under a separate coupling state.

[0057] Figure 10 This is a schematic diagram of the stator 1 current with the maximum current fluctuation without using the optimized switching method of the present invention, according to an embodiment of the low-impact modeling method for segmented power supply of linear motor based on thyristors.

[0058] Figure 11This is a schematic diagram of the stator 3 current with the maximum current fluctuation without using the optimized switching method of the present invention, which is an embodiment of the low-impact modeling method for segmented power supply of linear motor based on thyristors.

[0059] Figure 12 yes Figure 11 This is a schematic diagram of the current transformer current with the maximum current fluctuation without using the optimized switching method of the present invention, which is an embodiment of the low-impact modeling method for segmented power supply of linear motor based on thyristors.

[0060] Figure 13 This is a schematic diagram of the stator 1 current with the minimum current fluctuation without using the optimized switching method of the present invention, according to an embodiment of the low-impact modeling method for segmented power supply of linear motor based on thyristors.

[0061] Figure 14 This is a schematic diagram of the stator 3 current with the minimum current fluctuation without using the optimized switching method of the present invention, according to an embodiment of the low-impact modeling method for segmented power supply of linear motor based on thyristors.

[0062] Figure 15 This is a schematic diagram of the current transformer current with minimum current fluctuation without using the optimized switching method of the present invention, which is an embodiment of the low-impact modeling method for segmented power supply of linear motor based on thyristors.

[0063] Figure 16 This is a schematic diagram of a low-impact current switching method in one embodiment of the low-impact modeling method for segmented power supply of linear motors based on thyristors of the present invention.

[0064] Figure 17 This is a schematic diagram of the stator 1 switching current of a low-impact current switching method for segmented power supply of linear motor based on thyristors, according to an embodiment of the present invention.

[0065] Figure 18 This is a schematic diagram of the stator 3 switching current of a low-impact current switching method for segmented power supply of linear motor based on thyristors, according to an embodiment of the present invention.

[0066] Figure 19 This is a schematic diagram of the current switching device for low-impact current switching in an embodiment of the low-impact current switching of the present invention, which is based on the segmented power supply low-impact modeling method for linear motors using thyristors. Detailed Implementation

[0067] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0068] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0069] This invention provides a low-impact modeling and switching method for segmented power supply of linear motors based on thyristors. This method switches the segmented power supply under parallel power supply structure without the need for external cables by using the mover position information and voltage phase angle, thereby reducing the inrush current caused by stator parallel connection and zero-state response during the switching process.

[0070] This invention discloses a low-impact modeling method for segmented power supply of a linear motor based on thyristors, wherein the linear motor includes a stator n with A n B n C n Phase, where n is the number of stators in the linear motor, characterized in that the modeling method includes:

[0071] Step S10: Based on the relative positions of the mover and stator after the linear motor starts, obtain the coupling state of the linear motor; the coupling state includes no coupling state, first parallel coupling state, separate coupling state and second parallel coupling state;

[0072] Step S20: When the linear motor starts and there is no mover covering it, the linear motor is in an uncoupled state, and a mathematical model of the uncoupled state is constructed.

[0073] When two phases of the three phases of the stator below the relative position of the mover of the linear motor are connected, the linear motor is in the first parallel coupling state, and a mathematical model of the first parallel coupling state is constructed.

[0074] When one of the three phases of the stator before the relative position of the mover of the linear motor is zero-crossing and turned off, the linear motor is in a separated coupling state, and a mathematical model of the separated coupling state is constructed.

[0075] When the remaining phase of the three phases of the next stator of the linear motor is turned on, the linear motor is in the second parallel coupling state, and a mathematical model of the second parallel coupling state is constructed.

[0076] To more clearly illustrate the thyristor-based segmented power supply low-impact modeling and switching method for linear motors according to the present invention, the steps in the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0077] The first embodiment of the thyristor-based segmented power supply low-impact modeling method for linear motors is described in detail below:

[0078] like Figure 1The diagram shows a linear motor segmented power supply structure according to an embodiment of the thyristor-based low-impact modeling method for segmented power supply of a linear motor. Power supply 1 supplies power to the odd-numbered stator segments, such as stator 1, stator 3, etc. Power supply 2 supplies power to the even-numbered stator segments, such as stator 2, stator 4, etc. Based on the mover position information, three anti-parallel thyristors are used to switch the power on and off of the segmented stators. The switching process is as follows:

[0079] (1) In the initial position, the end of the mover is aligned with the beginning of the stator 1, and the thyristor switches of stator 1 (A1-B1-C1) and stator 2 (A2-B2-C2) are turned on at the same time, and the mover begins to move.

[0080] (2) When the end of the mover leaves the end of the stator 1, close the thyristor switch (A1-B1-C1) of the stator 1 and open the thyristor switch (A3-B3-C3) of the stator 3.

[0081] (3) The switching methods for the other stators are similar.

[0082] Step S10: Based on the relative positions of the mover and stator after the linear motor starts, obtain the coupling state of the linear motor; the coupling state includes no coupling state, first parallel coupling state, separate coupling state and second parallel coupling state.

[0083] like Figures 2-6 The diagram shown illustrates various states of an embodiment of the thyristor-based segmented power supply low-impact modeling method for linear motors according to the present invention, including... Figure 2 and Figure 6 Uncoupled state Figure 3 The first parallel coupling state Figure 4 Separated coupling state and Figure 5 The second parallel coupling state.

[0084] Step S20: When the linear motor starts and there is no mover covering it, the linear motor is in an uncoupled state, and a mathematical model of the uncoupled state is constructed.

[0085] Figure 2 and Figure 6 All are in a non-coupled state. Figure 2 This occurs when the mover just leaves stator 1, canceling the stator's thyristor trigger signal, but the current does not cross zero and turn off. The current equation in this state can be derived from the equation of the motor without mover coverage.

[0086] The equations for the motor without a mover cover are shown in equations (1) and (2):

[0087]

[0088]

[0089] Among them, R A R B R C These are the three-phase stator resistances of the linear motor, u A u B u C These are the three-phase stator voltages of the linear motor, i A i B i C These are the three-phase currents of the linear motor, Ψ A Ψ B Ψ C These are the three-phase stator flux linkages of a linear motor, L A L B L C These are the three-phase stator inductances of the linear motor, L AB For the mutual inductance of the stator of phase A and phase B of the linear motor, L BC For the mutual inductance of the stator of the linear motor in phases B and C, L AC P represents the mutual inductance between the A-phase and C-phase stators of a linear motor, where P is the differential factor.

[0090] Given a three-phase positive sequence voltage, a symmetrical load, and current in an uncoupled state where stator resistance and leakage inductance are ignored, an uncoupled state mathematical model can be constructed, as shown in equation (3):

[0091]

[0092] Among them, i A i B i C Here, U represents the current of the three-phase converter, U is the amplitude of the input voltage of the linear motor, ω is the angular frequency of the stator input voltage of the linear motor, and l represents the current of the three-phase converter. ms Let t be the stator inductance of the linear motor, and t be the time variable.

[0093] When two phases of the three phases of the next stator of the linear motor are connected, the linear motor is in the first parallel coupling state, and a mathematical model of the first parallel coupling state is constructed.

[0094] Figure 3 In the first parallel coupling state, when two phases (e.g., phases A3 and B3) in the next stator are connected in the uncoupled state in section (1), the system enters the first parallel coupling state. The mathematical model of the first parallel coupling state is shown in equation (4):

[0095]

[0096] Where t1 is the moment when the linear motor enters the first parallel coupling state, τ = l ms / R s R is the time constant. sThis is the stator resistance of the linear motor.

[0097] According to equation (4), the minimum current of the converter in this state is in the range of π / 6 to π / 2, and the maximum current fluctuation during this period is 1.3 times.

[0098] When one of the three phases of the stator before the relative position of the mover of the linear motor is zero-crossing and turned off, the linear motor is in a separated coupling state, and a mathematical model of the separated coupling state is constructed.

[0099] Figure 4 For the separated coupling state, this state is the state after the thyristor current of one phase (e.g., phase A1) of the stator is turned off at the zero point before the first parallel coupling state in section (2). The mathematical model of the separated coupling state is shown in equation (5):

[0100]

[0101] From equations (3) and (5), it can be seen that the current amplitude in this state does not exceed 1.5 times that under no coupling.

[0102] When the remaining phase of the three phases of the next stator of the linear motor is turned on, the linear motor is in the second parallel coupling state, and a mathematical model of the second parallel coupling state is constructed.

[0103] Figure 5 The second parallel coupling state is the state after the remaining phase of the next stator (e.g., phase C3) is connected in the separated coupling state of section (3). The mathematical model of the second parallel coupling state is shown in equation (6):

[0104]

[0105] Where t2=π / (2ω)+t1 is the moment when the linear motor enters the second parallel coupling state.

[0106] Combining equations (2), (5), and (6), it can be seen that this state occurs in the interval 5π / 6 to 7π / 6, and the maximum current fluctuation in this state does not exceed 1.3 times.

[0107] Although the steps in the above embodiments are described in the above order, those skilled in the art will understand that in order to achieve the effect of this embodiment, different steps do not need to be executed in such an order. They can be executed simultaneously (in parallel) or in a reverse order. These simple variations are all within the protection scope of this invention.

[0108] The second embodiment of the present invention provides a low-impact switching method for segmented power supply of a linear motor based on thyristors, the switching method comprising:

[0109] Step T10: When the ratio of the moving part of the linear motor to the stator is zero, the linear motor is in an uncoupled state. The switching angle of the parallel segmented power supply of the linear motor is obtained.

[0110] Step T20: Determine the value of the switching angle and execute:

[0111] If the switching angle is 0, then the linear motor switches between uncoupled, first parallel coupled, separate coupled, second parallel coupled, and uncoupled states using the first switching method:

[0112] When the B and C phases of the next stator with the relative position of the mover are turned on, the linear motor enters the first parallel coupling state and maintains conduction π / 6;

[0113] When the relative position of the mover is such that the B phase of the stator before the zero crossing is turned off, the linear motor enters the separated coupling state and remains on π / 3;

[0114] When the moving part is in the relative position of the next stator, phase A of the linear motor enters the second parallel coupling state and remains in conduction for π / 3.

[0115] When the relative position of the mover is reversed, the A and C phases of the stator are turned off at zero crossing, and the linear motor enters a decoupled state, completing the state switching of the linear motor.

[0116] If the switching angle is π / 3, then the linear motor will switch between uncoupled, first parallel coupled, separate coupled, second parallel coupled, and uncoupled states using the second switching method:

[0117] When the relative positions of the moving part and the next stator are connected, the linear motor enters the first parallel coupling state and maintains conduction π / 6;

[0118] When the relative position of the mover is such that the A phase of the stator before the zero crossing is turned off, the linear motor enters the separated coupling state and remains on π / 3;

[0119] When the C phase of the next stator relative to the moving part is turned on, the linear motor enters the second parallel coupling state and maintains conduction π / 3;

[0120] When the relative position of the mover is reversed, the A and B phases of the stator are turned off at zero crossing, and the linear motor enters a decoupled state, completing the state switching of the linear motor.

[0121] If the switching angle is 2π / 3, then the linear motor will switch between uncoupled, first parallel coupled, separate coupled, second parallel coupled, and uncoupled states using the third switching method:

[0122] When the relative position of the mover is turned on, the A and C phases of the next stator are connected, and the linear motor enters the first parallel coupling state and maintains conduction π / 6;

[0123] When the relative position of the mover is such that the C phase of the stator before the zero crossing is turned off, the linear motor enters the separated coupling state and remains on π / 3;

[0124] When the B phase of the next stator relative to the moving part is turned on, the linear motor enters the second parallel coupling state and maintains conduction π / 3;

[0125] When the relative position of the mover is reversed, the A and B phases of the stator are turned off at zero crossing, and the linear motor enters a decoupled state, completing the state switching of the linear motor.

[0126] like Figures 7-8 The image shows the effect of different switching angles on converter current fluctuations under the first parallel coupling state in one embodiment of the low-impact modeling method for segmented power supply of linear motors based on thyristors according to the present invention. Figure 7 To illustrate the impact of different switching angles on the system under steady state, Figure 8 To take into account the impact of different switching angles on the system during the zero-state response of the stator winding.

[0127] Considering the zero-state response of the stator winding, the current equation for the first parallel coupling state is shown in equation (7):

[0128]

[0129] Combining equations (4) and (7), we can obtain equation (8):

[0130]

[0131] Where t1 is the moment when the linear motor enters the first parallel coupling state, τ = l ms / R s is the time constant.

[0132] From equation (8), it can be seen that entering this state at time π / 3 can avoid the zero-state response of the stator winding, and the system can then transition from the state with... Figure 8 The relationship in becomes Figure 7 Similarly, when entering the second parallel coupling state at 5π / 6, the influence of the stator's zero-state response on the system can be avoided.

[0133] like Figure 9 As shown, this is an embodiment of the low-impact modeling method for segmented power supply of linear motor based on thyristors of the present invention. Under the separate coupling state, different switching angles affect the current fluctuation of the converter. The change of phase B current in equation (5) when the power angle is π / 2 to 5π / 6 is verified, and the maximum current fluctuation does not exceed 1.5 times.

[0134] like Figures 10-12 The figure shows the maximum current fluctuation without using the optimized switching method of this invention, as an embodiment of the thyristor-based segmented power supply low-impact modeling method for linear motors. Figure 10 For the current of stator 1, Figure 11 For the current in stator 3, Figure 12 The current is the current of the converter. The current equation for the three-phase windings conducting simultaneously is shown in equation (9):

[0135]

[0136] Solving equation (9) yields equation (10):

[0137]

[0138] Where t0 is the moment when all three phase windings are turned on simultaneously.

[0139] Since the stator current is relatively small when the stator is connected in parallel, the stator parallel connection problem is ignored at this time. From equation (10), it can be seen that the maximum amplitude fluctuation of the zero-state response of the winding is related to the maximum current of the three-phase winding at the switching point. From equation (3), it can be seen that the maximum amplitude of the three-phase current occurs at the electroplating angles of 0, π / 3, and 2π / 3. Taking the switching angle of 0 as an example, simulation is performed on Simulik. Figure 11 The three-phase windings are switched on at 0.46s. Figure 10 The current in phase A is at its maximum value, thus generating approximately twice the inrush current at 0.47s.

[0140] like Figures 13-15 The figure shows the minimum current fluctuation without using the optimized switching method of this invention, as an embodiment of the thyristor-based segmented power supply low-impact modeling method for linear motors. Figure 13 For the current of stator 1, Figure 14 For the current in stator 3, Figure 15 Let be the current of the converter. From equation (3), it can be seen that the minimum amplitude of the three-phase current occurs at π / 6, π / 2, and 5π / 6. Taking a switching angle of π / 6 as an example, simulations are performed on Simulik. Figure 13 It can be seen that the maximum current of the converter before switching is 80A. Figure 14 When the three-phase winding of the stator is turned on at time t5, it can be seen from equation (10) that the converter is in Figure 15 A surge current of 150A is generated in 0.47s. Compared to Figure 12 The converter current in the middle is 160A, which reduces the inrush current by 12.5%.

[0141] like Figure 16 The diagram shown illustrates a low-impact current switching method, an embodiment of the thyristor-based segmented power supply low-impact modeling method for linear motors according to the present invention. Figure 2 Based on various mathematical models of state switching, combined with Figure 3The zero-state response of the stator in equation (8). When the ratio of the mover covering the stator is zero, a suitable voltage phase angle is found for switching to minimize converter fluctuations. Since the three-phase currents are symmetrical and the switching method is independent of the current sign, when phases B3 and C3 are turned on first and then phase A3 is turned on, the electrical angles corresponding to each state lag by π / 3 compared to the example; when phases A3 and C3 are turned on first and then phase B3 is turned on, the electrical angles corresponding to each state lead by π / 3 compared to the example. The switching method is as follows:

[0142] (1) If the switching angle is 0, phases B3 and C3 in the next stator are immediately turned on, and the system is in the first parallel coupling state. After the first parallel coupling state is maintained for π / 6, the thyristor current of phase B1 is turned off at the zero point, and the system enters the separated coupling state. After the separated coupling state is maintained for π / 3, phase A3 is turned on, and the system enters the second parallel coupling state. After the second parallel coupling state is maintained for π / 3, the thyristor currents of phases A1 and C1 are turned off at the zero point, and the system enters the uncoupled state, and the switching is completed.

[0143] (2) If the switching angle is π / 3, then phases A3 and B3 in the next stator are immediately turned on, and the system is in the first parallel coupling state; after the first parallel coupling state is maintained for π / 6, the thyristor current of phase A1 is turned off at the zero point, and the system enters the separate coupling state; after the separate coupling state is maintained for π / 3, phase C3 is turned on, and the system enters the second parallel coupling state; after the second parallel coupling state is maintained for π / 3, the thyristor currents of phases A1 and B1 are turned off at the zero point, and the system enters the uncoupled state, and the switching is completed.

[0144] (3) If the switching angle is 2π / 3, then phases A3 and C3 in the next stator are immediately turned on, and the system is in the first parallel coupling state; after the first parallel coupling state is maintained for π / 6, the thyristor current of phase C1 is turned off at the zero point, and the system enters the separated coupling state; after the separated coupling state is maintained for π / 3, phase B3 is turned on, and the system enters the second parallel coupling state; after the second parallel coupling state is maintained for π / 3, the thyristor currents of phases A1 and B1 are turned off at the zero point, and the system enters the uncoupled state, and the switching is completed.

[0145] like Figures 17-19 The diagram shown illustrates the switching current for low-impact current switching in one embodiment of the thyristor-based segmented power supply low-impact modeling method for linear motors according to the present invention. Figure 17 For the current of stator 1, Figure 18 For the current in stator 3, Figure 19 This refers to the converter current. Taking the example of first conducting phases A3 and B3 and then conducting phase C3, according to... Figure 16 The switching method was verified by building a simulation platform on Simulink.

[0146] (1) When the mover covers the stator zero, Figure 17 If t = 0.46 ~ t1, then the system is Figure 2 In the uncoupled state, the maximum current is 80A.

[0147] (2) In Figure 18 When phases A3 and B3 of stator 3 are turned on at time t1, the system enters... Figure 3 The first parallel coupling state in the process.

[0148] (3) In Figure 17 At 0.465s, the A1 phase current crosses zero and is turned off, and the system enters... Figure 4 In the separated coupling state, according to equation (5), the maximum current fluctuation in this state is 150A. Figure 19 The values ​​from 0.465s to t4 are shown.

[0149] (4) In Figure 18 At time t4, phase C3 is activated, and the system enters [the following state / entry / phase]. Figure 5 In the second parallel coupling state, the current equation when C3 is turned on is shown in equation (11):

[0150] R s i C3 +L s P(i C3 )=Usin(ωt+2π / 3) (11)

[0151] Simplifying equation (11) yields equation (12):

[0152]

[0153] When C3 is switched on at 5π / 6, it can be seen from equation (12) that no zero-state response will occur. Due to the symmetry of the three-phase current, the changes of the B and C phase currents in the interval 5π / 6 to 7π / 6 during the second parallel coupling are the same as the changes of the A and B phase currents in the interval π / 6 to π / 2 during the first parallel coupling.

[0154] (5) In Figure 17 At 0.47s, the currents in phases B1 and C1 cross zero and are turned off, and the system enters... Figure 6 The uncoupled state has been switched over.

[0155] Simulation results show that the structure of multiple power supplies in parallel without external cables affects the switching current of the linear motor's segmented power supply. When switching three phases simultaneously, the converter generates a maximum inrush current twice the normal value. By controlling the current switching angle, the inrush current can be reduced by 12.5%. To further reduce the inrush current, a method is adopted where two phase thyristors are turned on first, followed by the third phase thyristor. This invention controls the turn-on time of each thyristor based on the voltage phase angle, making the maximum inrush current of the converter 1.5 times that of normal operation. Compared with traditional switching methods, this reduces the current surge by 50%.

[0156] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working process and related descriptions of the linear motor described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0157] It should be noted that the thyristor-based segmented power supply low-impact modeling and switching method for linear motors provided in the above embodiments is only an example of the division of the above functional modules. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the modules or steps in the embodiments of the present invention can be further decomposed or combined. For example, the modules in the above embodiments can be merged into one module, or further divided into multiple sub-modules to complete all or part of the functions described above. The names of the modules and steps involved in the embodiments of the present invention are only for distinguishing the various modules or steps and are not considered as an improper limitation of the present invention.

[0158] An electronic device according to a third embodiment of the present invention includes:

[0159] At least one processor; and

[0160] A memory communicatively connected to at least one of the processors; wherein,

[0161] The memory stores instructions that can be executed by the processor to implement the above-described thyristor-based segmented power supply low-impact modeling and switching method for linear motors.

[0162] A computer-readable storage medium according to a fourth embodiment of the present invention stores computer instructions, which are executed by the computer to implement the above-described thyristor-based segmented power supply low-impact modeling and switching method for linear motors.

[0163] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working process and related descriptions of the storage device and processing device described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0164] Those skilled in the art will recognize that the modules and method steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. The programs corresponding to the software modules and method steps can be placed in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disks, removable disks, CD-ROMs, or any other form of storage medium known in the art. To clearly illustrate the interchangeability of electronic hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in electronic hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the invention.

[0165] The terms “first”, “second”, etc., are used to distinguish similar objects, not to describe or indicate a specific order or sequence.

[0166] The term "comprising" or any other similar term is intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus / device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent in such process, method, article, or apparatus / device.

[0167] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A method for modeling low-impulse segmented power supply of a linear motor based on thyristors, the linear motor comprising A n , B n , C n phases of a stator n, n being the number of stators of the linear motor, characterized in that, The modeling method comprises: In step S10, the coupling state of the linear motor is obtained based on the relative position of the mover and the stator after the linear motor is started; the coupling state comprises a decoupling state, a first parallel coupling state, a split coupling state and a second parallel coupling state; In step S20, when the mover does not cover the linear motor after the linear motor is started, the linear motor is in the decoupling state, and a decoupling state mathematical model is constructed; The decoupling state mathematical model is expressed as: ； wherein are the three-phase currents of the linear motor, respectively, is the amplitude of the input voltage of the linear motor, is the angular frequency of the input voltage of the linear motor stator, is the linear motor stator inductance, is the time variable; When two phases in the three phases of the stator are connected when the relative position of the mover of the linear motor is below a certain position, the linear motor is in the first parallel coupling state, and a first parallel coupling state mathematical model is constructed; The first parallel coupling state mathematical model is expressed as: ； wherein is the time instant at which the linear motor enters the first parallel coupling state, is the time constant, is the linear motor stator resistance; When one phase in the three phases of the stator is off when the relative position of the mover of the linear motor is before a certain position, the linear motor is in the split coupling state, and a split coupling state mathematical model is constructed; The split coupling state mathematical model is expressed as: ； When the remaining one phase in the three phases of the stator is connected when the relative position of the mover of the linear motor is below a certain position, the linear motor is in the second parallel coupling state, and a second parallel coupling state mathematical model is constructed; The second parallel coupling state mathematical model is expressed as: ； wherein is the moment when the linear motor enters the second parallel coupling state.

2. The thyristor-based linear motor segmented power supply low-impact modeling method according to claim 1, characterized in that, The moment when the linear motor enters the second parallel coupling state which is expressed as: 。 3. A low-impact switching method for segmented supply of a linear motor based on thyristors, based on a low-impact modeling method for segmented supply of a linear motor based on thyristors according to any one of claims 1-2, characterized in that, The switching method comprises: In step T10, when the mover covers the stator at a proportion of zero, the linear motor is in the decoupling state, and a switching angle of parallel segmented power supply of the linear motor is obtained; In step T20, the value of the switching angle is judged, and the following is executed: If the switching angle is 0, the state switching of the linear motor from uncoupling to first parallel coupling to separate coupling to second parallel coupling to uncoupling is performed through the first switching method; if the switching angle is / 3, the state switching of the linear motor from uncoupling to first parallel coupling to separate coupling to second parallel coupling to uncoupling is performed through the second switching method; if the switching angle is , the state switching of the linear motor from uncoupling to first parallel coupling to separate coupling to second parallel coupling to uncoupling is performed through the third switching method. The first switching method is: The B and C phases of the lower stator relative to the position of the moving part are turned on, and the linear motor enters the first parallel coupling state and maintains the conduction ; The B-phase zero-crossing off of the front stator of the mover relative position, the linear motor enters the separate coupling state and maintains conduction ; The A-phase of the lower stator relative to the position of the moving sub, the linear motor enters the second parallel coupling state and maintains conduction ; When the A and C phases of the stator before the relative position of the mover pass through zero and are off, the linear motor enters the decoupling state, and the state switching of the linear motor is completed; the second switching method is: The A and B phases of the lower stator relative to the position of the moving part are turned on, and the linear motor enters the first parallel coupling state and maintains the conduction ; The mover relative position of the front stator A-phase zero-crossing off, linear motor into separate coupling state and maintain the conduction ; The C-phase of the lower stator relative to the position of the moving sub, the linear motor enters the second parallel coupling state and maintains conduction ; When the B and C phases of the stator before the relative position of the mover pass through zero and are off, the linear motor enters the decoupling state, and the state switching of the linear motor is completed; and the third switching method is: The A and C phases of the lower stator relative to the position of the moving part are turned on, and the linear motor enters the first parallel coupling state and maintains the conduction ; The C-phase zero-crossing turn-off of the front mover relative position, the linear motor enters the separate coupling state and maintains conduction ; The B phase of the lower stator relative to the position of the moving sub, the linear motor enters the second parallel coupling state and maintains conduction ; When the A and B phases of the stator before the relative position of the mover pass through zero and are off, the linear motor enters the decoupling state, and the state switching of the linear motor is completed.

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