Long-stator linear motor boosting system with short-time high-power output

Abstract

The invention discloses a long-stator linear motor boosting system with short-time high-power output. The system comprises an energy storage unit, a current conversion unit, a driving unit and a control unit, the converter unit is connected with the energy storage unit, the driving unit and the control unit. The control unit is respectively connected with the energy storage unit and the driving unit; through mutual cooperation of the energy storage unit and the current conversion unit, the system can be compatible with external direct current network power supply, the requirements of the linear motor boosting system for the voltage and capacity of the energy storage system are reduced, the impact on the direct current network is also reduced, meanwhile, through design of the driving unit, the operation reliability of the linear motor boosting system is enhanced, and the service life of the linear motor boosting system is prolonged. And the failure rate of the linear electric boosting system is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of traction power supply systems, and in particular to a long-stator linear motor booster system with short-term high-power output. Background Art

[0002] At present, in the field of linear electric propulsion, unlike rotary motors, the movement of long-stator linear motors is mostly reciprocating. When the linear motor reaches the target thrust or target speed, it is often expected that the motor rotor can be quickly braked to zero speed. Although the conventional method of relying on inverter electric braking is feasible, the power electronic system has a high failure rate, which reduces the reliability of the linear propulsion system. Secondly, the working mode of the linear electric propulsion system is mostly short-term high-power output. In the external power grid system, the short-term high-power energy demand of the traction condition has a great impact on the external power grid; in the system where the energy storage system is directly connected to the inverter unit, since the inverter unit has high requirements for bus voltage stability, a large-capacity high-voltage energy storage system needs to be configured, and the system design is difficult. In addition, the linear electric propulsion system often requires compatibility with on-grid and off-grid power supply, but the existing linear electric propulsion system has poor compatibility with on-grid operation.

[0003] In view of this, it is a technical problem that needs to be urgently solved by technical personnel in this field to provide a long-stator linear motor thrust system with high operating reliability, strong adaptability and high compatibility, short-term high-power output. Summary of the invention

[0004] In order to solve the above technical problems, the purpose of the present invention is to provide a long-stator linear motor thruster system with short-term high-power output, which can be compatible with external DC power supply, reduces the requirements for voltage and capacity, and reduces the impact on the DC network. At the same time, it enhances the reliability of the operation of the linear electric thruster system and reduces the failure rate of the linear electric thruster system.

[0005] The technical solution provided by the present invention is as follows: A long-stator linear motor booster system with short-term high-power output, comprising: an energy storage unit, a current conversion unit, a drive unit and a control unit; The current conversion unit is connected to the energy storage unit, the driving unit and the control unit respectively; The control unit is connected to the energy storage unit and the driving unit respectively; The energy storage unit is used to be compatible with an external DC network, so that the external DC network can charge the energy storage unit; The current conversion unit is used to reduce the fluctuation of the low voltage of the energy storage unit; The driving unit is used to provide traction and braking force; The control unit is used to monitor the energy storage unit, the current conversion unit and the drive unit.

[0006] Preferably, the energy storage unit specifically includes: an energy storage subunit, a bidirectional charging subunit and a power storage subunit; The bidirectional charging subunit is connected to the energy type energy storage subunit and the power type energy storage subunit respectively; The power type energy storage subunit is connected to the current conversion unit; The energy storage subunit is used to store total energy; The bidirectional charging subunit is used to supplement electric energy for the energy storage subunit and the power storage subunit; The power type energy storage subunit is used to store the electric energy of a single cycle operation.

[0007] Preferably, the conversion unit specifically includes: a bidirectional DC-DC conversion subunit, a DC-AC inverter subunit and an AC-AC bidirectional switch subunit; The bidirectional DC-DC conversion subunit is connected to the power type energy storage subunit and the DC-AC inverter subunit respectively; The DC-AC inverter subunit is connected to the AC-AC bidirectional switch subunit; The AC-AC bidirectional switch subunit is connected to the driving unit; The bidirectional DC-DC conversion subunit is used to transfer the energy of the power storage subunit to the DC-AC inverter subunit; The DC-AC inverter subunit is used to convert the energy transmitted by the bidirectional DC-DC conversion subunit into AC electrical energy; The AC-AC bidirectional switch subunit is used to supply power to the drive unit according to control requirements.

[0008] Preferably, the driving unit is a permanent magnet linear motor with a long stator having a permanent magnet linear motor mover at the front end and a damping device at the end.

[0009] Preferably, the long-stator permanent magnet linear motor comprises a traction section; the traction section is formed by stacking soft magnetic materials, wherein the soft magnetic material comprises silicon steel sheets or amorphous alloys.

[0010] Preferably, when the traction section is running, the output thrust target or the running speed target is achieved by controlling the permanent magnet linear motor mover.

[0011] Preferably, the long-stator permanent magnet linear motor further comprises a braking segment; the iron core of the braking segment is made of solid carbon steel.

[0012] Preferably, when the braking section is in operation, the permanent magnet linear motor mover completes braking from high speed to near zero speed through the iron core of the braking section.

[0013] The present invention provides a long-stator linear motor assist system with short-term high-power output, comprising: an energy storage unit, a current conversion unit, a drive unit and a control unit; the current conversion unit is respectively connected to the energy storage unit, the drive unit and the control unit; the control unit is respectively connected to the energy storage unit and the drive unit; the system cooperates with the energy storage unit and the current conversion unit to be compatible with external DC power supply, thereby reducing the linear motor assist system's requirements for energy storage system voltage and capacity, and also reducing the impact on the DC network. At the same time, the design of the drive unit enhances the reliability of the linear electric assist system's operation and reduces the failure rate of the linear electric assist system. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0015] Figure 1 It is a structural schematic diagram of a long-stator linear motor thrust-assisting system with short-term high-power output in an embodiment of the present invention; Figure 2 The figure is a schematic diagram of the working principle of a long-stator linear motor thrust-assisting system with short-term high-power output in an embodiment of the present invention. DETAILED DESCRIPTION

[0016] In order to enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0017] It should be noted that when an element is referred to as being "fixed on" or "set on" another element, it can be directly on the other element or indirectly set on the other element; when an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0018] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0019] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, "multiple" and "several" mean two or more, unless otherwise clearly and specifically defined.

[0020] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the conditions under which this application can be implemented. Therefore, they have no substantive technical significance. Any structural modification, change in proportional relationship or adjustment of size should still fall within the scope of the technical content disclosed in this application without affecting the effects and purposes that can be achieved by this application.

[0021] like Figure 1 As shown, the embodiment of the present invention provides a long-stator linear motor booster system with short-term high-power output, including: an energy storage unit 1, a current conversion unit 2, a drive unit 3 and a control unit 4; The current conversion unit 2 is connected to the energy storage unit 1, the driving unit 3 and the control unit 4 respectively; The control unit 4 is connected to the energy storage unit 1 and the driving unit 3 respectively; The energy storage unit 1 is used to be compatible with an external DC network, so that the external DC network can charge the energy storage unit 1; The current conversion unit 2 is used to reduce the fluctuation of the low voltage of the energy storage unit 1; The driving unit 3 is used to provide traction and braking force; The control unit 4 is used to monitor the energy storage unit 1 , the current conversion unit 2 and the driving unit 3 .

[0022] In actual use, a short-term high-power output long-stator linear motor propulsion system is designed with an energy storage unit, a current conversion unit, a drive unit and a control unit; wherein the current conversion unit is respectively connected to the energy storage unit, the drive unit and the control unit; the control unit is respectively connected to the energy storage unit and the drive unit; the compatibility of the short-term high-power output long-stator linear motor propulsion system is improved by making the energy storage unit compatible with the external DC network, and then the current conversion unit is used to reduce the fluctuation of the low voltage of the energy storage unit; the drive unit provides kinetic energy for the train operation, and finally the control unit monitors the state, parameter setting, operation, shutdown and reset of the energy storage unit; monitors the state, parameter setting, operation, shutdown and reset of the current conversion part; monitors the real-time position sampling, speed sampling, temperature monitoring and vibration monitoring of the drive unit, and the control unit also includes human-computer interaction, wherein the human-computer interaction is a device with an operation panel, a touch screen, etc. suitable for accepting external commands and presenting the system status.

[0023] Preferably, the energy storage unit 1 specifically includes: an energy storage subunit 11, a bidirectional charging subunit 12 and a power storage subunit 13; The bidirectional charging subunit 12 is connected to the energy storage subunit 11 and the power storage subunit 13 respectively; The power type energy storage subunit 13 is connected to the current conversion unit 2; The energy storage subunit 11 is used to store total energy; The bidirectional charging subunit 12 is used to supplement electric energy for the energy storage subunit 11 and the power storage subunit 13; The power type energy storage subunit 13 is used to store the electric energy of a single cycle operation.

[0024] In actual use, the energy storage unit is composed of an energy storage subunit, a bidirectional charging subunit and a power storage subunit, wherein the energy storage subunit is composed of a high energy density energy storage device, including but not limited to a high energy density energy storage battery, and the energy storage subunit stores the total energy required for the long stator linear motor booster system to work multiple times. During the normal operation of the long stator linear motor booster system, the bidirectional charging subunit transmits the energy of the energy storage subunit or the energy of the external power grid to the power storage subunit in a constant power or variable power mode that does not affect the stability of the power grid, so as to replenish the power storage subunit with electric energy; when the energy storage subunit is short of energy, the external power grid can replenish the energy storage subunit with electric energy through the bidirectional charging subunit. The power storage subunit includes but is not limited to supercapacitors, pulse capacitors or flywheel energy storage devices, and the power storage subunit stores the electric energy for the long stator linear motor booster system to work in a single cycle. When the long stator linear motor booster system is in traction mode, it provides short-term, high-power energy output for the linear motor operation; during the whole working process, it can accept energy storage subunits or external power grids to supplement its power through bidirectional charging subunits. The energy storage unit can be compatible with external power grid power supply and energy storage subunit power supply, and can reduce the power demand for external power grids or power storage subunits during operation.

[0025] Preferably, the conversion unit 2 specifically includes: a bidirectional DC-DC conversion subunit 21, a DC-AC inverter subunit 22 and an AC-AC bidirectional switch subunit 23; The bidirectional DC-DC conversion subunit 21 is connected to the power type energy storage subunit 13 and the DC-AC inverter subunit 22 respectively; The DC-AC inverter subunit 22 is connected to the AC-AC bidirectional switch subunit 23; The AC-AC bidirectional switch subunit 21 is connected to the driving unit 3; The bidirectional DC-DC conversion subunit 21 is used to transmit the energy of the power type energy storage subunit 13 to the DC-AC inverter subunit 22; The DC-AC inverter subunit 22 is used to convert the energy transmitted by the bidirectional DC-DC conversion subunit 21 into AC electrical energy; The AC-AC bidirectional switch subunit 23 is used to supply power to the drive unit 3 according to control requirements.

[0026] In actual use, the converter unit consists of a bidirectional DC-DC conversion subunit, a DC-AC inverter subunit, and an AC-AC bidirectional switch subunit. Under traction conditions, the bidirectional DC-DC conversion subunit transmits the energy of the power storage subunit to the DC-AC inverter subunit with the goal of outputting a stable voltage, and the DC-AC inverter subunit converts the energy transmitted by the bidirectional DC-DC conversion subunit into AC power to drive the linear motor. Under braking conditions, the DC-AC inverter subunit feeds back the AC power generated by the braking of the linear motor to the DC bus, and the bidirectional DC-DC conversion subunit stores the energy fed back to the DC side by the DC-AC inverter subunit into the power storage subunit. The AC-AC bidirectional switch subunit connects different stator segments of the linear motor on the AC side of the DC-AC inverter subunit and supplies power to different stator segments according to control requirements. The bidirectional DC-DC conversion subunit stabilizes the bus voltage of the DC-AC inverter subunit, reduces the requirements for low voltage fluctuations of the energy storage unit, and also reduces the voltage level and total capacity requirements of the power storage subunit; in this embodiment, the AC-AC bidirectional switch subunit is composed of multiple switches that realize bidirectional current flow, and is a segmented power supply actuator for the motor.

[0027] Preferably, the driving unit 3 is a permanent magnet linear motor with a long stator having a permanent magnet linear motor mover at the front end and a damping device at the end.

[0028] In actual application, the driving unit is a long-stator permanent magnet linear motor with a permanent magnet linear motor mover at the front end and a damping device at the end. The damping device at the end of the linear motor realizes braking of the mover from near zero speed to zero speed. The device is not limited to pneumatic or hydraulic equipment.

[0029] Preferably, the long-stator permanent magnet linear motor comprises a traction section; the traction section is formed by stacking soft magnetic materials, wherein the soft magnetic material comprises silicon steel sheets or amorphous alloys.

[0030] In actual use, the iron core of the traction section is made of laminated soft magnetic materials such as silicon steel sheets or amorphous alloys to reduce eddy current losses in the stator core. In the traction section, the system controls the permanent magnet linear motor rotor to achieve the output thrust target or operating speed target.

[0031] Preferably, the long-stator permanent magnet linear motor further comprises a braking segment; the iron core of the braking segment is made of solid carbon steel.

[0032] In actual use, the long-stator permanent magnet linear motor also includes a braking section. The iron core of the braking section is made of solid carbon steel material to increase the eddy current loss of the stator core, thereby providing the required braking force for the braking section.

[0033] Preferably, when the braking section is in operation, the permanent magnet linear motor mover completes braking from high speed to near zero speed through the iron core of the braking section.

[0034] In actual application, in the braking section, the permanent magnet linear motor rotor can completely rely on the eddy current force induced in the stator core of the braking section to complete braking from high speed to near zero speed; since the traction section and the braking section only differ in the stator core material and manufacturing process, after braking is completed, the rotor is pulled to the working starting point at a low speed under the action of the system's reverse traction force.

[0035] The present invention provides another specific implementation method, as shown in the attached specification. Figure 2 As shown in the figure, the working principle of the long stator linear motor booster system with short-term high power output is: 1) The energy storage subunit is connected to the bidirectional charging subunit and the switch CB1 through the switch CB2, and CB1 is connected to the external DC power supply network interface; the bidirectional charging subunit is connected to the power storage subunit and the external DC power supply network interface through the switches CB4 and CB3; 2) The power storage subunit is connected to the low voltage side of the bidirectional DC-DC conversion subunit, and the high voltage side of the bidirectional DC-DC conversion subunit is connected to the DC-AC inverter subunit. In this embodiment, three inverters are used to complete the stator control of the linear motor. The actual number of inverter units in the system is configured according to the switching time of the switch unit, the running speed of the mover, and the ratio of the mover to the stator segment to ensure the continuity of thrust during operation; 3) The output of the DC-AC inverter unit is connected to different stator segments in sequence through switches. In this embodiment, the first switch is connected to the stator segment numbered 3x-2, the second inverter is connected to the stator segment numbered 3x-1, and the third inverter is connected to the stator segment numbered 3x (x is a positive integer greater than 0). The drive unit includes a long stator linear motor and accessories to achieve different functions. The long stator linear motor is designed with a traction segment and a brake segment according to its use. The traction segment is made of insulated silicon steel sheets or amorphous materials laminated together, and the brake segment is made of solid carbon steel; ①When operating off-grid, switches CB2 and CB4 are closed, and switches CB1 and CB3 are opened. When operating on-grid, switches CB1 and CB4 are closed, and switches CB2 and CB3 are opened. When the energy storage subunit is charging, switches CB2 and CB3 are closed, and switches CB1 and CB4 are opened.

[0036] ② During operation, the operating voltage of the power energy storage subunit varies widely. Under the conditions that the output capacity of the power energy storage subunit and the input capacity of the bidirectional DC-DC conversion subunit permit, the operating voltage of the power energy storage subunit can be reduced to 50% of the rated voltage, or even lower.

[0037] ③ When the permanent magnet linear motor moves to the braking area, the DC-AC inverter unit can perform active braking control or adopt an uncontrolled mode. The braking force generated by the eddy current action of the braking section can quickly reduce the speed of the mover from high speed to near zero speed. The mechanical damping device at the end of the braking section completely reduces the speed of the mover to zero.

[0038] It should be noted that the control unit in this embodiment is also responsible for completing the power supply control of the stator segment and the closed-loop control of the mover speed.

[0039] It should be understood that the use of "method", "device", "unit" and / or "module" in this application is only a method for distinguishing different components, elements, parts, portions or assemblies at different levels. However, if other words can achieve the same purpose, the word can be replaced by other expressions.

[0040] As shown in this application and claims, unless the context clearly indicates an exception, the words "a", "an", "a kind" and / or "the" do not refer to the singular, but also include the plural. Generally speaking, the terms "include" and "comprise" only indicate the inclusion of clearly identified steps and elements, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements. The elements defined by the sentence "includes a..." do not exclude the existence of other identical elements in the process, method, commodity or device that includes the elements.

[0041] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0042] If a flow chart is used in the present application, the flow chart is used to illustrate the operations performed by the system according to the embodiment of the present application. It should be understood that the preceding or following operations are not necessarily performed accurately in order. On the contrary, each step can be processed in reverse order or simultaneously. At the same time, other operations can also be added to these processes, or a certain step or several steps of operations can be removed from these processes.

[0043] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A long-stator linear motor booster system with short-term high-power output, characterized in that: include: Energy storage unit, current conversion unit, drive unit and control unit; The current conversion unit is connected to the energy storage unit, the driving unit and the control unit respectively; The control unit is connected to the energy storage unit and the driving unit respectively; The energy storage unit is used to be compatible with an external DC network, so that the external DC network can charge the energy storage unit; The current conversion unit is used to reduce the fluctuation of the low voltage of the energy storage unit; The driving unit is used to provide traction and braking force; The control unit is used to monitor the energy storage unit, the current conversion unit and the drive unit.

2. The long-stator linear motor booster system with short-term high-power output according to claim 1 is characterized in that: The energy storage unit specifically includes: an energy type energy storage subunit, a bidirectional charging subunit and a power type energy storage subunit; The bidirectional charging subunit is connected to the energy type energy storage subunit and the power type energy storage subunit respectively; The power type energy storage subunit is connected to the current conversion unit; The energy storage subunit is used to store total energy; The bidirectional charging subunit is used to supplement electric energy for the energy storage subunit and the power storage subunit; The power type energy storage subunit is used to store the electric energy of a single cycle operation.

3. The long-stator linear motor booster system with short-term high-power output according to claim 2 is characterized in that: The conversion unit specifically includes: a bidirectional DC-DC conversion subunit, a DC-AC inverter subunit and an AC-AC bidirectional switch subunit; The bidirectional DC-DC conversion subunit is connected to the power type energy storage subunit and the DC-AC inverter subunit respectively; The DC-AC inverter subunit is connected to the AC-AC bidirectional switch subunit; The AC-AC bidirectional switch subunit is connected to the driving unit; The bidirectional DC-DC conversion subunit is used to transfer the energy of the power storage subunit to the DC-AC inverter subunit; The DC-AC inverter subunit is used to convert the energy transmitted by the bidirectional DC-DC conversion subunit into AC electrical energy; The AC-AC bidirectional switch subunit is used to supply power to the drive unit according to control requirements.

4. The long-stator linear motor booster system with short-term high-power output according to claim 1 is characterized in that: The driving unit is specifically a long-stator permanent magnet linear motor with a permanent magnet linear motor mover disposed at the front end and a damping device disposed at the rear end.

5. The long-stator linear motor booster system with short-time high-power output according to claim 4 is characterized in that: The long-stator permanent magnet linear motor comprises a traction section; the traction section is formed by laminating soft magnetic materials, wherein the soft magnetic materials comprise silicon steel sheets or amorphous alloys.

6. The long-stator linear motor booster system with short-term high-power output according to claim 5 is characterized in that: When the traction section is running, the output thrust target or the running speed target is achieved by controlling the permanent magnet linear motor mover.

7. The long-stator linear motor booster system with short-term high-power output according to claim 4 is characterized in that: The long-stator permanent magnet linear motor also includes a braking section; the iron core of the braking section is made of solid carbon steel.

8. The long-stator linear motor booster system with short-time high-power output according to claim 7 is characterized in that: When the braking section is running, the permanent magnet linear motor mover completes braking from high speed to near zero speed through the iron core of the braking section.

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