A segmented LPDSLIM primary magnetic field orientation method and apparatus

Abstract

This invention discloses a segmented LPDSLIM primary field orientation method and apparatus, belonging to the field of motor control technology. The method includes: calculating the primary total flux linkage based on the primary voltage and current, and designing a third-order bandpass filter to effectively remove the DC and ramp components in the flux linkage, while significantly reducing harmonic levels. This greatly improves the estimation accuracy of the primary total flux linkage, laying the foundation for high-precision primary field orientation control. Furthermore, to obtain the key frequency parameters for third-order bandpass filter design, this invention directly calculates the frequency value by analyzing the phase angle of the primary total flux linkage, eliminating the need for the cumbersome frequency-locked loop structure found in traditional control systems and greatly simplifying the control system structure.

Description

Technical Field

[0001] This invention belongs to the field of motor control technology, and more specifically, relates to a method and apparatus for primary magnetic field orientation of a segmented long primary double side linear induction motor (LPDSLIM). Background Technology

[0002] Linear drive devices typically utilize a rotary motor combined with a conversion mechanism, such as a wire rope, chain, drive belt, or lead screw. However, these systems suffer from drawbacks including large size, high frictional losses, and low efficiency. In contrast, linear induction motors directly convert electrical energy into linear motion without the need for intermediate conversion devices, effectively improving energy transfer efficiency, reducing mechanical losses, and offering advantages such as simple structure, convenient maintenance, and good heat dissipation. Therefore, they are widely used in fields such as rail transportation and electromagnetic launch.

[0003] LPDSLIM is a specially designed linear induction motor characterized by a long primary and a short secondary. The secondary is made of lightweight aluminum, offering advantages such as simple structure and high thrust-to-weight ratio, making it particularly suitable for high-speed operating environments. However, because the primary length far exceeds the secondary, powering the entire primary would lead to increased motor leakage inductance and reduced voltage utilization. Therefore, the long primary is typically segmented, employing a segmented power supply strategy, including segmented series power supply and segmented parallel power supply.

[0004] Due to insufficient accuracy of the secondary model in segmented LPDSLIM and the influence of edge effects, the accuracy of secondary magnetic field orientation is limited, making traditional vector control methods based on secondary magnetic field orientation insufficient to meet the requirements of high-performance control. Therefore, some researchers have turned to exploring vector control methods based on primary magnetic field orientation, the control performance of which is highly dependent on the accuracy of primary magnetic field orientation. In view of this, there is an urgent need to develop a high-precision primary magnetic field orientation device and method suitable for segmented LPDSLIM to further improve its control performance. Summary of the Invention

[0005] In view of the above-mentioned defects or improvement needs of the existing technology, the purpose of this invention is to provide a segmented LPDSLIM primary magnetic field orientation method and device, which aims to design a third-order bandpass filter to filter out the DC component and ramp component in the primary total flux linkage and suppress the harmonic components therein, so as to obtain a high-precision primary total flux linkage phase angle, laying the foundation for the segmented LPDSLIM vector control method based on primary magnetic field orientation.

[0006] To achieve the above objectives, according to one aspect of the present invention, a segmented LPDSLIM primary field orientation method is provided, comprising:

[0007] S1. Based on the segmented LPDSLIM primary mathematical model, estimate the primary total flux linkage using the primary voltage and primary total current;

[0008] S2. Design a third-order bandpass filter to filter the primary total flux linkage, remove the DC component and ramp component, and suppress the harmonic components to obtain the primary total flux linkage filtered value; the initial parameters of the third-order bandpass filter are preset values, and the system is started by a given initial primary total flux linkage frequency;

[0009] S3. Calculate the primary total flux amplitude and primary total flux phase angle based on the primary total flux filtering value to achieve primary magnetic field orientation;

[0010] S4. Calculate the primary total flux linkage frequency using the primary total flux linkage phase angle, which is used to update the parameters of the third-order bandpass filter. Return to S2.

[0011] In one embodiment, S1 includes: based on the primary voltage u pα u pβ Number of primary power supply segments m, primary resistance R p and primary total current i pα i pβ Calculate the primary total flux linkage ψ pα ψ pβ The calculation formula is:

[0012]

[0013] In one embodiment, S2 includes: based on the frequency of the primary total flux linkage Design a third-order bandpass filter to filter the primary total flux linkage ψ. pα ψ pβ Filtering is performed to obtain the primary total flux linkage filter value ψ pαf ψ pβf The transfer function of the designed third-order bandpass filter is:

[0014]

[0015] In one embodiment, S3 includes:

[0016] S31. Based on the primary total flux linkage filter value ψ pαf ψ pβf Calculate the primary total flux linkage magnitude ψ pm The calculation formula is:

[0017] S32. Based on the primary total flux linkage α-axis filter value ψ pαf and primary total flux linkage amplitude ψ pm Calculate the cosine value of the phase angle of the primary total flux linkage. The calculation formula is

[0018] S33. Based on the primary total flux linkage β-axis filter value ψ pβf and primary total flux linkage amplitude ψ pm Calculate the sine value of the primary total flux linkage phase angle. The calculation formula is

[0019] S34. The sine value of the primary total flux linkage phase angle As a condition for judgment, the primary total flux phase angle is determined.

[0020] In one embodiment, S34 includes:

[0021] S341. If For a primary total flux linkage phase angle greater than or equal to zero, the formula for calculating the phase angle is:

[0022]

[0023] S342. If When the primary total flux linkage phase angle is less than zero, the formula for calculating the phase angle is:

[0024]

[0025] In one embodiment, S4 includes:

[0026] S41. Calculate the primary total flux linkage angle and θ sum ;

[0027] S42. Regarding the primary total flux linkage angle and θ sum Perform differentiation to obtain the primary total flux linkage frequency.

[0028] In one embodiment, S41 includes:

[0029] S411. Detect the number of times n, the phase angle of the primary total flux linkage, returns to zero;

[0030] S412. Calculate the sum of the primary total flux linkage angles. The calculation formula is as follows:

[0031] According to another aspect of the present invention, a segmented LPDSLIM primary magnetic field orientation device is provided, characterized in that it comprises:

[0032] The primary total flux linkage calculation module is used to calculate the primary total flux linkage based on the segmented LPDSLIM primary mathematical model, using the primary voltage and primary total current.

[0033] The primary total flux linkage third-order bandpass filter module is used to perform third-order bandpass filtering on the primary total flux linkage to remove the DC component and ramp component, and suppress the harmonic components to obtain the primary total flux linkage filter value.

[0034] The primary total flux linkage amplitude and phase angle calculation module is used to calculate the amplitude of the primary total flux linkage based on the primary total flux linkage filter value, and then determine its phase angle;

[0035] The primary total flux linkage frequency calculation module is used to calculate the primary total flux linkage frequency using the primary total flux linkage phase angle, providing key parameters for the design of third-order bandpass filters.

[0036] In summary, compared with the prior art, the above-described technical solutions conceived by this invention can achieve the following beneficial effects:

[0037] (1) This invention provides a segmented LPDSLIM primary magnetic field orientation method, which obtains accurate primary total flux phase and amplitude, laying the foundation for a segmented LPDSLIM vector control method based on primary magnetic field orientation.

[0038] (2) This scheme designs a third-order bandpass filter to filter the primary total flux linkage, which can effectively remove the DC component and ramp component, and can significantly suppress the harmonic component, thereby improving the estimation accuracy of the primary total flux linkage.

[0039] (3) By accurately calculating the phase angle of the primary total flux linkage, this scheme can directly obtain the primary total flux linkage frequency, thus providing key parameters for the design of the third-order bandpass filter. This process avoids the use of frequency-locked loops in traditional control systems, thereby simplifying the system structure. Attached Figure Description

[0040] Figure 1 This is a flowchart of the segmented LPDSLIM primary magnetic field orientation method provided in an embodiment of the present invention.

[0041] Figure 2 This is a control block diagram of the segmented LPDSLIM primary magnetic field orientation method provided in the embodiments of the present invention.

[0042] Figure 3 This is a schematic diagram of the primary total flux linkage calculation module provided in an embodiment of the present invention.

[0043] Figure 4 This is a schematic diagram of the structure of the primary total flux third-order bandpass filter module provided in an embodiment of the present invention.

[0044] Figure 5 This is a schematic diagram of the primary total flux linkage amplitude and phase angle calculation module provided in an embodiment of the present invention.

[0045] Figure 6 This is a schematic diagram of the primary total flux linkage frequency calculation module provided in an embodiment of the present invention. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0047] Example 1

[0048] like Figure 1 As shown, this embodiment provides a segmented LPDSLIM primary field orientation method, including:

[0049] S1. Based on the segmented LPDSLIM primary mathematical model, estimate the primary total flux linkage using the primary voltage and primary total current.

[0050] S2. Design a third-order bandpass filter to filter the primary total flux linkage, removing the DC and ramp components and suppressing harmonic components to obtain the primary total flux linkage filtered value. The initial parameters of the third-order bandpass filter are preset values, and the system is started by a given initial primary total flux linkage frequency.

[0051] S3. Calculate the primary total flux linkage amplitude and primary total flux linkage phase angle based on the primary total flux linkage filter value to achieve primary magnetic field orientation.

[0052] S4. Calculate the primary total flux linkage frequency using the primary total flux linkage phase angle, which is used to update the parameters of the third-order bandpass filter. Return to S2.

[0053] In this embodiment, S1 includes: based on the primary voltage u pα u pβ Number of primary power supply sections m, primary resistance R p and primary total current i pα i pβ Calculate the primary total flux linkage ψ pα ψ pβ The calculation formula is:

[0054]

[0055] In this embodiment, S2 includes: based on the primary total flux frequency Design a third-order bandpass filter to filter the primary total flux linkage ψ. pα ψ pβ Filtering is performed to obtain the primary total flux linkage filter value ψ pαf ψ pβf The transfer function of the designed third-order bandpass filter is:

[0056]

[0057] In this embodiment, S3 includes:

[0058] S31. Based on the primary total flux linkage filter value ψ pαf ψ pβf Calculate the primary total flux linkage magnitude ψ pm The calculation formula is:

[0059] S32. Based on the primary total flux linkage α-axis filter value ψ pαf and primary total flux linkage amplitude ψ pm Calculate the cosine value of the phase angle of the primary total flux linkage. The calculation formula is

[0060] S33. Based on the primary total flux linkage β-axis filter value ψ pβf and primary total flux linkage amplitude ψ pm Calculate the sine value of the primary total flux linkage phase angle. The calculation formula is

[0061] S34. The sine value of the primary total flux linkage phase angle As a condition for judgment, the primary total flux phase angle is determined.

[0062] In this embodiment, S34 includes:

[0063] S341. If For a primary total flux linkage phase angle greater than or equal to zero, the formula for calculating the phase angle is:

[0064]

[0065] S342. If When the primary total flux linkage phase angle is less than zero, the formula for calculating the phase angle is:

[0066]

[0067] In this embodiment, S4 includes:

[0068] S41. Calculate the primary total flux linkage angle and θ sum ;

[0069] S42. Regarding the primary total flux linkage angle and θsum Perform differentiation to obtain the primary total flux linkage frequency.

[0070] S41 includes:

[0071] S411. Detect the number of times n, the phase angle of the primary total flux linkage, returns to zero;

[0072] S412. Calculate the sum of the primary total flux linkage angles. The calculation formula is as follows:

[0073] Example 2

[0074] like Figure 2 As shown, this embodiment provides a segmented LPDSLIM primary field-oriented device, including: a primary total flux linkage calculation module, a primary total flux linkage third-order bandpass filtering module, a primary total flux linkage amplitude and phase angle calculation module, and a primary total flux linkage frequency calculation module. The primary total flux linkage calculation module is used to calculate the primary total flux linkage. The primary total flux linkage third-order bandpass filtering module is used to perform third-order bandpass filtering on the primary total flux linkage. The primary total flux linkage amplitude and phase angle calculation module is used to calculate the amplitude and phase angle of the primary total flux linkage. The primary total flux linkage frequency calculation module is used to calculate the primary total flux linkage frequency, providing key parameters for the design of the third-order bandpass filter.

[0075] Specifically, the primary total flux linkage calculation module is used to calculate the primary voltage u. pα u pβ Number of primary power supply segments m, primary resistance R p and primary total current i pα i pβ Calculate the primary total flux linkage ψ pα ψ pβ The primary total flux linkage third-order bandpass filter module is used to filter the primary total flux linkage based on its frequency. Design a third-order bandpass filter to filter the primary total flux linkage ψ. pα ψ pβ Filtering is performed to obtain the primary total flux linkage filter value ψ pαf ψ pβf The primary total flux linkage amplitude and phase angle calculation module is used to calculate the primary total flux linkage filtering value ψ. pαf ψ pβf Calculate the magnitude ψ of the primary total flux linkage. pm and phase angle The primary total flux linkage frequency calculation module is used to calculate the primary total flux linkage frequency based on the phase angle. Calculate the primary total flux frequency This provides key parameters for the design of third-order bandpass filters.

[0076] Specifically, such as Figure 3As shown, the primary total flux linkage calculation module includes: first, second, third, and fourth proportional controllers, first and second adders, and first and second integrators.

[0077] The first proportional controller will input the primary voltage α-axis component u. pα Multiply by the number of primary power supply segments m to obtain the α-axis component of the total primary voltage mu. pα The second proportional controller will input the α-axis component i of the primary total current. pα Multiplied by the primary resistance R p The primary total internal resistance voltage drop α-axis component is obtained. The input of the first adder is connected to the first proportional controller and the second proportional controller to calculate the total back EMF α-axis component. The input of the first integrator is connected to the first adder to integrate the total back EMF α-axis component to obtain the primary total flux linkage α-axis component ψ. pα The third proportional controller will input the primary voltage β-axis component u. pβ Multiply by the number of primary power supply segments m to obtain the β-axis component of the total primary voltage mu. pβ The fourth proportional controller will input the β-axis component of the primary total current i. pβ Multiplied by the primary resistance R p The first adder is used to obtain the β-axis component of the total primary internal resistance voltage drop. The inputs of the second adder are connected to the third and fourth proportional controllers to calculate the β-axis component of the total back EMF. The input of the second integrator is connected to the second adder to integrate the β-axis component of the total back EMF to obtain the β-axis component ψ of the primary total flux linkage. pβ .

[0078] Specifically, such as Figure 4 As shown, the primary total flux third-order bandpass filter module includes: third, fourth, fifth, sixth, seventh, and eighth adders; fifth and sixth proportional controllers; first, second, third, and fourth multipliers; and third, fourth, fifth, sixth, seventh, and eighth integrators.

[0079] The input of the third adder is connected to the third integrator, for the α-axis component ψ of the primary total flux linkage. pα The difference between the output of the third integrator and the output of the fourth adder is calculated. The input of the fourth adder is connected to the third adder and is used to calculate the primary total flux linkage α-axis filter value ψ between the output of the third adder and the output of the third-order bandpass filter. pαf The input of the third integrator is connected to the fourth adder, used to integrate the output of the fourth adder. The input of the fifth proportional controller is connected to the fourth adder, used to proportionally amplify the output of the fourth adder. The input of the fifth adder is connected to both the fifth proportional controller and the fourth integrator, used to calculate the difference between them. The input of the first multiplier is connected to the fifth adder, used to multiply the output of the fifth adder by the input frequency ω. ψpMultiplication. The input of the fifth integrator is connected to the first multiplier and is used to integrate the output of the first multiplier to obtain the primary total flux linkage α-axis filter value ψ. pαf The input of the second multiplier is connected to the input frequency ω. ψp and primary total flux linkage α-axis filter value ψ pαf This performs the product operation between the two. The input of the fourth integrator is connected to the second multiplier and is used to integrate the output of the second multiplier. The input of the sixth adder is connected to the sixth integrator and performs the product operation on the β-axis component ψ of the primary total flux linkage. pβ The difference between the output of the sixth integrator and the output of the seventh adder is calculated. The input of the seventh adder is connected to the sixth adder and is used to calculate the primary total flux linkage β-axis filter value ψ between the output of the sixth adder and the output of the third-order bandpass filter. pβf The input of the sixth integrator is connected to the seventh adder, used to integrate the output of the seventh adder. The input of the sixth proportional controller is connected to the seventh adder, used to proportionally amplify the output of the seventh adder. The input of the eighth adder is connected to the sixth proportional controller and the seventh integrator, used to calculate the difference between them. The input of the third multiplier is connected to the eighth adder, used to multiply the output of the eighth adder by the input frequency ω. ψp Multiplication. The input of the eighth integrator is connected to the third multiplier, and is used to integrate the output of the third multiplier to obtain the primary total flux linkage β-axis filter value ψ. pβf The input of the fourth multiplier is connected to the input frequency ω. ψp and primary total flux linkage β-axis filter value ψ pβf This allows for the multiplication of the two components. The input of the seventh integrator is connected to the fourth multiplier, and it is used to perform integration on the output of the fourth multiplier.

[0080] Specifically, such as Figure 5 As shown, the primary total flux linkage amplitude and phase angle calculation module includes: fifth, sixth, seventh, and eighth multipliers, ninth and tenth adders, square root extractor, inverse cosine calculator, and decision unit.

[0081] The fifth multiplier is used to filter the input primary total flux linkage α-axis value ψ. pαf Perform the squaring operation to obtain ψ pαf 2 The sixth multiplier is used to exponentiate the input primary total flux linkage β-axis filtered value to obtain ψ. pβf 2 The output of the ninth adder is connected to the fifth and sixth multipliers to calculate ψ. pαf 2 and ψ pβf 2 and ψ pαf 2 +ψ pβf2 The input of the square root extractor is connected to the ninth adder, used to extract ψ. pαf 2 +ψ pβf 2 Perform the square root operation to obtain the primary total flux linkage amplitude ψ. pm The input of the seventh multiplier is connected to the square root extractor, used to implement the primary total flux linkage α-axis filtering value ψ. pαf With primary total flux linkage amplitude ψ pm Divide to obtain the cosine of the total flux linkage phase angle. The input of the eighth multiplier is connected to the square root extractor to implement the primary total flux linkage β-axis filter value ψ. pβf With primary total flux linkage amplitude ψ pm Divide to obtain the sine value of the primary total flux linkage phase angle. The input of the inverse cosine calculator is connected to the seventh multiplier to solve for one input of the decision circuit. The input of the tenth adder is connected to the inverse cosine calculator to obtain the other solution of the decision circuit. The input of the decision circuit is connected to the inverse cosine calculator, the tenth adder, and the eighth multiplier. The eighth multiplier outputs the sine value of the primary total flux linkage phase angle. As a decision condition of the decision-maker, when the decision condition When the condition is greater than or equal to zero, the output of the decision unit is the output of the inverse cosine calculator. If the value is greater than zero, the output of the decision unit is the output of the tenth adder.

[0082] Specifically, such as Figure 6 As shown, the primary total flux linkage frequency calculation module includes: angle calculation and differentiator.

[0083] Angles and calculations are used based on the primary total flux phase angle. Calculate the primary total flux linkage angle and θ sum The input of the differentiator is connected to the angle and calculation, used to calculate the primary total flux linkage angle and θ. sum Differentiate to obtain the primary total flux linkage frequency.

[0084] In summary, compared with the prior art, the present invention has the following advantages:

[0085] This invention provides a segmented LPDSLIM primary field orientation method, which obtains accurate primary total flux linkage phase, laying the foundation for segmented LPDSLIM vector control methods based on primary field orientation. More specifically, this scheme designs a third-order bandpass filter to filter the primary total flux linkage, effectively removing DC and ramp components and significantly suppressing harmonic components, thus improving the estimation accuracy of the primary total flux linkage. Furthermore, this invention directly obtains the primary total flux linkage frequency through precise calculation of the primary total flux linkage phase angle, providing key parameters for the design of the third-order bandpass filter. This process avoids the use of frequency-locked loops in traditional control systems, thereby simplifying the system structure.

[0086] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A segmented LPDSLIM primary magnetic field orientation method, characterized in that, Includes the following steps: S1. Based on the segmented LPDSLIM primary mathematical model, estimate the primary total flux linkage using the primary voltage and primary total current; S2. A third-order bandpass filter is used to filter the primary total flux linkage, removing the DC and ramp components and suppressing harmonic components to obtain the primary total flux linkage filtered value; the initial parameters of the third-order bandpass filter are preset values; including: based on the frequency of the primary total flux linkage. Design a third-order bandpass filter to filter the primary total flux linkage. , Filtering is performed to obtain the primary total flux linkage filter value. , The transfer function of the designed third-order bandpass filter is: ； S3. Calculate the primary total flux linkage amplitude and phase angle based on the primary total flux linkage filter value to achieve primary magnetic field orientation; including: S31. Based on the primary total flux linkage filter value , Calculate the primary total flux linkage magnitude The calculation formula is: ; S32. Based on the primary total flux linkage α Axis filter value and primary total flux linkage amplitude Calculate the cosine value of the phase angle of the primary total flux linkage. The calculation formula is: ; S33. Based on the primary total flux linkage β Axis filter value and primary total flux linkage amplitude Calculate the sine value of the primary total flux linkage phase angle. The calculation formula is: ; S34. The sine value of the primary total flux phase angle. As a condition for judgment, the primary total flux phase angle is determined; S341. If For a primary total flux linkage phase angle greater than or equal to zero, the formula for calculating the phase angle is: S342. If When the primary total flux linkage phase angle is less than zero, the formula for calculating the phase angle is: S4. Calculate the primary total flux linkage frequency using the primary total flux linkage phase angle, which is used to update the parameters of the third-order bandpass filter. Return to S2. S41. Calculate the primary total flux linkage angle and ; S42. Regarding the primary total flux linkage angle and Perform differentiation to obtain the primary total flux linkage frequency. .

2. The segmented LPDSLIM primary magnetic field orientation method as described in claim 1, characterized in that, The primary total magnetic flux in S1 , The calculation formula is: in, , For primary voltage, For the number of primary power supply sections, For primary resistors, , This represents the primary total current.

3. The segmented LPDSLIM primary magnetic field orientation method as described in claim 1, characterized in that, S41 includes: S411. Detect the number of times the primary total flux phase angle returns to zero. n ; S412. Calculate the sum of the primary total flux linkage angles. The calculation formula is as follows: .

4. A segmented LPDSLIM primary magnetic field orientation device, characterized in that, include: The primary total flux linkage calculation module is used to calculate the primary total flux linkage based on the segmented LPDSLIM primary mathematical model, using the primary voltage and primary total current. The primary total flux linkage third-order bandpass filter module is used to perform third-order bandpass filtering on the primary total flux linkage to remove the DC component and ramp component, and suppress the harmonic components to obtain the primary total flux linkage filter value. The initial parameters of the third-order bandpass filter are preset values; including: based on the frequency of the primary total flux linkage. Design a third-order bandpass filter to filter the primary total flux linkage. , Filtering is performed to obtain the primary total flux linkage filter value. , The transfer function of the designed third-order bandpass filter is: ； The primary total flux linkage amplitude and phase angle calculation module is used to calculate the amplitude of the primary total flux linkage based on the primary total flux linkage filter value, and then determine its phase angle; including: Based on the primary total flux linkage filter value , Calculate the primary total flux linkage magnitude The calculation formula is: ; According to the primary total magnetic flux α Axis filter value and primary total flux linkage amplitude Calculate the cosine value of the phase angle of the primary total flux linkage. The calculation formula is: ; According to the primary total magnetic flux β Axis filter value and primary total flux linkage amplitude Calculate the sine value of the primary total flux linkage phase angle. The calculation formula is: ; The sine of the primary total flux phase angle As a condition for judgment, the primary total flux phase angle is determined; like For a primary total flux linkage phase angle greater than or equal to zero, the formula for calculating the phase angle is: like When the primary total flux linkage phase angle is less than zero, the formula for calculating the phase angle is: The primary total flux linkage frequency calculation module is used to calculate the primary total flux linkage frequency using the primary total flux linkage phase angle, providing parameters for the design of third-order bandpass filters; it includes: Calculate the primary total flux linkage angle and ; For the primary total flux angle and Perform differentiation to obtain the primary total flux linkage frequency. .

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