A method and system for controlling operation of a washing machine motor based on fundamental voltage control

Abstract

The application discloses a washing machine motor operation control method and system based on fundamental wave voltage control, and relates to the technical field of washing machine motor control. The method comprises the following steps: S1, offline calculation of a relationship curve between the fundamental wave voltage and the reference voltage in the over-modulation region and storage of the curve in the memory; S2, calculation of the fundamental wave voltage by using a field-oriented control algorithm, wherein the d-axis and q-axis components of the fundamental wave voltage and the stator voltage are obtained through a speed loop and a current loop; S3, if the fundamental wave voltage is in the linear modulation region or exceeds the over-modulation region, an SVPWM algorithm in a 120-degree coordinate system is used for modulation; if the fundamental wave voltage is in the over-modulation region, an over-modulation algorithm in the 120-degree coordinate system is used to calculate the three-phase voltage action time, and finally, the SVPWM algorithm is used for modulation. The application directly takes the fundamental wave voltage as a control target, avoids the uncertainty caused by the inconsistency between the reference voltage and the fundamental wave voltage, and thus realizes accurate control of the fundamental wave voltage which has an actual effect.

Description

Technical Field

[0001] This invention relates to the field of washing machine motor control technology, specifically to a washing machine motor operation control method and system based on fundamental voltage control. Background Technology

[0002] Washing machines are essential household appliances. During operation, the washing machine motor needs to run in washing and spin-drying modes to complete the washing process. During spin-drying, the motor needs to operate at high speeds. The SVPWM algorithm in a 120-degree coordinate system is a highly efficient motor control algorithm. It constructs a complex plane synthetic space voltage vector using three-phase voltage as the basic voltage vector and solves for the action time of the voltage vector in a 120-degree coordinate system. Without overmodulation, the modulation range is within the inscribed circle of the hexagon formed by the six basic voltage vectors, and the phase voltage utilization rate is 57.7350%, meaning the maximum modulated space voltage vector is 57.7350% of the DC voltage. To improve the DC voltage utilization rate, an overmodulation algorithm (e.g., CN111224599A) is introduced. This algorithm changes the reference voltage to allow the modulated voltage vector to exceed the inscribed circle range, thereby improving voltage utilization. Once the target voltage vector reaches its maximum, if further increases in speed are desired, field weakening control is required.

[0003] While existing overmodulation algorithms can improve DC voltage utilization, only the fundamental voltage in the output has a practical effect on motor drive. Because there is a non-linear relationship between the reference voltage and the modulated fundamental voltage, they do not correspond, making the actual fundamental voltage unpredictable and unable to be precisely set as needed, thus limiting the system's control accuracy. Existing overmodulation algorithms are based on reference voltage modulation. When the reference voltage exceeds the linear modulation range, methods such as reducing the reference voltage and changing its phase are needed to alter the fundamental voltage vector's action time, confining the reference voltage within a limiting hexagon. Therefore, the magnitude of the fundamental voltage, which has a practical effect, cannot be directly controlled after modulation. Summary of the Invention

[0004] To address the issue that existing overmodulation algorithms can only indirectly obtain the output voltage by adjusting the reference voltage, and the fundamental voltage with actual effect cannot be directly determined, resulting in insufficient control accuracy, this invention proposes a washing machine motor operation control method and system based on fundamental voltage control. This method directly uses the fundamental voltage as the control target, avoiding the uncertainty caused by the inconsistency between the reference voltage and the fundamental voltage, thereby achieving precise control of the fundamental voltage with actual effect.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a washing machine motor operation control method based on fundamental voltage control, comprising the following steps: S1, calculate the relationship curve between the fundamental voltage and the reference voltage in the overmodulation region offline and store the curve in memory; S2 uses a field-oriented control algorithm to calculate the fundamental voltage. The d-axis and q-axis components of the fundamental voltage are obtained through the speed loop and the current loop. S3. If the fundamental voltage is within the linear modulation region or exceeds the overmodulation region, the SVPWM algorithm in the 120-degree coordinate system is used for modulation. If the fundamental voltage is in the overmodulation region, the overmodulation algorithm in the 120-degree coordinate system is used to calculate the three-phase voltage action time, and finally the SVPWM algorithm is used for modulation. When it exceeds the overmodulation region, single-current field weakening control is used.

[0006] In this technical solution, the relationship between the fundamental voltage and the reference voltage is first calculated and a corresponding relationship curve is generated. Then, the fundamental voltage is calculated, and the control algorithm to be adopted is determined based on the magnitude of the fundamental voltage. If the fundamental voltage is in the overmodulation region, the three-phase voltage action time is calculated based on the above relationship curve and the overmodulation algorithm, and then SVPWM modulation is performed.

[0007] The present invention is further configured such that step S1 includes: S11 divides the overmodulation region into overmodulation region I and overmodulation region II; S12, through analysis, the fundamental voltage F1 and the reference voltage in the overmodulation I and II regions are derived respectively. The mathematical expression between them; S13, calculates and stores F1 offline. The corresponding curve.

[0008] In practical applications, the required reference voltage can be obtained directly from the target fundamental voltage F1. Then, the duration of action is calculated by substituting the values ​​into the modulation algorithm.

[0009] The present invention is further configured such that when the fundamental voltage is in the linear modulation region, the fundamental voltage is less than 57.7350% of the DC voltage; when the fundamental voltage is in the overmodulation region, the fundamental voltage is greater than 57.7350% of the DC voltage and less than 63.6619% of the DC voltage; and when the fundamental voltage exceeds the overmodulation region, the fundamental voltage is greater than 63.6619% of the DC voltage.

[0010] In this technical solution, the magnitude of the fundamental voltage F1 is used to determine which control algorithm to adopt, so that the washing machine motor can achieve a higher speed and a better cleaning effect.

[0011] The present invention is further configured such that S11 includes adjustment of the over-modulation I region, wherein the modulation I region is the area between the inscribed circle and the circumscribed circle of the output limiting hexagon; the adjustment of the over-modulation I region includes: within this region, part of the trajectory of the reference voltage vector falls within the limiting hexagon and no adjustment is required; the other part is outside the limiting hexagon, and the amplitude of the reference voltage needs to be reduced to limit the excess part within the boundary of the limiting hexagon.

[0012] The present invention is further configured such that: S11 includes adjustment of the modulation II region, the modulation II region being the area outside the circumcircle of the output limiting hexagon, the adjustment of the modulation II region including: constructing an auxiliary equilateral triangle, adjusting the reference voltage inside the triangle to the boundary of the hexagon; outputting the closest basic voltage vector for the reference voltage outside the triangle; and outputting two basic voltage vectors simultaneously in certain specific regions.

[0013] The present invention is further configured such that step S12 includes: for the overmodulated I region, without adjusting the phase of the reference voltage, the expression for the A-phase voltage can be obtained by decomposing the spatial voltage vector of the first quadrant to the real axis; by calculating the content of the fundamental voltage in the A-phase voltage, the content of the fundamental voltage in the voltage after the reference voltage is modulated can be obtained.

[0014] The present invention is further configured such that step S12 includes: for modulation region II, the phase of the reference voltage needs to be adjusted, and the spatial voltage vector of the first quadrant is decomposed to the real axis to obtain the expression of phase A voltage; the content of fundamental voltage in phase A voltage is calculated to obtain the content of fundamental voltage in the voltage after modulation of the reference voltage.

[0015] The present invention is further configured such that step S12 includes: using MATLAB software to solve for the relationship between the reference voltage vector before and after overmodulation and the actual effective fundamental voltage obtained after overmodulation.

[0016] In this technical solution, after obtaining the fundamental voltage content of the overmodulation I region and the overmodulation II region, MATLAB software is used for calculation.

[0017] The present invention is further configured such that, in step S3, if the fundamental voltage is in the overmodulation region, the curve in step S1 is retrieved, the reference voltage corresponding to the fundamental voltage F1 is queried, and then the overmodulation algorithm in the 120-degree coordinate system is used to calculate the three-phase voltage action time, and then SVPWM modulation is performed.

[0018] In this technical solution, since the relationship curve between the fundamental voltage and the reference voltage is stored in memory, it can be queried and retrieved at any time.

[0019] A washing machine motor operation control system based on fundamental voltage control, applicable to the aforementioned washing machine motor operation control method based on fundamental voltage control, includes a calculation module and a control module connected to the calculation module. The calculation module can calculate the relationship curve between the fundamental voltage and the reference voltage offline, and the control module can determine the specific control algorithm to be used based on the magnitude of the fundamental voltage.

[0020] In this technical solution, the calculation module is connected to the control module. The calculation module can execute the contents of steps S1 to S2, and the control module can execute the contents of step S3.

[0021] The present invention can bring the following beneficial effects: The present invention provides a washing machine motor operation control method based on fundamental voltage control, which can directly use the required fundamental voltage as the control target, avoid the uncertainty caused by the inconsistency between the reference voltage and the fundamental voltage, and thus achieve precise control of the fundamental voltage that has a practical effect. Furthermore, the technical solution of the present invention can effectively improve the limiting voltage for entering the field weakening control, and improve the operating performance of the washing machine motor under high-speed conditions. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the synthesis of reference voltage vectors in a 120-degree coordinate system.

[0023] Figure 2 This is a schematic diagram of the overmodulation I-region adjustment strategy.

[0024] Figure 3 This is a schematic diagram of the overmodulation II zone adjustment strategy.

[0025] Figure 4 This is a schematic diagram of the output voltage of phase A in the overmodulated I region.

[0026] Figure 5 This is a schematic diagram of the output voltage of phase A in the overmodulated region II.

[0027] Figure 6 This is a schematic diagram of the relationship between the reference voltage and the fundamental voltage.

[0028] Figure 7 This is a flowchart of the overmodulation algorithm.

[0029] Figure 8 This is a block diagram for single-current field weakening control. Detailed Implementation

[0030] Example 1 Existing overmodulation algorithms can only indirectly obtain the output voltage by adjusting the reference voltage. However, the fundamental voltage, which has practical effect, cannot be directly determined, leading to insufficient control precision. This embodiment proposes a washing machine motor operation control method based on fundamental voltage control, combined with... Figures 1 to 8 It mainly includes the following three steps.

[0031] Step S1: In the overmodulation region, calculate and obtain the relationship curve between the fundamental voltage and the reference voltage offline, and store the curve in memory.

[0032] Step S2: The fundamental voltage is calculated according to the magnetic field orientation control algorithm. The d-axis and q-axis components of the required fundamental voltage are obtained through the speed loop and current loop, and the fundamental voltage is calculated by the sum of squares.

[0033] Step S3 involves determining the range of the fundamental voltage calculated in step S2, and then selecting the appropriate control algorithm. If the fundamental voltage is within the linear modulation region, the SVPWM algorithm in the 120-degree coordinate system is used for modulation. If the fundamental voltage is within the overmodulation region, the overmodulation algorithm in the 120-degree coordinate system is used to calculate the three-phase voltage duration, and finally the SVPWM algorithm is used for modulation. If the fundamental voltage exceeds the overmodulation region, the single-current field weakening control algorithm described above is used to calculate... Then, the SVPWM algorithm in the 120-degree coordinate system is used for modulation.

[0034] In this technical solution, the relationship between the fundamental voltage and the reference voltage is first calculated and a corresponding relationship curve is generated. Then, the fundamental voltage is calculated, and the control algorithm to be adopted is determined based on the magnitude of the fundamental voltage. If the fundamental voltage is in the overmodulation region, the three-phase voltage action time is calculated based on the above relationship curve and the overmodulation algorithm, and then SVPWM modulation is performed.

[0035] When the fundamental voltage is in the linear modulation region, the magnitude of the fundamental voltage F1 is less than 57.7350% of the DC voltage. When the fundamental voltage is in the overmodulation region, the fundamental voltage F1 is less than 63.6619% of the DC voltage and greater than 57.7350% of the DC voltage. When the fundamental voltage exceeds the overmodulation region, the fundamental voltage is greater than 63.6619% of the DC voltage.

[0036] In this technical solution, the magnitude of the fundamental voltage F1 is used to determine which control algorithm to adopt, so that the washing machine motor can achieve a higher speed and a better cleaning effect.

[0037] For the SVPWM algorithm in the 120-degree coordinate system Figure 1 This is a schematic diagram of reference voltage vector synthesis, where, For the reference voltage vector, , and These are the three-phase bridge arm voltages, each spatially 120 degrees apart; For the three-phase bridge arm switching cycle, , and For the duration of the three-phase voltage application, taking into account equal and The opposite of the sum, let equal minus , equal minus Then there is equal Plus Two-phase stationary coordinate system axes and three-coordinate system With the axes coinciding, we can obtain the following using the law of sines: Equal to the square root of 3 multiplied by Divide by Then multiply by the square root of 3. With half The sum of, Equal to the square root of 3 multiplied by Divide by .according to The numerical relationship can distinguish the three sectors in the coordinate system. Let , and The smallest one is 0, which can produce a typical five-segment SVPWM modulation waveform.

[0038] when When all are greater than or equal to 0, equal ,when Less than or equal to and Less than or equal to 0 When greater than or equal to 0, equal ,when Greater than and Greater than or equal to 0 When less than or equal to 0, equal .

[0039] To reduce the switching harmonic content in the output voltage, it is converted to a seven-segment SVPWM by zero-splitting. For a given... , and The duration of action of the zero vector for minus , and The maximum value of the three. Increasing the zero vector's action time to the middle two segments transforms it into a seven-segment SVPWM. The adjusted switching action times of the three-phase bridge arms are as follows: equal Plus Divide by 2, equal Plus Divide by 2, equal Plus Divide by 2.

[0040] Step S1 mainly includes the following sub-steps.

[0041] Step S11: The overmodulation region is mainly divided into overmodulation region I and overmodulation region II.

[0042] Step S12: Through analysis, mathematical expressions between the fundamental voltage F1 and the reference voltage Uref in the overmodulation I and II regions are derived respectively.

[0043] Step S13: Calculate and store the corresponding curves of F1 and Uref offline.

[0044] In practical applications, the required reference voltage can be obtained directly from the target fundamental voltage F1. Then, the duration of action is calculated by substituting the values ​​into the modulation algorithm.

[0045] For step S11, refer to Figure 2 The region between the inscribed circle and the circumscribed circle of the output limiting hexagon is defined as the overmodulation I region. The adjustment strategy for the overmodulation I region is as follows: within this region, part of the trajectory of the reference voltage vector falls within the limiting hexagon and no adjustment is required; the other part is outside the limiting hexagon, and the amplitude of the reference voltage needs to be reduced to limit the excess part within the boundary of the limiting hexagon.

[0046] More specifically, if the reference voltage Greater than DC voltage DC voltage that is less than 2 / 3 of the square root of 3 If the trajectory of the reference voltage vector falls within the limiting hexagon, then the trajectory outside the limiting hexagon is adjusted by reducing the amplitude of the reference voltage.

[0047] and These are the reference voltage vectors before and after adjustment. Figure 2 Within the area shown According to the volt-second balance principle, and The following two conditions must be met, the first condition being: equal Plus The second condition is: equal Plus .

[0048] The output trajectory lies on the boundary of the limiting hexagon. near It needs to output continuously within the cycle. ,but equal And thus obtain equal Divide by Multiply by Similarly, such as near ,but equal And thus obtain equal Divide by Multiply by .

[0049] The adjustment process of modulation region II is as follows: construct an auxiliary equilateral triangle, adjust the reference voltage inside the triangle to the hexagonal boundary; output the closest basic voltage vector for the reference voltage outside the triangle; and output two basic voltage vectors simultaneously in certain specific regions.

[0050] The overmodulation II region is defined as the area outside the circumcircle of the output limiting hexagon, i.e., the region containing the reference voltage vector. Greater than 2 / 3 of the DC voltage And less than 2 divided by the square root of 3 and then multiplied by the DC voltage At this point, the reference voltage vector is completely outside the moduloable range. For example... Figure 3 As shown, construct auxiliary equilateral triangles ADH and DGI with side lengths of... For the reference voltage vector inside the auxiliary triangle, adjust its trajectory to the boundary of the limiting hexagon, and for the reference voltage vector outside the auxiliary triangle, adjust it to be the closest basic voltage vector.

[0051] When the reference voltage vector intersects with the straight lines IG and AH, the outputs need to be maintained at [values ​​to be filled in]. , Voltage vectors, respectively equal to 0 equal as well as equal and It equals 0.

[0052] When the reference voltage vector intersects with the straight lines ID and HD, simultaneous output is required. , There are two voltage vectors, therefore we have equal as well as equal .

[0053] In other regions, the overmodulation method is the same as in overmodulation region I.

[0054] Overmodulation algorithms introduce harmonic components into the voltage; the fundamental voltage is actually the driving force. Fourier transform can be used to obtain the reference voltage in overmodulation regions I and II. The relationship between the modulated fundamental voltage and the fundamental voltage is as follows, thereby achieving direct and precise control of the fundamental voltage that actually plays a role.

[0055] For the overmodulated I region, there is no need to adjust the phase of the reference voltage. The expression for the phase A voltage can be obtained by decomposing the spatial voltage vector in the first quadrant onto the real axis. By calculating the content of the fundamental voltage in the phase A voltage, the content of the fundamental voltage in the voltage modulated by the reference voltage can be obtained.

[0056] In this embodiment, reference Figure 4 ,when Greater than or equal to 0 and less than or equal to , Greater than or equal to and The difference is less than or equal to and The sum of these two values ​​means that there is no need to adjust the reference voltage; the cosine can be calculated directly. Greater than or equal to and less than or equal to and difference, Greater than or equal to and The sum of and less than or equal to When doing so, the reference voltage needs to be confined within a hexagon before the cosine can be calculated.

[0057] when Greater than or equal to 0 and less than or equal to hour, equal to reference voltage Multiply The cosine value; when Greater than or equal to and less than or equal to and When the difference is, equal Divide by the square root of 3 and then divide by The cosine value, then multiplied by The cosine value; when Greater than or equal to and The difference is less than or equal to and When and when, equal to reference voltage Multiply The cosine value when Greater than or equal to and The sum of and less than or equal to hour, equal Divide by the square root of 3 and then divide by The sine value, then multiplied by The cosine value.

[0058] observe Figure 4 In the middle triangle OGD, where, and Equal, both are Divide by the square root of 3 and then divide by The arcsine value can be obtained from geometric relationships. for Divide by the square root of 3 and then divide by The arcsine value, minus .exist Within the range, Fourier transform can be used to obtain the harmonics of phase A voltage. , It equals 4 divided by π and then multiplied by and The integral of the product of ωt over the interval from 0 to π / 2.

[0059] When solving for the fundamental voltage, n is taken as 1, and the relationship between the fundamental voltage and the reference voltage vector in the phase voltage is obtained: Equal to the square root of 3 multiplied by Divide by π again, then multiply by the first intermediate value, then add 6, divide by π, and multiply again. The first intermediate quantity is 1 plus... and The sine of the difference, divided by 1 and subtracted and The sine of the difference is taken as the natural logarithm of the quotient.

[0060] For modulation region II, the phase of the reference voltage needs to be adjusted, and the spatial voltage vector in the first quadrant can be decomposed to the real axis to obtain the expression for phase A voltage; the content of the fundamental voltage in phase A voltage is calculated to obtain the fundamental voltage content in the voltage modulated by the reference voltage.

[0061] refer to Figure 5 ,when Greater than or equal to 0 and less than or equal to At the same time, maintain output. The voltage of phase A is constant. .when Greater than or equal to Less than or equal to and difference, Greater than or equal to and The sum of and less than or equal to At that time, the reference voltage is not changed. The phase, but the reference voltage needs to be... The size is limited to a limiting hexagon. When Greater than or equal to and The difference is less than or equal to and When summing, both should be output simultaneously. and The voltage of phase A is constant. .

[0062] More specifically, when Greater than or equal to 0 and less than or equal to hour, equal to 2 / 3 ,when Greater than or equal to and less than or equal to and When the difference is, equal Divide by the square root of 3 and then divide by and The cosine of the difference, then multiplied by The cosine value; when Greater than or equal to and The difference is less than or equal to and When and when, equal to 1 / 3 ;when Greater than or equal to and The sum of and less than or equal to hour, equal Divide by the square root of 3 and then divide by The sine value, then multiplied by The cosine value.

[0063] Observe the MOF of the triangle. and They are equal, and both are Divide by the square root of 3 and then divide by The arcsine value can be obtained from geometric relationships. for minus Divide by the square root of 3 and then divide by The arcsine value. Similarly, the relationship between the fundamental voltage and the reference voltage vector in the phase voltage of the overmodulated region II can be obtained through Fourier analysis.

[0064] Equal to the square root of 3 multiplied by Divide by π again, then multiply by the second intermediate quantity, add 4, divide by π again, and multiply by π again. Then multiply by The sine value; where the second intermediate quantity is 1 plus and The sine of the difference, divided by 1 and subtracted and The sine of the difference is taken as the natural logarithm of the quotient.

[0065] Step S12 also includes: using MATLAB software to solve for the reference voltage vectors before and after overmodulation. The actual effective fundamental voltage obtained after overmodulation The relationship between them. (Reference) Figure 6 The calculated curve is stored in memory, and the fundamental voltage is found by looking up a table. Corresponding reference voltage To achieve control over the fundamental voltage Precise control. The maximum value is 63.6619%. Compared to the control method without overmodulation algorithm, the phase voltage utilization rate is improved by 5.9089%, and the line voltage utilization rate is improved by 10.2345%.

[0066] In step S3, if the fundamental voltage is in the overmodulation region, the curve in step S1 is retrieved, the reference voltage corresponding to the fundamental voltage F1 is queried, and then the overmodulation algorithm in the 120-degree coordinate system is used to calculate the three-phase voltage action time, and then SVPWM modulation is performed.

[0067] For the single-current field weakening control algorithm, refer to Figure 8 Specifically, this includes maintaining the voltage output at its maximum during field weakening control. Through the aforementioned overmodulation algorithm, the maximum voltage is reduced from... Upgraded to Two PID controllers are used. The first PID controller takes the error between the target speed and the actual speed as input and outputs the required D-axis negative current. The second PID controller takes the error between the required D-axis negative current and the actual D-axis current as input and outputs the D-axis voltage. After obtaining the D-axis voltage, according to... Find , equal .

[0068] This invention introduces an overmodulation algorithm in a 120-degree coordinate system into the control algorithm of a washing machine motor. Through Fourier analysis, it calculates the relationship between the reference voltage vector and the modulated fundamental voltage, achieving direct and precise control of the fundamental voltage and unifying the calculation process between the linear modulation and overmodulation regions. This improves the phase voltage utilization rate from 57.7350% to... The phase voltage utilization rate increased by 5.9089%, corresponding to a 10.2345% increase in line voltage utilization. In the field weakening control range, the phase voltage entering field weakening control also increased from... Upgraded to This allows the washing machine motor to achieve higher speeds and better cleaning results.

[0069] This embodiment can bring the following technical effects: 1. Calculate the fundamental voltage using Fourier transform. and reference voltage The corresponding curves between them enable direct and precise control of the fundamental voltage that is actually useful; 2. Improve the voltage utilization rate of the washing machine motor by using an overmodulation algorithm in a 120-degree coordinate system; 3. Through an overmodulation algorithm, the limiting voltage entering the field weakening control is reduced from... Raise to .

[0070] Example 2 This embodiment proposes a washing machine motor operation control method based on fundamental voltage control, which mainly includes the following three steps.

[0071] Step S1: In the overmodulation region, calculate and obtain the relationship curve between the fundamental voltage and the reference voltage offline, and store the curve in memory.

[0072] Step S2: The fundamental voltage is calculated according to the magnetic field orientation control algorithm. The d-axis and q-axis components of the required fundamental voltage are obtained through the speed loop and current loop, and the fundamental voltage is calculated by the sum of squares.

[0073] Step S3 involves determining the range of the fundamental voltage calculated in step S2, and then selecting the appropriate control algorithm. If the fundamental voltage is within the linear modulation region, the SVPWM algorithm in the 120-degree coordinate system is used for modulation. If the fundamental voltage is within the overmodulation region, the overmodulation algorithm in the 120-degree coordinate system is used to calculate the three-phase voltage duration, and finally the SVPWM algorithm is used for modulation. If the fundamental voltage exceeds the overmodulation region, the single-current field weakening control algorithm described above is used to calculate... Then, the SVPWM algorithm in the 120-degree coordinate system is used for modulation.

[0074] When the fundamental voltage is in the linear modulation region, the magnitude of the fundamental voltage F1 is less than 57.7350% of the DC voltage. When the fundamental voltage is in the overmodulation region, the fundamental voltage F1 is less than 63.6619% of the DC voltage and greater than 57.7350% of the DC voltage. When the fundamental voltage exceeds the overmodulation region, the fundamental voltage is greater than 63.6619% of the DC voltage.

[0075] In this technical solution, the magnitude of the fundamental voltage F1 is used to determine which control algorithm to adopt, so that the washing machine motor can achieve a higher speed and a better cleaning effect.

[0076] In this technical solution, the relationship between the fundamental voltage and the reference voltage is first calculated and a corresponding relationship curve is generated. Then, the fundamental voltage is calculated, and the control algorithm to be adopted is determined based on the magnitude of the fundamental voltage. If the fundamental voltage is in the overmodulation region, the three-phase voltage action time is calculated based on the above relationship curve and the overmodulation algorithm, and then SVPWM modulation is performed.

[0077] For step S11, the region between the inscribed circle and the circumscribed circle of the output limiting hexagon is defined as the overmodulation I region. The adjustment strategy for the overmodulation I region is as follows: within this region, part of the trajectory of the reference voltage vector falls within the limiting hexagon and no adjustment is required; the other part is outside the limiting hexagon, and the amplitude of the reference voltage needs to be reduced to limit the excess part within the boundary of the limiting hexagon.

[0078] The adjustment process of modulation region II is as follows: construct an auxiliary equilateral triangle, adjust the reference voltage inside the triangle to the hexagonal boundary; output the closest basic voltage vector for the reference voltage outside the triangle; and output two basic voltage vectors simultaneously in certain specific regions.

[0079] Based on the aforementioned method for controlling the operation of a washing machine motor using fundamental voltage control, this embodiment also proposes a control system for the operation of a washing machine motor using fundamental voltage control. This system includes several modules, primarily a calculation module and a control module. The control module is connected to the calculation module. The calculation module can calculate the relationship curve between the fundamental voltage and the reference voltage offline. The calculation module can execute steps S1 to S2 as described above. The control module can determine the specific control algorithm to be used based on the magnitude of the fundamental voltage. The control module can execute step S3 as described above.

Claims

1. A method for controlling the operation of a washing machine motor based on fundamental voltage control, characterized in that, Includes the following steps: S1, calculate the relationship curve between the fundamental voltage and the reference voltage in the overmodulation region offline and store the curve in memory; S2 uses a field-oriented control algorithm to calculate the fundamental voltage. The d-axis and q-axis components of the fundamental voltage are obtained through the speed loop and the current loop. S3. If the fundamental voltage is within the linear modulation region or exceeds the overmodulation region, the SVPWM algorithm in the 120-degree coordinate system is used for modulation. If the fundamental voltage is in the overmodulation region, the overmodulation algorithm in the 120-degree coordinate system is used to calculate the three-phase voltage action time, and finally the SVPWM algorithm is used for modulation. When it exceeds the overmodulation region, single-current field weakening control is used.

2. The method for controlling the operation of a washing machine motor based on fundamental voltage control according to claim 1, characterized in that, Step S1 includes: S11 divides the overmodulation region into overmodulation region I and overmodulation region II; S12, through analysis, the fundamental voltage F1 and the reference voltage in the overmodulation I and II regions are derived respectively. The mathematical expression between them; S13, calculates and stores F1 offline. The corresponding curve.

3. A method for controlling the operation of a washing machine motor based on fundamental voltage control according to claim 1 or 2, characterized in that, When the fundamental voltage is in the linear modulation region, the fundamental voltage is less than 57.7350% of the DC voltage; when the fundamental voltage is in the overmodulation region, the fundamental voltage is greater than 57.7350% of the DC voltage and less than 63.6619% of the DC voltage; when the fundamental voltage exceeds the overmodulation region, the fundamental voltage is greater than 63.6619% of the DC voltage.

4. The method for controlling the operation of a washing machine motor based on fundamental voltage control according to claim 2, characterized in that, S11 includes adjustment of the over-modulation I region, which is the area between the inscribed circle and the circumscribed circle of the output limiting hexagon's trajectory of the reference voltage vector. The adjustment of the overmodulation I region includes: within this region, the trajectory of the reference voltage vector partially falls within the limiting hexagon and requires no adjustment; the other part is outside the limiting hexagon, and the amplitude of the reference voltage needs to be reduced to confine the excess part within the boundary of the limiting hexagon.

5. A method for controlling the operation of a washing machine motor based on fundamental voltage control according to claim 2 or 4, characterized in that, S11 includes adjustment of the over-modulation II region, where the trajectory of the reference voltage vector is outside the circumcircle of the output limiting hexagon. The adjustment of the modulation II region includes: constructing an auxiliary equilateral triangle; adjusting the reference voltage inside the triangle to the boundary of the hexagon; outputting the closest basic voltage vector for the reference voltage outside the triangle; and outputting two basic voltage vectors simultaneously in certain specific regions.

6. The washing machine motor operation control method based on fundamental voltage control according to claim 5, characterized in that, Step S12 includes: for the overmodulated I region, there is no need to adjust the phase of the reference voltage. The expression for the A-phase voltage can be obtained by decomposing the spatial voltage vector of the first quadrant to the real axis; by calculating the content of the fundamental voltage in the A-phase voltage, the content of the fundamental voltage in the voltage after the reference voltage is modulated can be obtained.

7. The method for controlling the operation of a washing machine motor based on fundamental voltage control according to claim 6, characterized in that, Step S12 further includes: for the modulation II region, the phase of the reference voltage needs to be adjusted, and the spatial voltage vector of the first quadrant is decomposed to the real axis to obtain the expression of the A-phase voltage; the content of the fundamental voltage in the A-phase voltage is calculated to obtain the fundamental voltage content in the voltage after the reference voltage is modulated.

8. The washing machine motor operation control method based on fundamental voltage control according to claim 7, characterized in that, Step S12 further includes: using MATLAB software to solve for the relationship between the reference voltage vector before and after overmodulation and the actual effective fundamental voltage obtained after overmodulation.

9. A method for controlling the operation of a washing machine motor based on fundamental voltage control according to claim 1 or 2, characterized in that, In step S3, if the fundamental voltage is in the overmodulation region, the curve in step S1 is retrieved, the reference voltage corresponding to the fundamental voltage F1 is queried, and then the overmodulation algorithm in the 120-degree coordinate system is used to calculate the three-phase voltage action time, and then SVPWM modulation is performed.

10. A washing machine motor operation control system based on fundamental voltage control, applicable to the washing machine motor operation control method based on fundamental voltage control as described in any one of claims 1-9, characterized in that, It includes a calculation module and a control module connected to the calculation module. The calculation module can calculate the relationship curve between the fundamental voltage and the reference voltage offline. The control module can determine the specific control algorithm to be used based on the magnitude of the fundamental voltage.

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