Dual three-phase permanent magnet synchronous motor hybrid modulation current harmonic suppression method based on voltage compensation

Abstract

The invention discloses a dual three-phase permanent magnet synchronous motor hybrid modulation current harmonic suppression method based on voltage compensation. The method comprises the following steps: 1, calculating a required reference voltage vector by a main control unit; step 2, generating and outputting a reference voltage vector by a reference voltage vector calculation module; 3, after coordinate transformation, decomposing the reference voltage vector into two parts: an SVPWM (Space Vector Pulse Width Modulation) signal and a harmonic compensation PWM signal; 4, performing weighted fusion on the harmonic compensation PWM signal and the SVPWM signal in a PWM generation module to generate a PWM signal; and 5, the PWM signal drives the voltage source type inverter, the output voltage of each phase is decomposed according to the direct current bus voltage, the dual three-phase permanent magnet synchronous motor is driven to realize accurate torque control and low-harmonic operation, and meanwhile, the sampling signal is continuously input into the main control unit and the harmonic compensation PWM modulation module to form closed-loop regulation. According to the invention, high-efficiency and low-harmonic motor driving can be realized, and the stability and reliability of the system are greatly improved.

Description

Technical Field

[0001] The present invention relates to a space vector pulse width modulation method for a dual three-phase permanent magnet synchronous motor, and in particular to a voltage compensation-based hybrid modulation current harmonic suppression method for a dual three-phase permanent magnet synchronous motor. Background Art

[0002] In recent years, with the increasing demand for high power density, high efficiency, and low torque ripple, dual three-phase permanent magnet synchronous motors (PMSMs) have been widely used in aerospace, electric vehicles, ship propulsion, and industrial automation due to their unique winding structure and space vector distribution. Dual three-phase motors utilize two sets of three-phase windings, effectively reducing torque ripple and exhibiting excellent fault tolerance. However, to fully utilize the DC bus voltage, conventional space vector pulse width modulation (SVPWM) methods generate concentrated harmonics at the inverter switching frequency and its integer multiples, particularly the fifth and seventh harmonics, when synthesizing the main voltage vector on the fundamental plane. This increases current harmonics, exacerbating vibration and noise, and thus impacting the system's electromagnetic compatibility and overall efficiency. Therefore, it is necessary to develop a novel hybrid modulation method that combines SVPWM modulation with harmonic compensation. While maintaining fundamental control accuracy and dynamic response, compensation is performed on the harmonic sub-plane to effectively suppress current harmonics and improve the system's electromagnetic compatibility and overall operational performance. Summary of the Invention

[0003] To address the current harmonics issues associated with traditional SVPWM modulation methods in dual three-phase permanent magnet synchronous motor control, this paper provides a hybrid modulation method for dual three-phase permanent magnet synchronous motors based on voltage compensation. This method uses traditional SVPWM modulation to generate the fundamental voltage vector. It also utilizes a hybrid modulation method combining current feedback and voltage compensation with a specific harmonic elimination (SHE) PWM algorithm in the harmonic subplane to compensate for the fifth and seventh harmonics in the current, thereby increasing DC bus utilization, reducing harmonic content, and improving electromagnetic compatibility.

[0004] The purpose of the present invention is achieved through the following technical solutions:

[0005] A method for suppressing current harmonics of a dual three-phase permanent magnet synchronous motor hybrid modulation based on voltage compensation comprises the following steps:

[0006] Step 1: The main control unit calculates the required reference voltage vector based on the input ;

[0007] Step 2: The reference voltage vector calculation module generates and outputs a reference voltage vector;

[0008] Step 3: After coordinate transformation, the reference voltage vector is decomposed into two parts: one part enters the SVPWM modulation module to generate the SVPWM signal; the other part enters the harmonic compensation PWM modulation module to generate the harmonic compensation PWM signal;

[0009] Step 4: The harmonic compensation PWM signal and the SVPWM signal are weighted and fused in the PWM generation module to generate the final PWM signal;

[0010] Step 5: The PWM signal drives the voltage source inverter, which decomposes the output voltage of each phase according to the DC bus voltage, and drives the dual three-phase permanent magnet synchronous motor to achieve precise torque control and low harmonic operation. At the same time, the sampling signal is continuously input into the main control unit and the harmonic compensation PWM modulation module to form a closed-loop regulation.

[0011] Compared with the prior art, the present invention has the following advantages:

[0012] 1. The present invention adopts a hybrid modulation scheme to accurately superimpose the SVPWM signal and the harmonic compensation PWM signal in the time domain and amplitude. The final output PWM signal not only maintains a high DC bus utilization rate, but also effectively suppresses the high-frequency harmonics caused by the inverter switching action, reduces current harmonics, and significantly reduces the vibration, noise and electromagnetic interference during motor operation while ensuring the torque, speed and position control accuracy, thereby improving the overall electromagnetic compatibility.

[0013] 2. The present invention is applicable to high-demand fields such as aviation, ships and electric vehicles. It can realize high-efficiency and low-harmonic motor drive and has good dynamic response and fault tolerance, thereby greatly improving system stability and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a component of the current harmonic suppression method of dual three-phase permanent magnet synchronous motor hybrid modulation based on voltage compensation;

[0015] Figure 2 It is a component of SVPWM modulation;

[0016] Figure 3 It is a component of harmonic compensation PWM modulation;

[0017] Figure 4 Generates components for PWM;

[0018] Figure 5 This is a vector control block diagram of a dual three-phase permanent magnet synchronous motor hybrid modulation current harmonic suppression method based on voltage compensation. In the figure, Indicates the given speed of the motor, ω indicates the actual speed of the motor, Indicates the given value of q-axis and d-axis current, i q、i d Indicates the actual value of the q-axis and d-axis current, Indicates the current given value of axis z1 and axis z2, i z1 、i z2 Indicates the actual value of the current of the z1 axis and z2 axis, u q 、u d It represents the q-axis and d-axis voltage components output after PI adjustment, u α 、u β Indicates u q 、u d The α-axis and β-axis voltage components obtained by Park inverse transformation, u z1 、u z2 It represents the z1-axis and z2-axis voltage components output after PI regulation, ABC and DEF represent six-phase PWM signals, and u ABC 、u DEF Indicates six-phase voltage, i ABC 、i DEF Indicates six-phase current. DETAILED DESCRIPTION

[0019] The technical solution of the present invention is further described below with reference to the accompanying drawings, but is not limited thereto. Any modification or equivalent replacement of the technical solution of the present invention that does not depart from the spirit and scope of the technical solution of the present invention should be included in the scope of protection of the present invention.

[0020] The present invention provides a method for suppressing current harmonics of a dual three-phase permanent magnet synchronous motor hybrid modulation based on voltage compensation, such as Figure 1 and Figure 5 As shown, the following steps are included:

[0021] Step 1: The main control unit 1 calculates the required reference voltage vector according to the input :

[0022]

[0023] in, represents the reference voltage vector, Indicates the harmonic components contained in the reference voltage vector, Indicates the fundamental component contained in the reference voltage vector, and the fundamental part satisfies , Indicates the phase of the reference voltage vector;

[0024] Step 2: The reference voltage vector calculation module 2 generates and outputs a reference voltage vector.

[0025] Step 3: After coordinate transformation, the reference voltage vector is decomposed into two parts: one part enters the SVPWM modulation module 3 to generate an SVPWM signal; the other part enters the harmonic compensation PWM modulation module 4 to generate a harmonic compensation PWM signal.

[0026] like Figure 2 As shown, the SVPWM modulation process includes reference voltage vector 3-1, sector judgment 3-2, duty cycle calculation 3-3, and SVPWM signal generation 3-4. The harmonic compensation PWM modulation module 4 first obtains the reference voltage vector from the reference signal calculation module 2. , which contains the amplitude and phase information required for motor operation and satisfies (Here In this process, it is not involved in compensation and is processed in the harmonic compensation PWM modulation module 4). The phase of the reference voltage vector in the α–β coordinate system is calculated. represents the component of the reference voltage vector on the α axis, The component of the reference voltage vector on the β axis. The phase of the reference voltage vector is determined by the sector where it is located. Then, the reference voltage vector is decomposed into two adjacent basic vectors using the SVPWM modulation principle. Their action time in the current sampling period is calculated respectively. The calculation formula is: 、 ,in, is the DC bus voltage. and The SVPWM signal is generated based on the allocation rule of the zero vector.

[0027] like Figure 3 As shown in Figure 4, the harmonic compensation PWM modulation process includes sampling current signals 4-1, extracting harmonic parameters 4-2, calculating sampling current errors 4-3, calculating harmonic elimination parameters 4-4, calculating voltage compensation 4-5, and generating harmonic compensation PWM signals 4-6. The SVPWM modulation module 3 first collects the six-phase currents of the motor through the current sensor, and obtains the harmonic space current components through VSD coordinate transformation. 、 ; Then, the digital filtering algorithm is used to perform spectrum analysis on the sampled current signal to extract the high-frequency harmonic interference parameters, especially the voltage components of the 5th and 7th harmonics. and and its corresponding phase angle and According to the formula Calculate the harmonic voltage components that need to be compensated; at the same time, in order to compensate for the current deviation caused by load fluctuations and nonlinear effects in the system, calculate the current error based on the sampled current signal ,in Indicates the target current, Represents the sampling current; using the feedback gain Get the voltage compensation amount through the formula Combining feedback compensation with harmonic elimination compensation, It represents the final harmonic compensation signal, and finally a specific harmonic elimination PWM algorithm is used to generate a harmonic compensation PWM signal.

[0028] Step 4: The harmonic compensation PWM signal and the SVPWM signal are weighted and fused in the PWM generation module 5 to generate the final PWM signal.

[0029] like Figure 4 As shown, the PWM generation process includes SVPWM signal 5-1, harmonic compensation PWM signal 5-2, signal fusion weighting 5-3, duty cycle calculation 5-4, and PWM switch sequence generation 5-5. The PWM generation module 5 receives the SVPWM signal and the harmonic compensation PWM signal respectively, and uses the dynamic weighting coefficient and And the weighted fusion formula The two signals are fused in time domain and amplitude. Represents the fused reference signal; then according to the fused reference signal and DC bus voltage , using the formula Calculate the action time of each basic vector, Indicates the DC bus voltage, represents the duty cycle, and these times are allocated to various switching states, ultimately generating a PWM switching sequence that meets the requirements, driving the voltage source inverter 6 to output the corresponding voltage waveform.

[0030] Step 5: The PWM signal drives the voltage-source inverter 6, which decomposes the DC bus voltage into phase output voltages, driving the dual three-phase permanent magnet synchronous motor 7 to achieve precise torque control and low-harmonic operation. Simultaneously, the sampled signal 8 is continuously fed into the main control unit 1 and the harmonic compensation PWM modulation module 4, forming a closed-loop regulation loop.

Claims

1. A method for suppressing current harmonics of a dual three-phase permanent magnet synchronous motor with hybrid modulation based on voltage compensation, characterized in that The method comprises the following steps: Step 1: The main control unit calculates the required reference voltage vector based on the input ; Step 2: The reference voltage vector calculation module generates and outputs a reference voltage vector; Step 3: After coordinate transformation, the reference voltage vector is decomposed into two parts: one part enters the SVPWM modulation module to generate the SVPWM signal; the other part enters the harmonic compensation PWM modulation module to generate the harmonic compensation PWM signal; Step 4: The harmonic compensation PWM signal and the SVPWM signal are weighted and fused in the PWM generation module to generate the final PWM signal; Step 5: The PWM signal drives the voltage source inverter, which decomposes the output voltage of each phase according to the DC bus voltage, and drives the dual three-phase permanent magnet synchronous motor to achieve precise torque control and low harmonic operation. At the same time, the sampling signal is continuously input into the main control unit and the harmonic compensation PWM modulation module to form a closed-loop regulation.

2. The method for suppressing current harmonics of a dual three-phase permanent magnet synchronous motor hybrid modulation based on voltage compensation according to claim 1 is characterized in that The generation process of the SVPWM signal is as follows: the harmonic compensation PWM modulation module first obtains the reference voltage vector from the reference signal calculation module , through the formula The phase of the reference voltage vector in the α–β coordinate system is calculated. represents the component of the reference voltage vector on the α axis, The component of the reference voltage vector on the β axis, Represents the phase of the reference voltage vector, according to The phase of the reference voltage vector is determined by the sector where the reference voltage vector is located. Then, the reference voltage vector is decomposed into two adjacent basic vectors using the SVPWM modulation principle, and their action time in the current sampling period is calculated respectively. and , and finally according to and The SVPWM signal is generated based on the allocation rule of the zero vector.

3. The method for suppressing current harmonics of a dual three-phase permanent magnet synchronous motor hybrid modulation based on voltage compensation according to claim 2 is characterized in that described and The calculation formula is 、 ,in, is the DC bus voltage.

4. The method for suppressing current harmonics of a dual three-phase permanent magnet synchronous motor hybrid modulation based on voltage compensation according to claim 1 is characterized in that The generation process of the harmonic compensation PWM signal is as follows: the SVPWM modulation module first collects the six-phase current of the motor through the current sensor, and obtains the harmonic space current component through VSD coordinate transformation. 、 ; Then, the digital filtering algorithm is used to perform spectrum analysis on the sampled current signal to extract the high-frequency harmonic interference parameters, especially the voltage components of the 5th and 7th harmonics. and and its corresponding phase angle and ; Calculate the harmonic voltage components that need to be compensated; at the same time, in order to compensate for the current deviation caused by load fluctuations and nonlinear effects in the system, calculate the current error based on the sampled current signal ; Using feedback gain Get the voltage compensation amount through the formula Combining feedback compensation with harmonic elimination compensation, It represents the final harmonic compensation signal, and finally a specific harmonic elimination PWM algorithm is used to generate a harmonic compensation PWM signal.

5. The method for suppressing current harmonics of a dual three-phase permanent magnet synchronous motor hybrid modulation based on voltage compensation according to claim 4 is characterized in that The calculation formula of the harmonic voltage component is: in, Indicates the harmonic components contained in the reference voltage vector.

6. The method for suppressing current harmonics of a dual three-phase permanent magnet synchronous motor hybrid modulation based on voltage compensation according to claim 4 is characterized in that The current error The calculation formula is: in, Indicates the target current, Indicates the sampling current.

7. The method for suppressing current harmonics of a dual three-phase permanent magnet synchronous motor hybrid modulation based on voltage compensation according to claim 1, 2, 3 or 4, characterized in that The reference voltage vector The calculation formula is: in, represents the reference voltage vector, Indicates the harmonic components contained in the reference voltage vector, Indicates the fundamental component contained in the reference voltage vector.

8. The method for suppressing current harmonics of a dual three-phase permanent magnet synchronous motor hybrid modulation based on voltage compensation according to claim 7 is characterized in that described , Indicates the phase of the reference voltage vector.

9. The method for suppressing current harmonics of a dual three-phase permanent magnet synchronous motor hybrid modulation based on voltage compensation according to claim 1 is characterized in that The PWM signal generation process is as follows: the PWM generation module receives the SVPWM signal and the harmonic compensation PWM signal respectively, and uses the dynamic weighting coefficient and And the weighted fusion formula The two signals are fused in time domain and amplitude. represents the fused reference signal, Represents the fundamental component contained in the reference voltage vector, Represents the final harmonic compensation signal; then according to the fused reference signal and DC bus voltage , using the formula Calculate the action time of each basic vector, Indicates the DC bus voltage, Represents the duty cycle, and allocates these times to each switching state, ultimately generating a PWM switching sequence that meets the requirements and driving the voltage source inverter to output the corresponding voltage waveform.

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