A method for harmonic regulation of a multiphase self-excited synchronous machine

Abstract

The application discloses a kind of multi-phase self-excited synchronous motor harmonic regulation methods, it relates to motor control field, the number of phase of the multi-phase self-excited synchronous motor is eleven, the control system of multi-phase self-excited synchronous motor includes multi-phase closed-loop inverter controller, adopts Clarke / Park Transform decouples 11-phase current signals output by multi-phase self-excited synchronous motor to four harmonic planes and one fundamental plane, then motor control system selects a target harmonic plane according to demand, corresponding current component together with the current component of fundamental plane is handled by multi-phase closed-loop inverter controller, forms SPWM Pulse sequence, to control the on-off of each IGBT Device in multi-phase closed-loop inverter controller to realize the output of alternating voltage.The application realizes the dynamic adjustment of rotor magnetic field, the flexible promotion of motor maximum torque output capacity, and the efficient, adaptive operation in wide speed range.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of motor control, more particularly to a kind of multi-phase self-excitation synchronous motor harmonic regulation method. BACKGROUND

[0002] In the field of motor control, three-phase motor is widely used due to its mature technology and simple structure, but its inherent limitations are increasingly prominent: first, to achieve rotor excitation enhancement, it is usually necessary to inject harmonic current by open-winding structure, however, there is a close coupling between the harmonic current and the fundamental current responsible for energy conversion, making it difficult to decouple and increasing control complexity;Second, the existing self-excitation scheme faces insufficient excitation in the low speed area, and it is difficult to independently adjust the excitation current in the high speed area, with low efficiency of field weakening control. To break through the above bottleneck, multi-phase motor emerges as the times require, which increases the degree of freedom of phase to create conditions for accurate injection of resonant current. However, the multi-phase system also brings more complex control strategy, greater control difficulty, and traditional modulation techniques are difficult to meet its demand for harmonic directional injection. PWM

[0003] Therefore, the present application makes further research on the basis, and the present application is produced. SUMMARY

[0004] The purpose of the present application is to provide a kind of multi-phase self-excitation synchronous motor harmonic regulation method, which realizes the decoupling of fundamental current and harmonic current, the control method is simple, and the operation efficiency of system can be effectively improved, and the multi-phase self-excitation motor can be self-adapted excitation regulation in wide speed range.

[0005] To achieve the above purpose, the solution of the present application is:

[0006] A kind of multi-phase self-excitation synchronous motor harmonic regulation method, the number of phases of the multi-phase self-excitation synchronous motor is eleven, and the control system of the multi-phase self-excitation synchronous motor includes a multi-phase closed-loop inverter controller, which is transformed to decouple 11-phase current signals output by the multi-phase self-excitation synchronous motor into four harmonic planes and one fundamental plane, then the motor control system selects a target harmonic plane according to requirements, the current component corresponding to the target harmonic plane is processed together with the current component of the fundamental plane by the multi-phase closed-loop inverter controller to form pulse sequence, so as to control the on-off of each device in the multi-phase closed-loop inverter controller to realize the output of alternating voltage. Clarke / Park SPWM IGBT

[0007] The method comprises the following steps:

[0008] Step 1, obtain five planes: use the multi-phase closed-loop inverter controller to transform the 11-phase current signals output by the multi-phase self-excitation synchronous motor into four harmonic planes and one fundamental plane. Clarke / park ​​​​The Clarke transformation in the transformation transforms the 11-phase current signals outputted by the multiphase self-excited synchronous motor into five different α - β coordinate planes, and the five different α - β coordinate planes respectively correspond to one fundamental plane and four harmonic planes.

[0009] Step 2-1, selection of the fundamental plane, the fundamental plane is selected according to the fundamental current phase difference in step 1, and the fundamental current phase difference is j × , j , wherein the pole pair number of the fundamental current is represented, and the calculation formula of the mechanical angle difference in the multiphase self-excited synchronous motor is = , wherein represents the slot number of the multiphase self-excited synchronous motor;

[0010] Step 2-2, 11-phase fundamental currents are calculated through the fundamental current expression corresponding to the fundamental plane, and the fundamental current expression is:

[0011] i k = I cos [ ωt - j ×( k -1) ], k =1, 2,..., 11,

[0012] , wherein k represents the number of phases of the multiphase self-excited synchronous motor, i k represents the k -phase fundamental current, I represents the current amplitude, ω represents the fundamental current angular frequency calculated according to the speed of the multiphase self-excited synchronous motor, t represents time.

[0013] Step 3-1, selection of the target harmonic plane, first, a relationship between the excitation current size of the multiphase self-excited synchronous motor and the harmonic current is established, and the relationship is , wherein D represents the related parameter combination term of the motor, represents the excitation current, h represents the harmonic order, is the current angular velocity, The amplitude of the harmonic current is given; then, the excitation current under the influence of the harmonic order corresponding to the four harmonic planes is comprehensively considered, and the harmonic planes that are coupled with the harmonics of the fundamental current are deducted from the four harmonic planes, so as to select the harmonic plane with the best excitation effect as the target harmonic plane.

[0014] Step 3-2: Obtain the harmonic currents. Calculate the 11-phase harmonic currents using the harmonic current expression corresponding to the target harmonic plane. The harmonic current expression is:

[0015] i kh = I h cos ( ω h t - h ×( k -1) ), k =1, 2, ..., 11,

[0016] In the formula, i kh Represented as the first k Phase winding harmonic current, ω h This represents the angular frequency of a given high-frequency harmonic current. i kh Indicates the first k Phase winding harmonic current, I h Indicates the amplitude of harmonic current. h Indicates the harmonic order.

[0017] Step 4, use Clarke / park In transformation park The transformation converts the 11-phase fundamental current and 11-phase harmonic current into current components, each of which corresponds to a specific current component. i q , i d , i qh and i dh ,in, i q and i d These represent the stator currents on the fundamental wave plane. d Axis current components and q Axis current components, i qh and i dhrespectively represent the stator current on the target harmonic plane d axial current component and q axial current component.

[0018] The multi-phase closed-loop inverter controller comprises an inverter and a nested control system, the inverter is

[0019] a twelve-phase inverter, the nested control system takes a speed loop as an outer loop and a current loop as an inner loop; in step 5, the nested control system receives each current component and performs adjustment processing, and outputs an 11-phase voltage signal after Clarke / park inverse transformation, the 11-phase voltage signal is obtained by SPWM modulation to obtain SPWM a pulse sequence, and is output to the twelve-phase inverter, so that each IGBT device in the twelve-phase inverter is turned on and off according to the SPWM pulse sequence, and outputs equivalent alternating voltage to the multi-phase self-excited synchronous motor.

[0020] Before step 2-1, the matching detection process between the current phase sequence and the number of current pole pairs is to establish the relationship between the current phase sequence and the air gap harmonic, and then combine the mechanical angle difference to match the obtained current phase sequence with the number of current pole pairs; wherein the relationship between the current phase sequence and the air gap harmonic is as follows:

[0021] the air gap harmonic of the order of h is h = sΘ(s + mc), c e Z ,

[0022] the air gap harmonic of the order of h is h = sΘ(mc s), c e Z sΘ , wherein h represents the order of spatial harmonic, represents the fundamental current phase angle, s represents the order of the current phase sequence, Figure 1 is the mechanical winding displacement factor, m represents the number of phases of the multi-phase self-excited synchronous motor, c is an integer, Z represents a set of integers.

[0023] By employing the above method, the present invention achieves the following beneficial effects: Through independently selected and controlled fundamental and harmonic planes, separate management of torque generation and magnetic field excitation is realized. The fundamental plane is used for torque control, with its fundamental current given by the speed loop; the harmonic plane is responsible for excitation regulation, and the frequency and amplitude of its harmonic current can be autonomously adjusted in a closed loop. This allows the harmonic magnetic field to be directionally generated, thereby significantly reducing excitation energy consumption. Compared with existing technologies, the present invention achieves dynamic adjustment of the rotor magnetic field, flexible improvement of the motor's maximum torque output capability, and efficient, adaptive operation over a wide speed range. It also improves operating efficiency under different working conditions, exhibits good dynamic adaptability, and uses a simple control method. Attached Figure Description

[0024] Figure 2 This is a structural topology diagram of the multiphase self-excited synchronous motor in this invention.

[0025] Figure 3 This is a circuit topology diagram of the motor control system in this invention.

[0026] Figure 4 This is a circuit diagram of the twelve-phase inverter in this invention.

[0027] Figure 5 This is a star diagram of the slots corresponding to the current phase sequence in this invention.

[0028] Figure 6 This is a graph showing the relationship between the frequency of the harmonic current and the amplitude of the excitation current at j=1 in this invention.

[0029] Figure 7 This is a graph showing the relationship between the frequency of the harmonic current and the amplitude of the excitation current at j=2 in this invention.

[0030] Figure 8 This is a simulation diagram of the induced electromotive force of the harmonic winding with j=1 in this invention.

[0031] Figure 9 This is a simulation diagram of the induced electromotive force of the harmonic winding with j=2 in this invention.

[0032] Figures 1-9 This is a radial air gap magnetic flux density diagram under the influence of harmonics with different pole pair numbers in this invention. Detailed Implementation

[0033] To further explain the technical solution of the present invention, the present invention will be described in detail below through specific embodiments.

[0034] This invention provides a harmonic control method for a multiphase self-excited synchronous motor, such as... SPWM As shown, the multiphase self-excited synchronous motor has eleven phases and is based on a motor control system commonly used in multiphase self-excited synchronous motors.

[0035] The aforementioned motor control system includes a multi-phase closed-loop inverter controller, which comprises a twelve-phase inverter and a nested control system. This nested control system employs a conventional dual-closed-loop control system, specifically a current loop and a speed loop, with the current loop as the inner loop and the speed loop as the outer loop. In this embodiment, the current loop includes a current PI controller, and the speed loop includes a speed PI controller; both the current PI controller and the speed PI controller are conventional controllers. It should be noted that the input quantities, output quantities, and processing methods in the aforementioned current loop and speed loop are all conventional operations. Furthermore, in this embodiment, the aforementioned motor control system also includes a sinusoidal pulse width modulation module (i.e.,... SPWM (module), this Take SPWM The module uses an existing conventional sinusoidal pulse width modulation module, which obtains... SPWM Pulse sequences are a standard operating procedure, and at the same time IGBT The pulse sequence is output to the twelve-phase inverter to enable each phase of the twelve-phase inverter to... Figure 3 The switching of devices on and off is a conventional operation; among them, the twelve-phase inverter adopts the existing conventional twelve-phase inverter, such as a 12-phase inverter. IGBT As shown, it includes several IGBT Components, each ω The devices are respectively corresponding to g 1 、g 2 、....、 g 22 .

[0036] It is worth mentioning that the method for obtaining the fundamental reference current is a conventional method. Specifically, in a multiphase self-excited synchronous motor, a conventional rotary encoder is used to obtain the rotor mechanical angle, which is... Then, the fundamental current angular frequency is obtained by differentiating the rotor mechanical angle over time and multiplying it by the number of rotor pole pairs. This fundamental current angular frequency is... ω Then, the target speed of the multiphase self-excited synchronous motor is determined. With fundamental current angular frequency Figure 1 The input is fed into the speed loop, and the output from the speed PI controller in the speed loop is given to the fundamental reference current. The fundamental reference current is... .

[0037] The aforementioned multiphase self-excited synchronous motor adopts existing conventional self-excited synchronous motors, such as... Figure 2As shown, it includes a rotor and a stator, the stator is sleeved outside the rotor in a conventional manner, and the stator is wound with a stator winding in a conventional manner, and the harmonic winding and the excitation winding are arranged on the rotor in a conventional manner; in this embodiment, taking an eleven-phase eleven-slot four-pole motor as an example, the mechanical angle difference between adjacent windings in the multi-phase self-excited synchronous motor is = 11 sets of windings as a whole.

[0038] In this embodiment, the multi-phase self-excited synchronous motor control method is specifically: as shown in Clarke / Park , using SPWM transformation, decoupling the 11-phase current signal output by the multi-phase self-excited synchronous motor to four harmonic planes and one fundamental plane, then the motor control system selects a target harmonic plane according to the demand, the current component corresponding to the target harmonic plane, together with the current component of the fundamental plane, is processed by a multi-phase closed-loop inverter controller to form IGBT a pulse sequence, so as to control the on-off of each Figure 2 device in the multi-phase closed-loop inverter controller to realize the output of alternating voltage. It should be noted that Clarke / park in the T K coordinate transformation of k phase k =11) winding, which includes Clarke / park transformation, T K -1 indicates Clarke / park inverse transformation.

[0039] In detail, the multi-phase self-excited synchronous motor control method has the following specific steps.

[0040] Step 1, get five planes: use the Clarke transformation in the Clarke transformation to transform the 11-phase current signal output by the multi-phase self-excited synchronous motor into five different α - β coordinate planes, and the five different α - β coordinate planes correspond to one fundamental plane and four harmonic planes respectively.

[0041] In detail, the current signal output by the multi-phase self-excited synchronous motor is i a 、i b 、...、i z and i kIn the embodiment, each current signal can be sampled by a conventional current sensor to obtain eleven-phase current feedback signals.

[0042] Further, the above-mentioned Clarke is transformed into

[0043] ,

[0044] In the above-mentioned Clarke transformation, five different a-β coordinate planes can be generated, that is, 10 vectors in the above formula are orthogonal to each other, that is, one fundamental wave plane and four harmonic wave planes, because the number of stator phases of the multi-phase self-excited synchronous motor is 11. It is worth mentioning that the current amounts of different pole pairs in the 11-phase current signals (i.e., stator currents) are separated and decoupled into respective a-β coordinate planes, so as to realize independent control of the fundamental wave current and the harmonic wave current.

[0045] Step 2-1, selection of the fundamental wave plane, the fundamental wave plane is selected from step 1 according to the phase difference of the fundamental wave current, specifically: the mechanical angle difference (i.e., the interval angle between adjacent slots of the stator) in the multi-self-excited synchronous motor is obtained, and the phase difference of the fundamental wave current is j × , j , where p represents the number of pole pairs of the fundamental wave current, and the number of pole pairs of the fundamental wave current is the same as that of the multi-phase self-excited synchronous motor; wherein the calculation formula of the mechanical angle difference in the multi-phase self-excited synchronous motor is = , wherein p represents the number of slots of the multi-phase self-excited synchronous motor.

[0046] For example, in the embodiment, the number of pole pairs of the fundamental wave current is j = 4, and the phase difference of the fundamental wave current of the adjacent windings is: 4 × , that is, 4 × = , then the phase difference of 4 I cos is selected as the fundamental wave plane in the transformation of step 1, that is, the plane with = 4 is obtained as the fundamental wave plane. h

[0047] Step 2-2, according to the fundamental wave current expression corresponding to the fundamental wave plane selected in step 2-1, the eleven-phase fundamental wave current is calculated, and the fundamental wave current expression is:

[0048] i k = ωt [ ω - j ×( k ​​-1) ], k =1, 2,..., 11,

[0049] wherein, k denotes the number of phases of the multiphase self-excited synchronous motor, i k denotes the first k phase fundamental current, I denotes the current amplitude, = I cos denotes the fundamental current angular frequency calculated according to the rotating speed of the multiphase self-excited synchronous motor, t denotes time; in the embodiment, j =4, the fundamental current expression is: i k ωt [ Figures 5-9 -4×( k- 1) ], k =1, 2,..., 11.

[0050] Step 3-1, selection of the target harmonic plane, the target harmonic plane is selected by the excitation effect and decoupling requirement, and the specific method is as follows:

[0051] First, a relationship between the excitation current size of the multiphase self-excited synchronous motor and the harmonic current is established, and the relationship is, wherein, D denotes the motor related parameter mixed term, denotes the excitation current, h denotes the harmonic order, is the current angular velocity, is the harmonic current amplitude.

[0052] Then, the excitation current under the influence of the harmonic order of 1, 2, 3 and 5 is obtained, that is, h =1, 2, 3, 5, considering the time harmonic effect, the harmonic plane with coupling relationship with the harmonic of the fundamental current is deducted in the four harmonic planes, and the harmonic plane with the best excitation effect is selected.

[0053] For example, as shown in FIG. 1, in the embodiment, the above formula can be used to obtain, Icos =1, h =2, =1, h =1, =1, h =1, h =1, ωt [3(Icos -4× k -1) ) ωt (3 cos -1× k -1) , the expression of the harmonic current pole pair number 1 harmonic plane is: i 1h I h ω h = sΘ(s + mc), c e Z h t -1× k -1) , therefore, in order to avoid affecting excitation and increasing the difficulty of control, the harmonic current pole pair number 2 harmonic current is selected for excitation. It should be noted that in this paper, the harmonic current pole pair number corresponds to the value of the harmonic order.

[0054] As a preferred mode, when the fundamental current is unchanged, the same harmonic current is injected in different planes, that is, the harmonic current pole pair number is different, and the excitation current size is different, so in this embodiment, the plane corresponding to the harmonic current pole pair number 2 (i.e. h = 2) is taken as the target harmonic plane.

[0055] It should be noted that when selecting the fundamental plane and the harmonic plane, the current phase sequence is determined by the phase difference of the fundamental current and the phase difference of the harmonic current of the adjacent windings in the multi-phase self-excited synchronous motor, and then the influence of the current phase sequence on the pole pair magnetic field is analyzed to realize the accurate mapping of the current phase sequence and the fundamental current pole pair number and the harmonic current pole pair number, so that the subsequent excitation and torque distribution are distributed in the magnetic field with different pole numbers. The fundamental plane and the four harmonic planes correspond to different current pole pair numbers.

[0056] To expand, before step S2, the process of matching the current phase sequence and the current pole pair number is as follows: first, the relationship between the current phase sequence and the air gap harmonic (i.e. the pole pair magnetic field) is as follows,

[0057] The th air gap harmonic of the h rad / s speed forward rotation is h = sΘ(mc s), c e Z ,

[0058] The th air gap harmonic of the h rad / s speed reverse rotation is sΘ sΘ , wherein h represents the spatial harmonic order, represents the fundamental current phase angle, s ​​the order of the phase sequence of the current, mj is the mechanical winding displacement factor, m is the number of phases of the multiphase self-excited synchronous motor, c is an integer, Z is the set of integers; in the multiphase self-excited synchronous motor, the coil winding on each stator tooth of the stator forms a phase, therefore, in the present embodiment V = d = 1, the coil windings collectively form the stator winding.

[0059] Further, the main wave number of the stator magnetomotive force is calculated as V , the calculation formula is: q = Z / 2 Figure 4 = c / d , wherein, q is the number of slots per pole per phase of the multiphase self-excited synchronous motor, Z is the number of slots of the multiphase self-excited synchronous motor, m is the number of phases of the multiphase self-excited synchronous motor, j is the number of fundamental current pole pairs; c / d is the calculation result of q should be an irreducible proper fraction, in the multiphase self-excited synchronous motor, when d is even, the main wave number of the stator magnetomotive force is cos / 2, and when d is odd, the main wave number of the stator magnetomotive force is V = d It should be noted that the main wave number of the stator magnetomotive force is determined by the number of pole pairs of the stator winding current, in the present embodiment Z = 11 slots, m = 11 phases, j = 4, therefore the main wave number of the stator magnetomotive force is V = 4. The rotor is a field winding structure (i.e. without permanent magnets), and the main wave number of the rotor magnetomotive force is determined by the number of rotor pole pairs Pr , according to the conventional design of the multiphase self-excited synchronous motor, the number of rotor pole pairs needs to match the main wave number of the stator magnetomotive force, i.e. , so that the interaction of the stator and rotor magnetic fields generates a constant electromagnetic torque.

[0060] Further, to ensure that the generated main wave number of the stator magnetomotive force is V = 4, to match the number of rotor pole pairs, the angular interval between adjacent slots of the stator in the multiphase self-excited synchronous motor is , i.e. the mechanical angle difference between adjacent windings in the multiphase self-excited synchronous motor, the calculation formula is: = , in the present embodiment = In the embodiment, the fundamental current phase difference is j × , j= 4, that is, the fundamental current phase difference is 4× = , the current phase sequence is: 1→4→7→10→2→5→8→11→3→6→9, and the slot position star type is shown in ω .

[0061] If the harmonic current pole pair number is selected as 2, that is, the harmonic current phase difference between adjacent windings is , then the current phase sequence is 1→7→2→8→3→9→4→10→5→11→6. Correspondingly, if the harmonic current pole pair number is selected as 1, that is, the harmonic current phase difference between adjacent windings is , then the current phase sequence is 1→2→3→4→5→6→7→8→9→10→11.

[0062] In the embodiment, when h =4, the fundamental current phase difference is , corresponding to the generated fundamental magnetic field with a fundamental current pole pair number of 4; when h =1, the harmonic current phase difference is , corresponding to the generated harmonic magnetic field with a harmonic current pole pair number of 1. Among them, the current phase sequence reflects the current magnetic field distribution, and the current phase sequence takes the first phase winding current as the reference, and the current phase difference at the same time is ordered by the phase number from small to large; it is worth mentioning that the value of the obtained spatial harmonic order corresponds to the current pole pair number, and the current pole pair number is determined by the plane of the injected current.

[0063] Step 3-2, obtaining the harmonic current, calculating the 11-phase harmonic current through the harmonic current expression corresponding to the target harmonic plane, and the harmonic current expression is:

[0064] i kh = I h ω ( V ≠ Pr h t - h ×( k -1) ), k =1, 2,..., 11,

[0065] In the formula, i kh indicates the harmonic current of the first k phase winding, Clarke / park hdenotes the given high-frequency harmonic current angular frequency, I h denotes the harmonic current amplitude, h denotes the harmonic order.

[0066] In the four harmonic planes, such as h =1, h =2, h =3 and h =5, the rotor magnetomotive force order does not match the rotor pole pair number, i.e. park , thus each harmonic plane does not participate in the generation of torque, and is only used for excitation regulation in the multi-phase self-excited synchronous motor, and does not participate in the electromechanical energy conversion; in the fundamental wave plane, the stator magnetomotive force order matches the rotor pole pair number, i.e. V= Pr= 4, so as to realize effective electromagnetic torque output.

[0067] Step 4, the eleven-phase fundamental wave current and harmonic current are respectively transformed into current components by using Clarke / park transformation in the transformation, park the eleven-phase fundamental wave current and harmonic current are respectively transformed into current components by using i q , i d , i qh and i dh , wherein, i q and i d respectively denote the d axis current component and the q axis current component of the stator current in the fundamental wave plane, i qh and i dh respectively denote the d axis current component and the q axis current component of the stator current in the target harmonic plane.

[0068] In the embodiment, Clarke / park the eleven-phase Clarke / park transformation in the transformation is a conventional operation, and thus will not be described.

[0069] Step 5, the current components in step 4 are input into a nested control system, and after the adjustment processing of the system, the output is given to SPWM inverse transformation. After the SPWM inverse transformation, the output is an 11-phase voltage signal, which respectively corresponds to U ar 、 Ubr 、...、U zr and U kr The 11-phase voltage signal is transmitted through SPWM Modulation, to obtain IGBT A pulse sequence is generated, and a twelve-phase inverter is output. The twelve-phase inverter is based on... Clarke / park Pulse sequence, controlling each of its internal components park The switching on and off of the device outputs an equivalent AC voltage.

[0070] To elaborate, in a nested control system, there are speed loops and current loops. The input quantity in the current loop is... 、 and , and Represented on the harmonic plane q Shaft reference current and d Shaft reference current.

[0071] Furthermore, after proper decoupling, the plane without injected current is 0. At the same time, for the small amount of interference coupling that exists in actual control, zero control can be set through the current loop to suppress it.

[0072] The above clarke In the inverse transform, i qh 、i dh 、i q and i d Both are the DC components of the current in a rotating coordinate system, after... Tclarke After the inverse transformation, we can obtain the following: a-β Two-phase alternating currents (90 degrees out of phase) in the coordinate plane, then after... Tpark After the inverse transformation, the 11-phase voltage signal in the natural coordinate system is obtained, and then output to the stator windings of the permanent magnet synchronous motor. This process is a standard operation of coordinate transformation. The aforementioned... T k -1 That is Clarke -1 × park -1 , ​ The five planes resulting from the transformation only require processing the injection plane (fundamental wave + selected pole-log harmonics). ​ Transformation and inverse transformation give the current angular velocity, i.e., the current frequency.

[0073] Compared with the prior art, the application forms one fundamental wave plane and five harmonic wave planes through multi-plane decoupling, wherein the speed loop only acts on the fundamental wave plane to ensure torque generation, and the harmonic currents of the harmonic wave planes are controlled by independent current loops, thereby realizing excitation and torque decoupling.

[0074] In addition, the excitation and torque are distributed to magnetic fields with different pole pair numbers, and dynamic frequency adjustment is used, that is, the size and frequency of the harmonic current are flexibly adjusted according to different working condition requirements; the rotor magnetic field strength is adjusted by adjusting the excitation current size to eliminate the coupling source of excitation and torque in the traditional self-excited motor, so that the excitation current (harmonic) and the torque current (fundamental wave) are completely independent in space, frequency and control loop, that is, the harmonic current can realize independent closed-loop control, closed-loop adjustment of the amplitude and frequency is achieved, and the amplitude and frequency can be independently set according to the working condition requirements.

[0075] The above only describes the preferred embodiments of the present application, and any equivalent changes and modifications made within the scope of the claims of the present application shall belong to the scope of the claims of the present application.

Claims

1. A method for harmonic regulation of a multiphase self-excited synchronous machine, the multiphase self-excited synchronous machine having eleven phases, and a control system of the multiphase self-excited synchronous machine comprising a multiphase closed-loop inverter controller, characterized in that: Adopting Clarke / Park transformations, the 11-phase current signals outputted by the multiphase self-excited synchronous motor are decoupled into four harmonic planes and one fundamental plane, then the motor control system selects a target harmonic plane according to requirements, and the corresponding current components, together with the current components of the fundamental plane, are processed by the multiphase closed-loop inverter controller to control the on-off of each IGBT device in the multiphase closed-loop inverter controller to realize the output of alternating voltage. comprising the following steps: step 1, acquiring five planes: adopting the Clarke / park Clarke transformation in the transformation transforms 11-phase current signals output by the multiphase self-excited synchronous motor into five different α - β coordinate planes, and the five different α - β coordinate planes respectively correspond to one fundamental plane and four harmonic planes; Step 2-1, selection of the fundamental plane, the fundamental plane is selected according to the fundamental current phase difference in step 1, the fundamental current phase difference is j × , j represents the pole pair number of the fundamental current, wherein the calculation formula of the mechanical angle difference in the multiphase self-excited synchronous motor is = , wherein represents the slot number of the multiphase self-excited synchronous motor; Step 2-2, the 11-phase fundamental currents are calculated by the fundamental current expression corresponding to the fundamental plane, and the fundamental current expression is: i k = I cos [ ωt - j ×( k -1) ], k =1、2、...、11， wherein k denotes the number of phases of the multiphase self-excited synchronous machine, i k denotes the first k phase fundamental current, I denotes the current amplitude, ω denotes the fundamental current angular frequency calculated from the rotational speed of the multiphase self-excited synchronous machine, t denotes the time.

2. A method of harmonic regulation of a multiphase self-excited synchronous machine according to claim 1, characterized in that: Step 3-1, the selection of the target harmonic plane, first, the relationship between the excitation current of the multi-phase self-excited synchronous motor and the harmonic current is established, which is, , wherein, D represents the motor-related parameter mixed term, represents the excitation current, h represents the harmonic order, is the current angular velocity, is the harmonic current amplitude; Then, the magnetizing currents under the influence of the harmonic orders corresponding to the four harmonic planes are considered comprehensively in time harmonic, the harmonic planes having coupling relationship with the harmonic of the fundamental current are deducted from the four harmonic planes to select the harmonic plane having optimal magnetizing effect as the target harmonic plane; Step 3-2, the 11-phase harmonic currents are calculated by the harmonic current expression corresponding to the target harmonic plane, and the harmonic current expression is: i kh = I h cos ( ω h t - h ×( k -1) )， k =1、2、...、11， wherein i kh denotes the k phase winding harmonic current, ω h denotes the given high frequency harmonic current angular frequency, I h denotes the harmonic current amplitude, h denotes the harmonic order.

3. A method of harmonic regulation of a multiphase self-excited synchronous machine according to claim 2, characterized in that: Step 4, using Clarke / Park in the transformation Park The transformation transforms the 11-phase fundamental current and the 11-phase harmonic current into current components, each of the currents corresponding to i q , i d , i qh and i dh wherein, i q and i d denote the d axis current component and the q axis current component of the stator current in the fundamental plane, i qh and i dh denote the d axis current component and the q axis current component of the stator current in the target harmonic plane.

4. A method of harmonic regulation of a multiphase self-excited synchronous machine according to claim 3, characterized in that: The multi-phase closed-loop inverter controller comprises an inverter and a nested control system, the inverter is a twelve-phase inverter, the nested control system takes a speed loop as an outer loop and takes a current loop as an inner loop; in step 5, the nested control system receives each current component and carries out adjusting processing, and the adjusted current component is output to a twelve-phase inverter through a modulation process. Clarke / Park After inverse transformation, an 11-phase voltage signal is output, the 11-phase voltage signal is modulated to obtain SPWM a pulse sequence, and is output to a twelve-phase inverter, so that each device in the twelve-phase inverter is turned on and off according to the pulse sequence, and an equivalent alternating voltage is output to the multi-phase self-excited synchronous motor. SPWM IGBT SPWM ​​​ 5. A method of harmonic regulation of a multiphase self-excited synchronous machine according to claim 2, characterized in that: Before step 2-1, the matching detection process between the current phase sequence and the current pole pair number is as follows: first, the relationship between the current phase sequence and the air gap harmonic is established, then the obtained current phase sequence is matched with the current pole pair number in combination with the mechanical angle difference; wherein, the relationship between the current phase sequence and the air gap harmonic is as follows: With rotating in the positive direction at a speed of 1,000 rad / s h the 2nd air-gap harmonic is h=sΘ(s+mc),c∈Z , With rotating at a speed of 1 rad / s h the second air-gap harmonic is h=sΘ(mc s),c∈Z wherein h denotes the spatial harmonic order, denotes the fundamental current phase angle, s denotes the sequence of the current phase sequence, sΘ is the mechanical winding displacement factor, m denotes the number of phases of the polyphase self-excited synchronous machine, c is an integer, Z denotes the set of integers.

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