High-speed electro-magnetic doubly salient motor control method based on commutation angle closed loop
Through the control method based on the commutation angle closed loop, the excitation current and commutation angle parameters are adaptively adjusted, which solves the problem of insufficient torque output capability of the high-speed electrical excitation double-pole motor, and achieves more efficient torque output.
Patent Information
- Application Number
- CN202411210132.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-30
- Publication Date
- 2025-01-10
AI Technical Summary
Under high-speed electric excitation double-pole motors, the excitation current and commutation angle parameters are difficult to directly obtain through analytical calculation methods, resulting in the failure to fully utilize the torque output capability.
The commutation angle closed-loop control method is adopted, and the excitation current and commutation angle parameters are adaptively adjusted through variable step length disturbance and observation algorithm, and the commutation angle of the next electrical cycle is adjusted by comparing the intersection point of the three-phase current waveform with the reference position. Parameters to ensure that the intersection of the three-phase current waveform is aligned with the intersection of the back potential waveform.
The torque output capability of the high-speed electric excitation dual-pole motor is effectively improved, and the maximum average torque output is achieved by adaptively adjusting the excitation current and commutation angle parameters.
Smart Images
Figure CN119298762A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of electrically excited double-pole motors, and in particular to a high-speed electrically excited double-pole motor control method based on a commutation angle closed loop. Background Art
[0002] The excitation winding and armature winding of the high-speed electrically excited double-pole motor are installed on the stator, and there are no windings and permanent magnets on the rotor. The excitation magnetic field is adjustable and the structure is simple and reliable. It is suitable for high-speed operation and has good application prospects in aircraft starting / generation systems, wind power generation systems, new energy vehicles and other fields.
[0003] The influence of the excitation current and commutation angle parameters of the electrically excited doubly salient motor on the torque under high-speed operation conditions is mutually coupled, and due to the strong nonlinearity of the motor electromagnetic parameters, the optimal excitation current and commutation angle parameters are difficult to obtain directly through analytical calculation methods, and the torque output capacity of the electrically excited doubly salient motor cannot be fully utilized. Therefore, it is urgent to study the adjustment method of the excitation current and commutation angle parameters of the electrically excited doubly salient motor under high-speed operation conditions to improve its torque output capacity. Summary of the invention
[0004] An embodiment of the present invention provides a high-speed electrically excited double-salient pole motor control method based on a commutation angle closed loop. The commutation angle closed loop control is adopted, and the excitation current is determined by a variable step size disturbance and an observation algorithm. The excitation current and the commutation angle parameters can be adaptively adjusted, thereby effectively improving the torque capacity of the high-speed electrically excited double-salient pole motor drive system.
[0005] To achieve the above object, the embodiments of the present invention adopt the following technical solutions:
[0006] In a first aspect, an embodiment of the present invention provides a method comprising:
[0007] A high-speed electrically excited double-salient-pole motor control method based on a commutation angle closed loop, comprising:
[0008] S1. During the operation of the high-speed electrically excited double-salient-pole motor, the positions of the intersections of the three-phase back-electromotive force waveforms are obtained and used as reference positions;
[0009] S2, sampling the current and determining the three-phase current of the high-speed electrically excited double-salient-pole motor, and then determining the position of the intersection of the three-phase current waveform in each electrical cycle;
[0010] S3, comparing the position of the intersection of the three-phase current waveform with the reference position to obtain a comparison result, wherein the comparison result includes: the difference between the feedback position and the reference position of the intersection of the three-phase current waveform in the current electrical cycle;
[0011] S4. Adjust the commutation angle parameters of the next electrical cycle of the high-speed electrically excited double-salient pole motor according to the comparison result.
[0012] Wherein, the torque of the high-speed electrically excited double-salient-pole motor is: Where T p is the total torque output of a single phase, i p is the armature current, L p is the phase winding self-inductance, i f is the excitation current, L pf is the mutual inductance between the field winding and the phase winding, θ is the rotor position angle, and p is any phase among A, B, and C. The second term in the formula is the field torque, which is generated by the interaction of the field current, the armature current, and the rate of change of the mutual inductance. Therefore, a continuous torque output can be generated by passing the corresponding current through the two-phase armature winding with changing inductance at any rotor position, that is, in the case of positive field current, a positive current is passed through the winding in the rising inductance area, and a negative current is passed through the winding in the falling inductance area.
[0013] During the commutation process of the high-speed electrically excited double-pole motor, the intersection of the ideal three-phase current waveform is aligned with the intersection of the corresponding three-phase back electromotive force waveform. The ideal three-phase current waveform is obtained through the conduction scheme of the maximum torque characteristic of the high-speed electrically excited double-pole motor, and the conduction scheme of the maximum torque characteristic of the high-speed electrically excited double-pole motor includes: for each rotor position, the torque of all possible three-phase current combinations is obtained through finite element simulation; then, by comparing the torque of all possible three-phase current combinations, the three-phase current that can generate the maximum average torque under the same current amplitude is selected and its waveform is recorded as the ideal three-phase current waveform.
[0014] Further, in S3, it includes: detecting whether an electrical cycle has passed, if not, recording the three-phase current and excitation current in the current electrical cycle; if yes, calculating the average torque and excitation current step size of the high-speed electrically excited double-pole motor; according to the difference dT between the average torque of the current electrical cycle and the average torque of the previous electrical cycle avg The difference between the reference excitation current of the current electrical cycle and the previous electrical cycle Determine the reference excitation current for the next electrical cycle, which includes four status conditions:
[0015] Case I: dT avg ≤0 and
[0016] Case II: dT avg ≤0 and
[0017] Case III: dT avg >0 and
[0018] Case IV: dT avg >0 and
[0019] According to the reference excitation current of the next electrical cycle, a processing model of the next electrical cycle is determined.
[0020] Among them, the processing model of the next electrical cycle includes: for cases I and III, the reference excitation current of the next electrical cycle is reduced by one step compared with the current electrical cycle; for cases II and IV, the reference excitation current of the next electrical cycle is increased by one step compared with the current electrical cycle.
[0021] Specifically, the processing model further includes: is the reference excitation current for the next electrical cycle, is the reference excitation current of the current electrical cycle, Δi f (k+1) is the step length that needs to be changed in the next electrical cycle, and k is a positive integer;
[0022] Δi f (k+1)=Δi f (k)×dT avg (k)÷dT avg (k-1), dT avg (k) is the average torque T of the current electrical cycle avg (k) and the average torque T of the previous electrical cycle avg (k-1) difference, where dT avg (k-1) = T avg (k-1)-T avg (k-2).
[0023] The three-phase armature winding of the high-speed electrically excited double-pole motor adopts a star connection mode, the power converter adopts a three-phase full-bridge inverter, and the excitation regulation circuit adopts an H-bridge circuit; the basic inductance model of the high-speed electrically excited double-pole motor includes a rising zone, a falling zone and a constant zone; when the high-speed electrically excited double-pole motor is in any rotor position, there are always two-phase armature winding inductances in the changing zone and the changing directions are opposite, and the remaining one-phase armature winding inductance remains unchanged.
[0024] The high-speed electrically excited double-salient-pole motor is equipped with a position sensor and a current sensor; wherein, during the operation of the high-speed electrically excited double-salient-pole motor, the rotor position is detected by the position sensor, and the rotor position θ e Calculate the speed and compare the calculated speed n with the reference speed n * The reference three-phase current is output through the PI regulator. The three-phase current i is measured by current sensors A 、i B and i C Sampling, sampling result i p With reference three-phase current The difference is input into the PI regulator, and then the driving signal is output to the three-phase full-bridge inverter according to the determined state.
[0025] During the operation of the high-speed electrically excited double-salient-pole motor, the excitation current i is measured by a current sensor. f Sampling, according to the sampled excitation current i f and the three-phase current i A 、i B 、i C Calculate the average torque T avg , and then use T avg Get reference excitation current And the reference excitation current and the sampled excitation current i f The difference is input into the PI regulator, and the PI regulator outputs a driving signal to the H-bridge circuit.
[0026] The high-speed electrically excited double-salient pole motor control method based on commutation angle closed loop provided by the embodiment of the present invention can obtain the position of the intersection of the three-phase back electromotive force waveforms through simulation as a reference position; obtain the three-phase current through current sampling, detect and feedback the position of the intersection of the three-phase current waveform in each electrical cycle through the intersection of the three-phase current waveform; compare the position of the intersection of the three-phase current waveform with the reference position; and use the difference between the feedback position and the reference position of the intersection of the three-phase current waveform in the current electrical cycle to adjust the commutation angle parameters of the next electrical cycle. By adopting the commutation angle closed loop control, the excitation current is determined by the variable step size disturbance and observation algorithm, and the excitation current and commutation angle parameters can be adaptively adjusted, thereby effectively improving the torque capacity of the high-speed electrically excited double-salient pole motor drive system. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0028] Figure 1 A system structure block diagram of a high-speed electrically excited double-salient-pole motor control method based on a commutation angle closed loop provided in an embodiment of the present invention;
[0029] Figure 2A schematic diagram of a conduction scheme for the maximum torque characteristics of a high-speed electrically excited double-salient-pole motor provided by an embodiment of the present invention;
[0030] Figure 3 A structural diagram of a three-phase full-bridge inverter provided in an embodiment of the present invention;
[0031] Figure 4 A flow chart of a variable step-size perturbation and observation algorithm provided by an embodiment of the present invention;
[0032] Figure 5 This is a structural diagram of an H-bridge circuit provided in an embodiment of the present invention. DETAILED DESCRIPTION
[0033] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. The embodiments of the present invention will be described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be interpreted as limiting the present invention. It can be understood by those skilled in the art that, unless specifically stated, the singular forms "one", "one", "said" and "the" used herein may also include plural forms. It should be further understood that the term "including" used in the specification of the present invention refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or their groups. It should be understood that when we say that an element is "connected" or "coupled" to another element, it can be directly connected or coupled to other elements, or there may also be intermediate elements. In addition, the "connection" or "coupling" used here may include wireless connection or coupling. The term "and / or" used herein includes any unit and all combinations of one or more associated listed items. It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meaning as generally understood by those of ordinary skill in the art to which the present invention belongs. It should also be understood that terms such as those defined in general dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless defined as herein.
[0034] The present invention discloses a high-speed electrically excited double-salient-pole motor control method based on a commutation angle closed loop. The implementation steps of the scheme are as follows:
[0035] Step 1): The intersection of the three back electromotive force waveforms is obtained by simulation as a reference position;
[0036] Step 2): Current sampling obtains three-phase current, and the intersection of the three-phase current waveform is detected and fed back in each electrical cycle;
[0037] Step 3): Compare the position of the intersection of the three-phase current waveform with the reference position;
[0038] Step 4): The difference between the feedback position and the reference position of the intersection of the three-phase current waveforms in the current electrical cycle is used to adjust the commutation angle parameters of the next electrical cycle.
[0039] The high-speed electrically excited doubly salient-pole motor control method can control the position of the intersection of the three-phase current waveform near the reference position; under different operating conditions, the commutation angle parameters can be adaptively adjusted through the commutation angle closed loop.
[0040] like Figure 1 The system structure block diagram of the high-speed electrically excited double-salient-pole motor control method based on the commutation angle closed loop provided by the embodiment of the present invention is shown. The controlled object is a high-speed electrically excited double-salient-pole motor, whose three-phase armature winding adopts a star connection mode, the power converter adopts a three-phase full-bridge inverter, and the excitation regulation circuit adopts an H-bridge circuit. Among them, the high-speed electrically excited double-salient-pole motor control method based on the commutation angle closed loop adopts the traditional speed outer loop and current inner loop control, and the rotor position is detected by the position sensor, and the rotor position θ is obtained. e Calculate the speed and compare the calculated speed n with the reference speed n * The reference three-phase current is output through the PI regulator. The three-phase current i is measured by current sensors A 、i B and i C Sampling, the sampled three-phase current i p With reference three-phase current The difference is input to the PI regulator, and the state is judged by combining the commutation angle closed loop to output the drive signal to drive the three-phase full-bridge inverter. At the same time, the excitation current i f Sampling, according to the sampled excitation current i f With the three-phase current i A 、i B 、i C Calculate the average torque T avg , the perturb and observe algorithm uses the calculated average torque T avg Give the reference excitation current And the reference excitation current and the sampled excitation current i f The difference is input to the PI regulator, and the PI regulator outputs a driving signal to drive the H-bridge circuit.
[0041] The commutation angle closed loop is a closed loop of the sampled three-phase current ip Perform three-phase current waveform intersection detection and calculate the position of the detected three-phase current waveform intersection θ c With reference position Compare and adaptively adjust the commutation angle parameters.
[0042] like Figure 2 The diagram shows a schematic diagram of a conduction scheme for the maximum torque characteristic of a high-speed electrically excited double-pole motor, wherein the conduction scheme for the maximum torque characteristic of a high-speed electrically excited double-pole motor refers to: obtaining the torque of all possible three-phase current combinations by a finite element simulation method at each rotor position; then, by comparing the torque of all possible three-phase current combinations, selecting a conduction scheme that can generate the maximum average torque at the same current amplitude. An ideal three-phase current waveform is derived from the conduction scheme for the maximum torque characteristic of a high-speed electrically excited double-pole motor, and the positions of the intersections of the ideal three-phase current waveforms are aligned with the positions of the intersections of the corresponding three-phase back electromotive force waveforms during the commutation process; the commutation process refers to the process in which the armature current changes.
[0043] like Figure 3 The structure diagram of the three-phase full-bridge inverter provided by the embodiment of the present invention is shown, wherein Q1-Q6 are MOSFET power tubes, D1-D6 are reverse parallel diodes, U dc is the DC bus voltage. Figure 2 The schematic diagram of the conduction scheme of the maximum torque characteristic of the high-speed electrically excited double-pole motor is shown, and the three-phase armature winding is energized with the drive signal given by the commutation angle closed loop.
[0044] like Figure 4 The flowchart of the variable step-size perturbation and observation algorithm provided by an embodiment of the present invention is shown. The average torque of the high-speed electrically excited double-pole motor is affected by the excitation current, three-phase current and commutation angle parameters, and the average torque of the high-speed electrically excited double-pole motor first increases and then decreases with the increase of the excitation current. Among them, the excitation current is determined by the proposed variable step-size perturbation and observation algorithm. The basic idea of the variable step-size perturbation and observation algorithm is: when the excitation current is far away from the optimal excitation current, a larger excitation current step is used to increase the convergence speed; when the excitation current is close to the optimal excitation current, the excitation current step is reduced to ensure the convergence accuracy; the optimal excitation current refers to the excitation current when the average torque of the high-speed electrically excited double-pole motor is the largest.
[0045] The specific implementation method is: first determine whether an electrical cycle has passed. If not, record the three-phase current and excitation current within an electrical cycle; if an electrical cycle has passed, calculate the average torque and the step size of the excitation current. Then, based on the difference dT between the average torque of the current electrical cycle and the average torque of the previous electrical cycle, avg The difference between the reference excitation current of the current electrical cycle and the previous electrical cycle Generates the reference excitation current for the next electrical period, of which there are four cases:
[0046] Case I: dT avg ≤0 and
[0047] Case II: dT avg ≤0 and
[0048] Case III: dT avg >0 and
[0049] Case IV: dT avg >0 and
[0050] In cases I and III, the reference excitation current of the next electrical cycle is reduced by one step compared to the current electrical cycle; conversely, in cases II and IV, the reference excitation current of the next electrical cycle is increased by one step compared to the current electrical cycle.
[0051] The step size of the excitation current is variable, and the reference excitation current of the next electrical cycle is The reference excitation current of the current electrical cycle and the step size Δi required for the next electrical cycle f (k+1) decision, that is:
[0052]
[0053] The next electrical cycle requires a step size Δi to change f (k+1) is the step size Δi that needs to be changed in the current electrical cycle f (k), dT avg (k) and dT avg (k-1) decision, namely:
[0054] Δi f (k+1)=Δi f (k)×dT avg (k)÷dT avg (k-1)
[0055] Among them, dT avg (k) is the average torque T of the current electrical cycle avg (k) and the average torque T of the previous electrical cycle avg The difference of (k-1), that is:
[0056] dT avg (k) = T avg (k)-T avg (k-1)
[0057] By analogy, we can get dT avg The expression of (k-1), that is:
[0058] dT avg (k-1) = T avg (k-1)-T avg (k-2)
[0059] Among them, T avg (k-2) represents the average torque of the previous electrical cycle.
[0060] The variable step size disturbance and observation algorithm combined with the excitation current closed loop can adaptively adjust the magnitude of the excitation current and can quickly and accurately achieve the optimal excitation current.
[0061] like Figure 5 The figure shows the H-bridge circuit structure provided by the embodiment of the present invention, wherein Q7 to Q 10 For MOSFET power tube, D7~D 10 They are reverse parallel diodes, U f is the supply voltage of the H-bridge circuit, and the output end of the H-bridge circuit is connected to the excitation winding. Figure 4 The variable step size perturbation and observation algorithm shown adaptively adjusts the magnitude of the excitation current and provides a corresponding drive signal to energize the excitation winding.
[0062] The embodiment of the present invention discloses a control method for a high-speed electrically excited double-salient pole motor based on a commutation angle closed loop, which belongs to the field of electrically excited double-salient pole motors. The control method of the present invention adaptively adjusts the commutation angle parameters of the high-speed electrically excited double-salient pole motor by aligning the intersection points of the three-phase current waveform with the intersection points of the corresponding three-phase back-electromotive force waveforms; in addition, the excitation current of the high-speed electrically excited double-salient pole motor is determined by the proposed variable step size perturbation and observation algorithm to obtain the maximum average torque. The control method of the present invention can adaptively adjust the excitation current and commutation angle parameters, effectively improving the torque capacity of the high-speed electrically excited double-salient pole motor drive system.
[0063] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment. The above is only a specific implementation method of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or replacements that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.
Claims
1. A high-speed electrically excited double-salient-pole motor control method based on a commutation angle closed loop, characterized in that: include: S1. During the operation of the high-speed electrically excited double-salient-pole motor, the positions of the intersections of the three-phase back-electromotive force waveforms are obtained and used as reference positions; S2, sampling the current and determining the three-phase current of the high-speed electrically excited double-salient-pole motor, and then determining the position of the intersection of the three-phase current waveform in each electrical cycle; S3, comparing the position of the intersection of the three-phase current waveform with the reference position to obtain a comparison result, wherein the comparison result includes: the difference between the feedback position and the reference position of the intersection of the three-phase current waveform in the current electrical cycle; S4. Adjust the commutation angle parameters of the next electrical cycle of the high-speed electrically excited double-salient pole motor according to the comparison result.
2. The method according to claim 1, characterized in that The torque of the high-speed electrically excited double-salient-pole motor is: Where T p is the total torque output of a single phase, i p is the armature current, L p is the phase winding self-inductance, i f is the excitation current, L pf is the mutual inductance between the field winding and the phase winding, θ is the rotor position angle, and p is any phase among A, B, and C.
3. The method according to claim 1, characterized in that During the commutation process of the high-speed electrically excited double-salient-pole motor, the positions of the intersection points of the ideal three-phase current waveforms are aligned with the positions of the intersection points of the corresponding three-phase back electromotive force waveforms. The ideal three-phase current waveform is obtained through the conduction scheme of the maximum torque characteristic of the high-speed electrically excited double-pole motor, and the conduction scheme of the maximum torque characteristic of the high-speed electrically excited double-pole motor includes: for each rotor position, obtaining the torque of all possible three-phase current combinations through finite element simulation; Then, by comparing the torques of all possible three-phase current combinations, the three-phase current that can produce the maximum average torque under the same current amplitude is selected and its waveform is recorded as the ideal three-phase current waveform.
4. The method according to claim 1, characterized in that: In S3, this includes: Detect whether an electrical cycle has passed, if not, record the three-phase current and excitation current in the current electrical cycle; if yes, calculate the average torque and step length of the excitation current of the high-speed electrically excited double-pole motor; According to the difference dT between the average torque of the current electrical cycle and the previous electrical cycle avg The difference between the reference excitation current of the current electrical cycle and the previous electrical cycle Determine the reference excitation current for the next electrical cycle, which includes four status conditions: Case I: dT avg ≤0 and Case II: dT avg ≤0 and Case III: dT avg >0 and Case Iv: dT avg >0 and According to the reference excitation current of the next electrical cycle, a processing model of the next electrical cycle is determined.
5. The method according to claim 4, characterized in that The processing model for the next electrical cycle includes: for cases I and III, the reference excitation current for the next electrical cycle is reduced by one step compared with the current electrical cycle; for cases II and IV, the reference excitation current for the next electrical cycle is increased by one step compared with the current electrical cycle.
6. The method according to claim 5, characterized in that The processing model also includes: is the reference excitation current for the next electrical cycle, is the reference excitation current of the current electrical cycle, Δi f (k+1) is the step size that needs to be changed in the next electrical cycle, and k is a positive integer; Δi f (k+1)=Δi f (k)×dT avg (k)÷dT avg (k-1), dT avg (k) is the average torque T of the current electrical cycle avg (k) and the average torque T of the previous electrical cycle avg (k-1) difference, where dT avg (k-1) = T avg (k-1)-T avg (k-2).
7. The method according to claim 1, characterized in that The three-phase armature winding of the high-speed electrically excited double-salient-pole motor adopts a star connection mode, the power converter adopts a three-phase full-bridge inverter, and the excitation regulation circuit adopts an H-bridge circuit; The basic inductance model of the high-speed electrically excited double-salient-pole motor includes a rising region, a falling region and a constant region; When the high-speed electrically excited double-salient-pole motor is in any rotor position, the inductances of the armature windings of two phases are always in a changing zone and the changing directions are opposite, and the inductance of the armature winding of the remaining phase remains unchanged.
8. The method according to claim 7, characterized in that The high-speed electrically excited double-salient-pole motor is equipped with a position sensor and a current sensor; wherein, during the operation of the high-speed electrically excited double-salient-pole motor, the rotor position is detected by the position sensor, and the rotor position θ is obtained by using the acquired e Calculate the speed and compare the calculated speed n with the reference speed n * The reference three-phase current is output through the PI regulator. The three-phase current i is measured by current sensors A 、i B and i C Sampling, sampling result i p With reference three-phase current The difference is input into the PI regulator, and then the driving signal is output to the three-phase full-bridge inverter according to the determined state.
9. The method according to claim 8, characterized in that Also includes: During the operation of the high-speed electrically excited double-salient-pole motor, the excitation current i is measured by a current sensor. f Sampling, according to the sampled excitation current i f and the three-phase current i A 、i B 、i C Calculate the average torque T avg , and then use T avg Get reference excitation current And the reference excitation current and the sampled excitation current i f The difference is input into the PI regulator, and the PI regulator outputs a driving signal to the H-bridge circuit.