CN-121749814-B - Novel SRG voltage regulation method based on flux linkage prediction

Abstract

The invention belongs to the field of motor control, and discloses a novel SRG voltage regulation method based on flux linkage prediction. The method is based on an equation of flux linkage change rate and voltage, flux linkage-current-position characteristics of a switched reluctance generator are obtained through off-line measurement, a two-dimensional data table is constructed according to the characteristics, and a flux linkage distribution function is constructed according to multi-target requirements. And acquiring a reference flux linkage according to the rotor position at the current moment, and entering a cost function with a flux linkage prediction function at the next moment. The operation state with the minimum value of the cost function is used as a switching signal to be applied to the power converter, thereby achieving the effect of controlling the output voltage of the switched reluctance generator. The effectiveness of the SRG novel voltage regulation method is verified through simulation, the SRG novel voltage regulation method is simple in logic, good in instantaneity and high in identification precision, has an important effect on improving the stability of the output voltage of the switch reluctance generator, and has the characteristics of being simple in algorithm, easy to realize and the like.

Inventors

• GE LEFEI
• DONG JINLIN
• LI HONGBING
• DU NAN
• LI WEILIN
• MENG HAIYING
• ZHAO YONG
• SONG SHOUJUN

Assignees

• 西北工业大学

Dates

Publication Date

20260512

Application Date

20260227

Claims (5)

1. 1. The novel SRG voltage regulation method based on flux linkage prediction is characterized by comprising the following steps of: Step 1, acquiring the flux linkage characteristic of a switched reluctance generator and constructing a two-dimensional data table ph (i ph Θ), wherein, ph For flux linkage, i ph is phase current, θ is rotor position; Step 2, theta on ~θ ov is a commutation area of the switched reluctance generator, theta on is an opening angle, and theta ov is a commutation overlap angle at which the front edge of the rotor pole meets the rear edge of the stator pole; step 3, according to the reference current I ref and the phase-change overlap angle theta ov , making them pass through two-dimensional lookup table ph (i ph Θ) to obtain a reference flux linkage Programming a function of flux linkage with respect to position in a commutation area of the switched reluctance generator: wherein, theta on is the opening angle of the switch reluctance generator, and theta ph is the rotor position of the switch reluctance generator at the current moment; Step 4, planning a function of a flux linkage related to the position after phase inversion of the switched reluctance generator and before turn-off: wherein, theta off is the turn-off angle of the switch reluctance generator, max The flux linkage of the switch reluctance generator at the turn-off angle is adopted; Step 5, the separation angle theta se between the rotor pole trailing edge and the stator pole leading edge is a fixed value, and is determined by the structure of the switched reluctance generator; Step 6, programming a function of flux linkage in a section from a turn-off angle theta off to a separation angle theta se of the switch reluctance generator with respect to the rotor position: Wherein, the se Motor flux linkage at separation angle θ se ; Step 7, according to the operation characteristic of the switch reluctance generator, the separation angle theta se is up to the termination angle theta end of the phase current, the winding can not absorb energy from the outside and convert the energy into electric energy to be output, in order to improve the generating efficiency of the switch reluctance generator, the smaller the time is, the better the time is, therefore, the larger the flux linkage change rate is, the better the larger the flux linkage change rate is, but the larger the flux linkage change rate can not be increased without limit, according to the phase voltage and flux linkage slope formula, the winding resistance voltage drop is ignored, and the formula is: wherein t is time; bringing the rotor position into the resulting flux linkage has a constraint on the rate of change of rotor position: Wherein, the U ph is the phase voltage for the rotation angular velocity of the switch reluctance generator; Step 8, taking the maximum value of the flux linkage rate of change along with the rotor position as the flux linkage slope according to the limiting condition, and planning a function of the flux linkage in a section from a separation angle theta se to a phase current termination angle theta end of the switched reluctance generator relative to the rotor position: Step 9, constructing a flux linkage distribution function according to the obtained function of flux linkage of each interval on the rotor position: Step 10, adjusting prediction error compensation based on the flux linkage prediction voltage of the switch reluctance motor, and predicting the flux linkage value of the next moment in different switch states according to the measured value of the motor operation parameter of the current k moment in order to eliminate the current moment prediction error at the next moment due to the error in the flux linkage prediction link ph (k+1); Wherein, the ph (K) is the current moment flux linkage value, T s is the control sampling period, S ph (k+1) is the switch state u dc at the moment (k+1) is the power converter bus voltage, i ph (k) is the motor phase current at the moment k, and R ph is the phase winding resistance; Constructing a cost function J: And calculating cost functions in different switching states, controlling the power converter by adopting the switching state with the minimum cost function value, realizing tracking control of a flux linkage distribution function, and further completing tracking control of output voltage based on flux linkage prediction control.
2. 2. The method for regulating the SRG novel voltage based on flux linkage prediction according to claim 1, wherein, In step 1, the formula of the flux linkage slope and the phase voltage is: wherein U ph is phase voltage, R ph is phase winding resistance, and t is time; In different operating states of the switched reluctance generator, the relationship between the phase voltage U ph and the output voltage U dc is: the output voltage can be controlled by programming the flux linkage slope.
3. 3. The method for regulating the SRG novel voltage based on flux linkage prediction according to claim 2, wherein, The commutation overlap angle θ ov is calculated as: Where τ is the rotor pole pitch of the switched reluctance generator, β s is the stator pole arc, and β r is the rotor pole arc.
4. 4. The method for regulating the SRG novel voltage based on flux linkage prediction according to claim 3, wherein, The calculation formula of the separation angle theta se is as follows: 。
5. 5. The method for regulating the SRG novel voltage based on flux linkage prediction according to claim 4, wherein, Motor flux linkage in calculating separation angle theta se se The method comprises the following steps: Wherein θ end is the termination angle of the phase current.

Description

Novel SRG voltage regulation method based on flux linkage prediction Technical Field The invention belongs to the field of motor control, and relates to a novel SRG voltage regulation method based on flux linkage prediction. Background The Switched Reluctance Generator (SRG) has the advantages of simple structure, firmness, low cost, reliable operation, flexible control, high operation efficiency, strong fault tolerance capability and the like, and has wide application prospect in the fields of aviation, wind power generation and the like. In recent years, attention has been paid to the fact that electric vehicles and multi-motor aircraft drive systems have become powerful candidates. The SRG is a motor with a double salient pole stator and rotor structural design, and in the power generation operation process, the magnetic path flux guide can present nonlinear change along with the change of the relative positions of the stator and the rotor, so that a linear correlation model is difficult to establish between output electric parameters and an operation state. This problem is directly manifested in the output voltage of the SRG, which can lead to large fluctuations in the output voltage. In order to solve the above problems, the scholars select motor control as an in-point of study, and sequentially propose Angular Position Control (APC), pulse width modulation control (PWM), current Chopping Control (CCC), and Model Predictive Control (MPC) to suppress the output voltage ripple of the SRG. For example, the literature 'Xia Linsen. Switched reluctance generator system research and performance optimization [ D ]. Chinese mining university, 2024.doi: 10.27623/d.cnki.gzkyu.2024.002297' indicates that the SRG doubly salient structure causes magnetic circuit flux nonlinearity, and output electrical parameters and operation states are difficult to establish linear correlation, so that model predictive control is difficult to accurately track an output voltage target, output voltage pulsation is remarkable at low rotation speed, and parameter tuning is complex. The invention constructs a flux linkage distribution function by utilizing the characteristic that the SRG flux linkage is approximately linearly changed along with the rotor position, and the flux linkage track is smoother by a table look-up method and multi-interval flux linkage planning, so that the influence of nonlinearity on the output voltage is reduced fundamentally. Meanwhile, by combining an MPC controller model and predicting flux linkage values in different switch states, the optimal control signal is output by minimizing a cost function as a target, so that the output voltage regulation precision is improved, and the output voltage pulsation is effectively restrained. Disclosure of Invention In order to effectively control the output voltage of the SRG and simultaneously reduce the output voltage pulsation of the SRG, the invention provides a novel SRG voltage regulating method based on flux linkage prediction, which is used for regulating the output voltage of a Switched Reluctance Generator (SRG) according to the relation between the output voltage of the SRG and the flux linkage slope. The invention uses magnetic linkage curve as medium, and builds magnetic linkage distribution function and MPC controller model by table look-up method. The simulation result proves the superiority of the method by comparing the method with other typical control methods through experiments under different conditions. The technical scheme of the invention is as follows: a novel SRG voltage regulation method based on flux linkage prediction comprises the following steps: Step 1, acquiring the flux linkage characteristic of a switched reluctance generator and constructing a two-dimensional data table ph(iph Θ), wherein,ph The flux linkage is i ph, the phase current is i ph, the theta is the rotor position, and the formula of the flux linkage slope and the phase voltage is: wherein U ph is phase voltage, R ph is phase winding resistance, and t is time; In different operating states of the switched reluctance generator, the relationship between the phase voltage U ph and the output voltage U dc is: The output voltage can be controlled by planning the magnetic linkage slope; Step 2, theta on~θov is a commutation area of the switched reluctance generator, theta on is an opening angle, theta ov is a commutation overlap angle where a rotor pole front edge meets a stator pole rear edge, and a calculated commutation overlap angle theta ov is: Wherein τ is the rotor pole pitch of the switched reluctance generator, β s is the stator pole arc, and β r is the rotor pole arc; step 3, according to the reference current I ref and the phase-change overlap angle theta ov, making them pass through two-dimensional lookup table ph(iph Θ) to obtain a reference flux linkageProgramming a function of flux linkage with respect to position in a commutation area of the switched reluctance