CN103916056A - Fault-tolerant operation control method of 12/8 single-winding bearing-free switch reluctance motor - Google Patents

Abstract

The invention discloses a fault-tolerant operation control method of a 12/8 single-winding bearing-free switch reluctance motor, and belongs to the technical field of control over the switch reluctance motor. Firstly, a 12/8 single-winding bearing-free switch reluctance motor mathematical model is built in a two-degree-of-freedom coordinate system of a fault-phase winding, and then suspension force is compensated according to the compensation principle that the sum of the current of a compensation tooth pole winding and the current of a tooth pole winding opposite to a fault tooth pole in the radial direction is equal to the sum of the current of other pair of two fault-phase tooth pole windings opposite to each other in the radial direction. The fault-tolerant operation control method of the 12/8 single-winding bearing-free switch reluctance motor reduces leakage flux of the motor, unifies the control methods in the different suspension force directions by introducing coefficients, and improves the output torque as much as possible under the condition of guaranteeing stable suspension.

Description

12/8 simplex winding bearingless switched reluctance motor error-tolerant operation control method

Technical field

The invention discloses 12/8 simplex winding bearingless switched reluctance motor error-tolerant operation control method, belong to the technical field of switched Reluctance Motor Control.

Background technology

Stators for Switched Reluctance Motors and rotor are salient-pole structure, and rotor, without winding and permanent magnet, there will not be permanent magnet high temperature demagnetization problem; On stator, be wound with centralized winding, make winding overhang shorter, when motor operation, heat energy loss mainly concentrates on stator, cooling convenience.Because it is firm in structure, fault-tolerance strong, control simple, high reliability, be suitable for the operation at a high speed and under mal-condition, its application has covered many occasions such as electric automobile, boats and ships, textile machine, and has unique advantage in high speed situation such as Aero-Space.

Along with the development of modern science and technology, various application scenarios are day by day harsh to the requirement of power-driven system, and the high-speed electric expreess locomotive that volume is little, lightweight, power density is high more and more obtains people's concern.Motor speed constantly strides forward to high speed, ultrahigh speed, not only can improve the power density of motor, also can reduce the volume weight of system.But high rotating speed has inevitably aggravated the friction between rotating shaft and bearing, cause heating and wearing and tearing, reduce bearing life, when serious, may cause motor to run well, the reliability of equipment cannot be guaranteed.This series of problem has limited further developing of high speed and super high speed motor.

Bearing-free switch reluctance motor is to utilize magnetic bearing and motor stator structure similitude,, on motor stator, increase a set of suspending windings, become a kind of New-type electric machine that possesses rotation simultaneously and certainly suspend.For realizing magnetic suspension function, a set of suspending windings of the extra increase of double winding bearing-free switch reluctance motor, this has increased the complexity of design of electrical motor and assembling, also relates to magnetic field superposition control simultaneously.And the manufacture of simplex winding motor is identical with common electric machine with processing, thereby can reduce the difficulty of processing of motor.Regular tap reluctance motor adds that through appropriate reconstruction corresponding control strategy just can be exchanged into bearing-free switch reluctance motor, and corresponding cost is also just much lower.For this reason, scholars' simplex winding bearing-free switch reluctance motor suspension technology that begins one's study.

Though bearing-free switch reluctance motor possesses every advantage of switched reluctance machines, but the generation of suspending power makes motor need more complicated magnetic field to control, and therefore the fault-tolerant control of bearing-free switch reluctance motor can not simply copy and transplant the fault tolerant control method of traditional switch reluctance motor.The fault freedom of research bearing-free motor can improve system reliability, thereby promotes its practicalization.Therefore need select suitable control strategy to guarantee the stable suspersion of winding failure rear motor and the output of electromagnetic torque, for the reliability consideration of simplex winding bearing-free switch reluctance motor provides reference, Research Significance is great.

Summary of the invention

Technical problem to be solved by this invention is the deficiency for above-mentioned background technology, and 12/8 simplex winding bearingless switched reluctance motor error-tolerant operation control method is provided.

The present invention adopts following technical scheme for achieving the above object:

12/8 simplex winding bearingless switched reluctance motor error-tolerant operation control method, comprises the steps:

Step 1, in the two degrees of freedom coordinate system of fault phase winding, set up 12/8 simplex winding bearing-free switch reluctance motor Mathematical Modeling:

$F_{\mathrm{\α}}=\frac{\∂W}{\∂\mathrm{\α}}=K_{f1}\left(\mathrm{\θ}\right)\left\{\begin{array}{c}{N_s}^2(i_{\mathrm{normal}1}+i_{\mathrm{normal}3})(i_{\mathrm{normal}1}-i_{\mathrm{normal}3})\\ +\frac{2{N_s}^{2}A\left(\mathrm{\θ}\right)}{4A\left(\mathrm{\θ}\right)+4B\left(\mathrm{\θ}\right)}(i_{\mathrm{normal}1}-i_{\mathrm{normal}3})[i_{\mathrm{normal}2}+i_{\mathrm{normal}4}-(i_{\mathrm{normal}1}+i_{\mathrm{normal}3})]\\ +\frac{{2N_s}^{2}B\left(\mathrm{\θ}\right)}{4A\left(\mathrm{\θ}\right)+4B\left(\mathrm{\θ}\right)}(i_{\mathrm{normal}1}-i_{\mathrm{normal}3})[i_{\mathrm{fault}2}+i_{\mathrm{fault}4}-(i_{\mathrm{fault}1}+i_{\mathrm{fault}3})]\end{array}\right\}$

$+K_{f2}\left(\mathrm{\θ}\right)\left\{\begin{array}{c}-\frac{N_s^2}{2}[\sqrt{3}(i_{\mathrm{fault}1}^2-i_{\mathrm{fault}3}^2)+(i_{\mathrm{fault}2}^2-i_{\mathrm{fault}}^2)]\\ +\frac{N_s^{2}B\left(\mathrm{\θ}\right)}{4A\left(\mathrm{\θ}\right)+4B\left(\mathrm{\θ}\right)}[\sqrt{3}(i_{\mathrm{fault}}-i_{\mathrm{fault}3})+(i_{\mathrm{fault}4}-i_{\mathrm{fault}2})][(i_{\mathrm{fault}1}+i_{\mathrm{fault}3})-(i_{\mathrm{fault}4}+i_{\mathrm{fault}2})]\\ +\frac{N_s^{2}A\left(\mathrm{\θ}\right)}{4A\left(\mathrm{\θ}\right)+4B\left(\mathrm{\θ}\right)}[\sqrt{3}(i_{\mathrm{fault}1}-i_{\mathrm{fault}3})+(i_{\mathrm{fault}4}-i_{\mathrm{fault}2})][(i_{\mathrm{normal}1}+i_{\mathrm{normal}3})-(i_{\mathrm{normal}2}+i_{\mathrm{normal}4})]\end{array}\right\}$

$F_{\mathrm{\β}}=\frac{\∂W}{\∂\mathrm{\β}}=K_{f1}\left(\mathrm{\θ}\right)\left\{\begin{array}{c}{N_s}^2(i_{\mathrm{normal}2}+i_{\mathrm{normal}4})(i_{\mathrm{normal}2}-i_{\mathrm{normal}4})\\ +\frac{2{N_s}^{2}A\left(\mathrm{\θ}\right)}{4A\left(\mathrm{\θ}\right)+4B\left(\mathrm{\θ}\right)}(i_{\mathrm{normal}2}-i_{\mathrm{normal}4})[i_{\mathrm{normal}1}+i_{\mathrm{normal}3}-(i_{\mathrm{normal}2}+i_{\mathrm{normal}4})]\\ +\frac{2{N_s}^{2}B\left(\mathrm{\θ}\right)}{4A\left(\mathrm{\θ}\right)+4B\left(\mathrm{\θ}\right)}(i_{\mathrm{normal}2}-i_{\mathrm{normal}4})[i_{\mathrm{sb}1}+i_{\mathrm{sb}3}-(i_{\mathrm{sb}2}+i_{\mathrm{sb}4})]\end{array}\right\}$

$+K_{f2}\left(\mathrm{\θ}\right)\left\{\begin{array}{c}-\frac{N_s^2}{2}[(i_{\mathrm{fault}1}^2-i_{\mathrm{fault}3}^2)-\sqrt{3}(i_{\mathrm{fault}2}^2-i_{\mathrm{fault}4}^2)]\\ +\frac{N_s^{2}B\left(\mathrm{\θ}\right)}{4A\left(\mathrm{\θ}\right)+4B\left(\mathrm{\θ}\right)}[\sqrt{3}(i_{\mathrm{fault}2}-i_{\mathrm{fault}4})+(i_{\mathrm{fault}1}-i_{\mathrm{fault}3})][(i_{\mathrm{fault}1}+i_{\mathrm{fault}3})-(i_{\mathrm{fault}2}+i_{\mathrm{fault}4})]\\ +\frac{N_s^{2}A\left(\mathrm{\θ}\right)}{4A\left(\mathrm{\θ}\right)+4B\left(\mathrm{\θ}\right)}[\sqrt{3}(i_{\mathrm{fault}2}-i_{\mathrm{fault}4})+(i_{\mathrm{fault}1}-i_{\mathrm{fault}3})][(i_{\mathrm{normal}1}+i_{\mathrm{normal}3})-(i_{\mathrm{normal}2}+i_{\mathrm{normal}4})]\end{array}\right\}$

Wherein, F _α, F _βbe respectively fault phase required radial suspension force in its corresponding α, the β degree of freedom, K _f1(θ), K _f2(θ), A (θ), B (θ) be the coefficient relevant with motor size and rotor position angle, N _sfor umber of turn, i _fault1, i _fault2, i _fault3, i _fault4for each tooth utmost point winding current of the phase that breaks down, i _normal1, i _normal2, i _normal3, i _normal4for the mutually each winding current of correspondence compensation,

In the time that winding failure compensates, fault tooth utmost point winding current and conducting phase current are not set to 0, above-mentioned Mathematical Modeling is winding open fault compensation Mathematical Modeling;

Step 2, simplified model, equals another compensation principle to two radially relative tooth utmost point winding current sums of fault phase according to the compensation tooth utmost point winding current tooth utmost point winding current sum radially relative with the fault tooth utmost point and obtains:

The compensation tooth utmost point winding current tooth utmost point winding current radially relative with the fault tooth utmost point, two tooth utmost point winding currents that another group of fault phase is radially relative, simultaneously inlet coefficient k.

As the further prioritization scheme of described 12/8 simplex winding bearingless switched reluctance motor error-tolerant operation control method, determine the value of inlet coefficient k according to fault phase required radial suspension force in the α degree of freedom:

As fault phase required radial suspension force F in the α degree of freedom _αbe greater than or equal to zero, the tooth utmost point winding current radially relative with the fault tooth utmost point do not reach limiting value, when the compensation tooth utmost point winding current value of reaching capacity,

$k\≥\frac{i_{\max }}{\sqrt{i_{\max }^2-N_s^2{X}_{B0}^2{i}_{\max }^2{K}_{f10}}}\sqrt{D_0},$

As fault phase required radial suspension force F in the α degree of freedom _αbe greater than or equal to zero, tooth utmost point winding current reach capacity value radially relative with the fault tooth utmost point, when compensation tooth utmost point winding current does not reach limiting value,

$k\≥\frac{-{2i}_{\max }{X}_{B1}\sqrt{\frac{F_{\mathrm{\α}}}{D_1}}+\sqrt{{4i}_{\max }^2{X}_B^2\frac{F_{\mathrm{\α}}}{D_1}+4(i_{\max }^2+\frac{F_{\mathrm{\α}}}{N_s^2{K}_{f11}})(\frac{F_{\mathrm{\α}}}{N_s^2{K}_{f11}}-X_B^2\frac{F_{\mathrm{\α}}}{D_1})}}{2(\frac{F_{\mathrm{\α}}}{N_s^2{K}_{f11}}-X_B^2\frac{F_{\mathrm{\α}}}{D_1})},$

As fault phase required radial suspension force F in the α degree of freedom _αbe greater than or equal to zero, the tooth utmost point winding current radially relative with the fault tooth utmost point do not reach limiting value, when compensation tooth utmost point winding current does not reach limiting value,

$k\≥\sqrt{\frac{K_{f1}\left(\mathrm{\θ}\right)X_B^2\left(\mathrm{\θ}\right)}{\sqrt{3}{K}_{f2}\left(\mathrm{\θ}\right)X_A\left(\mathrm{\θ}\right)}+1},$

As fault phase required radial suspension force F in its corresponding α degree of freedom _αbe less than at 1 o'clock, k=0,

Wherein, K _f10, X _b0, D ₀for K _f1(θ), X _b(θ), the value of D (θ) in the time that rotor position angle is 0 °, K _f11, X _b1, D ₁for K _f1(θ), X _b(θ), the value of D (θ) in the time that rotor position angle is-15 °, i _maxfor limiting value.

The present invention adopts technique scheme, has following beneficial effect: reduce motor flux leakage, can also be by inlet coefficient, the control mode of different suspending power directions is unified, and in the situation that guaranteeing stable suspersion, improve as much as possible output torque simultaneously.The method control is simple, is easy to realize, and gives full play to the advantage that switched reluctance motor error-tolerant ability is strong, can further accelerate the practical of bearing-free motor.

Accompanying drawing explanation

Fig. 1 is 12/8 structure simplex winding bearing-free switch reluctance motor A, B, C three-phase linear inductance distribution schematic diagram.

Fig. 2 is 12/8 structure simplex winding bearing-free switch reluctance motor winding distribution schematic diagram.

Fig. 3 is A ₁fault B ₃compensation F _αthe each winding current schematic diagram of >0 motor three-phase.

Fig. 4 is A ₁fault B ₃compensation F _αthe each winding current schematic diagram of <0 motor three-phase.

Fig. 5 is that k value is asked for flow chart.

Fig. 6 is simplex winding bearingless switched reluctance motor error-tolerant operation control method control block diagram.

Embodiment

Below in conjunction with accompanying drawing, the technical scheme of invention is elaborated.

The present invention proposes simplex winding bearingless switched reluctance motor error-tolerant operation control method, with 12/8 structural electromotor A phase A ₁tooth utmost point fault is the feasibility that example is set forth error-tolerant operation control method of the present invention.

12/8 structure simplex winding bearing-free switch reluctance motor three-phase linear inductance distribution map as shown in Figure 1.As seen from the figure, in single-phase conducting situation, A phase inductance is in the time of rising area, and B phase inductance is in decline district, and C phase inductance, close to zero, provides suspending power limited in one's ability, therefore, in the time that A has tooth utmost point winding failure mutually, compensates suspending power by B phase tooth utmost point winding.Visible, in the time of certain phase tooth utmost point winding failure, select and the opposite polarity adjacent phase of fault phase inductance slope of curve phase by way of compensation.While being A phase tooth utmost point winding failure, the compensation of B phase tooth utmost point winding; When B phase tooth utmost point winding failure, the compensation of C phase tooth utmost point winding; When C phase tooth utmost point winding failure, the compensation of A phase tooth utmost point winding.

12/8 structure simplex winding bearing-free switch reluctance motor winding distributes as shown in Figure 2: A phase rotor has A ₁, A ₂, A ₃, A ₄four tooth utmost point windings, B phase rotor has B ₁, B ₂, B ₃, B ₄four tooth utmost point windings, C phase rotor has C ₁, C ₂, C ₃, C ₄four tooth utmost point windings, P _a1, P _a2, P _a3, P _a4for air-gap permeance corresponding to each tooth utmost point winding., A _α, A _βaxle arrow has represented respectively α positive direction and the β positive direction of A phase.Work as A ₁when tooth utmost point winding failure, available B ₃or B ₄the compensation of tooth utmost point winding, under identical excitation condition, B ₃tooth utmost point winding is at A _αsuspending power component amplitude maximum on axle, therefore determines B ₃tooth utmost point winding is suspending power compensation winding.

A tooth utmost point winding breaks down, and is not that all direction suspending powers all lack.Therefore different directions low suspension power control mode is different, in order to simplify control, the control mode of different directions can be unified.A ₁when winding failure, open B ₃winding compensates suspending power, as required F _α>0 or F _αwhen <0, A phase inductance L _a, the mutually each tooth utmost point of A winding current i _a, B phase inductance L _b, the mutually each tooth utmost point of B winding current i _b, C phase inductance L _c, the mutually each tooth utmost point of C winding current i _calong with the schematic diagram of rotor position angle θ is distinguished as shown in Figure 3, Figure 4, under different suspending power directions, each winding current is different.

Below with A ₁tooth utmost point winding failure is example, and determining of compensation principle and inlet coefficient k value is described.

Work as A ₁when tooth utmost point winding failure, B ₃for compensation tooth utmost point winding.I _sa1be the fault tooth utmost point winding current i in model _fault1, i _sa3be the tooth utmost point winding current i radially relative with the fault tooth utmost point _fault3, i _sa2, i _sa4another that is fault phase is to two radially relative tooth utmost point winding current i _fault2, i _fault4, i _sb3be compensation tooth utmost point winding current i _normal3, i _sb1be the tooth utmost point winding current i radially relative with compensating the tooth utmost point _normal1, i _sb2, i _sb4be compensation phase another to tooth utmost point winding current i _normal2, i _normal4, making fault tooth utmost point winding current is 0, making not conducting phase winding electric current is 0, obtains setting up the winding open fault compensation Mathematical Modeling of 12/8 simplex winding bearing-free switch reluctance motor in the two degrees of freedom coordinate system of fault phase winding:

$F_{\mathrm{\&alpha;}}=K_{f1}\left(\mathrm{\&theta;}\right){N_s}^2{i}_{\mathrm{sa}3}\left\{\begin{array}{c}-i_{\mathrm{sa}3}+\frac{i_{\mathrm{sb}3}B\left(\mathrm{\&theta;}\right)}{2(A\left(\mathrm{\&theta;}\right)+B\left(\mathrm{\&theta;}\right))}\\ -\frac{A\left(\mathrm{\&theta;}\right)}{2(A\left(\mathrm{\&theta;}\right)+B\left(\mathrm{\&theta;}\right))}(i_{\mathrm{sa}2}+i_{\mathrm{sa}4}-i_{\mathrm{sa}3})\end{array}\right\}$

$+K_{f2}\left(\mathrm{\&theta;}\right){N_s}^2\left\{\begin{array}{c}\frac{\sqrt{3}}{2}{i}_{\mathrm{sb}3}^2-\frac{\sqrt{3}B\left(\mathrm{\&theta;}\right)}{4(A\left(\mathrm{\&theta;}\right)+B\left(\mathrm{\&theta;}\right))}{i}_{\mathrm{sb}3}^2\\ +\frac{\sqrt{3}{i}_{\mathrm{sb}3}A\left(\mathrm{\&theta;}\right)}{4\left(A\left(\mathrm{\&theta;}\right)B\left(\mathrm{\&theta;}\right)\right)}(i_{\mathrm{sa}2}+i_{\mathrm{sa}4}-i_{\mathrm{sa}3})\end{array}\right\}$

$F_{\mathrm{\&beta;}}=K_{f1}\left(\mathrm{\&theta;}\right){N_s}^2(i_{\mathrm{sa}2}-i_{\mathrm{sa}4})\left\{\begin{array}{c}(i_{\mathrm{sa}2}+i_{\mathrm{sa}4})\\ +\frac{A\left(\mathrm{\&theta;}\right)(i_{\mathrm{sa}3}-i_{\mathrm{sa}2}-i_{\mathrm{sa}4})}{2(A\left(\mathrm{\&theta;}\right)+B\left(\mathrm{\&theta;}\right))}\\ +\frac{B\left(\mathrm{\&theta;}\right)i_{\mathrm{sb}3}}{2(A\left(\mathrm{\&theta;}\right)+B\left(\mathrm{\&theta;}\right))}\end{array}\right\}$

$+K_{f2}\left(\mathrm{\&theta;}\right){N_s}^2\left\{\begin{array}{c}\frac{i_{\mathrm{sb}3}^2}{2}-\frac{\sqrt{3}{i}_{\mathrm{sb}3}^{2}B\left(\mathrm{\&theta;}\right)}{4(A\left(\mathrm{\&theta;}\right)+B\left(\mathrm{\&theta;}\right))}\\ -\frac{i_{\mathrm{sb}3}A\left(\mathrm{\&theta;}\right)}{4(A\left(\mathrm{\&theta;}\right)+B\left(\mathrm{\&theta;}\right))}(i_{\mathrm{sa}3}-i_{\mathrm{sa}2}-i_{\mathrm{sa}4})\end{array}\right\},$

K _f1(θ), K _f2(θ), A (θ), B (θ) are coefficient relevant to motor size and rotor position angle.

As required F _αwhen >0, A ₁winding failure is by B ₃winding compensation, known according to the Mathematical Modeling after the compensation of winding open circuit, the suspending power in a direction and four tooth utmost point winding current i _sb3, i _sa2, i _sa3and i _sa4related, for reducing leakage field impact, for simplifying suspending power control, adopt i simultaneously _sb3+ i _sa3=i _sa2+ i _sa4compensation principle, now four tooth utmost point winding current expression formulas are:

$i_{\mathrm{sb}3}=k\sqrt{\frac{F_{\mathrm{\&alpha;}}}{N_s^2(K_{f1}\left(\mathrm{\&theta;}\right)X_B^2\left(\mathrm{\&theta;}\right)+\sqrt{3}{K}_{f2}\left(\mathrm{\&theta;}\right)X_A\left(\mathrm{\&theta;}\right))}}---\left(1\right),$

$i_{\mathrm{sa}3}=X_B\left(\mathrm{\&theta;}\right)i_{\mathrm{sb}3}+\sqrt{\frac{(k^2-1)F_{\mathrm{\&alpha;}}}{N_s^2{K}_{f1}\left(\mathrm{\&theta;}\right)}}---\left(2\right),$

$i_{\mathrm{sa}2}=\frac{i_{\mathrm{sa}3}+i_{\mathrm{sb}3}}{2}+\frac{K_{f2}\left(\mathrm{\&theta;}\right)N_s^2{X}_A\left(\mathrm{\&theta;}\right)i_{\mathrm{sb}3}^2-F_{\mathrm{\&beta;}}}{2K_{f1}\left(\mathrm{\&theta;}\right)N_s^2(i_{\mathrm{sa}3}+i_{\mathrm{sb}3}+2X_B\left(\mathrm{\&theta;}\right)i_{\mathrm{sb}3})}---\left(3\right),$

$i_{\mathrm{sa}4}=\frac{i_{\mathrm{sa}3}+i_{\mathrm{sb}3}}{2}+\frac{F_{\mathrm{\&beta;}}-K_{f2}\left(\mathrm{\&theta;}\right)N_s^2{X}_A\left(\mathrm{\&theta;}\right)i_{\mathrm{sb}3}^2}{2K_{f1}\left(\mathrm{\&theta;}\right)N_s^2(i_{\mathrm{sa}3}+i_{\mathrm{sb}3}+2X_B\left(\mathrm{\&theta;}\right)i_{\mathrm{sb}3})}---\left(4\right),$

$X_A\left(\mathrm{\&theta;}\right)=\frac{3A\left(\mathrm{\&theta;}\right)+B\left(\mathrm{\&theta;}\right)}{4A\left(\mathrm{\&theta;}\right)+4B\left(\mathrm{\&theta;}\right)},X_B\left(\mathrm{\&theta;}\right)=\frac{-A\left(\mathrm{\&theta;}\right)+B\left(\mathrm{\&theta;}\right)}{4A\left(\mathrm{\&theta;}\right)+4B\left(\mathrm{\&theta;}\right)}---\left(5\right),$

F _βfor the radial load that A produces in β direction, i _sb3, i _sa2, i _sa3and i _sa4be respectively B ₃, A ₂, A ₃and A ₄tooth utmost point winding current, k is the coefficient of introducing.

A ₁tooth utmost point winding breaks down, according to i _sb3+ i _sa3=i _sa2+ i _sa4and suspending power expression formula can be tried to achieve the now expression formula of four tooth utmost point winding currents.Contrast is found, F _αfour tooth utmost point winding current expression formulas when <0 and F _αfour tooth utmost point winding current expression formulas of >0 k=0 in season are identical.Accordingly, the compensation policy of different suspending power directions can be unified.If required F _α<0, k=0, now suspending power is without compensation, i _sb3=0; Required F _αwhen >0, k>=1.

Suspending power compensates in inductance decline district, produces negative torque, is therefore guaranteeing under the prerequisite suspending, and should improve as much as possible torque output.When given suspending power, the torque difference that different value of K is corresponding.When given identical suspending power, k value is larger, and the average torque of output is also larger.But the each current value of winding is relevant to k value, because winding current exists maximum operation value, k value can not be infinitely great.

Simultaneously from formula (1)-(4), i _sb3in the time of 0 ° of rotor position angle, get maximum, i _sa3during in rotor position angle-15 °, get maximum, therefore both can not get electric current threshold limit value simultaneously, can point situation be asked for by k value based on this:

（a）i _sb3=i _max，0≤i _sa3<i _max

I _sb3get current limit 0 ° of rotor position angle, the span that k can be tried to achieve in convolution (1), (2) is:

$k\&GreaterEqual;\frac{i_{\max }}{\sqrt{i_{\max }^2-N_s^2{X}_{B0}^2{i}_{\max }^2{K}_{f10}}}\sqrt{D_0}---\left(6\right),$

$D\left(\mathrm{\&theta;}\right)=N_s^2(K_{f1}\left(\mathrm{\&theta;}\right)X_B^2\left(\mathrm{\&theta;}\right)+\sqrt{3}{K}_{f2}\left(\mathrm{\&theta;}\right)X_A\left(\mathrm{\&theta;}\right))$

Wherein K _f10, X _b0, D ₀for K _f1(θ), X _b(θ), the value of D (θ) in the time that rotor position angle is 0 °.

（b）i _sa3=i _max，0≤i _sb3<i _max

$k\&GreaterEqual;\frac{-{2i}_{\max }{X}_{B1}\sqrt{\frac{F_{\mathrm{\&alpha;}}}{D_1}}+\sqrt{{4i}_{\max }^2{X}_B^2\frac{F_{\mathrm{\&alpha;}}}{D_1}+4(i_{\max }^2+\frac{F_{\mathrm{\&alpha;}}}{N_s^2{K}_{f11}})(\frac{F_{\mathrm{\&alpha;}}}{N_s^2{K}_{f11}}-X_B^2\frac{F_{\mathrm{\&alpha;}}}{D_1})}}{2(\frac{F_{\mathrm{\&alpha;}}}{N_s^2{K}_{f11}}-X_B^2\frac{F_{\mathrm{\&alpha;}}}{D_1})}---\left(7\right),$

Wherein K _f11, X _b1, D ₁for K _f1(θ), X _b(θ), the value of D (θ) in the time that rotor position angle is-15 °.

（c）0≤i _sa3<i _max，0≤i _sb3<i _max

Now the span of k is:

$k\&GreaterEqual;\sqrt{\frac{K_{f1}\left(\mathrm{\&theta;}\right)X_B^2\left(\mathrm{\&theta;}\right)}{\sqrt{3}{K}_{f2}\left(\mathrm{\&theta;}\right)X_A\left(\mathrm{\&theta;}\right)}+1}---\left(8\right),$

Go up according to this analysis and can obtain k value and choose flow process as shown in Figure 5, as required F _αwhen <0, k is 0; As required F _αwhen >0, determine the value of k according to each current limit, improve as far as possible output average torque.

Ask for four tooth utmost point winding current i according to different value of K _sb3, i _sa2, i _sa3and i _sa4, by the current tracking control of winding power circuit, realize the real-time tracking of four winding currents, suspend thereby realize motor stabilizing.Fig. 6 is simplex winding bearingless switched reluctance motor error-tolerant operation control method control block diagram, two radial displacement signals detect through current vortex sensor, be converted to the signal of telecommunication, by poor to itself and set-point, through the set-point of PID adjuster output both direction suspending power, then calculate suspending power by fault-tolerant operation control mode and compensate required given value of current value, realize electric current by system controller and follow the tracks of in time, thereby reach the object of real-time control suspending power.

The present invention is with A phase A ₁fault is that example is introduced simplex winding bearingless switched reluctance motor error-tolerant operation control method, and the method is equally applicable to the A situation that other windings break down mutually.Meanwhile, the method is also applicable to the situation of other two-phase winding failure.When winding failure appears in B mutually, compensated by C phase winding; When winding failure appears in C mutually, compensated by A phase winding, error-tolerant operation control method and A phase winding Fault Compensation method are similar.The present invention is the value of determining inlet coefficient k according to fault phase required radial suspension force in the α degree of freedom, similarly, also can determine according to fault phase required radial suspension force in the β degree of freedom value of inlet coefficient k.

The present invention is take simplex winding bearing-free switch reluctance motor as control object, and the each tooth utmost point of this motor winding is all controlled separately.In the time that tooth utmost point winding of motor breaks down, in order to reduce the negative torque of generation, by tooth utmost point winding of adjacent phase, suspending power is compensated, and still normally of other phases.Because tooth utmost point winding failure is different on the suspending power impact of different directions, compensation way is also different.Control mode that the present invention carries not only can reduce motor flux leakage, can also be by inlet coefficient, the control mode of different suspending power directions is unified, in the situation that guaranteeing stable suspersion, improve as much as possible output torque simultaneously.The method control is simple, is easy to realize, and gives full play to the advantage that switched reluctance motor error-tolerant ability is strong, can further accelerate the practical of bearing-free motor.

Claims (2)

1.12/8 simplex winding bearingless switched reluctance motor error-tolerant operation control method, is characterized in that comprising the steps:

Step 1, in the two degrees of freedom coordinate system of fault phase winding, set up 12/8 simplex winding bearing-free switch reluctance motor Mathematical Modeling:

$F_{\mathrm{\&alpha;}}=\frac{\&PartialD;W}{\&PartialD;\mathrm{\&alpha;}}=K_{f1}\left(\mathrm{\&theta;}\right)\left\{\begin{array}{c}{N_s}^2(i_{\mathrm{normal}1}+i_{\mathrm{normal}3})(i_{\mathrm{normal}1}-i_{\mathrm{normal}3})\\ +\frac{2{N_s}^{2}A\left(\mathrm{\&theta;}\right)}{4A\left(\mathrm{\&theta;}\right)+4B\left(\mathrm{\&theta;}\right)}(i_{\mathrm{normal}1}-i_{\mathrm{normal}3})[i_{\mathrm{normal}2}+i_{\mathrm{normal}4}-(i_{\mathrm{normal}1}+i_{\mathrm{normal}3})]\\ +\frac{{2N_s}^{2}B\left(\mathrm{\&theta;}\right)}{4A\left(\mathrm{\&theta;}\right)+4B\left(\mathrm{\&theta;}\right)}(i_{\mathrm{normal}1}-i_{\mathrm{normal}3})[i_{\mathrm{fault}2}+i_{\mathrm{fault}4}-(i_{\mathrm{fault}1}+i_{\mathrm{fault}3})]\end{array}\right\}$

$+K_{f2}\left(\mathrm{\&theta;}\right)\left\{\begin{array}{c}-\frac{N_s^2}{2}[\sqrt{3}(i_{\mathrm{fault}1}^2-i_{\mathrm{fault}3}^2)+(i_{\mathrm{fault}2}^2-i_{\mathrm{fault}}^2)]\\ +\frac{N_s^{2}B\left(\mathrm{\&theta;}\right)}{4A\left(\mathrm{\&theta;}\right)+4B\left(\mathrm{\&theta;}\right)}[\sqrt{3}(i_{\mathrm{fault}}-i_{\mathrm{fault}3})+(i_{\mathrm{fault}4}-i_{\mathrm{fault}2})][(i_{\mathrm{fault}1}+i_{\mathrm{fault}3})-(i_{\mathrm{fault}4}+i_{\mathrm{fault}2})]\\ +\frac{N_s^{2}A\left(\mathrm{\&theta;}\right)}{4A\left(\mathrm{\&theta;}\right)+4B\left(\mathrm{\&theta;}\right)}[\sqrt{3}(i_{\mathrm{fault}1}-i_{\mathrm{fault}3})+(i_{\mathrm{fault}4}-i_{\mathrm{fault}2})][(i_{\mathrm{normal}1}+i_{\mathrm{normal}3})-(i_{\mathrm{normal}2}+i_{\mathrm{normal}4})]\end{array}\right\}$

$F_{\mathrm{\&beta;}}=\frac{\&PartialD;W}{\&PartialD;\mathrm{\&beta;}}=K_{f1}\left(\mathrm{\&theta;}\right)\left\{\begin{array}{c}{N_s}^2(i_{\mathrm{normal}2}+i_{\mathrm{normal}4})(i_{\mathrm{normal}2}-i_{\mathrm{normal}4})\\ +\frac{2{N_s}^{2}A\left(\mathrm{\&theta;}\right)}{4A\left(\mathrm{\&theta;}\right)+4B\left(\mathrm{\&theta;}\right)}(i_{\mathrm{normal}2}-i_{\mathrm{normal}4})[i_{\mathrm{normal}1}+i_{\mathrm{normal}3}-(i_{\mathrm{normal}2}+i_{\mathrm{normal}4})]\\ +\frac{2{N_s}^{2}B\left(\mathrm{\&theta;}\right)}{4A\left(\mathrm{\&theta;}\right)+4B\left(\mathrm{\&theta;}\right)}(i_{\mathrm{normal}2}-i_{\mathrm{normal}4})[i_{\mathrm{sb}1}+i_{\mathrm{sb}3}-(i_{\mathrm{sb}2}+i_{\mathrm{sb}4})]\end{array}\right\}$

$+K_{f2}\left(\mathrm{\&theta;}\right)\left\{\begin{array}{c}-\frac{N_s^2}{2}[(i_{\mathrm{fault}1}^2-i_{\mathrm{fault}3}^2)-\sqrt{3}(i_{\mathrm{fault}2}^2-i_{\mathrm{fault}4}^2)]\\ +\frac{N_s^{2}B\left(\mathrm{\&theta;}\right)}{4A\left(\mathrm{\&theta;}\right)+4B\left(\mathrm{\&theta;}\right)}[\sqrt{3}(i_{\mathrm{fault}2}-i_{\mathrm{fault}4})+(i_{\mathrm{fault}1}-i_{\mathrm{fault}3})][(i_{\mathrm{fault}1}+i_{\mathrm{fault}3})-(i_{\mathrm{fault}2}+i_{\mathrm{fault}4})]\\ +\frac{N_s^{2}A\left(\mathrm{\&theta;}\right)}{4A\left(\mathrm{\&theta;}\right)+4B\left(\mathrm{\&theta;}\right)}[\sqrt{3}(i_{\mathrm{fault}2}-i_{\mathrm{fault}4})+(i_{\mathrm{fault}1}-i_{\mathrm{fault}3})][(i_{\mathrm{normal}1}+i_{\mathrm{normal}3})-(i_{\mathrm{normal}2}+i_{\mathrm{normal}4})]\end{array}\right\}$

Wherein, F _α, F _βbe respectively fault phase required radial suspension force in its corresponding α, the β degree of freedom, K _f1(θ), K _f2(θ), A (θ), B (θ) be the coefficient relevant with motor size and rotor position angle, N _sfor umber of turn, i _fault1, i _fault2, i _fault3, i _fault4for each tooth utmost point winding current of the phase that breaks down, i _normal1, i _normal2, i _normal3, i _normal4for the mutually each winding current of correspondence compensation;

Step 2, in the time that winding failure compensates, fault tooth utmost point winding current and conducting phase current are not set to 0, obtain winding open fault compensation Mathematical Modeling by Mathematical Modeling described in step 1, equal another compensation principle to two radially relative tooth utmost point winding current sums of fault phase according to the compensation tooth utmost point winding current tooth utmost point winding current sum radially relative with the fault tooth utmost point and obtain:

The compensation tooth utmost point winding current tooth utmost point winding current radially relative with the fault tooth utmost point, two tooth utmost point winding currents that another group of fault phase is radially relative, simultaneously inlet coefficient k.

2. 12/8 simplex winding bearingless switched reluctance motor error-tolerant operation control method according to claim 1, is characterized in that, determines the value of inlet coefficient k according to fault phase required radial suspension force in the α degree of freedom:

As fault phase required radial suspension force F in the α degree of freedom _αbe greater than or equal to zero, the tooth utmost point winding current radially relative with the fault tooth utmost point do not reach limiting value, when the compensation tooth utmost point winding current value of reaching capacity,

$k\&GreaterEqual;\frac{i_{\max }}{\sqrt{i_{\max }^2-N_s^2{X}_{B0}^2{i}_{\max }^2{K}_{f10}}}\sqrt{D_0},$

As fault phase required radial suspension force F in the α degree of freedom _αbe greater than or equal to zero, tooth utmost point winding current reach capacity value radially relative with the fault tooth utmost point, when compensation tooth utmost point winding current does not reach limiting value,

$k\&GreaterEqual;\frac{-{2i}_{\max }{X}_{B1}\sqrt{\frac{F_{\mathrm{\&alpha;}}}{D_1}}+\sqrt{{4i}_{\max }^2{X}_B^2\frac{F_{\mathrm{\&alpha;}}}{D_1}+4(i_{\max }^2+\frac{F_{\mathrm{\&alpha;}}}{N_s^2{K}_{f11}})(\frac{F_{\mathrm{\&alpha;}}}{N_s^2{K}_{f11}}-X_B^2\frac{F_{\mathrm{\&alpha;}}}{D_1})}}{2(\frac{F_{\mathrm{\&alpha;}}}{N_s^2{K}_{f11}}-X_B^2\frac{F_{\mathrm{\&alpha;}}}{D_1})},$

As fault phase required radial suspension force F in the α degree of freedom _αbe greater than or equal to zero, the tooth utmost point winding current radially relative with the fault tooth utmost point do not reach limiting value, when compensation tooth utmost point winding current does not reach limiting value,

$k\&GreaterEqual;\sqrt{\frac{K_{f1}\left(\mathrm{\&theta;}\right)X_B^2\left(\mathrm{\&theta;}\right)}{\sqrt{3}{K}_{f2}\left(\mathrm{\&theta;}\right)X_A\left(\mathrm{\&theta;}\right)}+1},$

As fault phase required radial suspension force F in its corresponding α degree of freedom _αbe less than at 1 o'clock, k=0, wherein, K _f10, X _b0, D ₀for K _f1(θ), X _b(θ), the value of D (θ) in the time that rotor position angle is 0 °, K _f11, X _b1, D ₁for K _f1(θ), X _b(θ), the value of D (θ) in the time that rotor position angle is-15 °, i _maxfor limiting value.