CN102684577A - Fault-tolerant control method of permanent-magnet synchronous motor driving system - Google Patents

Abstract

The invention discloses a fault-tolerant control method of a permanent-magnet synchronous motor driving system. Under the normal working conditions of a phase-current sensor, the system adopts a normal current hysteresis control mode. When the phase-current sensor is detected to fail, the system enters a fault-tolerant control mode to perform out-phase check for an original switch signal obtained by the normal current hysteresis control mode, if the original switch signal and a last actual switch signal meet the out-phase principle, then the original switch signal directly serves as the actual switch signal to be outputted, and otherwise, the original switch signal is modified according to a minimum current deviation absolute value method so that the actual switch signal is obtained and outputted. The method has the advantages that a hardware structure of an existing driving system is unchanged, and the method is high in reliability, simple, feasible and the like.

Description

The fault tolerant control method of permagnetic synchronous motor drive system

Technical field

The invention belongs to motor-driven and control technology field, relate to the technology that a kind of permagnetic synchronous motor drives the fault-tolerant control of system.

Background technology

(various control methods emerge in an endless stream for Permanent magnet synchronous machine, high accuracy PMSM), high dynamic performance operation, and are wherein, typical with direct torque control and vector control two class methods in order to realize permagnetic synchronous motor.The category that belongs to vector control based on the id=0 control method (hereinafter to be referred as the control of current hysteresis ring) of current hysteresis ring in itself.Because the electric current hysteresis control method thereof does not rely on any parameter of electric machine, and simple in structure, be to use one of PMSM control method the most widely at present.Control method as most PMSM is the same, and the electric current hysteresis control method thereof needs current sensor to gather three-phase current.But in case current sensor breaks down, the PMSM drive system can't operate as normal.In order to improve the reliability of PMSM drive system, be necessary current sensor is carried out fault-tolerant control, this must be able to rely on remaining transducer to come the reconstruct three-phase current with regard to requiring.At present, the method for electric current reconstructing mainly contains two types: modulation method and modelling.As everyone knows, when frequency converter applied nonzero voltage space vector, dc bus current will reflect a certain phase current information.Because space vector modulating method (SVPWM) is adjacent two nonzero voltage space vectors to be synthesized obtain the target voltage vector in a control cycle, this just means that the dc bus current transducer can collect biphase current information in a switch periods.Modulation method mainly is exactly to utilize above-mentioned this characteristic to realize the reconstruct of three-phase current.But because the sampling of current sensor needs the regular hour, can there be certain measurement blind area in modulation method.Therefore, how eliminating and measure the blind area, keep the original state of SVPWM simultaneously as much as possible, is the research difficult point of modulation method.Prior art has adopted diverse ways to overcome the blind area.But what the electric current hysteresis control method thereof adopted is a kind of " bang-bang " control to electric current, does not adopt the SVPWM mode.Therefore, modulation method can not be used for the fault-tolerant control of the ring-like PMSM drive system of current hysteresis current sensor.And modelling is based on accurate motor mathematical model, relies on other physical quantitys (like voltage) to calculate three-phase current.The shortcoming of modelling is to rely on the more parameter of electric machine, and the robustness of control system descends.

Summary of the invention

Technical problem: the invention provides a kind of fault tolerant control method that strengthens the permagnetic synchronous motor drive system of the existing ring-like permagnetic synchronous motor drive system reliability of current hysteresis.

Technical scheme: the fault tolerant control method of permagnetic synchronous motor drive system of the present invention, in the control cycle of confirming according to the control system characteristic, carry out control flow, the control flow of each said control cycle comprises the steps:

1) the rotor-position signal θ that transmits of velocity calculator receiving position transducer _Mea, and obtain actual speed ω according to following formula _Mea:

${\mathrm{\ω}}_{\mathrm{mea}}=\frac{d{\mathrm{\θ}}_{\mathrm{mea}}}{\mathrm{dt}};$

2) the actual speed ω that sends according to velocity calculator of speed control _MeaWith the speed reference ω that sets _RefPassing ratio-integration is regulated and is obtained handing over shaft current reference value i _{Q_ref}

3) the phase current calculator is according to rotor-position signal θ _Mea, hand over shaft current reference value i _{Q_ref}With direct-axis current reference value i according to the control system property settings _{D_ref}, obtain three-phase current reference value i by following formula _{Abc_ref}, said three-phase current reference value i _{Abc_ref}Be by A phase current reference value i _{A_ref}, B phase current reference value i _{B_ref}With C phase current reference value i _{C_ref}The three-dimensional vector of forming:

4) the current hysteresis ring controller is according to the three-phase current reference value i that obtains in the said step 3) _{Abc_ref}With the phase current feedback signal i ' that stores in the last control cycle _{Abc_back}, obtain original threephase switch signal s according to following three formulas _{Abc_init}, the phase current feedback signal i ' that stores in the said last control cycle _{Abc_back}Be by the A phase current feedback signal i ' that stores in the last control cycle _{A_back}, B phase current feedback signal i ' _{B_back}With C phase current feedback signal i ' _{C_back}The three-dimensional vector of forming is for initial control cycle, i ' _{Abc_back}Value be 0, said s _{Abc_init}Be by A phase original switch signal s _{A_init}, B phase original switch signal s _{B_init}With C original switch signal s mutually _{C_init}The three-dimensional vector of forming:

$s_{a\_\mathrm{init}}=\left\{\begin{array}{c}1,i_{a\_\mathrm{ref}}-{i^{\&prime;}}_{a\_\mathrm{back}}>\mathrm{<figure-callout\; id="0"\; label="H"\; filenames="HDA00001680474000012.png,HDA00001680474000021.png"\; state="\{\{state\}\}">H</figure-callout>}\\ 0,i_{a\_\mathrm{ref}}-{i^{\&prime;}}_{a\_\mathrm{back}}<-H\end{array}\right.$

$s_{b\_\mathrm{init}}=\left\{\begin{array}{c}1,i_{b\_\mathrm{ref}}-{i^{\&prime;}}_{b\_\mathrm{back}}>\mathrm{<figure-callout\; id="0"\; label="H"\; filenames="HDA00001680474000012.png,HDA00001680474000021.png"\; state="\{\{state\}\}">H</figure-callout>}\\ 0,i_{b\_\mathrm{ref}}-{i^{\&prime;}}_{b\_\mathrm{back}}<-H\end{array}\right.$

$s_{c\_\mathrm{init}}=\left\{\begin{array}{c}1,i_{c\_\mathrm{ref}}-{i^{\&prime;}}_{c\_\mathrm{back}}>\mathrm{<figure-callout\; id="0"\; label="H"\; filenames="HDA00001680474000012.png,HDA00001680474000021.png"\; state="\{\{state\}\}">H</figure-callout>}\\ 0,i_{c\_\mathrm{ref}}-{i^{\&prime;}}_{c\_\mathrm{back}}<-H\end{array}\right.$

Wherein, H is the ring width of current hysteresis ring controller;

5) the dc bus current sampled value i that sends of fault-tolerant controller received current transducer _{Dc_mea}, A phase current sampling value i _{A_mea}With B phase current sampling value i _{B_mea}, receive the original threephase switch signal s that obtains in the said step 4) simultaneously _{Abc_init}

6) fault-tolerant controller judges according to failure criterion whether system the phase current sensor fault takes place, if break down, then abandons A phase current sampling value i _{A_mea}With B phase current sampling value i _{B_mea}, obtain phase current feedback signal i in reconstruct _{Abc_back}And with its storage back entering step 7), otherwise accept and believe A phase current sampling value i _{A_mea}With B phase current sampling value i _{B_mea}And with three-phase current sampled value i _{Abc_mea}Directly as phase current feedback signal i _{Abc_back}The storage back gets into step 8),

Wherein, i _{Abc_mea}Be by A phase current sampling value i _{A_mea}, B phase current sampling value i _{B_mea}With C phase current sampling value i _{C_mea}The three-dimensional vector of forming, i _{A_mea}And i _{B_mea}Directly measure i by corresponding phase current transducer _{C_mea}=-i _{A_mea}-i _{B_mea}

7) fault-tolerant controller is checked original threephase switch signal s _{Abc_init}Actual threephase switch signal s ' with a last control cycle _{Abc_actual}Whether meet not homophase principle, as meet, then with original threephase switch signal s _{Abc_init}Directly as actual threephase switch signal s _{Abc_actual}Output back gets into step 9), as does not meet, then according to minimum current absolute value of the bias method to original threephase switch signal s _{Abc_init}Make amendment and obtain actual threephase switch signal s _{Abc_actual}And output back entering step 9),

Wherein, the actual threephase switch signal s ' of a last control cycle _{Abc_actual}Be A phase actual switch signal s ' by a last control cycle _{A_actual}, B phase actual switch signal s ' _{B_actual}With C actual switch signal s ' mutually _{C_actual}The three-dimensional vector of forming is for initial control cycle, s ' _{Abc_actual}Value be 0, actual threephase switch signal s _{Abc_actual}Be by A phase actual switch signal s _{A_actual}, B phase actual switch signal s _{B_actual}With C actual switch signal s mutually _{C_actual}The three-dimensional vector of forming, described according to minimum current absolute value of the bias method to original threephase switch signal s _{Abc_init}The concrete steps of making amendment are:

71) obtain the three-phase current absolute value of the bias according to computes | Δ i _a|, | Δ i _b| with | Δ i _c|: | Δ i _a|=| i _{A_ref}-i' _{A_back}|, | Δ i _b|=| i _{B_ref}-i' _{B_back}|, | Δ i _c|=| i _{C_ref}-i' _{C_back}|;

The size of the three-phase current absolute value of the bias that obtains 72) more said step 71) is made amendment to the original switch signal of that minimum phase of phase current absolute value of the bias;

73) if said step 72) in revise the new threephase switch signal and the satisfied not homophase principle of the actual threephase switch signal of a last control cycle obtain, the new threephase switch signal that then modification is obtained is as actual threephase switch signal s _{Abc_actual}, otherwise the original threephase switch signal s to obtaining in the step 4) _{Abc_init}In the original switch signal of little that phase of phase current absolute value of the bias second make amendment, and the new threephase switch signal that modification is obtained is as actual threephase switch signal s _{Abc_actual}

8) with original threephase switch signal s _{Abc_init}Directly as actual threephase switch signal s _{Abc_actual}The output back gets into step 9);

9) finish the control flow of this control cycle, wait for next control cycle.

Among the present invention, the not homophase principle in the step 7) is meant: if the corresponding different respectively N of value mutually of two threephase switch signals that compare then satisfies not homophase principle, otherwise for not satisfying different phase principles, wherein, threephase switch signal s _AbcThe corresponding relation that is worth N mutually is following:

Wherein, be worth the possible value of N 1,2,3 mutually and represent A phase, B phase, C phase respectively, threephase switch signal s _AbcBe by A phase switching signal s _a, B phase switching signal s _bWith C phase switching signal s _cThe three-dimensional vector of forming.

Preferably, the reconstruct of step 6) obtains phase current feedback signal i _{Abc_back}Method following:

61) by dc bus current sampled value i _{Dc_mea}Actual threephase switch signal s ' with a last control cycle _{Abc_actual}Obtain the wherein phase current feedback signal of a phase through following formula,

62) will go up the step 61 of a control cycle) in the phase current feedback signal that obtains as the phase current feedback signal of second phase of this control cycle;

63) according to said step 61) with 62) obtain two mutually the phase current feedback calculated signals obtain the phase current feedback signal of third phase, thereby obtain phase current feedback signal i _{Abc_back}

Beneficial effect: the present invention compares with prior art, has following advantage:

1. compare with normal electric current hysteresis control method thereof; This method does not increase any hardware cost; Only, make drive system after any type phase current sensor fault takes place, can both keep the superior performance operation through revising the reliability that Control Software just can significantly strengthen existing drive system.Shown in accompanying drawing 3,4 and 5; After the phase current sensor fault takes place in t=3.90s constantly; Drive system in time gets into fault-tolerant control mode, and friendship shaft current and the phase current shown in accompanying drawing 5 shown in accompanying drawing 4 just have a small amount of increase, and the rotating speed shown in accompanying drawing 3 is unaffected basically.In addition, the phase current registration of phase current that the reconstruct shown in the accompanying drawing 5 obtains and actual measurement is very high, and this explains that also this method can provide comparatively accurate phase current signal under phase current sensor fault condition.

2. compare with existing fault tolerant control method based on modelling; This method does not come reconstruct to obtain the three-phase current feedback signal according to high-precision magneto model; And only be according to minimum current absolute value of the bias method the threephase switch signal that normal electric current hysteresis control method thereof generates to be done minor modifications; Obtain meeting the not new threephase switch signal of homophase principle thus, and the dc bus current signal that records with current sensor together reconstruct obtain high-precision three-phase current feedback signal.Because this method does not adopt high-precision magneto model, has just avoided introducing any magneto parameter yet, thereby has made the robustness of drive system under fault-tolerant control mode promote greatly.

Description of drawings

Fig. 1 is the system block diagram of the inventive method embodiment;

Fig. 2 is the FB(flow block) of the inventive method;

Fig. 3 is fault-tolerant process rotating speed experimental waveform;

Fig. 4 is that fault-tolerant process is handed over the shaft current experimental waveform;

Fig. 5 is fault-tolerant process A phase current experimental waveform.

Embodiment

The present invention will be described below with reference to accompanying drawings.

The system block diagram of embodiments of the invention is as shown in Figure 1, comprising: rectification circuit, filter circuit, control system, permagnetic synchronous motor, position transducer.Wherein, the parameter of permagnetic synchronous motor is: specified phase voltage U _N=220V, number of pole-pairs p _n=2, stator resistance R _s=0.665 Ω, the d-axis inductance L _d=7.623mH hands over the axle inductance L _q=7.623mH, permanent magnetism magnetic linkage ψ _f=0.783Wb, rated speed n _N=1500r/min; Confirm the Control Parameter used in the control flow according to the control system characteristic, in the present embodiment, get control cycle T _s=50 μ s, proportionality coefficient K _p=0.1, integral coefficient K _i=1, direct-axis current reference value i _{D_ref}=0, speed reference ω _Ref=1000r/min, current controller ring width H=0.Wherein, direct-axis current reference value i _{D_ref}=0 is a kind of preferable control mode of permagnetic synchronous motor in the embodiment of the invention, and the present invention is equally applicable to direct-axis current reference value i _{D_ref}≠ 0 permagnetic synchronous motor drive system; Current controller ring width H=0 is a kind of preferable setting means of ring width during the current hysteresis ring is controlled in the embodiment of the invention, and the present invention is equally applicable to the permagnetic synchronous motor drive system of ring width H ≠ 0.

The fault tolerant control method of permagnetic synchronous motor drive system of the present invention, under the phase current normal operation of sensor condition, system adopts normal current hysteresis ring control mode; When detecting the phase current transducer and break down, system gets into fault-tolerant control mode, and the original threephase switch signal s that normal electric current hysteresis control method thereof is obtained _{Abc_init}Monitor; If original threephase switch signal s _{Abc_init}Actual threephase switch signal s ' with a last control cycle _{Abc_actual}Satisfy not homophase principle, then directly with original threephase switch signal s _{Abc_init}As actual threephase switch signal s _{Abc_actual}Output, otherwise according to minimum current absolute value of the bias method to original threephase switch signal s _{Abc_init}Make amendment and amended threephase switch signal as actual threephase switch signal s _{Abc_actual}Output.Logical procedure diagram of the present invention is seen Fig. 2; Specifically; This method is carried out control flow in the control cycle of confirming according to the control system characteristic; When a control cycle finishes, get into next control cycle and proceed next control flow, the control flow of each said control cycle comprises following concrete steps:

1) the rotor-position signal θ that transmits of velocity calculator receiving position transducer _Mea, and obtain actual speed ω according to following formula _Mea:

${\mathrm{\&omega;}}_{\mathrm{mea}}=\frac{d{\mathrm{\&theta;}}_{\mathrm{mea}}}{\mathrm{dt}};$

Following formula is to obtain actual speed ω _MeaTheoretical formula, can't be in the real figure control system strict the realization, therefore, in the practical application generally through following formula being the actual speed ω that approximate conversion obtains being similar to _Mea, present embodiment adopts the approximate actual speed ω that obtains of following a kind of method _MeaBut the present invention is not limited only to this method:

${\mathrm{\&omega;}}_{\mathrm{mea}}\left(k\right)=\frac{{\mathrm{\&theta;}}_{\mathrm{mea}}\left(k\right)-{{\mathrm{\&theta;}}^{\&prime;}}_{\mathrm{mea}}}{20T_s};$

Wherein, θ ' _MeaThe rotor-position signal that transmits for the position transducer of calculating the 20th control cycle forward is for initial control cycle, θ ' _MeaValue is 0, and subscript m ea representes the implication that directly or indirectly measures;

2) the actual speed ω that sends according to velocity calculator of speed control _MeaWith the speed reference ω that sets _RefPassing ratio-integration is regulated and is obtained handing over shaft current reference value i _{Q_ref}, subscript ref representes the implication of reference value, ratio-integration adjustment process is following:

21) obtain integral Sum according to following formula

Sum＝K _i[ω _ref-ω _mea]+Sum'

Wherein, K _iBe integral coefficient, Sum' is the integral that a last control cycle obtains, and Sum ' initial value is 0;

22) obtain handing over shaft current reference value i according to following formula _{A_ref}

i _{q_ref}=K _p[ω _ref-ω _mea]+Sum

Wherein, K _pBe proportionality coefficient;

3) the phase current calculator is according to rotor-position signal θ _Mea, hand over shaft current reference value i _{Q_ref}With direct-axis current reference value i according to the control system property settings _{D_ref}, obtain three-phase current reference value i by following formula _{Abc_ref}, said three-phase current reference value i _{Abc_ref}Be by A phase current reference value i _{A_ref}, B phase current reference value i _{B_ref}With C phase current reference value i _{C_ref}The three-dimensional vector of forming:

4) the current hysteresis ring controller is according to the three-phase current reference value i that obtains in the said step 3) _{Abc_ref}With the phase current feedback signal i ' that stores in the last control cycle _{Abc_back}, subscript back representes the implication fed back to obtain original threephase switch signal s according to following three formulas _{Abc_init}, subscript init representes original implication, the phase current feedback signal i' that stores in the said last control cycle _{Abc_back}Be by the A phase current feedback signal i ' that stores in the last control cycle _{A_back}, B phase current feedback signal i ' _{B_back}With C phase current feedback signal i ' _{C_back}The three-dimensional vector of forming is for initial control cycle, i' _{Abc_back}Value be 0, said s _{Abc_init}Be by A phase original switch signal s _{A_init}, B phase original switch signal s _{B_init}With C original switch signal s mutually _{C_init}The three-dimensional vector of forming:

$s_{a\_\mathrm{init}}=\left\{\begin{array}{c}1,i_{a\_\mathrm{ref}}-{i^{\&prime;}}_{a\_\mathrm{back}}>\mathrm{<figure-callout\; id="0"\; label="H"\; filenames="HDA00001680474000012.png,HDA00001680474000021.png"\; state="\{\{state\}\}">H</figure-callout>}\\ 0,i_{a\_\mathrm{ref}}-{i^{\&prime;}}_{a\_\mathrm{back}}<-H\end{array}\right.$

$s_{b\_\mathrm{init}}=\left\{\begin{array}{c}1,i_{b\_\mathrm{ref}}-{i^{\&prime;}}_{b\_\mathrm{back}}>\mathrm{<figure-callout\; id="0"\; label="H"\; filenames="HDA00001680474000012.png,HDA00001680474000021.png"\; state="\{\{state\}\}">H</figure-callout>}\\ 0,i_{b\_\mathrm{ref}}-{i^{\&prime;}}_{b\_\mathrm{back}}<-H\end{array}\right.$

$s_{c\_\mathrm{init}}=\left\{\begin{array}{c}1,i_{c\_\mathrm{ref}}-{i^{\&prime;}}_{c\_\mathrm{back}}>\mathrm{<figure-callout\; id="0"\; label="H"\; filenames="HDA00001680474000012.png,HDA00001680474000021.png"\; state="\{\{state\}\}">H</figure-callout>}\\ 0,i_{c\_\mathrm{ref}}-{i^{\&prime;}}_{c\_\mathrm{back}}<-H\end{array}\right.$

Wherein, H is the ring width according to the current hysteresis ring controller of control system property settings;

5) the dc bus current sampled value i that sends of fault-tolerant controller received current transducer _{Dc_mea}, A phase current sampling value i _{A_mea}With B phase current sampling value i _{B_mea}, receive the original threephase switch signal s that obtains in the said step 4) simultaneously _{Abc_init}

6) fault-tolerant controller judges according to failure criterion whether system the phase current sensor fault takes place; Promptly when system satisfies any one in the following condition; Think the phase current sensor fault takes place; But following failure criterion is a kind of preferable implementation of present embodiment, the invention is not restricted to this failure criterion:

Condition 1:A phase current sampling value i _{A_mea}Perhaps B phase current sampling value i _{B_mea}Differ above 2A with last control cycle sampled value separately;

Condition 2: as original threephase switch signal s _{Abc_init}Be 100 or 011 o'clock, dc bus current sampled value i _{Dc_mea}Absolute value and A phase current sampling value i _{A_mea}Absolute value differ above 2A;

Condition 3: as original threephase switch signal s _{Abc_init}Be 101 or 010 o'clock, dc bus current sampled value i _{Dc_mea}Absolute value and B phase current sampling value i _{B_mea}Absolute value differ above 2A;

If the phase current sensor fault takes place, then abandons A phase current sampling value i _{A_mea}With B phase current sampling value i _{B_mea}, obtain phase current feedback signal i in reconstruct _{Abc_back}And with its storage back entering step 7), otherwise accept and believe A phase current sampling value i _{A_mea}With B phase current sampling value i _{B_mea}And with three-phase current sampled value i _{Abc_mea}Directly as phase current feedback signal i _{Abc_back}The storage back gets into step 8), and reconstruct obtains phase current feedback signal i _{Abc_back}Method following:

61) by dc bus current sampled value i _{Dc_mea}Actual threephase switch signal s ' with a last control cycle _{Abc_actual}Obtain the wherein phase current feedback signal of a phase through following formula,

62) will go up the step 61 of a control cycle) in the phase current feedback signal that obtains as the phase current feedback signal of second phase of this control cycle;

63) according to said step 61) with 62) obtain two mutually the phase current feedback calculated signals obtain the phase current feedback signal of third phase, thereby obtain phase current feedback signal i _{Abc_back}

Wherein, i _{Abc_mea}Be by A phase current sampling value i _{A_mea}, B phase current sampling value i _{B_mea}With C phase current sampling value i _{C_mea}The three-dimensional vector of forming, i _{A_mea}And i _{B_mea}Directly measure i by corresponding phase current transducer _{C_mea}=-i _{A_mea}-i _{B_mea}

7) fault-tolerant controller is checked original threephase switch signal s _{Abc_init}Actual threephase switch signal s ' with a last control cycle _{Abc_actual}Whether meet not homophase principle, the homophase principle is not meant: if the corresponding different respectively N of value mutually of two threephase switch signals that compare then satisfies not homophase principle, otherwise for not satisfying different phase principles, wherein, threephase switch signal s _AbcThe corresponding relation that is worth N mutually is following:

Wherein, be worth the possible value of N 1,2,3 mutually and represent A phase, B phase, C phase respectively, threephase switch signal s _AbcBe by A phase switching signal s _a, B phase switching signal s _bWith C phase switching signal s _cThe three-dimensional vector of forming;

Like original threephase switch signal s _{Abc_init}Actual threephase switch signal s ' with a last control cycle _{Abc_actual}Meet not homophase principle, then with original threephase switch signal s _{Abc_init}Directly as actual threephase switch signal s _{Abc_actual}Output back gets into step 9), as does not meet, then according to minimum current absolute value of the bias method to original threephase switch signal s _{Abc_init}Make amendment and obtain actual threephase switch signal s _{Abc_actual}And output back entering step 9),

Wherein, the actual threephase switch signal s ' of a last control cycle _{Abc_actual}Be A phase actual switch signal s ' by a last control cycle _{A_actual}, B phase actual switch signal s ' _{B_actual}With C actual switch signal s ' mutually _{C_actual}The three-dimensional vector of forming is for initial control cycle, s ' _{Abc_actual}Value be 0, actual threephase switch signal s _{Abc_actual}Be by A phase actual switch signal s _{A_actual}, B phase actual switch signal s _{B_actual}With C actual switch signal s mutually _{C_actual}The three-dimensional vector of forming, wherein, according to minimum current absolute value of the bias method to original threephase switch signal s _{Abc_init}The concrete steps of making amendment are:

71) obtain the three-phase current absolute value of the bias according to computes | Δ i _a|, | Δ i _b| with | Δ i _c|: | Δ i _a|=| i _{A_ref}-i' _{A_back}|, | Δ i _b|=| i _{B_ref}-i' _{B_back}|, | Δ i _c|=| i _{C_ref}-i' _{C_back}|;

The size of the three-phase current absolute value of the bias that obtains 72) more said step 71) is made amendment to the original switch signal of that minimum phase of phase current absolute value of the bias;

73) if said step 72) in revise the new threephase switch signal and the satisfied not homophase principle of the actual threephase switch signal of a last control cycle obtain, the new threephase switch signal that then modification is obtained is as actual threephase switch signal s _{Abc_actual}, otherwise the original threephase switch signal s to obtaining in the step 4) _{Abc_init}In the original switch signal of little that phase of phase current absolute value of the bias second make amendment, and the new threephase switch signal that modification is obtained is as actual threephase switch signal s _{Abc_actual}

8) with original threephase switch signal s _{Abc_init}Directly as actual threephase switch signal s _{Abc_actual}The output back gets into step 9);

9) finish the control flow of this control cycle, wait for next control cycle.

The above is merely preferred embodiments of the present invention; Protection scope of the present invention is not exceeded with above-mentioned execution mode; As long as the equivalence that those of ordinary skills do according to disclosed content is modified or changed, all should include in the protection range of putting down in writing in claims.

Claims (3)

1. the fault tolerant control method of a permagnetic synchronous motor drive system is characterized in that, this method is carried out control flow in the control cycle of confirming according to the control system characteristic, and the control flow of each said control cycle comprises the steps:

1) the rotor-position signal θ that transmits of velocity calculator receiving position transducer _Mea, and obtain actual speed ω according to following formula _Mea:

${\mathrm{\&omega;}}_{\mathrm{mea}}=\frac{d{\mathrm{\&theta;}}_{\mathrm{mea}}}{\mathrm{dt}};$

2) the actual speed ω that sends according to velocity calculator of speed control _MeaWith the speed reference ω that sets _RefPassing ratio-integration is regulated and is obtained handing over shaft current reference value i _{Q_ref}

3) the phase current calculator is according to rotor-position signal θ _Mea, hand over shaft current reference value i _{Q_ref}With direct-axis current reference value i according to the control system property settings _{D_ref}, obtain three-phase current reference value i by following formula _{Abc_ref}, said three-phase current reference value i _{Abc_ref}Be by A phase current reference value i _{A_ref}, B phase current reference value i _{B_ref}With C phase current reference value i _{C_ref}The three-dimensional vector of forming:

4) the current hysteresis ring controller is according to the three-phase current reference value i that obtains in the said step 3) _{Abc_ref}With the phase current feedback signal i ' that stores in the last control cycle _{Abc_back}, obtain original threephase switch signal s according to following three formulas _{Abc_init}, the phase current feedback signal i ' that stores in the said last control cycle _{Abc_back}Be by the A phase current feedback signal i ' that stores in the last control cycle _{A_back}, B phase current feedback signal i ' _{B_back}With C phase current feedback signal i ' _{C_back}The three-dimensional vector of forming is for initial control cycle, i ' _{Abc_back}Value be 0, said s _{Abc_init}Be by A phase original switch signal s _{A_init}, B phase original switch signal s _{B_init}With C original switch signal s mutually _{C_init}The three-dimensional vector of forming:

$s_{a\_\mathrm{init}}=\left\{\begin{array}{c}1,i_{a\_\mathrm{ref}}-{i^{\&prime;}}_{a\_\mathrm{back}}>H\\ 0,i_{a\_\mathrm{ref}}-{i^{\&prime;}}_{a\_\mathrm{back}}<-H\end{array}\right.,$

$s_{b\_\mathrm{init}}=\left\{\begin{array}{c}1,i_{b\_\mathrm{ref}}-{i^{\&prime;}}_{b\_\mathrm{back}}>H\\ 0,i_{b\_\mathrm{ref}}-{i^{\&prime;}}_{b\_\mathrm{back}}<-H\end{array}\right.,$

$s_{c\_\mathrm{init}}=\left\{\begin{array}{c}1,i_{c\_\mathrm{ref}}-{i^{\&prime;}}_{c\_\mathrm{back}}>H\\ 0,i_{c\_\mathrm{ref}}-{i^{\&prime;}}_{c\_\mathrm{back}}<-H\end{array}\right.$

Wherein, H is the ring width of current hysteresis ring controller;

5) the dc bus current sampled value i that sends of fault-tolerant controller received current transducer _{Dc_mea}, A phase current sampling value i _{A_mea}With B phase current sampling value i _{B_mea}, receive the original threephase switch signal s that obtains in the said step 4) simultaneously _{Abc_init}

6) fault-tolerant controller judges according to failure criterion whether system the phase current sensor fault takes place, if break down, then abandons A phase current sampling value i _{A_mea}With B phase current sampling value i _{B_mea}, obtain phase current feedback signal i in reconstruct _{Abc_back}And with its storage back entering step 7), otherwise accept and believe A phase current sampling value i _{A_mea}With B phase current sampling value i _{B_mea}And with three-phase current sampled value i _{Abc_mea}Directly as phase current feedback signal i _{Abc_back}The storage back gets into step 8),

Wherein, i _{Abc_mea}Be by A phase current sampling value i _{A_mea}, B phase current sampling value i _{B_mea}With C phase current sampling value i _{C_mea}The three-dimensional vector of forming, i _{A_mea}And i _{B_mea}Directly measure i by corresponding phase current transducer _{C_mea}=-i _{A_mea}-i _{B_mea}

7) fault-tolerant controller is checked original threephase switch signal s _{Abc_init}Actual threephase switch signal s ' with a last control cycle _{Abc_actual}Whether meet not homophase principle, as meet, then with original threephase switch signal s _{Abc_init}Directly as actual threephase switch signal s _{Abc_actual}Output back gets into step 9), as does not meet, then according to minimum current absolute value of the bias method to original threephase switch signal s _{Abc_init}Make amendment and obtain actual threephase switch signal s _{Abc_actual}And output back entering step 9),

Wherein, the actual threephase switch signal s ' of a last control cycle _{Abc_actual}Be A phase actual switch signal s ' by a last control cycle _{A_actual}, B phase actual switch signal s ' _{B_actual}With C actual switch signal s ' mutually _{C_actual}The three-dimensional vector of forming is for initial control cycle, s ' _{Abc_actual}Value be 0, actual threephase switch signal s _{Abc_actual}Be by A phase actual switch signal s _{A_actual}, B phase actual switch signal s _{B_actual}With C actual switch signal s mutually _{C_actual}The three-dimensional vector of forming, described according to minimum current absolute value of the bias method to original threephase switch signal s _{Abc_init}The concrete steps of making amendment are:

71) obtain the three-phase current absolute value of the bias according to computes | Δ i _a|, | Δ i _b| with | Δ i _c|:

|Δi _a|＝|i _{a_ref}-i′ _{a_back}|，|Δi _b|＝|i _{b_ref}-i′ _{b_back}|，|Δi _c|＝|i _{c_ref}-i′ _{c_back}|；

The size of the three-phase current absolute value of the bias that obtains 72) more said step 71) is made amendment to the original switch signal of that minimum phase of phase current absolute value of the bias;

73) if said step 72) in revise the new threephase switch signal and the satisfied not homophase principle of the actual threephase switch signal of a last control cycle obtain, the new threephase switch signal that then modification is obtained is as actual threephase switch signal s _{Abc_actual}, otherwise the original threephase switch signal s to obtaining in the step 4) _{Abc_init}In the original switch signal of little that phase of phase current absolute value of the bias second make amendment, and the new threephase switch signal that modification is obtained is as actual threephase switch signal s _{Abc_actual}

8) with original threephase switch signal s _{Abc_init}Directly as actual threephase switch signal s _{Abc_actual}The output back gets into step 9);

9) finish the control flow of this control cycle, wait for next control cycle.

2. the fault tolerant control method of permagnetic synchronous motor drive system according to claim 1; It is characterized in that: the not homophase principle in the said step 7) is meant: if the corresponding different respectively N of value mutually of two threephase switch signals that compare; Then satisfy not homophase principle; Otherwise for not satisfying different phase principles, wherein, threephase switch signal s _AbcThe corresponding relation that is worth N mutually is following:

Wherein, be worth the possible value of N 1,2,3 mutually and represent A phase, B phase, C phase respectively, threephase switch signal s _AbcBe by A phase switching signal s _a, B phase switching signal s _bWith C phase switching signal s _cThe three-dimensional vector of forming.

3. the fault tolerant control method of permagnetic synchronous motor drive system according to claim 1 is characterized in that, the described reconstruct of step 6) obtains phase current feedback signal i _{Abc_back}Method following:

61) by dc bus current sampled value i _{Dc_mea}Actual threephase switch signal s ' with a last control cycle _{Abc_actual}Obtain the wherein phase current feedback signal of a phase through following formula,

62) will go up the step 61 of a control cycle) in the phase current feedback signal that obtains as the phase current feedback signal of second phase of this control cycle;

63) according to said step 61) with 62) obtain two mutually the phase current feedback calculated signals obtain the phase current feedback signal of third phase, thereby obtain phase current feedback signal i _{Abc_back}

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