CN108173462A - A kind of two motor torque balance control methods - Google Patents

Abstract

The invention discloses a kind of two motor torque balance control methods.This method does not need to feedforward link, and it is fast and the advantages of almost without overshoot to inherit Direct Torque Control response torque speed, so improving torque unbalance response speed, and avoids the adjusting work of feed-forward coefficients, control framework is enormously simplified, improves the simplicity of its application.This method, which distributes more motor torques, to be incorporated in Direct Torque Control algorithm, so that torque balance control is carried out applied to two motors after being improved applied to the Direct Torque Control of single motor, so as to solve, response speed present in conventional method is slow and coefficient adjusts the problems such as cumbersome, promote motor torque unbalance response speed, abbreviation control structure, convenient for application.

Description

A kind of two motor torque balance control methods

Technical field

The invention belongs to motor field, specifically a kind of two motor torques balance control method.

Background technology

With the continuous development of China's modern industry and the continuous improvement of mechanical automation technology, often there is motor control The one equipment running of driving jointly of system requirements multiple electric motors.In entire production process, it should be ensured that these motors can cooperate with Operation.

In order to ensure that more motors can realize Synchronization Control, two ways can be passed through：Mechanical system and electric mode.Same Control technology is walked using initial stage, the extensive use in industrial automation production of mechanical synchronization control technology.Because of Mechanical course side The motor of formula is very reliable with being sequentially connected, and this connection mode is widely applied, but its shortcoming is increasingly using initial stage Significantly, the working condition of such as each motor influences each other, and there are serious couplings each other, more by chain, gear, axis etc. Contain accumulated error after grade link mechanism, use scope is also restrained, and certain occasions have been unable to meet the needs of modern scientist.

Power mode is adopted to control multi- drive synchronization be a kind of effective solution, people have been made this respect greatly Quantifier elimination.Wherein more motor torque balances are most important and most basic research in more motor balances.Traditional two motors turn Square balance control principle drawing is as shown in Figure 1, it can be seen that it is to realize two motors with the cooperation of PI links using the link that feedovers Torque balance.This just causes two problems：

1st, since conventional method is to coordinate to achieve the effect that torque balance using feedover link and PI links, so PI rings The delay effect of section also results in torque uneven, and then system needs a period of time adjusting to can be only achieved new balance, that is, passes System method response speed is slower；

2nd, since the size of feedforward parameter Ks that feedforward link uses needs repeatedly to attempt just to can determine that so that this method Application become complicated, and inappropriate Ks parameters can cause system unstable.

Invention content

In view of the deficiencies of the prior art, the technical issues of present invention intends to solve is to provide a kind of two motor torques balance control Method processed.This method does not need to feedforward link, and inherits Direct Torque Control response torque speed soon and almost without super The advantages of tune amount, so improving torque unbalance response speed, and avoids the adjusting work of feed-forward coefficients, greatly simplifies Control framework improves the simplicity of its application.

The technical solution that the present invention solves the technical problem is to provide a kind of two motor torque balance control methods, It is characterized in that this method includes the following steps：

(1) encoder in motor obtains two angle of rotor of motor θ_r1And θ_r2, rotational speed omega_r1And ω_r2, setting speed reference Value ω_r ^ref, using the torque reference value T of proportional-plus-integral controller (PI controllers) two motors of acquisition₁ ^*And T₂ ^*；

(2) the torque reference value of two motors is distributed equally, obtains (T₁ ^*+T₂ ^*)/2；

(3) Hall sensor obtains two motor stator voltage U_dc1And U_dc2, stator current i_s ^k ₁And i_s ^k ₂In this controlling cycle Interior sampled value calculates two motor current time stator magnetic linkage Ψ using flux observer and torque observer_s ^k ₁And Ψ_s ^k ₂、 Rotor flux Ψ_r ^k ₁And Ψ_r ^k ₂, torque T_e ^k ₁And T_e ^k ₂；

(3.1) flux observer calculates the stator magnetic linkage Ψ for obtaining current time_s ^k ₁And Ψ_sk₂, rotor flux Ψ_r ^k ₁With Ψ_r ^k ₂, and pass through stator magnetic linkage Ψ_s ^k ₁And Ψ_s ^k ₂To determine that two stator flux of motor currently distinguish the section at place：

ψ_r ^k ₁=ψ₁·θ_r1 (1)

ψ_s ^k ₁=L_s1i_s ^k ₁+ψ_r ^k ₁ (2)

ψ_r ^k ₂=ψ₂·θ_r2

(3)ψ_s ^k ₂=L_s2i_s ^k ₂+ψ_r ^k ₂(4)

In formula, Ψ₁With Ψ₂It is the rotor flux amplitude of two motors respectively, is the definite value that every motor has；L_s1With L_s2It is stator inductance respectively；

(3.2) torque observer calculates the torque T for obtaining current time_e ^k ₁And T_ek₂

In formula, p₁With p₂It is the number of pole-pairs of two motors respectively；

(4) for bi-motor in the torque at current time and the difference and the magnetic linkage at current time of expectation torque and expectation The difference of magnetic linkage selects respective optimal voltage vector；

(4.1) torque difference Δ T of two motors at current time is calculated_e1With Δ T_e2；

ΔT_e1=(T₁ ^*+T₂ ^*)/2-T_e ^k ₁ (7)

ΔT_e2=(T₁ ^*+T₂ ^*)/2-T_e ^k ₂ (8)

(4.2) magnetic linkage amplitude difference DELTA of two motors at current time is calculated | Ψ_s1| and Δ | Ψ_{s 2}|；

Δ|Ψ_s1|=| Ψ_s1 ^*|-|Ψ_s ^k ₁| (9)

Δ|Ψ_s2|=| Ψ_s2 ^*|-|Ψ_s ^k ₂| (10)

In formula, | Ψ_s1 ^*| and | Ψ₂ ^*| it is the expectation stator magnetic linkage amplitude output of two motors respectively；

(4.3) " Direct Torque Control vector selects table " is used to determine two respective optimal voltage vectors of motor, specifically It is the torque difference Δ T by section residing for stator flux of motor (I, II, III, IV, V, VI) and motor at current time_e With motor current time magnetic linkage amplitude difference DELTA | Ψ_s| determine optimal voltage vector；

(5) two optimal voltage vectors determined respectively using current period in next controlling cycle.

Compared with prior art, advantageous effect of the present invention is：This method, which distributes more motor torques, incorporates Direct Torque In control algolithm, so as to be turned after being improved applied to the Direct Torque Control of single motor applied to two motors Square balance control, adjusts the problems such as cumbersome slowly with coefficient so as to solve response speed present in conventional method, promotes motor Torque unbalance response speed, abbreviation control structure, convenient for application.

(1) faster dynamic responding speed：

This advantage is from two aspects：A. since the application proposes that algorithm avoids the feedforward link in traditional algorithm, So equilibrium state can be reached faster, so as to obtain better dynamic responding speed；B. the application algorithm due to the use of Direct Torque Control carries out torque tracking, so the response torque speed for inheriting Direct Torque Control is fast and almost without overshoot The advantages of amount, it is hereby achieved that faster response speed；

(2) control framework that is simpler and facilitating application：

This advantage derives from：Feedforward link in traditional algorithm includes feed-forward coefficients, needs to carry out for different operating modes It adjusts, generally requires just determine a proper value after repeatedly attempting, to answering for two motor torque balanced algorithms With increasing complexity；And the application proposes that algorithm avoids feedforward link, also just without the adjusting work of feed-forward coefficients, greatly Control framework is simplified greatly, improves the simplicity of its application.

Description of the drawings

Fig. 1 is that traditional two motor torques balance control principle drawing；

Fig. 2 is the control principle drawing of two motor torque balance control methods of the invention；

Specific embodiment

Specific embodiments of the present invention are given below.Specific embodiment is only used for that the present invention is further described, unlimited The application scope of the claims processed.

The present invention provides a kind of two motor torque balance control methods (referring to Fig. 2, abbreviation method), it is characterised in that should Method includes the following steps：

(1) encoder in motor obtains two angle of rotor of motor θ_r1And θ_r2, rotational speed omega_r1And ω_r2, setting speed reference Value ω_r ^ref, using the torque reference value T of proportional-plus-integral controller (PI controllers) two motors of acquisition₁ ^*And T₂ ^*；

(2) the torque reference value of two motors is distributed equally, obtains (T₁ ^*+T₂ ^*)/2；

(3) Hall sensor obtains two motor stator voltage U_dc1And U_dc2, stator current i_s ^k ₁And i_s ^k ₂In this controlling cycle Interior sampled value calculates two motor current time stator magnetic linkage Ψ using flux observer and torque observer_sk1 and Ψ_s ^k ₂、 Rotor flux Ψ_r ^k ₁And Ψ_r ^k ₂, torque T_e ^k ₁And T_e ^k ₂；

(3.1) flux observer calculates the stator magnetic linkage Ψ for obtaining current time_s ^k ₁And Ψ_s ^k ₂, rotor flux Ψ_r ^k ₁With Ψ_r ^k ₂, and pass through stator magnetic linkage Ψ_s ^k ₁And Ψ_s ^k ₂To determine that two stator flux of motor currently distinguish the section at place：

ψ_r ^k ₁=ψ₁·θ_r1 (1)

ψ_s ^k ₁Two L_s1i_s ^k ₁+ψ_r ^k ₁ (2)

ψ_r ^k ₂=ψ₂·θ_r2

(3)

ψ_s ^k ₂=L_s2i_s ^k ₂+ψ_r ^k ₂(4)

In formula, Ψ₁With Ψ₂It is the rotor flux amplitude of two motors respectively, is the definite value that every motor has；L_s1With L_s2It is stator inductance respectively；

(3.2) torque observer calculates the torque T for obtaining current time_e ^k ₁And T_ek₂

In formula, p₁With p₂It is the number of pole-pairs of two motors respectively；

(4) for bi-motor in the torque at current time and the difference and the magnetic linkage at current time of expectation torque and expectation The difference of magnetic linkage selects respective optimal voltage vector；

(4.1) torque difference Δ T of two motors at current time is calculated_e1With Δ T_e2；

ΔT_e1=(T₁ ^*+T₂ ^*)/2-T_e ^k ₁ (7)

ΔT_e2=(T₁ ^*+T₂ ^*)/2-T_e ^k ₂ (8)

(4.2) magnetic linkage amplitude difference DELTA of two motors at current time is calculated | Ψ_s1| and Δ | Ψ_s2|；

Δ|Ψ_s1|=| Ψ_s1 ^*|-|Ψ_s ^k ₁| (9)

Δ|Ψ_s2|=| Ψ_s2 ^*|-|Ψ_s ^k ₂| (10)

In formula, | Ψ_s1 ^*| and | Ψ₂ ^*| it is the expectation stator magnetic linkage amplitude output of two motors respectively；

(4.3) " Direct Torque Control vector selection table (table 1) " is used to determine two respective optimal voltage vectors of motor, Particular by section residing for stator flux of motor (I, II, III, IV, V, VI) and motor current time torque difference ΔT_eWith motor current time magnetic linkage amplitude difference DELTA | Ψ_s| determine optimal voltage vector；V in table₀₀₀, V₀₀₁, V₀₁₀, V₀₁₁, V₁₀₀, V₁₀₁, V₁₁₀, V₁₁₁It is corresponding 8 voltage vectors of 3 bridge arms, 8 kinds of on off states of two-level inverter respectively；

1 Direct Torque Control vector of table selects table

(5) two optimal voltage vectors determined respectively using current period in next controlling cycle.

The present invention does not address part and is suitable for the prior art.

Claims (1)

1. a kind of two motor torque balance control methods, it is characterised in that this method includes the following steps：

(1) encoder in motor obtains two angle of rotor of motor θ_r1And θ_r2, rotational speed omega_r1And ω_r2, setting speed reference value ω_r ^ref, using the torque reference value T of proportional-plus-integral controller (PI controllers) two motors of acquisition₁ ^*And T₂ ^*；

(2) the torque reference value of two motors is distributed equally, obtains (T₁ ^*+T₂ ^*)/2；

(3) Hall sensor obtains two motor stator voltage U_dc1And U_dc2, stator currentWithAdopting in this controlling cycle Sample value calculates two motor current time stator magnetic linkages using flux observer and torque observerWithRotor magnetic ChainWithTorqueWith

(3.1) flux observer calculates the stator magnetic linkage for obtaining current timeWithRotor fluxWithAnd Pass through stator magnetic linkageWithTo determine that two stator flux of motor currently distinguish the section at place：

In formula, Ψ₁With Ψ₂It is the rotor flux amplitude of two motors respectively, is the definite value that every motor has；L_s1With L_s2Point It is not stator inductance；

(3.2) torque observer calculates the torque for obtaining current timeWith

In formula, p₁With p₂It is the number of pole-pairs of two motors respectively；

(4) for bi-motor in the torque at current time and the difference of expectation torque and the magnetic linkage at current time and expectation magnetic linkage Difference select respective optimal voltage vector；

(4.1) torque difference Δ T of two motors at current time is calculated_e1With Δ T_e2；

(4.2) magnetic linkage amplitude difference DELTA of two motors at current time is calculated | Ψ_s1| and Δ | Ψ_s2|；

In formula, | Ψ_s1 ^*| and | Ψ₂ ^*| it is the expectation stator magnetic linkage amplitude output of two motors respectively；

(4.3) " Direct Torque Control vector selects table " is used to determine two respective optimal voltage vectors of motor, it is specifically logical Cross the torque difference Δ T of section residing for stator flux of motor (I, II, III, IV, V, VI) and motor at current time_eAnd electricity Machine is in the magnetic linkage amplitude difference DELTA at current time | Ψ_s| determine optimal voltage vector；

(5) two optimal voltage vectors determined respectively using current period in next controlling cycle.