CN105391365A - Static identification method for simultaneous detection of rotor resistance and excitation inductance - Google Patents

Abstract

The invention relates to a static identification method for simultaneous detection of rotor resistance and excitation inductance. The method includes the following steps: a stator resistor Rs, a stator leakage inductor Lso and an excitation mutual inductor Lm are connected in series and an input voltage us is loaded, two ends of the excitation mutual inductor Lm are connected in parallel with a series circuit of a rotor leakage inductor Lro and a rotor resistor Rr, the stator resistor Rs side is provided with stator current is, the rotor resistor Rr side is provided with rotor current ir, measurement is performed through stator side inductance, rotor resistance and excitation inductance, and stator side equivalent full leakage inductance is obtained through calculation. The static identification method for simultaneous detection of the rotor resistance and excitation inductance provided by the invention overcomes a dead zone effect, adopts a current closed loop to identify the rotor resistance and excitation mutual inductance, reduces influence brought by a stator side current change, and enables a measuring result to be relatively accurate.

Description

The static discrimination method of detection rotor resistance and magnetizing inductance while of a kind of

Technical field

The invention belongs to electric-power metering detection field, the static discrimination method of detection rotor resistance and magnetizing inductance while of particularly a kind of.

Background technology

At present, in the technical field detecting rotor resistance, many scholar engineers propose different metering systems.Such as: in model reference adaptive system, build adaptive rate identification stator resistance, according to the ratio under off-line state between stator, rotor resistance, on-line identification goes out rotor resistance, the shortcoming of the method be to rely on the precision of Stator resistance identification and stator and rotor resistance parameters when there being identical temperature rise change, both variation tendencies are unknown; Also have the method for the harmonic wave by injecting two kinds of different frequencies to stator current excitation component, bring extra noise to system like this, and have humorous wave interference to output voltage and output current.

Through retrieval, find one section of patent documentation relevant to this patent content, publication number is the on-line identification method of a kind of on-line identification method that the Chinese patent of CN102611382B provides parameter of electric machine, the rotor resistance particularly in speed-less sensor vector control system.Independent of the integration modified model voltage model flux observer of self adaptation full-order state observer, in system dynamic conditioning, utilize the process of magnetic linkage transient changing, adopt adaptive forgetting factor RLS in conjunction with integration improved electric pressing mold type flux observer to rotor resistance on-line identification; Adopt at interval of the regular hour to the certain harmonic wave of the of short duration injection of given rotor flux when systematic steady state runs, form magnetic linkage dynamic change, adopt adaptive forgetting factor RLS in conjunction with integration improved electric pressing mold type flux observer to rotor resistance identification, the rotor resistance value on line refreshable self adaptation full-order state observer.Rotor resistance on-line identification method of the present invention can calculate the change of the parameter of electric machine, and adjusts electric machine controller, improves the performance of electric machine controller.

But this ONLINE RECOGNITION method in operation, need when systematic steady state runs at interval of the regular hour to the certain harmonic wave of the of short duration injection of rotor flux, form magnetic linkage dynamic change, thus add the workload of control system, and can not detection rotor resistance and magnetizing inductance simultaneously.

Summary of the invention

The object of the invention is for the deficiencies in the prior art, propose a kind of inverter motor that is used for and drive, the static discrimination method of more accurate detection rotor resistance and magnetizing inductance simultaneously.

The present invention solves its technical problem and takes following technical scheme to realize:

While detection rotor resistance and the static discrimination method of magnetizing inductance, the method is by stator resistance R _s, stator leakage inductance L _so, excitation mutual inductance L _mconnect and load input voltage u _s, at excitation mutual inductance L _mtwo ends are parallel with a rotor leakage inductance L _rowith rotor resistance R _rseries circuit, stator resistance R _sthere is stator current i side _s, rotor resistance R _rthere is rotor current i side _r, measured by stator side inductance, rotor resistance and magnetizing inductance simultaneously, then by calculating the full leakage inductance of stator side equivalence.

And the step of described calculating is:

(1) input voltage makes stator current given to 30% rated current, at t after stable ₀moment output voltage u ₀for:

u ₀＝I _30％×R _s+u _dead

(2), after input voltage makes given value of current 0% wait for that magnetic flux is fully decayed, electric current again given 30%, waits for the △ t time, escapes the back-emf induced by motor leakage inductance, record output voltage u in the t1 moment ₁, therefore i _r=i _s, then following formula is set up:

$u_1=I_{30\%}\×R_r\×e^{-\frac{\mathrm{\Δ}t}{Tr}}+I_{30\%}\×R_s+u_{dead}.$

(3) calculate $\mathrm{\Δ}u=u_1-u_0=I_{30\%}\×R_r\×e^{-\frac{\mathrm{\Δ}t}{T_r}},$

Deng voltage attenuation to u ₂=Δ u*e ^-1+ u ₀time writing time t ₂, then known

$\left.\begin{array}{c}{T}_r=t_2-t_1\\ R_r=\frac{\mathrm{\Δ}u}{I_{30\%}\×e^{-\frac{\mathrm{\Δ}t}{Tr}}}\\ L_r=T_r\×R_r\\ L_m=L_r-L_{r\mathrm{\σ}}\≈L_r-\frac{1}{2}{L_{\mathrm{\σ}}}^{\′}\\ {L_m}^{\′}=\frac{L_m}{L_r}\×L_m\end{array}\right\}$

Wherein u _deadfor the error voltage caused because of nonlinear elements such as dead time effects, Δ t is set to leakage inductance time constant (for known quantity), and Tr is rotor time constant, and Lr is inductor rotor, L _σ' be the full leakage inductance of stator side equivalence.

Advantage of the present invention and good effect are:

While provided by the invention, the static discrimination method of detection rotor resistance and magnetizing inductance overcomes dead time effect, adopts current closed-loop to carry out identification to rotor resistance and excitation mutual inductance, reduces the impact that stator survey curent change brings, makes measurement result more accurate.

Accompanying drawing explanation

Fig. 1 is the T-shaped figure of testing of electric motors equivalence;

Fig. 2 is the schematic diagram that embodiment rotor resistance and magnetizing inductance measure time to time change.

Embodiment

Be further described the invention process below in conjunction with accompanying drawing, following examples are descriptive, are not determinate, can not limit protection scope of the present invention with this.

While detection rotor resistance and the static discrimination method of magnetizing inductance, the method is by stator resistance R _s, stator leakage inductance L _so, excitation mutual inductance L _mconnect and load input voltage u _s, at excitation mutual inductance L _mtwo ends are parallel with a rotor leakage inductance L _rowith rotor resistance R _rseries circuit, stator resistance R _sthere is stator current i side _s, rotor resistance R _rthere is rotor current i side _r, its measuring process is:

(1) input voltage makes stator current given to 30% rated current, at t after stable ₀moment output voltage u ₀for:

u ₀＝I _30％×R _s+u _dead

(2), after input voltage makes given value of current 0% wait for that magnetic flux is fully decayed, electric current again given 30%, waits for the △ t time, escapes the back-emf induced by motor leakage inductance, at t ₁moment record output voltage u ₁, as shown in Figure 1, during impact given value of current, because motor magnetic linkage can not suddenly change, therefore i _r=i _s, then following formula is set up:

$u_1=I_{30\%}\×R_r\×e^{-\frac{\mathrm{\Δ}t}{Tr}}+I_{30\%}\×R_s+u_{dead}$

Calculate deng voltage attenuation to u ₂=Δ u*e ^-1+ u ₀time writing time t ₂, then known

$\left.\begin{array}{c}{T}_r=t_2-t_1\\ R_r=\frac{\mathrm{\Δ}u}{I_{30\%}\×e^{-\frac{\mathrm{\Δ}t}{Tr}}}\\ L_r=T_r\×R_r\\ L_m=L_r-L_{r\mathrm{\σ}}\≈L_r-\frac{1}{2}{L_{\mathrm{\σ}}}^{\′}\\ {L_m}^{\′}=\frac{L_m}{L_r}\×L_m\end{array}\right\}$

Wherein u _deadfor the error voltage caused because of nonlinear elements such as dead time effects, Δ t is set to leakage inductance time constant (for known quantity), and Tr is rotor time constant, and Lr is inductor rotor, L _σ' be the full leakage inductance of stator side equivalence.

Meanwhile, see Fig. 2, the data for rotor resistance and magnetizing inductance are passed through to measure, and can carry out effective static identification.

Although disclose embodiments of the invention and accompanying drawing for the purpose of illustration, but it will be appreciated by those skilled in the art that: in the spirit and scope not departing from the present invention and claims, various replacement, change and amendment are all possible, therefore, scope of the present invention is not limited to the content disclosed in embodiment and accompanying drawing.

Claims (2)

1. while, a static discrimination method for detection rotor resistance and magnetizing inductance, is characterized in that: the method is by stator resistance R _s, stator leakage inductance L _so, excitation mutual inductance L _mconnect and load input voltage u _s, at excitation mutual inductance L _mtwo ends are parallel with a rotor leakage inductance L _rowith rotor resistance R _rseries circuit, stator resistance R _sthere is stator current i side _s, rotor resistance R _rthere is rotor current i side _r, measured by stator side inductance, rotor resistance and magnetizing inductance simultaneously, then by calculating the full leakage inductance of stator side equivalence.

2. the motor stator resistor detection method based on becoming carrier frequency according to claim 1, is characterized in that: the step of described calculating is:

(1) input voltage makes stator current given to 30% rated current, at t after stable ₀moment output voltage u ₀for:

u ₀＝I _30％×R _s+u _dead

(2), after input voltage makes given value of current 0% wait for that magnetic flux is fully decayed, electric current again given 30%, waits for the △ t time, escapes the back-emf induced by motor leakage inductance, at t ₁moment record output voltage u ₁, therefore i _r=i _s, then following formula is set up:

$u_1=I_{30\%}\×R_r\×e^{-\frac{\mathrm{\Δ}t}{Tr}}+I_{30\%}\×R_s+u_{dead}.$

(3) calculate $\mathrm{\Δ}u=u_1-u_0=I_{30\%}\×R_r\×e^{-\frac{\mathrm{\Δ}t}{T_r}},$

Deng voltage attenuation to u ₂=Δ u*e ^-1+ u ₀time writing time t ₂, then known

$\left.\begin{array}{c}{T}_r=t_2-t_1\\ R_r=\frac{\mathrm{\Δ}u}{I_{30\%}\×e^{-\frac{\mathrm{\Δ}t}{Tr}}}\\ L_r=T_r\×R_r\\ L_m=L_r-L_{r\mathrm{\σ}}\≈L_r-\frac{1}{2}{L_{\mathrm{\σ}}}^{\′}\\ {L_m}^{\′}=\frac{L_m}{L_r}\×L_m\end{array}\right\}$

Wherein u _deadfor the error voltage caused because of nonlinear elements such as dead time effects, Δ t is set to leakage inductance time constant (for known quantity), and Tr is rotor time constant, and Lr is inductor rotor, L _σ' be the full leakage inductance of stator side equivalence.