| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a technology that estimates the position of a rotor in a field having a low angular frequency. <P>SOLUTION: By subtracting a voltage drop based on d-axis current Id from a d-axis voltage command value Vd*, a d-axis induced voltage ed is obtained, and by subtracting a voltage drop based on q-axis current Iq from a q-axis voltage command value Vq*, a q-axis induced voltage eq is obtained. Estimated d-axis magnetic flux ϕd is obtained from the d-axis induced voltage ed by a correcting integrator 12. By dividing the estimated d-axis magnetic flux ϕd by the q-axis induced voltage eq, estimated angular velocity ω0 is obtained. By integrating the estimated angular velocity ω0, an estimated phase θ is obtained. The correcting integrator 12 includes a low-pass filter 13 and a high-pass filter 14 that have the cutoff frequency ωc, and an adder 16 that outputs the estimated d-axis magnetic flux ϕd by adding outputs from both filters 13 and 14. The correcting integrator 12 also includes a limiter 15 inputs the estimated d-axis magnetic flux ϕd to the high-pass filter 14 while limiting the upper limit of the estimated d-axis magnetic flux ϕd. To the low-pass filter 13 is input the d-axis induced voltage ed. <P>COPYRIGHT: (C)2013,JPO&INPIT |
