Phase angle estimation apparatus

A phase angle estimation apparatus which estimates a phase angle of a rotor for a motor including the rotor as a field, and N (N is an integer of 2 or greater) sets of coils each having respective drive systems, the phase angle estimation apparatus comprising:

• an applying unit configured to apply first pulse voltages, apply second pulse voltages at a timing different from a timing at which the first pulse voltages are applied, and apply third pulse voltages at a timing different from the timings at which the first and the second pulse voltages are applied, to the respective N sets of coils;
• an acquiring unit configured to acquire a first current vector which is a vector of a current flowing through at least one set of coils among the N sets of coils by application of the first pulse voltages, a second current vector which is a vector of a current flowing through the at least one set of coils by application of the second pulse voltages, and a third current vector which is a vector of a current flowing through the at least one set of coils by application of the third pulse voltages;
• and
• an estimating unit configured to estimate the phase angle on a basis of the first, the second and the third current vectors, wherein
• at least one of conditions are satisfied, the conditions are a condition that directions of vectors of the N sets of the first pulse voltages are different from each other, a condition that directions of vectors of the N sets of the second pulse voltages are different from each other, and a condition that directions of vectors of the N sets of the third pulse voltages are different from each other, and
• periods in which voltages having different directions of the vectors among the N sets of the first, the second and the third pulse voltages are applied at least partially overlap with each other.