Method for positioning rotor of switched reluctance motor with pulse number being self-adjustable along with speed

A method for positioning a rotor of a switched reluctance motor with a pulse number being self-adjustable along with speed, characterized in that a relationship between an instantaneous voltage of the switched reluctance motor and a magnetic flux in a winding is defined into formula (1), formula (1) being as follows:

• V
• ph
• =
• iR
• +
• ∂
• λ
• ∂
• i
• ⁢
• di
• dt
• +
• ∂
• λ
• ∂
• θ
• ⁢
• d
• ⁢
• θ
• dt
• =
• iR
• +
• L
• inc
• ⁢
• di
• dt
• +
• K
• v
• ⁢
• ω
• wherein Vph is a direct current bus voltage;
• i is an instantaneous phase current;
• R is a resistance of the winding;
• λ is magnetic flux of a connecting coil;
• Linc is an incremental inductance;
• Kv is a current-dependent counter electromotive force coefficient;
• ω is an angular speed of a rotor;
• working conditions of the switched reluctance motor are divided into a low-speed section, a medium-speed section and a high-speed section according to formula (1) in combination with a speed of the switched reluctance motor;
• wherein estimation of a motor rotor position at the low-speed section comprises:
• using one phase to drive excitation, and using other two idle phases to determine the rotor position of the switched reluctance motor;
• injecting a high-frequency current into the idle phases;
• selecting a sector for triggering according to comparison between a current response value and a current threshold, so as to determine the rotor position of the motor;
• estimation of a motor rotor position at the medium-speed section comprises:
• determining, according to a change of the number of injected pulses with the motor speed, the rotor position of the motor by querying a preset data table;
• estimation of a motor rotor position at the high-speed section comprises:
• setting a preset data table to represent a mapping relationship between a charging voltage and the rotor position;
• comparing the motor speed with a set threshold;
• charging a capacitor by a current response under a fixed voltage pulse, and collecting a voltage amplitude output by a capacitor side;
• querying the preset data table to obtain a corresponding real-time rotor position of the motor according to a capacitor charging voltage value.