关键词: 轮毂电机, 无位置传感器, 高频注入, 非线性, 跟踪精度

Abstract: Affected by the complex operating conditions of the electric vehicle, the use of position sensors in the in-wheel motors can produce a risk of lower reliability and safety. For this reason, the sensorless rotating high-frequency voltage injection method is studied. The traditional high-frequency injection method needs to integrate the ideal injection voltage to obtain current response expression. So the rotor position information is extracted, from negative sequence component. The study found that, limited by the carrier frequency, the degree of coincidence between ideal and actual injection voltage is low due to nonlinearity, which resulting in a large estimation error and system oscillation. To solve this problem, a new angle information extraction method is proposed. Increasing the voltage coincidence degree by advancing the phase of the injection signal. According to the three-phase voltage model, the rotor position information is finally extracted from the difference between two consecutive sampling current, in combination with the carrier cycle. The traditional method which requires integration directly is replaced. The position tracking accuracy and system dynamic performance are effectively improved. Finally, the startup performance and reliability are validated by theoretical analysis and experimental results.

Key words: in-wheel motor, sensorless, high-frequency injection, non-linearity, tracking accuracy