矢量控制电动执行器死区补偿新方法

逆变器的死区会导致电动执行器在低速时出现电流畸变,严重影响系统的稳定性。在理论上,根据电流的过零点可以进行死区补偿,但是在实际系统中,由于噪声的影响,难以检测精确的电流过零点,因此可能出现误补偿。针对以上问题,提出了一种新的死区补偿方法。对电流进行矢量分解,用电流的矢量角来间接判断电流的过零点,同时对阶跃补偿电压进行线性化处理,有效减小了可能的误补偿电压。为了验证算法,在一台0.8 k W矢量控制电动执行器上进行死区补偿实验和转速阶跃变化实验,实验结果表明,所提方法可以有效地对死区进行补偿,并明显改善了电动执行器的低速稳定性,由此证明了所提方法的有效性和可行性。

New dead time compensation method for vector controlled electric actuator

The dead time of inverter causes current distortion in low speed of electric actuator, which would affect the stability of the system. In theory, the dead time can be compensated by the current zero crossings. However, it is difficult to detect the zero crossings precisely because of the noise within the actual system, so error compensation may appear. Aiming at the problems above, a new dead time compensation approach is proposed. The current is resolved into vector and the current zero crossings can be indirectly determined by the vector angle. And also, the possible error compensation voltage is effectively reduced by linearization of the step compensation voltage. To verify the algorithm, a dead time compensation test and a speed step change test are fulfilled on a 0.8 kW vector controlled electric actuator. The experimental results show that the dead time is compensated effectively and the stability of the electric actuator in low speed is obviously improved so as the effectiveness and feasibility of the method is shown.