电动离心压气机主动控制扩稳方法研究

Investigation on Active Stabilization of the Electric Centrifugal Compressor

为了适应车用宽工况范围需求,燃料电池离心压气机需具有宽的稳定流量范围,而喘振限制了离心压气机小流量工况工作的稳定性。针对燃料电池离心压气机为电动离心压气机的特点,本文提出了一种通过控制电机转速动态变化的主动控制扩稳方法。通过试验研究发现,相较于无主动控制的情况,采用主动控制使电机转速以正弦波形式主动变化时,可削弱失速、喘振等引起的压力振动幅值,实现失速和喘振的抑制。当电机转速以频率为7 Hz,无量纲幅值为0.2%的正弦波形式变化时,在测试的低转速范围内,深喘起始的背压阀度均有减小,其中在40000 r·min^(-1)时减小最显著,相较于无主动控制情况减小达6.3%。

With the purpose of meeting the demand of wide operating range for vehicle,the centrifugal compressor for fuel cell stack needs a wide stable flow range,however,the surge limits the stability of the centrifugal compressor in low flow condition.In view of the characteristics that the centrifugal compressor for fuel cell stack is an electric centrifugal compressor,this paper proposes an active control method for range extension by controlling the motor speed.The experimental results show that,compared with the case without active control,when the motor speed changes actively in the form of sine wave by using active control,the amplitude of pressure vibration caused by stall and surge can be weakened,and the stall and surge can be suppressed.When the motor speed changes in the form of sine wave with a frequency of 7 Hz and a dimensionless amplitude of 0.2%,the back pressure valve degree at the inception of deep surge decreases in the low speed region,and the most significant decrease is at 40000 r·min^(-1),which is 6.3%less than that without active control.