Field Oriented Control-Based Reduction of the Vibration and Power Consumption of a Blood Pump

Abstract

Power quality and energy efficiency are of great importance in motor control. The motor of any medical device needs to have a smooth torque and minimal vibration in order to maximise its energy efficiency and patient comfort. Furthermore, in rotary blood pumps, excessive energy wasted due to vibration is converted into uncontrolled movement of the mechanical parts and thus could reduce the life of the motor-pump. Besides mechanical or hydraulic origin, one of the causes of vibration in any pump is torque ripple resulting from motor phase commutation. In this paper, using relevant equipment, two extreme scenarios were examined for vibration and electrical efficiency comparison due to power quality in a blood pump: one trapezoidal control with a trapezoidal phase current output; the other a field oriented control (FOC) with a non-distorted sinusoidal phase current. The test motor-pump was the Arteriovenous Fistula Eligibility (AFE) System that is used prior to haemodialysis. The trapezoidal technique was implemented utilising the Allegro a4941 fan driver (Allegro Microsystem, 2012), and the FOC technique was implemented using the Texas Instrument digital signal processor (TMS320F28335). The aim was to reduce the energy wasted over vibration, and to achieve smooth operation of the AFE System. Vibration was measured with a one-axis accelerometer; results showed considerably lower vibration due to less current ripple associated with the FOC control as well as lower power consumption.

Improved Performance for PMSM Sensorless Control Based on the LADRC Controller, ESO-Type Observer, DO-Type Observer, and RL-TD3 Agent

“…Figure 1 shows the block diagram of the FOC-type control structure for the PMSM control system. The system shown in (1) can be rewritten in the form given in system (2) [2,25]:…”

“…Typically, the overall control strategy of a PMSM is of the FOC type [1][2][3], which includes two cascaded control loops, the inner loop providing current control and the outer loop providing PMSM rotor speed control. Due to the multitude of applications and domains, among which we can mention robotics, computer peripherals, the aerospace industry, and electric drives [4,5], in which PMSM is used, the controllers implemented in the global FOC strategy have also evolved from simple to complex, i.e., from classical PItype controllers [6,7] to adaptive [8,9], predictive [10], or robust [11] type controllers [12,13].…”

Field Oriented Control untuk Pengaturan Kecepatan Motor BLDC pada Sepeda Motor Listrik

“…Untuk dapat mengatasi masalah ini maka kontroller FOC diperlukan untuk mengatur pembangkitan torsi yang sebanding dengan sinus dengan mengatur logika kontrol pada sudut pergantian menjadi 90 o sehingga torsi yang dihasilkan dari motor BLDC menjadi maksimal [14][15][16][17]. Keunggulan kontroller FOC dapat mengurangi getaran yang dihasilkan oleh motor yang disebabkan oleh penggunaan PWM switching, selain itu dengan menggunakan kontroller FOC, konsumsi daya yang diserap oleh motor menjadi efisien [18]. FOC bekerja dengan cara menggerakkan motor dengan torsi penuh, dan memantau posisi sudut rotor, kemudian mengubah tegangan tiga fasa sedemikian rupa sehingga back EMF pada jangkar selalu tetap 90 o terpisah dari fluks rotor.…”

Design of a Sensorless Field Oriented Control Drive for Brushless DC Motors

“…The most common method of driving a BLDC method is Trapezoidal control, which is also known as 6-Step commutation. Although this method is simple to implement, it has several drawbacks such as significant torque ripple, limited speed ranges and higher noise [2]. On the other hand, the FOC methodology overcomes these limitations while also delivering increased efficiency by maximizing the torque produced per unit current [3] [4].…”