Hybrid predictive control strategy for a low‐cost converter‐fed IM drive

Abstract

The converter consisting of a single-phase half-bridge rectifier and four-switch three-phase inverter is a low-cost power converter with complicated operating constraints. It is difficult to control by the conventional strategies. This study proposes a hybrid predictive control strategy with dual loops for this converter. In the outer loop, a proportional-integral controller is designed to regulate the dc-link voltage, capacitor voltage balancing, and the speed and flux of induction motors (IM). Also, in the inner loop, the finite set model predictive control is employed to control the ac input current and stator currents of the IM. The major advantages of the control strategy include: (i) easy to deal with complicated constraints and manage multiple control targets; (ii) without the need of modulators; (iii) good dynamic response. The simulation and experimental results indicate that the proposed method can guarantee the stable operation and good performance.

Approach for classifying direct PCs applied to AC motor drives

“…In these experiments, the steady-state performance of MPC2 is assessed for different weighting factors while sampling frequency is adjusted to 10 kHz, the nominal load is applied to the motor, and the motor rotates at 1500 rpm. On the basis of this figure, it is observed that the torque ripple reaches its minimum value when the weighting factor (λ) is adjusted to about 1.5 [the value calculated through (9)]. By increasing the weighting factor, the stator-flux ripple of MPC2 is reduced while the torque ripple is increased.…”

“…(v) MPC2 method: In this method, the cost function introduced in (8) is evaluated to select the best AVV, where Q is a weighting factor optimised to achieve the minimum torque ripple. The optimal weighting factor is calculated based on (9). After calculating the optimal Q, an AVV with the lowest cost is selected as the optimal VV.…”

“…In recent decades, predictive controllers (PCs) are repeatedly used in various applications such as diesel engine control [1,2], position control [3], aircraft control [4,5], gearshift control [6], and many other industrial applications [7]. Furthermore, these controllers are widely used in power electronics and AC motor drives [8][9][10][11][12]. PCs cover a very wide category of controllers.…”

Effective low‐cost solution using cascaded connection of two modified notch filters to mitigate the second and third harmonic currents in single‐phase dual‐stage half‐bridge microinverter

“…2a. According to (16)- (20), a mismatched capacitance causes the reference grid current containing both second-and third-order harmonic currents. As shown in Fig.…”

“…However, according to engineering design concepts, improving the control strategy without additional circuits is more interesting because it is simpler to implement, has lower cost, has no additional power loss, and does not complicate the overall circuitry. For grid-tied microinverters, the half-bridge topology [18][19][20][21][22][23][24][25] has many attractive features, such as a low component count, low cost, and high efficiency. However, there is a doubleline frequency ripple voltage on the dc-link as well; thus, a thirdorder harmonic current cannot be avoided.…”