Predictive Torque Control of Induction Machines Using Immediate Flux Control

Abstract

This paper proposes a new concept for the control of voltage-source inverter (VSI)-fed induction machines. The method uses a predictive algorithm and can be split into two parts. The purpose of the first part, i.e., predictive torque control (PTC), is to predict the stator reference flux vector corresponding to the reference torque at the end of the sampling interval. The second part of the method provides accurate tracing of the stator reference flux by selecting either an active or a zero voltage vector. This approach is called immediate flux control (IFC), where two possible variants are suggested. In the first variant, a simple and fast algorithm obtains minimal stator flux error by impressing either an active or a zero voltage vector throughout the entire sampling interval. Consequently, the switching frequency becomes very low, but current and torque ripple are considerable. The second IFC variant generates the stator flux more accurately by applying an active voltage vector only throughout a calculated time slot within a sampling interval, whereas, during the remaining time of the sampling interval, a zero voltage vector is impressed. As a result, higher switching frequency arises, but it is still lower than that with space vector modulation. Both IFC variants, together with PTC, require minimal processing time and were efficiently implemented in a digital signal processor, which controlled a 3-kW induction machine drive. The obtained experimental results confirm the validity of the proposed approach.

Advanced Control Strategies of Induction Machine: Field Oriented Control, Direct Torque Control and Model Predictive Control

“…The implementation of PTC method has three steps: estimate the variables which cannot be measured directly, calculate the predictive values of stator flux and electromagnetic torque and design the cost function [31][32][33].…”

Finite Control Set Model Predictive Control with Pulse Width Modulation for Torque Control of EV Induction Motors

“…The reference value for the q-axis stator current can be obtained from (13). If λ qr is set to be 0 following (14), (13) can be rewritten as follows:…”

“…Recently, model predictive control (MPC) methods have been applied to the control of induction motors [10]- [13]. The strategy of MPC is to define a cost index over future finite time steps.…”

Permanent Magnet Synchronous Machine Hybrid Torque Control

“…In summary, the linear combination of two vectors in the rotor flux reference frame does not allow reaching the reference point and obtaining a fixed modulation period. There are a few papers reporting control schemes applying two converter configurations by computing occurrence [18]- [21]. For example, [22] and [23] present different control schemes with the particularity of using two switching states during a fixed period.…”