RFOC implementation in four‐switch three phase inverter‐fed induction motor drive

Abstract

Purpose -This paper seeks to discuss the implementation of the rotor flux oriented control (RFOC) in a four-switch three-phase inverter (FSTPI)-fed induction motor drive. Design/methodology/approach -The implementation is achieved considering a current regulation of the FSTPI. Such a regulation is done thanks to bang-bang regulators. As far as the FSTPI is fed by a battery pack, the paper considers an electrical equivalent circuit of such a power supply. Findings -Simulation works, carried out considering the case of an ideal model of the battery pack and the case where the electrical equivalent circuit of the battery pack is taken into account, have shown that the drive dynamic performance are practically the same. Furthermore, and in order to highlight the performance of the induction motor fed by a FSTPI, these are compared with those obtained with the induction motor fed by a conventional six-switch three-phase inverter (SSTPI), considering both models of the battery pack. It has been found that the drive offers almost the same dynamic and steady-state performance.Research limitations/implications -The work should be extended by an experimental validation of the simulation results. Practical implications -The established results open up crucial benefits from the point of view of cost-effectiveness and volume-compactness improvements of induction motor drives especially in large-scale industries such as the automotive one where electric and hybrid propulsion systems are currently regarded as an interesting alternative to substitute or to assist the thermal propulsion systems. Originality/value -The implementation of the RFOC in FSTPI-fed induction motor drives is feasible and exhibits almost the same performance as those obtained by conventional SSTPI-fed induction motor drives under the same control strategies.

DTC of an FSTPI‐fed induction motor drive with extended speed range

“…The states of the upper-and lower-switches of a leg are complementary, which yields (van Der Broeck and van Wyk, 1984;Guermazi et al, 2007):…”

“…In the DTC strategies, the three phase voltages given by equation (2) are transformed into Concordia components V as and V bs which are given by Guermazi et al (2007): …”

“…The induction motor phase voltages are expressed in terms of the states of the upper switches (S 1 and S 2 ) as follows (van Der Broeck and van Wyk, 1984;Guermazi et al, 2007): …”

“…In this paper, is considered the case where a three‐phase induction motor with Y ‐connected phases is fed by a battery pack (automotive applications) through a FSTPI. Two phases of the three‐phase induction motor are connected to the FSTPI legs, while the third phase is connected to the middle point of the DC‐link voltage (van Der Broeck and van Wyk, 1984; Jacobina et al , 1995; El Badsi et al , 2007; Guermazi et al , 2007).…”

“…Let us assume that, the states of the four power switches of the FSTPI are denoted by the binary variables S 1 ‐ S 4 , where the binary “1” corresponds to an ON state and the binary “0” indicates an OFF state. The states of the upper‐ and lower‐switches of a leg are complementary, which yields (van Der Broeck and van Wyk, 1984; El Badsi et al , 2007; Guermazi et al , 2007): Equation 1 The induction motor phase voltages are expressed in terms of the states of the upper switches ( S 1 and S 2 ) as follows (van Der Broeck and van Wyk, 1984; El Badsi et al , 2007; Guermazi et al , 2007): Equation 2 The DTC represents a serious competitor for the rotor flux‐oriented control (RFOC). DTC strategies allow a direct generation of the power switch control signals rather than the generation of PWM signals in the case of RFOC strategies (Ben Salem and Masmoudi, 2007; Takahashi and Noguchi, 1986; Noguchi et al , 1999).…”