High Performance of Space Vector Modulation Direct Torque Control SVM-DTC Based on Amplitude Voltage and Stator Flux Angle

Abstract

Various aspects related to controlling induction motor are investigated. Direct torque control is an original high performance control strategy in the field of AC drive. In this proposed method, the control system is based on Space Vector Modulation (SVM), amplitude of voltage in direct-quadrature reference frame (d-q reference) and angle of stator flux. Amplitude of stator voltage is controlled by PI torque and PI flux controller. The stator flux angle is adjusted by rotor angular frequency and slip angular frequency. Then, the reference torque and the estimated torque is applied to the input of PI torque controller and the control quadrature axis voltage is determined. The control d-axis voltage is determined from the flux calculator. These q and d axis voltage are converted into amplitude voltage. By applying polar to Cartesian on amplitude voltage and stator flux angle, direct voltage and quadratures voltage are generated. The reference stator voltages in d-q are calculated based on forcing the stator voltage error to zero at next sampling period. By applying inverse park transformation on d-q voltages, the stator voltages in α and β frame are generated and apply to SVM. From the output of SVM, the motor control signal is generated and the speed of the induction motor regulated toward the rated speed. The simulation Results have demonstrated exceptional performance in steady and transient states and shows that decrease of torque and flux ripples is achieved in a complete speed range.

Robust Direct Torque Control with Super‐Twisting Sliding Mode Control for an Induction Motor Drive

“…If the hysteresis bandwidth is reduced the switching frequency of the inverter increases, which consequently raises the losses in the inverter [4]. The SVM is a way of reducing the ripples and the current distortions and offering an operation with a constant switching frequency by selecting the appropriate voltage vector for each sampling period [53]. The SVM principle is to modulate the components of the reference voltage vector and generate the corresponding inverter switching states.…”

Performance Analysis of DTC-SVM Sliding Mode Controllers-Based Parameters Estimator of Electric Motor Speed Drive

“…However, the basic DTC approach causes large torque and flux ripples, accompanied by acoustical noise, due to the uncontrolled switching frequency [3]. One way to decrease the ripples and to maintain a constant frequency is by the use of the space vector to modulation (SVM) [18,20]. The SVM technique refers to a special switching scheme of the six power transistors of a 3-phase PWM inverter.…”

“…The linear PI controllers and a space vector modulator are investigated by [18,19,34]. The hysteresis comparators of torque and flux are replaced by PI controllers.…”

“…Recently, many research efforts have been carried out to reduce the torque ripples and harmonics and to improve the uncontrolled commutation frequency. In fact, in order to reduce the level of torque and flux ripples, several researchers have proposed the use of multilevel inverters [12][13][14], and others have focused on SVM based inverter switching technique [15][16][17][18][19][20]. The inverter switching frequency is ensured constantly by space voltage vector modulation.…”

“…Then, it is possible to combine the advantages of space vector modulation with the advantages of the DTC strategy. In conventional DTC-SVM, PI controllers are used [18,19]. PI controllers are more suitable in the steady state condition and for linear systems.…”