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Principles of Energy Conversion
Published in Hamid A. Toliyat, Gerald B. Kliman, Handbook of Electric Motors, 2018
Hamid A. Toliyat, Gerald B. Kliman
Although the large majority of variable speed applications require only speed control in which the torque response is only of secondary interest, more challenging applications such a traction applications, servomotors and the like depend critically upon the ability of the drive to provide a prescribed torque whereupon the speed becomes the variable of secondary interest. The method of torque control in ac machines is called either vector control or, alternatively field orientation. Vector control refers to the manipulation of terminal currents, flux linkages and voltages to affect the motor torque, while field orientation refers to the manipulation of the field quantities within the motor itself. Because it is common for machine designers to visualize motor torque production in terms of the air-gap flux densities and mmfs instead of currents and fluxes that relate to terminal quantities, it is useful to begin first with a discussion of the relationship between the two viewpoints.
Induction Motor Control
Published in Richard E. Neapolitan, Kwang Hee Nam, AC Motor Control and Electrical Vehicle Applications, 2018
Richard E. Neapolitan, Kwang Hee Nam
The field oriented control, often called the vector control refers to all AC machine control methods that split the current vector into flux and torque components and control each of them independently. The basic control principle is the same as that of DC machine except the rotating reference frame. The phase currents are transformed into a synchronous reference frame whose d-axis is aligned with a flux vector. The d-axis current determines the flux magnitude, whereas the q-axis current, being orthogonal to the d-axis, controls the torque. In the case of IM, the control methods are sorted as rotor, stator, and air gap flux oriented schemes depending on the flux on which the frame is referenced. Among them the rotor flux oriented scheme is most popular for simplicity and good decoupling nature.
Permanent Magnet Synchronous Motor Drives
Published in Maurizio Cirrincione, Marcello Pucci, Vitale Gianpaolo, Power Converters and AC Electrical Drives with Linear Neural Networks, 2017
Maurizio Cirrincione, Marcello Pucci, Vitale Gianpaolo, Angelo Accetta
They differ from their DC counterpart in many aspects; the quasisinusoidal distribution of the air-gap flux is obtained both by the design of the rotor magnet and of the armature windings. The latter are sinusoidally distributed over the pole arc [4], while the PMs are usually tapered at the pole edges and shortened in order to occupy a smaller pole arc (120°). AC brushless motors are widely used in automotive applications, especially when high dynamic performance and accurate positioning are the main goals. Vector control is the main control methodology for this kind of motors since it permits obtaining performance comparable with classic DC machine.
Dual-model predictive control of two independent induction motors driven by a SiC nine-switch inverter
Published in International Journal of Electronics, 2023
The field-oriented control is a form of vector control. This technique controls the instantaneous electromagnetic torque of a three-phase ac machine similar to that of a separately excited DC motor whose armature winding is driven by a regulated current source. However, it should be taken into account that, unlike a dc motor, the space angle between the stator and rotor fields of the induction machine varies depending on the load torque. To develop a similar torque control strategy, the stator current can be divided into two components, i.e., torque- and flux-producing components. To simplify the torque expression given by (19) and make it similar to that of a dc motor, the direct axis of the reference frame is locked onto the rotor flux vector, namely . In this case, the electrical variables change slowly, similar to those of direct current motors.
Improved performance of photovoltaic array for water pumping by fuzzy control in sensorless vector control of induction motor drive
Published in International Journal of Ambient Energy, 2022
Vasu Koneti, K. Mahesh, Thalluru Anil Kumar
The main drawbacks of P&O technique are slow response, oscillations at maximum power point (MPP) in steady state and the poor performance during changing weather conditions has proposed in (Ahmed and Salam 2018). Later Incremental conductance algorithm has been used to track the maximum power from PV array at MPP and to achieve maximum irradiance of the PV array even in the dynamically changed weather conditions in (Md Rafi et al. 2019; Kumar et al. 2018). The voltage source invertor (VSI) drive is inherently more efficient, well suited for dynamic applications and switching is fast to convert DC–AC conversion of vector control of three phase induction motor drive. The single stage controlled drive for water pump reduces the cost of switches and switching losses has been developed by Md Rafi et al. (2019). The vector control is superior to scalar control in terms of precise control induction motor drive and high performance and accuracy. The vector control depends on current and voltage space orthogonal vectors and it is mostly .
A Combinational Sequence Duty Ratio Control of SPV Fed Variable Speed Induction Motor Drive Using Field Oriented Control
Published in Electric Power Components and Systems, 2022
Ankireddy Narendra, Venkataramana Naik N, Anup Kumar Panda
Vector control is also called field-oriented control (FOC). The FOC of the IM drive makes the decoupling of torque and flux constituents with the help of transformation [7, 8]. However, the field oriented control of IMD is further classified as indirect/direct vector control (IDVC/DVC) based on space angle calculations of rotor flux. In the direct vector control with the help of sensors such as search coil/hall-effect sensors, the rotor-flux space angle is measured directly. However, the sensors used in DVC are dependent on temperature, and hence the positing sensing is not acceptable all the time[9]. The indirect vector control determines the rotor flux angle as an integral sum of rotor slip and measured speed [10, 11]. The speed control of IMD is performed using FOC along with an inverter. However, the inherent control of the inverter is dependent upon its switching (pulse width modulation) technique [12, 13]. In the literature, many works have been carried toward switching methods such as square pulses [14] and sinusoidal pulse width modulation (SPWM) [15]. With the addition of a third harmonic component to SPWM, a third harmonic injection PWM (THIPWM) [16, 17] is obtained. However, based on the amount, either 1/4th or 1/6th of THI is added to the fundamental wave, the THIPWM either reduces the THD or improves the utilization of DC bus voltage, respectively. However, both the features of THIPWM are achieved simultaneously using space vector modulation (SVM) PWM [18]. But, the SVM-PWM requires substantial calculations to reduce the current ripple [19].