Induction Motor Speed Control Through Vector Control Approach

[Audio] INDUCTION MOTOR SPEED CONTROL THROUGH VECTOR CONTROL APPROACH PRESENTED BY R.MADHU SUDHAN PAPER ID: ICSCDS796.

[Audio] TOPICS TO BE COVERED: Abstract Introduction Control methods Control scheme Simulation results conclusion.

[Audio] Abstract: This paper presents the technique of vector control, often stated to as field-oriented control (FOC), is frequently utilize in Factory made applications to regulate speed and torque of IM drives. Vector control enables precise control of motor speed and torque by segmenting the stator current into components that produce torque and flux. The 3-phase Alternating current(AC) voltage & current signals are altered into a rotating reference frame, where the stator currents are divided into their torque and flux components, to achieve this. A PI controller uses the converted signals to produce the reference values for the torque (Tc) & flux components of the stator's current. The inverse Park transform is then used to turn these values back into three-phase signals, which creates the control signals for the motor drive. Keywords: Field oriented control(FOC), PI Converter, inverse park transform ,Vector control, Alternating Current ..

[Audio] Introduction: This paper presents a point which states that Induction motors continue to be most widely used motors in the industry, as is well known, due to their excellent performance and affordable price.[2] Advantageous operational characteristics of AC induction motors include power, durability, and ease of control. They are extensively used in a variety of applications, ranging from mechanical control mechanisms for residential appliances.[1] Despite this, using induction motors at their highest productivity levels is a challenging task because of their complicated numerical representation and non-straight trademark during immersion.[14]These elements lead to acceptance engine control issues and necessitate the use of advanced control computations, such as vector control.[4]Due to their high performance and low price, induction motors continue to be the most popular motors in the industry. It comprises great dependability, low cost, and widespread use in industrial applications, induction motors are practically completely maintenance-free.[10]When compared to a DC motor, it is robust, lighter, cheaper, more reliable, and nearly maintenance-free. The induction motor(IM) can be controlled in a variety of ways. V/f control is the oldest technique used among these.[9].

[Audio] Control methods: Fig.1. Control for induction motor(IM) using scalar and vector methods. From figure (1), Vector control and scalar control are two common methods used for controlling the speed & torque(Tc) of IM using variable frequency drive (VFD) sensors. Both methods use VFD sensors to vary the frequency of AC supply for the motor, which in turn affects the motor speed and torque. FOC is a more sophisticated control procedure that allows for precise and independent control of the motor speed & torque. In VC method, the AC voltage(V) and current are transformed into a two-dimensional space vector representation using Clarke and Park transformations. This transformation allows the relationship between the d-axis & q-axis components of the voltage (V) & current (I) to stand independently controlled, which can be used for controlling torque (Tc) and flux of the motor..

[Audio] From figure (2), VC is a procedure used for controlling the speed & torque (Tc) of IM. The main idea behind this control scheme is to treat the induction motor as a separately excited Direct current motor with a field flux & an armature current. This way, the induction motor(IM) can be controlled as a DC motor, even though it is an AC motor. The vector control scheme involves transforming the 3-phase Alternating Current-voltage and current (I) of the induction motor into 2-phase DC quantities, which can be used for controlling the motor's speed & Tc. The transformation is done using Clarke and Park transformations. Fig.2. Topology illustration of vector control of IM..

[Audio] Control scheme: DFOC is nothing but a control scheme used for induction motors that offer a fast dynamic response and high accuracy. DFOC control scheme uses a mathematical model or lookup table to calculate the switching signals required to control the current from stator & the flux from rotor. The table is depending up on the parameter's of the motor, such as stator resistance & inductance, rotor resistance & inductance. DFOC provides precise control of the motor with a fast dynamic response, which makes it suitable for robotics, and electric vehicles. However, it requires complex control algorithms and is more expensive than traditional control schemes.Figure 3 shows the DFOC Through rotor flux orientation method. Fig.3.DFOC Through Rotor Flux Orientation.

[Audio] Field-Oriented Control method named for (FOC) is the control scheme for induction motors that offer a fast dynamic response and high accuracy . Figure 4 shows the General Diagram of Rotor Flux FOC. FOC provides precise control of the motor with a fast dynamic response, which makes it perfectly good for robotics, electric vehicles. FOC has become a popular control scheme for induction motors because of its effectiveness in achieving high torque and speed control. However, FOC requires complex control algorithms and is more expensive than traditional control schemes. Fig.4.General Diagram Of Rotor Flux FOC.

[Audio] Simulation Results: Fig.6.depicts the waveforms of Voltage (Vab), Current (Iabc), Rotor speed, Electromagnetic Torque(Te) in induction motor under vector control reference frame. Fig.6.Output Wave forms.

[Audio] Fig.7. shows the waveforms of Rotor's Quadrant current (Iq), Direct current (Id) which have a magnitude ranging from +10A to -10A.

[Audio] Fig.9. demonstrates the wave forms of Iabc in which X-axis is taken as Time(sec) and Y-axis is taken as Current(A).It is three phase current waveform in which red coloured waveform is considered as Ia,the blue coloured waveform is considered as Ib,and the yellow coloured waveform is considered as Ic. Fig.9. Three phase Iabc waveform.

[Audio] Fig.10. displays the waveform of three phase voltage (Vabc).From the figure, we can see that the waveform varies the magnitude ranging from -800V to +800V..

[Audio] Conclusion: In conclusion, VC can be said as Field-Oriented Control is a sophisticated control scheme for induction motors that offers precise control of the motor's speed and torque with high dynamic response and accuracy. The control scheme involves controlling the stator current, rotor flux separately by a mathematical model to estimate motor's parameters Vector Control has been widely adopted in various industrial applications, including electric vehicles, robotics, and machine tools, due to its effectiveness in achieving high performance and efficiency. However, Vector Control requires complex algorithms and additional hardware, which makes it more expensive compared to other control schemes. Nonetheless, the benefits of Vector Control have made it a popular choice for applications that require high-performance motor control..

[Audio] Thank you. Thank You.