Development of variable voltage variable frequency drive system for induction motor speed control

 2.2.2 Scalar speed control of Dual Three Phase Induction Motor using 
Proportional Integral (PI) and Integral Proportional (IP) Controller 
This paper [15] is about proposing a scalar speed control of Dual Three Phase 
Induction Motor using PI and IP controller. Problem discussed in the paper is dynamic 
speed performance and the ability to reject the disturbance. Method used in this paper 
is by implementing the technique of Proportional Integral (PI) and Integral 
Proportional (IP) into constant V/F control strategy using MATLAB/Simulink. 
Besides, Park transformation mathematics is applied into the system. The simulation 
result shows the effect of the implementation of the proposed controller in terms of 
speed control error and perturbation rejection. Based on the result obtained it shows 
that IP controller has better performance in terms of rejection of load disturbance and 
PI controller has high performance in response time. This controller is extremely 
sensitive, control techniques are used such as reference adaptive control and sliding 
mode control.
Figure 2.2 show the block diagram of closed loop scalar control that was 
used in this paper. 

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Figure 2.2: Block diagram of closed-loop scalar control. [15] 
2.2.3 Variable Voltage Variable Frequency Speed Control of Induction Motor 
using FPGA-Xilinx 
This paper [16] is about proposing to analyze and calculate the different parameters 
like voltage and current in different parts of the converter and performance of three 
phase induction motor under steady state and transient condition. Proposed method 
used in this paper is Sinusoidal pulse width modulation (SPWM) for V/F scheme along 
with Proportional Integral (PI) controller using FPGA- Xilinx. The result obtained 
from Simulink shows that effect of the implementation of proposed sine pulse width 
modulation control technique and second order low pass filter under steady state and 
transient condition. The implementation of calculating the different parameter voltage 
and current in different parts of the converter under steady state and transient allows 
line current THD reduced.
Figure 2.3 shows the closed loop control for the three phase 
induction system used in this paper. 

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Figure 2.3: Block diagram for closed loop control of three-phase induction motor 
[16]