Anti-windup Proportional Integral Controller Research Articles

Analysis of AWPI Based Hybrid Grid-tied Inverter for Smart Energy Management System

Renewable energy sources are gaining popularity in recent years for power generation. The world has an abundance of pollution-free solar and wind energy; batteries play vital role for energy storage and all these sources combine to form a hybrid power system. Efficient management of the hybrid system via controlling the operation of its components is essential. In this article, a smart energy management system is proposed, where the control is focused on the hybrid grid-tied inverter. The inverter module is controlled through an anti-windup proportional-integral (AWPI) current and voltage controller. The performance of the proposed control system has been analyzed through current, and voltage Total Harmonic Distortion (THD) before and after grid integration. The suggested AWPI controller effectively mitigated the voltage drop and maintained the THD within the appropriate level. In addition, the proposed scheme of interest enhanced the steady-state response of the smart-grid system. The comparative analysis made among the intended controller and its counterparts inferred its superiority.

An adaptive CGPC based anti-windup PI controller with stability constraints for the intermittent power penetrated system

With the increasing penetration of the renewable energy, the modern power system is facing greater challenges to maintain the frequency stability, which can be studied with load frequency control (LFC). Since the conventional proportional integral (PI) controller can’t necessarily satisfy the ever-growing robustness requirement, an adaptive constrained generalized predictive control (CGPC) based anti-windup PI controller with stability constraints is proposed, which is referred to as CGPC-PI in this article. Wherein, the CGPC logic in the upper hierarchy acts as a real-time optimizer for the PI parameters in the lower hierarchy. The proposed control scheme inherits the self-tuning and adaptive control characteristics from CGPC and can maintain the facilities and control logic from PI. Furthermore, simpler stability constraints and performance improvement could be gained considering that PI is the actual implementing control method. Simulation experiments are conducted to reveal the frequency regulation performances in a Generation Rate Constraint (GRC) and Governor Deadband (GDB) involved interconnected power system with intermittent power penetration. The results can testify the superiority of CGPC-PI over the comparative methods in terms of the overshoot and damping performance, which includes:(1) CGPC-PI outperforms PI and CGPC. (2) the superiority is more obvious when working with varying disturbances which is big enough can trigger the anti-windup scheme. (3) CGPC-PI can enhance the frequency regulation performance of the intermittent power penetrated systems.

Anti-Windup PI Controller with Tracking for BLDC Motor Drive System: Modeling, Simulation and Implementation on Lab View Based FPGA

Most of the Brushless DC (BLDC) motors drives take up proportional integral (PI) controller and pulse width modulation (PWM) scheme for speed control. BLDC motor drive has strong saturation characteristics and saturation results in a windup phenomenon. This paper presents an Anti-windup drive for BLDC motor. An Anti-windup controller (AWC) with tracking has been employed and which has been modeled in MATLAB / Simulink and comparison has been done between conventional PI controller and AWC with tracking at different starting loads. In this paper, dynamic characteristics of the BLDC motor drive have been examined and results are validated with FPGA (Field Programmable Gate Array) based experimental set up.

An experimental investigation of scalar control-based induction motor drive using digital signal processor

This paper presents hardware implementation of anti-windup proportional integral (AWPI) controller-based scalar control of three phase induction motor (IM) drive using digital signal processer (DSP). The space vector pulse width modulation (SVPWM) is used generally for motor control application. The proposed control scheme is built on DSP which reduces speed error by using AWPI controller. The response of AWPI controller is used to modify amplitude and speed reference of rotating vector in stationary plane. The controller performance is assessed by MATLAB/Simulink simulation results and validated by experimental results using TMS320F28335 DelfinoTM kit. A comparative assessment is also presented between conventional PI controller and proposed controller. The proposed AWPI controller gives the better performance in terms of peak overshoot and settling time during transient conditions.

Sensorless SVM-Direct Torque Control for Induction Motor Drive Using Sliding Mode Observers

This paper presents an improved direct torque control strategy (DTC) for induction motor drive. The conventional DTC suffers from high torque ripples and variable switching frequency due to utilizing hysteresis comparators. The presented technique uses the space vector modulation in order to cover DTC drawbacks and reduce high torque and flux ripples by maintaining a fixed switching frequency. An anti-windup proportional integral controller is considered for the outer speed loop. Furthermore, the control design is combined with dual sliding mode observers for speed/flux and load torque estimation in order to improve the control performances and reduce different uncertainties. Moreover, they minimize the number of sensors to decrease the cost and increase the reliability of the system. The effectiveness of the sensorless method has been investigated by simulation and experimental validation using MATLAB/Simulink software with real time interface based on dSpace 1104 bored.

Automatic Control of Arterial Pressure for Hypotensive Patients using Phenylephrine

Developed in this paper is an automated closed-loop system that regulates the target blood pressure and maintains haemodynamic stability in hypotensive patients using the vasopressor drug phenylephrine. First, experimental studies are conducted on several healthy swine to identify dynamic mathematical models that quantify and predict blood pressure response to infusion of vasopressors. A first-order plus time-delay model structure has been selected to capture mean arterial pressure (MAP) response of patient’s subject to drug injection. Intra- and inter-patient variabilities of the model parameters have been identified and characterized. Then, an anti-windup proportional integral controller is designed, taking patient response variation in account. A nonlinear stochastic simulation environment has been developed to investigate the controller under diverse scenarios. Finally, automatic control of blood pressure is applied for the treatment of eight anesthetized swine subjected to hypotension induced by standard haemorrhage, spinal cord injury, and vasodilator injection. Results from clinical evaluations show that the proposed automated closed-loop control system is able to keep MAP near target and its performance is superior to that of manual control of infusion.

Comparison and Evaluation of Anti-Windup PI Controllers

This paper proposes a method for comparing and evaluating anti-windup proportional-integral (PI) control strategies. The so-called PI plane is used and its coordinate is composed of the error and the integral state. In addition, an anti-windup PI controller with integral state prediction is proposed. The anti-windup scheme can be easily analyzed and evaluated on the PI plane in detail. Representative anti-windup methods are experimentally applied to the speed control of a vector-controlled induction motor driven by a pulse width modulated (PWM) voltage-source inverter (VSI). The experimental results compare the anti-windup PI controllers. It is empathized that the initial value of the integral state at the beginning of the linear range dominates the control performance in terms of overshoot and settling time.

New antiwindup PI controller for variable-speed motor drives

The windup phenomenon appears and results in performance degradation when the proportional-integral (PI) controller output is saturated. A new antiwindup PI controller is proposed to improve the control performance of variable-speed motor drives, and it is experimentally applied to the speed control of a vector-controlled induction motor driven by a pulsewidth modulated (PWM) voltage-source inverter (VSI). The integral state is separately controlled, corresponding to whether the PI controller output is saturated or not. The experimental results show that the speed response has much improved performance, such as small overshoot and fast settling time, over the conventional antiwindup technique. Although the operating speed command is changed, similar control performance can be obtained by using the PI gains selected in the linear region.