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This paper presents an approach to design proportional - integral – derivative controllers for induction machines using measurements. Most control methods developed for induction machines are generally based on mathematical models. Due to complex dynamics of induction machines, identified models are often unable to perfectly describe their behaviour. Thus, the system performance will be limited by the quality of the identified model. Hence, developing control methods that do not require the availability of system model is advantageous. Here, we propose an approach that uses the frequency response data to directly design controllers. The main idea here is to find controller parameters so that the closed-loop frequency response fits a desired frequency response. Its main advantage is that errors associated with the modelling process are avoided. Moreover, the control design process does not depend on the order and complexity of the plant. A practical application to induction machines illustrates the efficac...

This paper presents the detailed modelling and experimental verification of a proposed three-phase Improved Switched Inductor Z-Source Inverter (ISL ZSI). Because of the limitations of classical Z-source inverter, the ISL ZSI has been proposed to increase the conversion voltage gain, to reduce the voltage stress on the capacitor of Z-network and to remove the inrush current. In this paper, a detailed model of the proposed inverter is presented and analyzed. PWM control and relationships of voltage gain and voltage stress versus modulation index are explained. Then, a detailed loss model for the ISL ZSI is derived. Simulation results are obtained to confirm the proposed topology and its loss model. Then, a prototype of 250 W is presented and experimentally tested. A good match is obtained for calculation, simulation and experiment.

Permanent magnet synchronous machines (PMSMs) are becoming popular in industries due to their fast transient response, high power density and high efficiency. This paper presents rotor field-orient...

This paper analyses the operation of an adaptive neuro-fuzzy inference system (ANFIS)-based maximum power point tracking (MPPT) for solar photovoltaic (SPV) energy generation system. The MPPT works on the principle of adjusting the voltage of the SPV modules by changing the duty ratio of the boost converter. The duty ratio of the boost converter is calculated for a given solar irradiance and temperature condition by a closed-loop control scheme. The ANFIS is trained to generate maximum power corresponding to the given solar irradiance level and temperature. The response of the ANFIS-based control system is highly precise and offers an extremely fast response. The response time is seen as nearly 1 ms for fast varying cell temperature and 6 ms for fast varying solar irradiance. The simulation is done for fast-changing solar irradiance and temperature conditions. The response of the proposed controller is also presented.

Multi-phase (more than three-phase) converters are required mainly for feeding variable speed multi-phase drive systems. This paper presents one such solution by using a direct AC-AC converter that can be used to supply a quasi-six-phase drive system. Carrier-based pulse-width modulation technique is developed for the proposed matrix converter configuration. The developed modulation technique is based on the comparison of high frequency carrier signals with the modulating signals to produce duty-ratios. Although carrier-based schemes are widely employed for control of voltage source inverters, they have only recently been used for controlling a three-phase to three-phase matrix converter. A similar concept is extended in this paper for controlling a three-phase to quasi- six-phase matrix converter. Two techniques are proposed: one outputs 0.75 of the input magnitude, and the second outputs up to 0.7764 of the input. This is the maximum value of the output voltage in the linear range that can be ac...

Building-integrated photovoltaic (BIPV) technology has become a major area of research due to environ-mental concerns. This article studies the feasibility of cladding high-rise towers in Doha with solar photovoltaic modules. Specifically, the case of the Qatar Financial Centre (QFC) is discussed. The major aim of the work is to evaluate the technical feasibility, economic impact and environmental effects of using photovoltaic panels on commercial towers in Qatar. Experimental data on solar irradiance and the effect of shading on the QFC Tower are presented. Numerical calculations are done using solar pathfinder software. The studies show that, although there is a significant amount of saving in CO2 emission by using BIPV on towers in Doha, the payback period is still very long due to the cheaper cost of grid electricity in Qatar and poor conversion efficiency of PV panels. The complete system layout is presented and viable solutions are investigated.

In the article, a new stator current controller for voltage source inverter is presented. The proposed controller is based on back-emf calculation and applied to induction motors. The controller sensitivity to load parameters is discussed. The proposed controller is based on the model of inverter load with inductance and back-emf. Load resistance is neglected assuming that switching period is small enough that the average voltage drop across the resistance may be included in the back-emf. Constant switching frequency is used in the proposed system. The controller is realized in simulation and experimentally using fixed-point digital signal processor (DSP) and programmable field programmable gate arrays (FPGA).

In this work, a new voltage space vector PWM method is developed. The problem of exact generation of small voltage vectors is discussed. Two methods for generating small inverter output voltage vectors are proposed. The influence of dead time is explained and its effect on the motor current is compensated. A squirrel cage induction motor with reduced supply voltage is used for testing the developed algorithm. Simulation and experimental results are carried out using fixed-point (DSP) and (FPGA). In addition, the practical realization of the proposed algorithm is discussed.

This paper analyses a three-to-five phase matrix converter to supply five-phase two-motor drive topology. It proposes simple direct duty ratio based pulse-width modulation (PWM) technique of a three-to-five phase matrix converter supplying a series/parallel connected five-phase AC motor drive system. The developed modulation technique is based on the comparison of a high frequency carrier signal with the duty ratio of the modulating signals. The major aim of the PWM is to generate two independent fundamental frequency components that will subsequently control the two series/parallel connected five-phase motors independently. The viability of the proposed control techniques is proven using analytical, simulation and experimental approaches.