‎ In this paper, the stand-alone photovoltaic system for cathodic protection of underground pipelines is presented. The proposed system offers continuous and automatic adjustment of the applied voltage so that the buried pipelines receive the exact current. A modified perturb and observe (P&O) algorithm for maximum power point tracking (MPPT) is used to improve dynamic and steady state performa...

Power system blackouts have become a serious problem for electric utilities especially in recent years. Different forms of system instability have emerged in recent blackouts, such as voltage instability and frequency instability. To counteract each form of system instability, special algorithms have been designed in the protection system, e.g. Under Frequency Load Shedding (UFLS) and Under Vol...

Steady-state dynamic simulation of a variable reluctance stepping motor is carried out by applying two different excitation voltages. First a single-step voltage is applied to the motor, and a sinusoidal voltage, as the first term of Fourier series of the single-step voltage, is then used as the input voltage of the motor. In both cases plots of machine torque, current and speed are presented. ...

Nowadays study of input voltage quality on induction motors behavior has become a controversial subject due to the wide application of these motors in the industry. The impact of grid voltage fluctuations on the performance of induction motors can be included in this area. The majority of papers devoted to the influence of voltage fluctuations on the induction motors are focusing only on the so...

The sensorless model predictive force control (SMPFC) is a strong method for controlling the drives of three-phase 4(6)-switch inverter linear induction motors. This kind of inverter can be employed for fault tolerant control in order to solve the problem of open/short circuit in 6-switch inverters (B6). This paper proposed a method for the SMPFC of a linear induction motor (LIM) with a 4-switc...

An intelligent method based on wavelet neural network (WNN) is presented in this study to estimate voltage harmonic distortion waveforms at a non-monitored sensitive load. Voltage harmonics are considered as the main type of waveform distortion in the power quality approach. To detect and analyze voltage harmonics, it is not economical to install power quality monitors (PQMs) at all buses. The ...

Insulator strings with several material and profiles are very common in overhead transmission lines. However, the electric field and voltage distribution of insulator string is uneven which may easily lead to corona, insulators’ surface deterioration and even flashover. So the calculation of the electric field and voltage distribution along them is a very important factor in the operation time....

Multilevel Inverters has big placement advantages in Power Electronics and its application can be mentioned to FACTS tools such as UPFC – D-STATCOM. Therefore, nowadays Multilevel Inverters have created vast field’s research and researchers are trying to present appropriate structures with fewer keys and greater advantages. The main advantages of Multilevel Inverters mentioned are low-key volta...