Reference Current Generation for Active Power Filtering in Single-Phase Power System

The study presents a new proposed reference current generation algorithm based on the synchronous reference frame (SRF) conventional algorithm in single-phase power system for an active power filtering. Shunt active power filter (SAPF) is often used as it can mitigate harmonic currents in the AC networks due to its superiority in dynamic-state conditions. The reference current generation algorithm is the most important control algorithms to control SAPF as it has the simplest implementation features. A proposed STF-based fundamental component identifier (STF-FCI) algorithm is implemented for the major improvements such as the removal of the unnecessary cosine function to reduce complexity of algorithm, employment of self-tuning filter (STF) to extract accurate fundamental component and to generate a sinusoidal reference current. The purpose of developing STF-FCI algorithm is to replace low pass filter (LPF) with a mean as it can generate a fast and accurate fundamental reference current to operate the SAPF in reducing the harmonics content of the power system and provide a fast response time in the dynamic-state conditions. This paper is presented under both steady-state which is capacitive (RC) load or inductive (RL) load as well as dynamic condition where capacitive load change to inductive load. The performance of steady-state condition will be evaluated in terms of THD values, ripple factor, power factor and phase difference. Under dynamic-state condition, the dynamic speed will be evaluated to capture the speed of the amplitude change in nonlinear load in a period of time. MATLAB-Simulink is used to design and evaluate the proposed STF-FCI algorithm with mean algorithm and LPF algorithm for comparison purpose. The simulation results had shown the major improvement when THD values, ripple factor, power factor and phase difference are reduced. The response time of the changing load is shorter by using mean algorithm compare to LPF algorithm. The simulation results obtained proved success when the proposed STF-FCI algorithm using mean algorithm are much better than LPF algorithm in steady-state and dynamic conditions under two voltage conditions i.e. ideal and distorted voltage.

Digital controller for active power filter based on P-Q theory under non-ideal main voltages

<span>This paper proposes a control strategy active power filter under non-ideal main voltages. The P-Q Theory is used to generate three-phase active power filter reference currents, but the P-Q Theory has a weakness when implemented under non ideal main voltages. This paper proposes a reference current generation method using modified P-Q Theory under non-ideal main voltages conditions. Before calculating the P-Q Theory, the non-ideal voltage at the source is normalized by using PLL to determine the phase angle which is then carried out by generating an ideal three-phase signal. The proposed method is simulated and implemented in a three-phase active power filter controller. The test results show the improvement in the performance of the P-Q Theory under non ideal main voltages with THD 7.21% to THD 3.29%.</span>

Hybrid Reference Current Generation Theory for Solar Fed UPFC System

The extensive usage of power electronic components creates harmonics in the voltage and current, because of which, the quality of delivered power gets affected. Therefore, it is essential to improve the quality of power, as we reveal in this paper. The problems of load voltage, source current, and power factors are mitigated by utilizing the unified power flow controller (UPFC), in which a combination of series and shunt converters are combined through a DC-link capacitor. To retain the link voltage and to maximize the delivered power, a PV module is introduced with a high gain converter, named the switched clamped diode boost (SCDB) converter, in which the grey wolf optimization (GWO) algorithm is instigated for tracking the maximum power. To retain the link-voltage of the capacitor, the artificial neural network (ANN) is implemented. A proper control of UPFC is highly essential, which is achieved by the reference current generation with the aid of a hybrid algorithm. A genetic algorithm, hybridized with the radial basis function neural network (RBFNN), is utilized for the generation of a switching sequence, and the generated pulse has been given to both the series and shunt converters through the PWM generator. Thus, the source current and load voltage harmonics are mitigated with reactive power compensation, which results in attaining a unity power factor. The projected methodology is simulated by MATLAB and it is perceived that the total harmonic distortion (THD) of 0.84% is attained, with almost a unity power factor, and this is validated with FPGA Spartan 6E hardware.

SAPF for Power Quality Improvement Based on PSODE Optimization Algorithm

PQ phenomenon has gain an overwhelming attention in recent years for extensive use of complicated industrial processes. In the modern world, the usage of intelligent algorithms to enhance power quality is increasing gradually as the present day utility system as a linear model is unsatisfactory and ineffective. This paper emphasis on comparative analysis of PSODE with traditional PSO and DE for the harmonic reduction in source current with optimal tuning of proportional integral (PI) controller gain values. The SAPF is dominant among the power quality conditioners used to limit the current variations that are induced in the utility system because of nonlinear loads. The reference current generation is based on PQ theory. The instantaneous switching of voltage source inverter (VSI) is taken care by hysteresis band current controller (HBCC). The pro-effective simulations are implemented in the MATLAB/SIMULINK environment, which even supports the efficacy of the present day power system.

Power Quality Improvement using DSTATCOM for Power System

Reactive power is created once this undulation is out of point in time with the voltage undulation thanks to inductance or capacitance load. Amp lag volt with associate angle for inductive load, lead volt for capacitor. The KVAR of the system should be compensated in order to smooth running of power system. There are various types of loads i.e. transformers, furnaces, induction motors etc. These types of loads require reactive power to sustain flux because this type of appliance major depends on flux density. Based on reactive power efficiency is regulated and efficiency of the system is incurred. DSTATCOM is a device which manages reactive power in a system. This device had quick management. Distribution synchronous compensator performance is carried out using Algorithm rule. This paper explains learning of reference current generation technique from decoupled amp management i. e p-q theory is based on voltage compensation using converter is utilized in this paper. Reference current developed by management topology are traced by compensator during physical phenomenon band management scheme. STATCOM module with HCC( Hysteresis current control ) square measured , generated and simulated in Matlab software using simulation . DSTATCOM is very efficient in controlling reactive power.

Sensorless PMSM Drive Implementation by Introduction of Maximum Efficiency Characteristics in Reference Current Generation

This paper presents the efficiency improvement in a speed closed-loop controlled permanent magnet synchronous machine (PMSM) sensorless drive. The drive efficiency can be improved by minimizing the inverter and the PMSM losses. These can be influenced by proper selection of DC-bus voltage and switching frequency of the inverter. The direct (d-) and quadrature (q-) axis current references generation methods, discussed in this paper, further improve the efficiency of the drive. Besides zero d-axis current reference control, the maximum torque per ampere (MTPA) characteristic is normally applied to generate the d- and q-axis current references in vector controlled PMSM drives. It assures control with maximum torque per unit of current but cannot assure maximum efficiency. In order to improve efficiency of the PMSM drive, this paper proposes the generation of d- and q-axis current references based on maximum efficiency (ME) characteristic. In the case study, the MTPA and ME characteristics are theoretically evaluated and determined experimentally by measurements on discussed PMSM drive. The obtained characteristics are applied for the d- and q-axis current references generation in the speed closed-loop vector controlled PMSM drive. The measured drive efficiency clearly shows that the use of ME characteristic instead of MTPA characteristic or zero d-axis current in the current references generation improves the efficiency of PMSM drive realizations with position sensor and without it—sensorless control.

Fuzzy hysteresis current control of five phase permanent magnet motor under open-circuit faults

This paper presents a new current controller of a PWM of multiphase PM machines with a fuzzy logic band. With this kind of system it is possible to determine optimal currents references which maximize the torque density of the system when one or two phases are open circuited. We propose in this paper to combine this optimal reference current generation with fuzzy hysteresis control band. This solution allows a good tracking of these unconventional reference currents with a fixed switching frequency for the VSI. The study carried on simulation via software MatLab/Simulink.