On the total power factor of lift systems

Purpose. To obtain relations determining the components of the total losses power with p-q-r power theory for three-phase four-wire energy supply systems, uniquely linking four components: the lowest possible losses power, losses power caused by the reactive power, losses power caused by the instantaneous active power pulsations, losses power caused by current flowing in the neutral wire. Methodology. We have applied concepts of p-q-r power theory, the theory of electrical circuits and mathematical simulation in Matlab package. Results. We have obtained the exact relation, which allows to calculate the total losses power in the three-phase four-wire energy supply system using three components corresponding to the projections of the generalized vectors of voltage and current along the pqr axis coordinates. Originality. For the first time, we have established a mathematical relationship between spatial representation of instantaneous values of the vector components and the total losses power in the three-phase four-wire energy supply systems. Practical value. We have elucidated an issue that using the proposed methodology would create a measuring device for determining the current value of the components of total losses power in three-phase systems. The device operates with measuring information about instantaneous values of currents and voltages.

Industrial robots are controlled by dedicated controllers, which are powered by single-phase or three-phase power supply system. The main power parameters characterizing the power supply system of these robots are: nominal supply voltage (1-phase: 100-120 V, 200-240 V or 3-phase 200-575 V AC), frequency of the supply voltage (50 or 60 Hz), nominal power consumed by industrial robot. The dynamics of power consumption in the power supply system of controlled robot can be studied by recording instantaneous values of voltages and currents in each phase of the power grid. In this article are presented results for measurements of mentioned instantaneous values for chosen single-phase powered robot, taken by specialized recorder. Obtained measurements from recorder allows to calculate numerically various energetic values in the power supply system of robot: peak-peak values, RMS values, coefficients of deformation and values of harmonic amplitudes (FFT), values of active, reactive and apparent power and the power coefficient (tgϕ). The analysis of waveforms of instantaneous values of voltage and current allows to determine the occurrence of transient states during work of robot axes and characterizing its duration and the range of value changes). Carried out analyses can be using to properly design protection systems of the power supply system, at eventual selection of filters for higher harmonics and to determine effective power consumption of studied robot. The analyses of transient states which occurred during work of studied robot in this publication significantly expand the knowledge about the dynamics of power consumption and its possible impact on the quality of electricity in the power supply grid.

A new application of the least error squares (LES) estimation algorithm is given for identifying, in the time domain, the active and reactive power from available samples of voltage and current waveforms. The digital available instruments used to monitor active, reactive and apparent power use such samples. A new definition for the active reactive and apparent power for sinusoidal and nonsinusoidal waveforms is discussed in this paper. It is shown that misleading reactive power compensation could be obtained if the circuit power factor is not well defined. Simulated results are presented for different waveforms, where the authors compare the results obtained with other available techniques.

A new method for generating and measuring active, reactive, and apparent power at power frequencies has been devised. It makes use of digital signal synthesis and discrete Fourier transform (DFT) evaluation based on a single master clock. This results in a significant reduction of synchronizing errors and thus in an uncertainty of only 2.5/spl times/10/sup -6/ (k=1).

The term power theory of circuits can be understood as the state of knowledge on their power properties. In that sense it is a set of true statements, interpretations, definitions and equations describing these properties. The theory of power, understood that way, is a collective product of those who seek an answer to the question why a load with the active power P usually demands a power source with an apparent power S greater than its active power. This question is closely related to the need for interpretation of power phenomena in electric circuits. Another factor is of a practical nature – power theory attempts to answer the question how the apparent power of the source can be reduced without the reduction in the load active power.

The aim of this paper is to evaluate the effect of the converter system on the power factor of the supply network .Therefore a 3-phase, 6-pulse , bridge converter is assembled and connected to a power supply through a 3-phase ac voltage regulator .The theoretical analysis is simulated using Fourier series analysis and Fast Fourier Transform ( FFT ) algorithm . The experimental measurements of distortion factor , displacement factor and total power factor are recorded . The experimental results are shown to be coincident with the theoretical results. The consideration of power factor improvement relative to distortion and displacement factors is discussed.

Paper present the project designed to correcting power factor for domestic, Commercial, Industrial. Which with hope to make the cost and energy usage efficient, because the energy source is depleting due to increase in population. Power factor is the ratio of real power and apparent power. This definition is mathematically represented as kW/kVA where kW is active power and kVA is apparent power (active + reactive). Reactive power is the non-working power generated by the magnetic and inductive load to generate magnetic flux. The increase in reactive power increase the apparent power so the power factor will decrease. Low pF will cause the industry to meet high demand thus making it less efficient. The main aim of this project is to increasing the current power factor of industries from 0.85 to 0.90. Power factor compensation contribute to reduction in current-dependent losses and increase energy efficiency while expanding the reliability of planning for future energy network. As technology develops, the gradual cost and efficiency penalty should reduce. Therefore, automatic power factor compensation device should become cost-effective and smaller device over time. That is the reason this project is using programmable device as it is a miniature architecture device.

The registering device for steady state parameters registration of power supply systems is proposed. This device allows the measurement of active, reactive and apparent power, power factor, voltages, currents and frequency. Gathered data can be transferred to PC through serial data cable.

Most of the two-stage converters for electric bike battery charging comprise of a boost converter for power factor correction (PFC) followed by a dc–dc converter with universal input voltage. These two-stage conversions suffer from poor efficiency and increased component count. In this paper, a single-stage switched inductor Cuk converter based PFC converter is proposed, which offers high step-down gain, low current stress, high efficiency, and reduced component count. The operational analysis and design equations for various components of the proposed converter are carried out in continuous current mode. This paper presents mathematical modeling, analysis, simulation, and experimentation on the proposed converter rated for 500 W, 48 V/10.4 A. The performance investigation of the proposed converter with respect to power quality indices like voltage total harmonic distortion (THD), current THD, and total power factor is carried out with various types of loads such as resistive load and battery load in both constant voltage (CV) and constant current (CC) mode. Furthermore, the dynamic performance of the proposed converter with battery charging is investigated in CV mode and CC mode with respect to the wide range of supply variations.

This paper presents an improved method to generate the compensation reference currents applied to a three-phase line-interactive Uninterruptible Power Supply (UPS) system with series and parallel active power line conditioning capabilities. The reference currents are used to compensate the reactive power and to eliminate harmonic currents generated from the non-linear loads, in a three-phase, four-wire system. The control strategy is based on the synchronous reference frame (SRF) method and the implemented current SRF-based controller does not have the task of compensating negative and zero sequence components at fundamental frequency of the load currents, due to unbalanced loads or unbalance source voltage conditions. Thus, the efficiency of the three-phase UPS system is increased when it is feeding unbalanced single-phase non-linear loads because the PWM parallel converter compensates only the harmonic load currents. Three strategies, employed to generate the reference currents, are discussed, such as, the SRF conventional strategy, the SRF single-phase strategy and the improved SRF single-phase strategy. Besides, the active powers that flow through the parallel PWM converter using the three presented strategies are shown and a comparative analysis of them is made to validate the predicted theoretical results.

The paper describes an improved digital recorder system which is being used to provide reference values of voltage, current, active, reactive and apparent powers and harmonic quantities for three-phase sinusoidal and nonsinusoidal calibrations. The system has been designed to be used in the laboratory at the National Research Council of Canada (NRC) or transported on-site for tests in electrical utility facilities. Test results have shown that for sinusoidal waveforms, the accuracy of the voltage and current measurements of the digital recorder is better than 25 /spl mu/V/V or /spl mu/A/A of full scale and better than 50 /spl mu/W/W of full scale for active and apparent power measurements. The accuracy of the system for measurements under the seven distorted waveforms conditions most commonly used at NRC is better than 50 /spl mu/V/V or /spl mu/A/A of full scale for voltage and current measurements and better than 100 /spl mu/W/W or /spl mu/VA/VA of full scale for active and apparent power measurements.

Electronic devices such as SMPS, UPS, rectifier and electronic ballast primarily require DC power supply. Electronic switching devices draw highly distorted input current (spikes with respect to the line voltage) for a short duration, due to their non-linear nature. This results in interference with other electrical equipment, increase in Total Harmonic Distortion (THD) and poor Power Factor (PF), which further results in poor output voltage regulation. Power factor correction (PFC) circuits are being increasingly used to mitigate the problems associated with poor power factor. This paper discusses an Active Power Factor Correction (APFC) technique using voltage feed forward and voltage feedback loop. It is based upon current wave shaping technique to get the source current in phase with the input voltage. Current wave shaping is achieved by implementing voltage control loop and current control loop. This paper explains the development of boost converter as a power factor correction controller, operating in continuous conduction mode (CCM). The boost converter is also designed to regulate the output voltage. The prototype of boost active PFC has been developed for single-phase rectifier, supplying load of 80W at 400V DC. Analysis has been carried out for different load conditions which prove that the PF can be improved from 0.6 to 0.98∼0.99 with THD reduction.

A power quality monitoring system based on MSP430 is proposed in this paper. The monitoring system uses the high accuracy electronic energy measurement integrated circuit ATT7022E and low power consumption microcontroller. The monitoring system can monitor voltage, current, active power, reactive power, apparent power, active energy, reactive energy, power factor, phase difference, and frequency. The communication function realized the data transmission by General Packet Radio Service. It is showed that the monitoring system is not only an accurate mete of electrical energy, but also to accurately detect the abnormality and record it. The monitoring system is convenient to the power system. Keywords-Power Quality; MSP430; ATT7022E;

A novel optical method for the measurement of ac electric power has been developed. It is mainly based on the electrooptic crystal multiplier, which is designed according to the dual transverse Pockels effect. By using this electro-optic device, the polarized light propagating along the threefold axis of the crystal can be modulated by the product signal of two orthogonal electric fields perpendicular to the light beam. Therefore, by separately converting the load current and load voltage into two transverse electric fields and simultaneously exerting the fields to the crystal, the instantaneous electric power signal can be obtained from the modulated emerging light. The optical sensing unit is merely composed of a polarizer, an electro-optic crystal, and a polarization beam splitter. The active power and apparent power can be measured simultaneously. The experimental results for the measurement of ac electric power employing a lithium niobate (LiNbO/sub 3/ or LN) crystal show good agreement with the theoretical analysis. The uncertainty and sensitivity of the measurement are also discussed. The research work presented in this paper will provide the theoretical and experimental foundation for the practical optical electric power transducer based on the dual transverse Pockels effect.

The rapid growth of smart manufacturing leads to an increase in the power consumption of the equipment used and has the challenges like misuse of equipment, operator safety, and protection of equipment from any electrical disturbances or sudden power surge. This paper aims in creating a smart access control unit with a Dual Access Energy Monitoring (DAEM) system. Here, the equipment is restricted to use by the authorized individual under its working limits. The access control for energy monitoring has been carried out using Radio Frequency Identification (RFID) and IEEE 802.11ac with the design of customized breakout board. The DAEM has been carried out by comparing the electrical characteristics like current, voltage, active power, apparent power, and power factor with their preset warning and trip threshold values. Using DAEM, the electrical circuit overload is prevented ensuring the operator’s safety. Moreover, the timer in the circuit will automatically disconnect the load from the mains after a timeout to prevent unnecessary wastage of energy.