Peak Clipping Research Articles

Analyzing Peak Clipping for Load Factor Improvement: Real Case Studies of a Solar Power Plant in a University Campus

Analyzing Peak Clipping for Load Factor Improvement: Real Case Studies of a Solar Power Plant in a University Campus

A Rolling-Adaptive Peak Clipping Control Strategy Coordinating RBE Recycling and PV Consumption

Electrified railway is one of the major users of electricity in the power system. The access of energy storage system (ESS) effectively solves the problems of peak traction load (TL) shock and regenerative braking energy (RBE) recycling, and the access of photovoltaic (PV) system improves environmental and economic benefits. However, in the current control strategy based on the electrified railway with ESS and PV, there are still problems of less optimal overall peak clipping effect of TL and insufficient penetration of renewable energy sources (RES) due to low utilization and lack of pre-processing capacity of ESS. Therefore, this paper proposes a rolling-adaptive peak clipping (RAPC) control strategy coordinating RBE recycling and PV consumption. Firstly, perform rolling peak clipping through dynamically divided implementation windows to make full use of the available energy in each time period. Secondly, according to the state of charge (SOC) of ESS and the specific working condition of TL, the ESS output is modified accordingly to perform adaptive deep peak clipping maximizing the consumption of PV energy and RBE. The simulation verified that the proposed strategy can improve the overall peak-clipping effect of TL, and achieve full recovery of RBE and complete consumption of PV energy under the same ESS configuration compared to the global optimization method. The results show that the RAPC control strategy can realize optimal peak-clipping and RBE utilization, and increase the PV penetration with limited ESS capacity, thus improving the economic benefits of the traction power supply system (TPSS) and promoting the energy transition of TPSS.

Real-Time Control Strategy of Tractive Load Peak Clipping and Valley Filling Based on Model Predictive Control

Access to energy storage devices (ESDs) is an effective way to solve the peak traction load shock and Regenerative Braking Energy (RBE) recycling. However, in the real-time operation of the system, there are problems of prediction errors affecting the control results and the problem of energy storage “dead time.” This article analyzes the mechanism of the energy storage “dead-time” problem and aims to solve this problem without increasing the energy storage capacity. Therefore, this article combines the ideas of rolling optimization and predictive control in the model predictive control (MPC) method and proposes an MPC method based on the adaptive correction (AC-MPC) of the State of Charge (SOC) of ESD. The predictive control can ensure the accuracy of power correction; the rolling optimization can reduce the global impact of each correction and reduce the complexity of the calculation. In addition, the rolling prediction in the rolling optimization link reduces the prediction error by reducing the prediction time scale, thus reducing the impact of the prediction error on the control results. The experimental data show that the proposed control strategy can effectively solve the two problems mentioned above, ensure the effect of peak reduction and RBE recovery, and improve the economy of system operation.

AI Powered IoT based Home Energy Management System towards DG Integration

This paper attempts to present an Internet of Things (IoT) based Home Energy Management System (HEMS) to accommodate Artificial Intelligence (AI) based Distributed Generation (DG) Integration in Smart Micro Grid environment. This work presents the feasibility of load and weather Big Data acquisition, online load forecasting /prediction, online load priority assignment, online peak clipping estimation on the cloud (Thingspeak). Load priority and peak clipping Demand Side Management (DSM) Techniques are used to run Load Management Algorithm (LMA) on the cloud which ultimately executes AI-based DG Integration at the load center. Based on the real time load and weather Big Data Load Priority Table (LPT) is generated on the cloud in order to assign the priority to the loads of the load center and online forecasting is also carried out on the cloud to estimate Total Power PT using Artificial Neural Network (ANN) and five different ML algorithms which are later utilized to estimate Threshold /Peak Clipping Power PTh. Using these LPT and PTh values LMA executes AI-based DG Integration. To that end, a novel IoT-based HEMS is designed and fabricated to run cloud-based LMA in order to accommodate proposed DG Integration. Amongst all the prediction algorithms trained on the cloud to estimate PTh, Linear Regression (LR) ML algorithm is witnessed to have lowest RMSE of 4.44e−13, MSE of 1.97e−25 and MAE of 2.11e−13. MATLAB 2018b licensed version is used to run ANN and ML algorithms based forecasting/prediction on the cloud.

Demand Side Management Techniques for Peak Reduction

Industrial growth is the back bone for the development of any nation. Industries are mainly dependent on electrical energy. But from the various studies, the sources for electrical energy are decreasing gradually, and in turn, the gap is increasing between the supplier and the load. The solution for this scenario is optimal utilization of resources. To overcome this problem , the concept Demand Side Management (DSM) has emerged in Power System Planning and Management. The principle objective of DSM is mutual understanding between the supplier and the consumer for maximizing benefits and minimizing inconvenience. The aim of this research work is selection and application of appropriate DSM techniques to industrial and domestic loads for peak load management and energy conservation, that is to control the maximum demand during the peak hours and saving the energy by using the energy efficient and intelligent appliances like air conditioners and water heaters. DSM includes techniques like the End Use Equipment Control, the Load Priority Technique, he Peak Clipping & Valley filling, the Differential Tariff and Resizing of the equipment. Depending upon the application, all the techniques may be applied sequentially, or only a few of them can be applied. There is a lot of ambiguity in the selection of DSM techniques, because the application of each DSM technique depends on the case study and the problem associated with the respective case study. After comprehensive understanding of a particular case, a thorough investigation and subsequent data analysis pave the way for the selection of appropriate DSM technique/techniques

Load Shifting and Peak Clipping for Reducing Energy Consumption in an Indian University Campus

This paper analyzes the intelligent use of time-varying electrical load via developing efficient energy utilization patterns using demand-side management (DSM) strategies. This approach helps distribution utilities decrease maximum demand and electrical energy billing costs. A case study of DSM implementation of electric energy utility for an educational building Alagappa Chettiar Government College of Engineering and Technology (ACGCET) campus was simulated. The new optimum energy load model was established for peak and off-peak periods from the system’s existing load profile using peak clipping and load shifting DSM techniques. The result reflects a significant reduction in maximum demand from 189 kW to 170 kW and a reduction in annual electricity billing cost from $11,340 to $10,200 (approximately 10%) in the upgraded system. This work highlights the importance of time of day (TOD) tariff structure consumers that aid reduction in their distribution system’s maximum demand and demand charges.

Joint Peak Clipping and Load Scheduling Based on User Behavior Monitoring in an IoT Platform

This article proposes a demand-side management (DSM) mechanism for energy management based on user behavior monitoring in a smart home. In the proposed mechanism, first through an analytic hierarchy process, the most influential factors related to power consumption are extracted. Next, by employing the K-means algorithm on the extracted factors, users are clustered. The user's clusters, the power grid state, and the user's real-time power consumption are inputs for a control unit. We present an interactive algorithm for the control unit, which causes peak reduction using peak clipping techniques. We also develop a day-ahead scheduling mechanism, which optimizes the load based on load shifting techniques. The proposed system is implemented in an Internet of Things (IoT) testbed consisting of four tiers-sensors, home gateways, server, and web portal. The central server is based on the Kaa IoT platform, an open-source platform widely used in the IoT domain. The performance of the proposed system is evaluated through simulation and a case study. Results confirm that the proposed system reduces the power consumption and costs for users and improves power grid performance in terms of the peak-to-average ratio.

Implementasi Demand Side Management (DSM) Pada Instalasi Pengolahan Air PDAM Mulia Baru

The Mulia Baru Water Treatment Plant (IPA) is one of 6 Water Treatment Plants owned by the Ketapang Regency PDAM that is indicated to use a large amount of electrical energy. From the data obtained during one year (January to December 2017), the average monthly electricity consumption is 128,016,667 kWh with an average.Drinking Water Production Volume per month of 144,119,833 m3. Therefore the average Specific Energy Consumption (SEC) value for 2017 is 0.89. Through the application of the Peak Clipping and Strategic Concervation DSM program, a decrease in peak load occurs at a time interval between 17:00 and 22:00, in this condition a decrease in load of 0.47 (%).For greater savings, it is necessary to schedule the operation of large loads at peak load times.

Analysis and Mitigation of Clipping Noise in Layered ACO-OFDM Based Visible Light Communication Systems

Due to the limited dynamic range of the off-the-shelf electrical and optical components, deliberate digital clipping (DDC) is widely applied to optical orthogonal frequency division multiplexing (OFDM) based visible light communication systems. In this paper, we present a theoretical characterization of the layered asymmetrically clipped optical OFDM (ACO-OFDM) signals subject to peak clipping. We decouple a clipped $L$ -layer ACO-OFDM symbol to $L$ single-layer ACO-OFDM symbols, each corresponding to a layer, and show that these symbols are subject to symmetrical peak clippings at random levels. Using Bussgang’s theorem, the resulting attenuation factors and variances of the additive noise associated with each layer are derived. It is shown that the clipping noise caused by the DDC mainly falls onto the first layer, and its impact is gradually reduced in the subsequent layers. In order to combat the clipping noise, a novel receiver based on decision aided reconstruction is proposed. Simulation results show that the proposed receiver can effectively mitigate the clipping noise, leading to significant improvement of bit error rates over the conventional receiver.

PAPR REDUCTION USING EFFICIENT PEAK CLIPPING TECHNIQUE IN OFDM SYSTEMS

Orthogonal frequency division multiplexing (OFDM) is the most popular modulation technique which is used for high speed communication system. It provides high spectral efficiency and low implementation complexity. However the main issue of OFDM is its high Peak to Average Power Ratio (PAPR) which results from sum of several sinusoidal signals. So the Efficient Peak Clipping Technique has used to reduce the peak-to-average power ratio (PAPR) of OFDM systems. By introducing different number of Subcarriers N, Up sampling factor k, Number of all samples n, Mapping Order M, and Phase Offset P, a desired level of PAPR has been achieved. At the same time by introducing the proposed technique better tradeoff between BER and SNR has been maintained.

A New Peak Clipping Algorithm for PAPR Reduction in OFDM

The peak-to-average-power ratio (PAPR) is one of the major problems of Orthogonal Frequency Division Multiplexing (OFDM) systems. Various PAPR reduction techniques have been given in the past. Among these techniques, the clipping technique has been widely adopted as a practical scheme because of its low computational complexity and simplicity in implementation, while the pre-coding technique is known to provide good PAPR reduction with improved bit error rate (BER) performance. In this paper, a combination of clipping and pre-coding is proposed to reduce PAPR with almost same BER performance as given by individual pre-coding technique. The proposed technique gives good result because the clipping noise of combined scheme would be less than that of single clipping. Also the clipping used in this paper is not hard as used in conventional clipping. A new clipping algorithm is proposed which is based on averaging of high amplitude samples. In addition, an another pulse shape called modified Bartlett Hanning (MBH) is proposed to generate pre-coding matrix and its performance is compared with square root raised cosine (SQRC) pulse shape.dB.

Heuristic approach for peak regions estimation in gamma-ray spectra measured by a NaI detector

In this paper, a heuristic approach based on Slavic's peak searching method has been employed to estimate the width of peak regions for background removing. Synthetic and experimental data are used to test this method. With the estimated peak regions using the proposed method in the whole spectrum, we find it is simple and effective enough to be used together with the Statistics-sensitive Nonlinear Iterative Peak–Clipping method.

Speech and Music Quality Ratings for Linear and Nonlinear Hearing Aid Circuitry

This study evaluated quality ratings for speech and music stimuli processed using peak clipping (PC), compression limiting (CL), and wide-dynamic range compression (WDRC) hearing aid circuitry. Eighteen listeners with mild-to-moderate hearing loss were binaurally fitted with behind-the-ear (BTE) hearing aids and instructed to rate the quality of speech under various conditions in quiet and noise and two genres of music. Results for speech revealed a slight preference for WDRC at 80 dB SPL, and equivalent ratings for the three circuits under all other listening conditions. Music ratings revealed a marginally significant preference for WDRC and a preference for classical over popular music. For music, judgments on pleasantness were the most influential on overall circuit preference.

Experimental Evaluation of Different Methods of Limiting the Maximum Output of Hearing Aids

A series of experiments designed to test the preferences of people with moderate to profound hearing losses for limiting the output of hearing aids by using peak clipping (PC), fast compression limiting (FCL), PC and FCL, and these three methods in combination with slow compression limiting (SCL) was conducted. Nineteen participants with moderate to profound sensorineural or mixed losses were recruited. In the first experiment, preferences for either PC or FCL were tested in a field trial in the participants' usual environments.A second experiment examined the acceptance of PC, FCL, and FCL + PC, using paired comparisons in a laboratory setting. The third experiment involved further paired comparisons in the laboratory to evaluate whether participants preferred PC, FCL, PC and FCL combined, or the three methods when combined with SCL. The participants showed no statistically significant preferences for either peak clipping or fast compression limiting in the field trial. In the laboratory trial, both FCL + PC and FCL were significantly preferred over PC alone, and the addition of FCL to PC was most advantageous to participants who required the lowest maximum limiting output. The most dramatic laboratory result was the convincing preference in paired comparison testing of combining SCL with PC and/or FCL. Slow compression limiting appears to be a desirable feature in hearing aids for clients with a moderate to profound hearing loss. Preferences were not as pronounced when peak clipping, fast compression limiting, and peak clipping plus fast compression limiting were compared, but participants favored the condition that had the least amount of peak clipping.

補聴器による語音聴取に対する衝撃音の影響

The purpose of this investigation was to examine how speech intelligibility is affected by an impact noise for listeners wearing a hearing aid. In this experiment, the subjects consisted of 10 sensorineural hearing-impaired and five normal hearing listeners. Sentences mixed with a single impact noise or without noise were presented randomly to subjects wearing a hearing aid. The hearing aids used in this experiment were digital hearing aids (TD-1) which compress the signals in the time domain, and conventional analog hearing aids with peak clipping (PC) or automatic gain control (AGC). The results demonstrated that the intelligibility of sentences mixed with an impact noise decreased when the hearing-impaired subjects wore the analog hearing aid. Interestingly, the decline in intelligibility arose in the phrases not only after the impact noise, but also before the noise. On the other hand, there was none or only a slight decrease in intelligibility, regardless of the impact noise, in the normal hearing subjects and the hearing-impaired wearing TD-1. These results indicate that the compression method adopted by TD-1 is useful for patients with sensorineural hearing loss even under conditions with impact noises. We believe that incompletely suppressed impact noises mask the speech signal, and thus causes a decrease in the speech recognition of hearing-impaired subjects wearing analog hearing aids.

Value of in situ measurement for evaluating effective hearing aid amplification at high sound pressure levels

A careful hearing aid fitting requires consideration of various characteristics of inner ear pathology. The recruitment phenomenon restricts the dynamic range of the impaired hearing and this increase the demands on the hearing aids for a satisfactory correction of the frequency characteristics as well as for an intensity reduction at higher sound pressure level SPL. For years data from coupler or KEMAR (Knowles Electronics Manikin of Acoustical Research) have served to estimate the real ear gain of a hearing aid at higher input levels. In previous papers we reported on some of the differences between coupler measurement and probe tube measurement. The object of this study was to investigate the differences between these two methods at higher input SPL. Therefore, we measured the real ear insertion gain as well as the output characteristics with a 2 cm3 coupler in 80 patients at input levels of 60 dB, 80 dB and 100 dB. The results show differences between the two methods up to 30 dB in both directions in the single patient. Furthermore, the highest compression rate was found in the middle and high frequency range which are crucial for speech discrimination. Consequently, probe tube measurement should be used not only to adjust the frequency characteristics of the hearing aid but also to characterise the real effect of Automatic Gain Control AGC and Peak Clipping PC on insertion gain at higher input SPL. Multichannel hearing aids should be used whenever possible to reduce the disturbances to speech discrimination at low frequencies.

Dynamic-range reduction by peak clipping or compression and its effects on phoneme perception in hearing-impaired listeners.

In this study, differences between dynamic-range reduction by peak clipping and single-channel compression for phoneme perception through conventional hearing aids have been investigated. The results from 16 hearing-impaired listeners show that compression limiting yields significantly better phoneme identification scores than does peak clipping if a strong reduction of the dynamic range has to be effected. In addition, some qualitative differences in confusion patterns could be established: the perception of low-frequency information appears to be relatively important in compression limiting; the perception of plosiveness is less important.

Dynamic-Range Reduction by Peak Clipping or Compression and its Effects on Phoneme Perception in Hearing-Impaired Listeners

Dynamic-Range Reduction by Peak Clipping or Compression and its Effects on Phoneme Perception in Hearing-Impaired Listeners

Objective Measures of Peak Clipping and Threshold Crossings in Continuous Speech

This study reports data on the statistics of instantaneous speech levels in continuous speech samples, with special emphasis on threshold crossings and other quantities related to peak clipping. All clipping thresholds for each speech sample are defined with respect to the individual speech level for that sample, specified in equivalent peak level (epl). Speech clipping is also treated as speech-correlated noise by assuming that it is caused not by a voltage limiting process, as actually occurs, but by an additive “phantom signal” that will cause the original signal to appear to be clipped. Empirical measures are obtained for the percent time a clipping level is exceeded, for the relation between phantom signal (i.e., noise) power and clipping level, and for the loss in signal power resulting from clipping. The relation is also established between epl and average (rms) power to allow signal power and signal-to-clipping noise levels to be specified.

Objective Measures of Peak Clipping and Threshold Crossings in Continuous Speech

This study reports data on the statistics of instantaneous speech levels in continuous speech samples, with special emphasis on threshold crossings and other quantities related to peak clipping. Peak clipping is also treated as speech-correlated noise by assuming that it is caused not by a voltage limiting process, as actually occurs, but by an additive “phantom noise signal” that will cause the original signal to appear to be clipped. Empirical measures are obtained for the percent time a clipping level is exceeded and for the relation between phantom signal (noise) power and clipping level. For each speech sample, clipping levels and power measurements are specified with respect to the equivalent peak level (epl), a recently developed speech level measure [J. Acoust. Soc. Amer. 44, 695–699, (1968)]