scholarly journals Autonomous Controller for Flexible Operation of Heat Pumps in Low-Voltage Distribution Network

Energies ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1482 ◽  
Author(s):  
Rakesh Sinha ◽  
Birgitte Bak-Jensen ◽  
Jayakrishnan Radhakrishna Radhakrishna Pillai

This paper aims to unleash the potential of a heat pump (HP) and its storage system, as a flexible consumer load, in the low-voltage (LV) distribution network by introducing an autonomous controller. Steady-state analysis using DigSILENT Power Factory, a power system analysis tool, is performed to verify the proposed hypothesis. The proposed controller manages to operate the individual HP and storage within the recommended operating limits of grid voltage, by sharing flexibility within the specific network. It has the capability of sensing local key control parameters for scheduling, re-scheduling, and decision-making on the operation of individual HPs. It also takes the thermal energy comfort of individual consumers into consideration. Measurement of local parameters such as grid voltage, supply temperature and level of cold water in the storage tank defines the priority for operation of HPs based on operating delays for turning it on and off. This enhances the sharing of flexibility for proper coordination, control, and management of HP systems in LV distribution networks with mutual technical benefits. From the results, the application of the proposed controller is found to be effective to manage grid congestions and local voltage regulation, satisfying the thermal energy requirements of the customer.

Author(s):  
Rilwan O. Oliyide ◽  
Liana M. Cipcigan

The impacts of uptake and electricity load profiles of Electric Vehicles (EVs) and Heat Pumps (HPs) on the low voltage (LV) distribution networks were analyzed. The United Kingdom (UK) has a legally mandated policy concerning reduction of greenhouse gasses (GHGs) emissions. Therefore, the integration of low carbon technologies (LCTs) especially EVs and HPs at the LV networks is expected to increase in the drive to reducing the GHGs emissions. Future uptake scenarios, adapted from the National Grid studies, of EVs and HPs were developed for a real and typical urban LV distribution network in Great Britain (GB). Gridlab-D, an agent-based power system simulation software, was used to model the LV distribution network. The model was run for four different scenarios considering seasonal load profiles and projected EVs and HPs uptakes for each of the year 2020, 2030, 2040 and 2050 respectively. The results were analyzed in terms of transformer loading, voltage profiles of the feeders, and the ampacity loading of the cables for the different scenarios of the years.


Author(s):  
Dilini Almeida ◽  
Jagadeesh Pasupuleti ◽  
Janaka Ekanayake

<span>Solar photovoltaic (PV) power generation has shown a worldwide remarkable growth in recent years. In order to achieve the increasing energy demand, a large number of residential PV units are connected to the low voltage (LV) distribution networks. However, high integration of solar PV could cause negative impacts on distribution grids leading to violations of limits and standards. The voltage rise has been recognized as one of the major implications of increased PV integration, which could significantly restrict the capacity of the distribution network to support higher PV penetration levels. This study addresses the performance of the off-load tap changing transformer under high solar PV penetration and a detailed analysis has been carried out to examine the maximum allowable PV penetration at discrete tap positions of the transformer. The maximum PV penetration has been determined by ensuring that all nodal voltages adhere to grid voltage statutory limits. The simulation results demonstrate that the first two tap positions could be adopted to control the grid voltage under higher PV penetrations thus facilitating further PV influx into the existing network.</span>


Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1121
Author(s):  
Rozmysław Mieński ◽  
Przemysław Urbanek ◽  
Irena Wasiak

The paper includes the analysis of the operation of low-voltage prosumer installation consisting of receivers and electricity sources and equipped with a 3-phase energy storage system. The aim of the storage application is the management of active power within the installation to decrease the total power exchanged with the supplying network and thus reduce energy costs borne by the prosumer. A solution for the effective implementation of the storage system is presented. Apart from the active power management performed according to the prosumer’s needs, the storage inverter provides the ancillary service of voltage regulation in the network according to the requirements of the network operator. A control strategy involving algorithms for voltage regulation without prejudice to the prosumer’s interest is described in the paper. Reactive power is used first as a control signal and if the required voltage effect cannot be reached, then the active power in the controlled phase is additionally changed and the Energy Storage System (ESS) loading is redistributed in phases in such a way that the total active power set by the prosumer program remains unchanged. The efficiency of the control strategy was tested by means of a simulation model in the PSCAD/EMTDC program. The results of the simulations are presented.


Author(s):  
Prof. Amruta Bijwar, Prof. Madhuri Zambre

Nowadays low voltage distribution network is considered as worldwide future generation distribution network. But the major concern is harmonics generation and steps taken to cancel those harmonics. In our proposed work, low voltage distribution network is designed with low voltage and harmonics are cancelled in our method. The combination of current control unit and voltage control unit will give extra reliable power solution to increase the required capacity of low voltage grids. The high voltage protection gears are used in worst environment for low voltage and low current distribution network test is preferable to assess a variety of operation uniqueness. Therefore, it has few restrictions in implementation of economic in addition to process methodologies. In our work a 48V direct current base up-scale low voltage distribution network test is urbanized to allow the copy and surveillance of a variety of phenomenon of direct current distribution networks. The proposed system provide stretchy pattern ability by introduce S-connectors and T-connectors module that will be proscribed distantly, and near real time monitor function through by means of a data acquisition system associated toward the nodes. Each connector be able to calculate Power, Voltage and current with up to 250 kHz frequency. To calculate power quality and to understand the performance of the distribution network, frequency analysis is required along with collected data.


Electrician ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 33
Author(s):  
Osea Zebua ◽  
Noer Soedjarwanto ◽  
Jemi Anggara

Intisari — Stabilitas tegangan telah menjadi perhatian yang penting dalam operasi jaringan distribusi tenaga listrik. Ketidakstabilan tegangan dapat menyebabkan kerusakan pada peralatan-peralatan listrik bila terjadi dalam waktu yang lama. Makalah ini bertujuan untuk merancang dan membuat peralatan deteksi stabilitas tegangan jangka panjang pada jaringan tegangan rendah. Sensor tegangan dan sensor arus digunakan untuk memperoleh data tegangan dan arus. Mikrokontroler Arduino digunakan untuk memproses perhitungan deteksi stabilitas tegangan jangka panjang dari data tegangan yang diperoleh dari sensor. Hasil deteksi kondisi stabilitas tegangan ditampilkan dengan indikator lampu led. Hasil pengujian pada jaringan distribusi tegangan rendah tiga fasa menunjukkan bahwa peralatan dapat mendeteksi gangguan stabilitas tegangan jangka panjang secara online dan dinamis.Kata kunci — Deteksi, stabilitas tegangan jangka panjang, jaringan distribusi tegangan rendah. Abstract — Voltage stability has become important concern in the operation of electric power distribution networks. Voltage instability can cause damage to electrical equipments if it occurs for a long time. This paper aims to design and build long-term voltage stability detection equipment on low-voltage network. Voltage sensors and current sensors are used to obtain voltage and current data. The Arduino microcontroller is used to process calculation of long-term voltage stability detection from data obtained from the sensors. The results of detection of voltage stability conditions are displayed with the LED indicators. Test result on three-phase low-voltage distribution network shows that equipment can detect long–term voltage stability disturbance online and dynamically.Keywords— Detection, long-term voltage stability, low-voltage distribution network.


Energies ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 2173
Author(s):  
Álvaro Rodríguez del Nozal ◽  
Esther Romero-Ramos ◽  
Ángel Luis Trigo-García

Voltage control in active distribution networks must adapt to the unbalanced nature of most of these systems, and this requirement becomes even more apparent at low voltage levels. The use of transformers with on-load tap changers is gaining popularity, and those that allow different tap positions for each of the three phases of the transformer are the most promising. This work tackles the exact approach to the voltage optimization problem of active low-voltage networks when transformers with on-load tap changers are available. A very rigorous approach to the electrical model of all the involved components is used, and common approaches proposed in the literature are avoided. The main aim of the paper is twofold: to demonstrate the importance of being very rigorous in the electrical modeling of all the components to operate in a secure and effective way and to show the greater effectiveness of the decoupled on-load tap changer over the usual on-load tap changer in the voltage regulation problem. A low-voltage benchmark network under different load and distributed generation scenarios is tested with the proposed exact optimal solution to demonstrate its feasibility.


2018 ◽  
Vol 7 (2.28) ◽  
pp. 362
Author(s):  
Raed A. Shalwala

One of the most important operational requirements for any electrical power network for both distribution and transmission level is voltage control. Many studies have been carried out to improve or develop new voltage control techniques to facilitate safe connection of distributed generation. In Saudi Arabia, due to environmental, economic and development perspectives, a wide integration of photovoltaic (PV) genera-tion in distribution network is expected in the near future. This development in the network may cause voltage regulation problems due to the interaction with the existing conventional control system. In a previous paper, a control system has been described using a fuzzy logic control to set the on-line tap changer for the primary substation. In this paper a new control system is proposed for controlling the power factor of individual PV invertors based on observed correlation between net active and reactive power at each connection. A fuzzy logic control has been designed to alter the power factor for the remote invertors from the secondary substation to keep the feeder voltage within the permissible limits. In order to confirm the validity of the proposed method, simulations are carried out for a realistic distribution network with real data for load and solar radiation. Results showing the performance of the new control method are presented and discussed.  


Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1182 ◽  
Author(s):  
Konstantinos Kotsalos ◽  
Ismael Miranda ◽  
Nuno Silva ◽  
Helder Leite

In recent years, the installation of residential Distributed Energy Resources (DER) that produce (mainly rooftop photovoltaics usually bundled with battery system) or consume (electric heat pumps, controllable loads, electric vehicles) electric power is continuously increasing in Low Voltage (LV) distribution networks. Several technical challenges may arise through the massive integration of DER, which have to be addressed by the distribution grid operator. However, DER can provide certain degree of flexibility to the operation of distribution grids, which is generally performed with temporal shifting of energy to be consumed or injected. This work advances a horizon optimization control framework which aims to efficiently schedule the LV network’s operation in day-ahead scale coordinating multiple DER. The main objectives of the proposed control is to ensure secure LV grid operation in the sense of admissible voltage bounds and rated loading conditions for the secondary transformer. The proposed methodology leans on a multi-period three-phase Optimal Power Flow (OPF) addressed as a nonlinear optimization problem. The resulting horizon control scheme is validated within an LV distribution network through multiple case scenarios with high microgeneration and electric vehicle integration providing admissible voltage limits and avoiding unnecessary active power curtailments.


Energies ◽  
2018 ◽  
Vol 11 (5) ◽  
pp. 1156 ◽  
Author(s):  
Nikoleta Andreadou ◽  
Evangelos Kotsakis ◽  
Marcelo Masera

The modernization of the distribution grid requires a huge amount of data to be transmitted and handled by the network. The deployment of Advanced Metering Infrastructure systems results in an increased traffic generated by smart meters. In this work, we examine the smart meter traffic that needs to be accommodated by a real distribution system. Parameters such as the message size and the message transmission frequency are examined and their effect on traffic is showed. Limitations of the system are presented, such as the buffer capacity needs and the maximum message size that can be communicated. For this scope, we have used the parameters of a real distribution network, based on a survey at which the European Distribution System Operators (DSOs) have participated. For the smart meter traffic, we have used two popular specifications, namely the G3-PLC–“G3 Power Line communication” and PRIME–acronym for “PoweRline Intelligent Metering Evolution”, to simulate the characteristics of a system that is widely used in practice. The results can be an insight for further development of the Information and Communication Technology (ICT) systems that control and monitor the Low Voltage (LV) distribution grid. The paper presents an analysis towards identifying the needs of distribution networks with respect to telecommunication data as well as the main parameters that can affect the Inverse Fast Fourier Transform (IFFT) system performance. Identifying such parameters is consequently beneficial to designing more efficient ICT systems for Advanced Metering Infrastructure.


Author(s):  
Satya PRAKASH ◽  
Manoj HANS ◽  
Vikas THORAT

The power distribution network has grown complex and vulnerable as it increases its demand. The system's reliability has become a prominent factor for the end-users, although the continuity of supply in the distribution network still remains a challenge. In order to achieve the same distribution, automation came into the picture. The term “Distribution Automation” usually refers to an advanced switching system, which works as a subsystem of the existing network. The purpose of the subsystem is to offer real-time observation and control in distribution networks and electricity market operations. Consequently, the development of an autonomous system for isolating failures and restoring power for the distribution of LV (low voltage)/MV (medium voltage) can be an attractive solution for improving energy facilities' reliability. Advanced management techniques are devices and algorithms used to analyze, diagnose, and predict conditions in a distribution network, as well as to identify and take appropriate corrective actions to eliminate, mitigate, and prevent power outages and power quality problems. To demonstrate the model, we used a PIC16F877, CT microcontroller, and a power supply unit.


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