Pertti Järventausta

Tampere University | UTA · Department of Electrical Engineering

Controlled electric vehicle (EV) charging at commercial locations has been seen as the key solution to mitigate the negative effects of uncontrolled charging on the power grid. In the scientific literature, EV users’ willingness to participate in charging control has been analyzed, and various control algorithms have been studied. However, there is...

Due to their various benefits, the number of electric vehicles (EVs) is increasing rapidly. Despite the extensive amount of EV charging related research, the power quality impacts of large-scale EV charging are still mostly unknown. In this paper, a data-driven approach is taken to assess the power quality quantities in large-scale commercial charg...

Smart electric vehicle (EV) charging is a widely studied topic, and multiple different solutions have been proposed in the scientific literature to execute various demand response objectives. However, most studies use assumptions and simplifications that may not hold in real‐life situations, and thus, the proposed solutions may have a diminished pr...

https://urn.fi/URN:ISBN:978-952-03-2791-0

Distributed electric power production by small-scale customers is increasing continuously. Photovoltaic production is a popular method of producing self-energy for customers. Additionally, power systems require more flexibility when weather-dependent renewable energy production increases. Small-scale customers can increase the self-consumption of s...

It is expected that a notable share of charging sites will face significant congestions in the future, and thus, an effective utilization of the available charging capacity will be highly needed. It has been shown that unbalanced electric vehicle (EV) charging loads may reduce the charging energy, which can lead to a reduced quality of charging ser...

This paper presents the design and applications of a data collection and supplementary control platform developed for energy-related applications of a modern office building. The challenges and possibilities of such a platform are discussed. The developed platform needed to aggregate and utilize available data and controls in buildings. The platfor...

In the scientific literature, various temporal resolutions have been used to model electric vehicle charging loads. However, in most studies, the used temporal resolution lacks a proper justification. To provide a strengthened theoretical background for all future studies related to electric vehicle charging load modeling, this paper investigates t...

In the scientific literature, it has been a common assumption that electric vehicles (EVs) draw a constant current during the whole charging session. In reality, EV charging profiles are not linear, and the non‐linearities have recently gained more attention. However, a thorough analysis of the influences of different charging profile modelling met...

The adaptive charging algorithms of today divide the available charging capacity of a charging site between the electric vehicles without knowing how much current each vehicle draws in reality. Thus, they are not able to detect deviations between the current set point at the charging station and the real charging current. This leads to a situation...

The inconvenient nature of non-ideal charging characteristics is demonstrated from a power system point of view. A new adaptive charging algorithm that accounts for non-ideal charging characteristics is introduced. The proposed algorithm increases the local network capacity utilization rate and reduces charging times. The first unique element of th...

As electric vehicles (EVs) are emerging, smart and adaptive charging algorithms have become necessary to ensure safe and efficient operation of the grid. In the scientific literature, most of the proposed charging control algorithms focus solely on EV usage-related behaviour, while the charging characteristics of EVs are overlooked. Herein, realist...

Electric vehicle (EV) charging is widely studied in the scientific literature. However, there seems to be a notable research gap regarding the charging power limitations of the on-board chargers of the EVs. In this paper, the present state of the maximum charging powers of the on-board chargers is thoroughly analysed using data from two commercial...

The sub-aggregation of electric vehicles provides significant potential to power systems in the form of ancillary services. This means with smart charging it is possible to shift loads from peak to off-peak hours. For the flexibility from privately owned electric vehicles to be offered to the electricity market, customer participation is crucial; h...

Abstract This study assesses the performance of a multivariate multi‐step charging load prediction approach based on the long short‐term memory (LSTM) and commercial charging data. The major contribution of this study is to provide a comparison of load prediction between various types of charging sites. Real charging data from shopping centres, res...

Microgrids are relatively small-scale electricity distribution systems utilizing local resources that can also include energy storage as well as heat and cool distribution units. Microgrid solutions are deployable in developed and developing countries alike. They can comprise blocks of flats and critical infrastructures such as hospitals; or serve...

The trends of electrification, decentralization, and digitalization underpin the transition of energy systems toward climate neutrality. These trends also create a new need for greater flexibility as situations of peak demand and excess production become acute and matching demand and supply becomes more challenging. The required flexibility can be...

The trends of electrification, decentralization and digitalization underpin the transition of energy systems towards climate neutrality. These trends also create a new need for greater flexibility as situations of peak demand and excess production become acute and matching demand and supply more challenging. The required flexibility can be addresse...

The number of electric vehicle (EV) users is strongly increasing so that today roughly every second registered vehicle in Norway is an EV. To increase the EV utilization, politics, industry and the EV users strongly promote the integration of fast charging infrastructure. While the future demand of fast charging sites is a well-studied topic, not m...

This study presents a practical control method for electric vehicle (EV) charging optimisation for detached and attached houses. The developed EV charging control method utilises real-time measurements to minimise charging costs of up to two EVs in a single household. Since some Finnish distribution system operators have already launched peak power...

It is well known that uncontrolled EV charging may cause high peak loads and overloading. However, limiting the EV charging power may also reduce the total energy, which can be charged into the EV in a certain time period. This might raise concerns especially among full electric vehicle users as they cannot use traditional fuels e.g. gasoline to co...

The profitability of domestic battery energy storage systems has been poor and this is the main barrier to their general use. It is possible to increase profitability by using multiple control targets. Market price-based electricity contracts and power-based distribution tariffs alongside storage of surplus photovoltaic energy make it possible to...

An increasing share of electric vehicles can mean excessive peak loads in low-voltage power distribution networks. Introducing peak shaving mechanisms to the charging systems, such overloads can be mitigated significantly. The first contribution of this study is to quantify the amount of flexibility that electric vehicles can contribute to peak loa...

Installations of photovoltaic (PV) systems on residential buildings have increased over the last few years, and this trend will continue. PV systems can increase the production of sustainable energy. Many homeowners want to do something to decrease their emissions or increase their energy self-sufficiency. The most important issue in the decision...

The formation of local energy systems (LES) is at a very early stage but their number is expected to increase rapidly. This paper aims to investigate the characteristics of the stakeholders and how their characteristics influence the activities they are engaged in regarding the LES emergence process. This way, our study lays the foundation for furt...

Energy systems are in a major process of transition from both technology and business perspective. The amount of distributed generation is increasing, load profiles are changing and new types of controllable and uncontrollable resources are being connected to the system (e.g. storage units, electric vehicles). In general, these resources are called...

The paper discusses electric vehicle (EV) charging control in apartment buildings in cases of high EV penetration. The introduced control method for EV charging utilizes real-time measurements and memorized peak power consumptions to determine a suitable charging power. The aim of the control method is to avoid an unnecessary increase to the...

The creation of future sustainable and efficient energy systems requires a cross-disciplinary approach in engineering education. In order for energy-related engineering students to be prepared for real-world situations after their studies, it is important that, while they are still studying, they obtain the basic skills for handling different conce...

This paper focuses on description of platform a architecture model, which promotes specific smart grid use cases, and integration of MultiPower research laboratory as a part of the platform. The platform is developed in HEILA (Integrated business platform of distributed energy resources) project and aims to merge diverge pilots and laboratories int...

Abstract in English: Small-scale solar power production is a potential part of the solution when the power system of Finland goes climate-neutral and becomes more resource-efficient. Photovoltaic (PV) systems do not necessarily need any support as they are currently profitable. If the energy produced were used for home consumption it would become e...

The popularity of small-scale residential energy production using photovoltaic power generation is predicted to increase. Self-production of electricity for self-consumption has become profitable mainly because of high-distribution costs and taxes imposed by the service providers on commercially produced electricity or because of the subsidies which...

The present energy system is facing various challenges in the near future due to changing demand and productions structures. Novel ideas are required to address the control of large number of the flexible resources. The paper aims to introduce integrated business platform of distributed energy resources in Finland. The platform is used to exchange...

Energy storage enables modification of the customer load profile from the grid perspective without leading to a decrease in comfort level. To meet the future challenges of the energy sector, distribution system operators (DSOs) in Finland have recently discussed power-based distribution tariffs (PBDTs) for small customers. The current distribution...

Battery energy storage (BES) systems have high capital costs and low operational costs. This means that in order to introduce profitable BES applications, a high utilization rate should be achieved. The target of this study was to analyze the profitability of the BES system connected to a low voltage distribution network. The BES system is used for...

Climate change and global economic pressures are strong drivers for energy economies to transition towards climate-neutrality, low-carbon economy and better energy and resource efficiencies. The response to these pressures, namely the increased use of renewable energy, creates a set of new challenges related to supply-demand balance for energy poli...

Traditional energy market is currently in transition towards a more flexible energy system in which energy generation is decentralized and based on renewable energy sources, technical platforms are intelligent, vast amount of data is generated and analyzed, and multiple actors are able to participate in various aspects of the energy process. End us...

The constantly spreading smart meters open new possibilities for load profiling. With smart meter measurements, standard customer class load profiles can be updated, customers can be clustered into similarly behaving groups, or individual load profiles can be created. This paper studies how these new smart meter data -based load profiling methods a...

To reach the 2030 decarbonization targets, EU Member States develop national strategies. We examine the views of key stakeholders in Finland to outline how those responsible for developing, steering and implementing the energy system assess the various solutions. The Finnish choices are of interest owing to the mixture of assets, constraints and pa...