Projects / Programmes
Micro-inverter for solar panels
| Code |
Science |
Field |
Subfield |
| 2.12.00 |
Engineering sciences and technologies |
Electric devices |
|
| Code |
Science |
Field |
| T190 |
Technological sciences |
Electrical engineering |
| Code |
Science |
Field |
| 2.02 |
Engineering and Technology |
Electrical engineering, Electronic engineering, Information engineering |
micro inverter, photovoltaic system, optimal inverter structure, integration of components, control realization for a system of micro invertes, communication between micro inverters and power meters, control realization for a systems of power plants with micro inverters, smart grids compatibility
Researchers (26)
Organisations (3)
Abstract
The project proposal has three goals:
The first and main goal is the development of a new Micro-Inverter (MI) concept for solar panels. The developed MI must fulfill the following criteria: its size must be small; the efficiency must exceed 95%; it must be realized without electrolytic capacitors, and it must provide assure galvanic isolation between the solar panel and AC output of the inverter. This will be achieved using an innovative approach by merging individual components and functionalities. The developed MI must fulfill all standards for MIs. Its local subordinate control units will communicate with the superordinate MI group central control unit.
The second goal is the development of a MI Group Central Control Unit (MIGCCU). It will be developed as a modular board able to operate as a part of a Smart Power Meter (SPM) or as a part of a standalone unit. The MIGCCU will use wireless communication with subordinate control units in individual MIs to get information about their status and available resources. The developed control algorithm running on the MIGCCU will provide references for the reactive power and in exceptional situations also references for reduction of the active power generation in individual MIs with the aim to assure the optimal distribution of reactive and active power generation among individual MIs. The MIGCCU will represent the entire group of IMs MIs toward the superior Low-Voltage Distribution Network Control (LVDNC) as a single Photovoltaic Power Plant (PVPP), providing information about PVPP status, electricity production and available resources. Implemented in the Smart Grid compatible SPM, the MIGCCU will use SPM communication to exchange information with the superordinate LVDNC implemented on the low-voltage distribution network data-concentrator.
The third goal is to develop the Low-Voltage Distribution Network Control (LVDNC) algorithm and to implement it on the low-voltage distribution network data-concentrator. The data-concentrators already exist in the smart metering systems. They collect data from the SPMs and transfer it to the superordinate system. A new generation of emerging high performance SPMs and data-concentrators with Smart Grid compatible robust high-speed communication will be adapted and modified to be suitable for implementation of developed LVDNC algorithms. This will enable an appropriate data exchange between the data-concentrator with implemented control algorithm and SPMs with MIGCCUs. Based on the values of the voltages, currents, active and reactive powers, statuses and available resources, collected form individual SPMs with MIGCCUs, the developed LVDNC algorithm will determine references for the reactive and in the case of emergency also for the active power generation. The control algorithm will assure stable network operation (primary aim), required power quality (voltage profiles) and minimization of transmission losses (secondary aims). The data-concentrator will provide the superordinate systems with summary information about the status, resources and power generation or consumption of the entire controlled low-voltage distribution network, which can be used in demand side management, including virtual power plant conceptss.
The proposed project merges research and development activities of companies Iskra Avtoelektrika d.d. and Iskraemeco d.d., University of Maribor and TECES toward development of a new, on the marked yet not existing complete solution, containing fully Smart Grid compatible and functional MI, MIGCCU integrated in the SPM and LVDNC algorithm implemented on the data-concentrator. Both companies are the project co-financiers and beneficiaries. Iskra Avtoelektrika d.d. is a global player on the marked of electric drives and propulsion systems, emerging with new product on the global marked of micro-inverters. Iskraemeco d.d. is among the leading world providers of devices and systems for electric energy measuring, registration and billing
Significance for science
In the scope of the research project the world novelties in the fields of Micro-Inverter (MI) concepts, Micro-Inverter Group Central Control Unit (MIGCCU), and local Low-Voltage Distribution Network Control (LVDNC) have been introduced. A completely new concept of a micro-inverter has been introduced, where a high-frequency link, a pulse-dense modulation and a decoupling circuit, which reduces the required capacitor size, were applied. The micro-inverter is able to accept the reference values for the reactive power generation and the active power curtailment. A completely new element, the MIGCCU, has been introduced. It exchanges information with MIs and LVDNC. Based on reference values received from LVDNC, the MIGCCU generates the reference values for the reactive power generation and active power curtailment for each individual MI, where the nonlinear efficiency characteristics of the photovoltaic module and MI are considered together with actual operating conditions of individual IMs. For the given reactive power generation, its algorithm provides the maximal active power output of the entire photovoltaic power plant equipped with micro-inverters. The LVDNC is a new element that has been introduced in the low-voltage distribution network. It acquires actual information about the voltages, current and powers from individual smart meters in the network. Based on this information it determines the optimal reference values for the reactive power generation and active power curtailment of individual photovoltaic power plants equipped with MIGCCUs and MIs. The aim of its algorithm is to provide a proper voltage profile in the distribution network and to reduce the network losses related with energy transmission. In order to test and evaluate the proposed solutions a unique and flexible experimental system has been established. Based on available measurements chains, signal processing, communications and control algorithms it enables a full control of its elements. The experimental system represents an infrastructure indispensable for the development, testing and evaluation of energy management systems and smart grid solutions.
Significance for the country
The impact of the research project on the development of Slovenia is multilateral. In the scope of the project a new knowledge has been acquired. It has been disseminated in research and scientific community, industry, education system and public services. In the research and scientific community, publications in the form of articles and conference papers contribute to the increased level of knowledge and exchange of new ideas. In the industry, this knowledge has already been at least partially transferred into new or improved products and new or improved technological solutions, improving the competitiveness of local industry on global market. In is to expect that it will result also in the increased incomes and new jobs. In the education system, the new knowledge has already been included in the curriculum for graduated, post graduated and Ph.D. students. This includes lectures, exercises and laboratory work, which all contributes to the dissemination of knowledge. The results of the project have already been presented to the distribution system operators, grid companies and energy suppliers. According to the data presented by the Elektro Inštitut Milan Vidmar (EIMV), the investment in the distribution network, requited to enable the installation of 1 kWp photovoltaic system, is between 400 and 500 EUR. The results of this project clearly show that these costs could be substantially reduced by the implementation of developed solutions in the form of “active” photovoltaic power plants and local low-voltage distribution network control. In this way, additional “active” photovoltaic power plants could be installed in the existing distribution networks without substantial additional costs.
Most important scientific results
Annual report
2013,
2014,
2015,
final report
Most important socioeconomically and culturally relevant results
Annual report
2013,
2014,
2015,
final report
