Research and development project
of a photovoltaic inverter
(financed jointly by CDTI)
The Center for Industrial Technological Development, E.P.E. (CDTI-E.P.E.) Is a Public Business Entity, under the Ministry of Science, Innovation and Universities, which promotes innovation and technological development of Spanish companies. It is the entity that channels the requests for help and support to the R + D + i projects of Spanish companies in the state and international spheres. Thus, the objective of the CDTI is to contribute to the improvement of the technological level of Spanish companies by developing the following activities:
- Technical-economic evaluation and granting of public aid for innovation through subsidies or partially reimbursable grants for R&D projects developed by companies.
- Management and promotion of Spanish participation in international technological cooperation programs.
- Promotion of the international transfer of business technology and support services for technological innovation.
- Support for the creation and consolidation of technology-based companies.
The project undertaken by Power Electronics was to develop a totally innovative photovoltaic solar inverter, consisting mainly of a functional power block and a control block. The power block would carry out the conversion of the voltage from the arrays of photovoltaic panels, and the control block would be used to configure, display and monitor the equipment.
The main characteristics that the team should have were the following:
- Power up to 3,500 kVA
- 98% minimum efficiency
The development of the project was structured as follows:
- Preliminary studies and requirements.
- Study and definition of topologies.
- Design and development of the inverter
- Prototype manufacturing.
- Prototype validation.
The work methodology proposed in this project was totally focused on achieving the objectives set by Power Electronics.
- Study and create new photovoltaic solar inverter topologies that provide the output with the target voltage values of the project.
- Analyze the control techniques and modulation algorithms associated with the power electronics of the new equipment.
- Design and develop a prototype power converter module based on three-level IGBTs technology for DC / AC conversion.
- Select the electronic components of the topologies under study.
- Develop the hardware of the inverter equipment, both the envelope and the power electronics as well as the control of the components of the equipment.
- Carry out the electrical, electronic and mechanical design of the prototypes according to the topologies and designs made.
- Create and validate a first investor prototype, both at a functional level and in compliance with the specifications and requirements defined in the project.
The requirements study resulted in a document specifying the requirements of the equipment, with a detailed description of them.
With the study and definition of topologies we managed to define the characteristics of the new inverter, as a high level specification, with the main blocks and functions that will define the system, and the steps to follow to begin with its development.
Next, the process of design and development of the equipment with which the electrical drawings were obtained (which include the designs of the power and control electronics), and mechanical, as well as the software associated with the equipment. This phase of the process also included the possible modifications that can be carried out throughout the development of the project, as a result of the functional verification tests and the validation of the integrated prototype.
With the prototypes completed, the testing and validation phase was carried out with which the first DC / DC converter prototype was obtained, validated to meet the project requirements and to operate under the established conditions and use cases.
As a result, a photovoltaic inverter was obtained whose main advantage is the integration into a single device of the power conversion functionality and the transformation to Medium Voltage for the subsequent transport of energy. All this results in a decrease in the cost of the equipment and therefore of the photovoltaic installations. On the other hand, the optimized mechanical design of the equipment and its ventilation systems manages to increase the thermal efficiency of the equipment and therefore the efficiency in its operation. Finally, the control algorithms of the equipment related to the protections, management of gaps, etc. were studied, studying those solutions that, complying with the regulations, will improve the performance and operation of the inverter.
- Grant awarded: 1,537,124 €