| 1. |
- Heuvelmans, Matthijs, 1982-
(författare)
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Modelling of Solar Irradiation on PV Cells and Panels
- 2014
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Ingår i: 14th International Symposium Topical Problems in the Field of Electrical and Power Engineering & Doctoral School of Energy and Geotehcnology II. ; , s. 142-149
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Konferensbidrag (refereegranskat)abstract
- In this paper, two methods for modelling solar irradiation are demonstrated, and verified by test results. The work is aimed at producing in-plane irradiation values that can serve as input for a photovoltaic (PV) module model. The aim is limited to grid-connected applications. The usefulness of the work lies in the fact that it can support making planning decisions without requiring detailed knowledge from the user, for example an installer of small-scale photovoltaic systems.Of the two methods, one relies on replicating the stochastic properties of the underlying process and the other method is aimed at creating a daily average irradiation profile. When used with a polycrystalline PV module model, bothmethods show good test results and similar accuracy. It is therefore suggested to use the method using average values, since it is simpler compared to the other method. It is accurate enough to be applied in a software tool.
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| 2. |
- Heuvelmans, Matthijs, 1982-, et al.
(författare)
-
Power Semiconductors for Voltage Source Converters in HVDC and STATCOM Applications
- 2015
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- With a steady increase in electricity consumption in both developed and developing regions combined with demand for sustainable energy infrastructure, trends towards more renewable energy sources and more open electricity markets are becoming more prominent. High Voltage DC (HVDC) connections and Static Synchronous Compensators (STATCOM) are two technologies that play a part in fulfilling this increasing demand. HVDC is beneficial in cases where production and consumption are geographically separated or for sub-sea cable transmissions. STATCOM helps to increase the capacity of AC transmission in addition to enhancing ac-grid voltage quality. A key component in both HVDC and STATCOM converters are the semiconductor switching devices. Switching devices have a fundamental impact on performance levels that can be obtained in terms of efficiency, reliability and functionality. This paper serves two purposes. The first is to give a historical overview of switching devices employed in HVDC transmission systems and STATCOMs. This starts with the use of mercury arc valves some 100 years ago and it continues with the semiconductor switching devices that are currently being employed in HVDC and STATCOM applications. A second purpose of this paper is to indicate developments in switching technology that are of interest for HVDC and STATCOM. In order to do this in a structured manner, the technologies are compared in terms of efficiency, reliability and functionality. Developments that are discussed in this paper are the emergence of Silicon Carbide (SiC) devices and the improvement of Insulated Gate Bipolar Transistor (IGBT) and Integrated Gate Commutated Thyristor (IGCT) devices in silicon. Currently, applications are based on silicon based thyristors or IGBT technology. Line commutated converters based on thyristors are cost-effective and efficient; however, due to lack of controlled turn-off capability, functionality is limited. Using voltage source converter technology with semiconductors having turn-off capability, such as the IGBT, increased functionality is obtained. The IGCT, a gate controlled thyristor with turn-off capability, has lower conduction losses compared to an IGBT with the same active area. In case a modular multilevel converter is used, the switching frequency of the individual switches can be reduced for the same performance. This leads to a shift towards the importance of having low conduction losses as opposed to low switching losses. A further shift can be achieved by using soft-switching techniques. Regarding SiC devices, different maturity is reached for unipolar and bipolar devices. Unipolar devices in SiC have been marketed successfully at low voltages (≤ 1700V). An example is SiC Schottky diodes for power factor correctors. For the voltages typically applied in HVDC and STATCOM, the drift region resistance would impose serious limitations on efficiency (if high current densities are used). Bipolar devices such as SiC IGBTs and IGCTs have been demonstrated in laboratory setups and results have been published; however, reliable operation is currently impeded due to the propagation of crystal lattice defects which causes rapid degradation of such devices.
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| 3. |
- Heuvelmans, Matthijs, 1982-, et al.
(författare)
-
Soft-Switching Cells for High-Power Converters
- 2014
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Ingår i: Industrial Electronics Society, IECON 2014 - 40th Annual Conference of the IEEE. - : IEEE conference proceedings. ; , s. 1806-1812
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Konferensbidrag (refereegranskat)abstract
- This paper describes the use of the Auxiliary Reso-nant Commutated Pole (ARCP) converter topology for the cellsof a Modular Multilevel Converter. The workings of the ARCPtopology are explained as well as the calculation method usedto compare the efficiency to a conventional solution. Comparisonis done for an HVDC as well as for a STATCOM application.In both cases, use of the ARCP topology can lead to significantreductions in switching losses. The implications of these findingsare dealt with as well. These include a higher possible switchingfrequency and a higher practically feasible cell voltage.
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