The EU has concluded that it needs a fully functioning and integrated internal electricity market to face the challenges of integrating renewable energy sources into the electricity grid. The European Commission has created guidelines for what the legislation is supposed to contain to create such a market. The so called grid codes are today around ten codes which successively are being implemented in national legislation for all member states. They regard connection-, marketand operation of the electricity grid and consists of several legal requirements for all member states. This study is divided in three parts. In the first part challenges with more renewable energy sources are described and the technical strategies that are suitable to solve those challenges. The second part describes an analysis of the connection- and operational codes on behalf of Ellevio, a distribution system operator in Sweden. They are interested in how the new legislation will affect their work and which new costs that will appear. The third part contains an overall study about the German electricity system since they have a lot of renewable energy sources in their production. The purpose was to see how they have handled challenges within their grid and their view on the new legislation. The overall result in this study was that the grid codes will change the role for Ellevio, which in the following years will have to handle higher information flow between grid users and Svenska kraftnät, which is the transmission system operator in Sweden. An another result was that the technical strategies are included in the legal requirements of the codes and that the legal requirements have been influenced to a great extent by the current German legislation.

Grid codes are becoming more demanding on power generating units due to the factthat the complexity of the power grid is increasing. The penetration of wind powerhas grown over the last years and it is clear that wind farms need to be addressedwith the same type of grid codes as conventional generation units. There is howeveran undeniable difference between the technology in conventional synchronousgeneration units, and the asynchronous generation units in wind farms. This thesis has reviewed the current grid code in Sweden and compared it to the newcode proposed by ENTSO-E, “the Requirements for Generators”, in the aspect ofwind farms with an installed power of 30 MW or more. The comparison has beencomplemented by an analysis of how wind farms of two different technologies(Doubly fed induction generators and full power converters) can meet therequirements and technical proposals have been given on how to be able to meetcompliance with the new grid codes. The Requirements for Generators contains many non-exhaustive and optionalrequirements, because of this it has been difficult to, at this stage, exactly point outthe technical impact on the grid connection of future wind farms in Sweden. For manyof the requirements in the Requirements for Generators there is no equivalent in theSwedish Grid Code (SvK FS2005:2) but counterparts can thus be found in existingpractices and therefor does not imply any major differences for the industry. The requirements of frequency regulation, synthetic inertia and reactive powercapability are the main components of the RfG which will require additional softwareand hardware installations for future wind farms in Sweden.

To reach EU’s climate and energy target an integrated electricity market is considered to be required (Klessmann, et al., 2011; Boie, et al., 2014; Becker, et al., 2013). As a result the European Commission decided to form a set of rules, named the Network Codes, to create a single European market (ENTSO-E, 2013b). The Network Codes will affect Distribution- and Transmission System Operators, grid users and production units as well as all the other actors on the electricity market (Eurelectric, n.d.a). Concerns regarding what the Network Codes’ actual consequences are have been expressed within the line of business (Swedish Energy, 2013a). Therefore the purpose of this master’s thesis was to determine and furthermore illustrate the consequences the Network Codes will have, in current version, for a Swedish non-transmission system connected electricity company and determine what actions need to be taken. The purpose has been addressed by conducting interviews, document studies and by utilizing a change management model, the Intervention Strategy Model, introduced by Paton & McCalman (2000). The structured approach that is the nature of the model was used when determining the consequences the Network Codes enforce and what actions a non-transmission system connected electricity company has to take to cope with them. To further facilitate the determination of these actions this study was conducted on a non-transmission system connected electricity company, in this thesis named Electricity Company A. The investigation of the concerns expressed within the line of business illustrated that the concerns were diverse but a majority of them might be incorporated into either of the following groups, simulation models, demand side aggregator and information handling. Out of these groups information handling was by far the area of greatest concern with issues primarily connected to the Distribution System Operator. Consequently this thesis focused on the Distribution System Operator’s perspective. The analysis of the area of greatest concern, presented in two flow charts, clearly showed the increased amount of communication enforced by the Network Codes. This increased information handling results in numerous possible organisational consequences for the Distribution System Operator, for example might new systems be required and some existing systems be used with or without adaption. Furthermore, the extra workload could possibly be handled by the existing personnel, in some cases after complementary education, but it might also require new personnel. Finally the Network Codes open up for the possibility for the Distribution System Operator to define certain details which may be conducted individually or in cooperation with other Distribution System Operators. Which of these possible consequences that will affect a specific company is, however, dependent on its preconditions. The study on Electricity Company A reveals that the numerous actions required to handle the new communication were not as significant as the line of business might have feared. For Electricity Company A, primarily a new system is needed to handle the real-time values and some of the existing systems need to be updated. Additionally the combined extra work load might require extra personnel for Electricity Company A even though the individual work assignments are fairly small. The actions required should be fairly similar for companies of approximately equal size but might be more extensive for smaller non-transmission system connected electricity companies. All companies need, however, to conduct an individual analysis to determine which specific actions are required for them. The conclusions of this thesis aspired, and partly succeeded, to be generalizable on a European level. One example of this is the usage of the Intervention Strategy Model which proved applicable for determining which specific actions are required for all European electricity companies. Furthermore the concerns presented and the possible consequences of the increased information handling found, are generalizable but not complete for all European electricity companies. This thesis focused on one part of the complex Network Codes’ consequences and consequently further research is needed to fully understand the consequences for the electricity business in total.

The current model for electricity generation is based on power plants connected to the transmission network. This provides electricity to the distribution network and after that to the consumers. To ensure the security of the electrical network and prevent a blackout, the performance of every electricity generation unit connected to the network is quantified in grid codes. In the case of the French transmission system, the requirements regarding the performance are written in a document produced by the French Transmission System Operator (TSO). Various events with various configurations of connection to the network have to be simulated and the corresponding performance has to be evaluated. The aim of these simulations is to determine the stability of the generators and key elements, including the response time on the active power after events such as a short circuit.Taking into account the amount of generators connected to the transmission network, the need for optimization appears and is the purpose of this Master Thesis. To perform those simulations in an efficient way on all the generators owned by the main French electricity producer, EDF, this Master Thesis contributes with a tool called AuDySim coded with the softwares MATLAB and EUROSTAG. The implemented tool allows the user to configure an electricity generation unit before realizing all the simulations specified by the TSO and produces a report containing the results by means of curves and data. The simulations and the production of the report are achieved automatically to create a gain of time and resources.In order to validate the performance of the tool, two case studies are performed on different types of power plants. The two case studies analyzed present a hydraulic and a nuclear power plant. In the results the performance of each type of power plant is assessed focusing on the rotor angle stability of the machine and key elements, such as the voltage and the active power. These results lead to the conclusion that AuDySim fulfills its mission, by achieving automatically an analysis of the performance of an electrical generation unit and producing it in a report. / Den nuvarande elproduktionsmodellen baseras på kraftverk som är direktkopplade till stamnätet. Stamnätet i sin tur matar distributionsnätet som därefter levererar el till slutkonsumenterna. För att säkerställa stamnätets integritet samt säkerhet och undvika strömavbrott kvantifieras prestandan hos varje generator som är ansluten till det med hjälp av nätkoder. När det gäller det franska stamnätet skrivs prestandakraven i ett dokument som utfärdas av den franska transmissionssystemoperatören (TSO). Olika händelser med olika anslutningskonfigurationer måste simuleras där dess prestanda ska utvärderats. Syftet med dessa simuleringar är att identifiera stabiliteten vid varje elproduktionsenhet med bl. a. dess reaktionstid för den aktiva effekten efter kortslutningar.Med tanke på antalet generatorer som är anslutna till stamnätet framträder ett behov för överföringsoptimering vilket är syftet med detta examensarbete. För att utföra dessa simuleringar på ett effektivt sätt på alla generatorer som ägs av den ledande franska elproducenten, EDF, bidrar denna avhandling med ett verktyg som heter AuDySim kodat i mjukvarorna MATLAB och EUROSTAG. Verktyget gör det möjligt för användaren att konfigurera en elproduktionsenhet innan man utför alla simuleringar som specificeras av TSO:n och samtidigt producerar en rapport som innehåller grafisk- och data resultat. Både simuleringar och rapporten produceras automatiskt för att optimera en bearbetningstid och resursanvändning.För att validera verktygets prestanda utförs två fallstudier på olika typer av kraftverk. De två fallstudierna fokuserar på ett hydraulisk- respektive ett kärnkraftverk. I resultaten utvärderas prestanda för varje typ av kraftverk, med fokus på maskinens rotorvinkelstabilitet och andra viktiga faktorer, såsom spänning och aktiv effekt. Resultat leder till slutsatsen att AuDySim uppfyller sitt uppdrag genom att automatiskt analysera prestanda hos en elektrisk generationsenhet och presentera analysen i en rapport.