In the present power delivery environment, electricity as a product has become more competitive than before.
Modern electrical devices are complex in terms of their functionalities and are more sensitive to the quality of the supplied electricity.
The PQ level in the network is also highly influenced by PQ emission behaviors of customer's devices and the network characteristics.
During the last decades, PQ related complaints have increased largely.
It ultimately leads to better design of mitigation devices like Dynamic Voltage Restorer (DVR), Distribution Static Synchronous Compensator (DSTATCOM) and Unified Power Quality Conditioner (UPQC) to alleviate various power quality related problems.
The main objective of this thesis is to develop a model of DVR, DSTATCOM and UPQC for enhancement of power quality DVR is one of the custom power devices that are used as an effective solution for the protection of sensitive loads against voltage disturbances in power distribution system.
The main objectives of this thesis are defined as: "Analyze main PO problems and their consequences to various involved parties in the network.
Next, define optimal PQ criteria at the customer's point of connection (POC) and finally specify responsibilities of the involved parties".
A summary of the research work reported in this thesis is as follows: • Obtained a deeper insight in PQ problems around the world • Developed typical network models for computer simulations on different PQ phenomena (such as flicker, harmonics and voltage dips) and verified the results with field measured data • Gathered practical information on various technical and financial consequences of inadequate PQ for different parties namely: the network operators, the customers and the equipment manufacturers • Made an inventory on various existing (and developing) standards and technical documents on PQ around the world.
Then, compared the limits given on various PQ parameters in those standards/documents and discussed their relevance and applicability in the future • A proposal is given about optimal PQ limits (for flicker, harmonics) at the low voltage (LV) customer's POC Also, the average and maximum values of voltage dips in the networks are estimated • Suitable planning level limit values for flicker, harmonics and voltage dips are proposed • PQ related responsibilities of the customers, network operators and device manufacturer at the customer's POC are defined The main conclusions and thesis contributions are: • It is found that a harmonization among the presently available PQ standards is required and a dedicated set of global standards is needed to get optimal PQ at the customer's POC Various limiting values on different PQ parameters (e.g.