Design and Performance Assessment of Harmonic Filters Using EMTP

In order to permit access to a public electricity network, a network operator will impose compliance with certain technical requirements, which must be met by the potential network user seeking the connection to the network. These technical requirements are typically quite extensive and detailed and generally include requirements for compliance with power quality standards, including harmonic distortion standards. As a result of the requirement to comply with harmonic distortion standards and the requirements therein, it is sometimes necessary to provide harmonic filtering in order to ensure the public network will remain within the required harmonic distortion limits under all normal operating conditions. This presentation gives a study case for a connection to a 400kV network which required design and installation of a number of filters in order to ensure compliance with the harmonic distortion limits on the public network. As part of the assessment and design process, a number of studies was undertaken in order to ensure all aspects of the filter system design perform as required, under all operating conditions. These studies included: • harmonic propagation and distortion calculations, • filter configuration and optimisation studies, • filter loading studies, • filter transient studies, • filter protection studies. The tool used in the assessments was EMTP. The presentation will demonstrate certain aspects of the EMTP capability and use in steady state and electromagnetic transient studies applied to the filter system design, validation and compliance studies.