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protection relay testing frequency

Technical papers
Testing of elastomeric isolators for nuclear power plants
Nowadays, the design of nuclear power plants (NPP) is characterized by enhanced safety level. In particular, GEN III+ and GEN IV reactors have to be highly secure and designed to withstand extremely severe external events such as floods, tsunamis, tornadoes, plane crashes, fires and, in particular, earthquakes. Seismic isolation is considered the most promising technology […]
Technical papers
Assessing the impact of transmission investments on the Italian Ancillary Services Market using MODIS simulator
The justification of transmission investments is becoming more complex and challenging with respect to the past decades since environmentally friendly solutions shall be adopted and the benefits for the society must be clearly highlighted and quantified. Clear and objective indicators of the benefits arising from transmission projects are playing a key role to foster the […]
Technical papers
Issues related to spark discharges
In the general public environment, ambient power-frequency electric fields are relatively small, except when near high-voltage (HV) transmission lines. Electric fields from aerial HV transmission lines are greatest directly under the conductors and decrease with. In occupational environments, elevated electric fields also exist in HV substations/switchyards, and in particular under busbars/equipment. Other sources of power-frequency […]
Technical papers
Field measurements and frequency domain modeling of a 400 kV underground cable line
The length of XLPE-insulated underground cable lines in the European HV / EHV network is experiencing a fast growth due to the increasing number of submarine interconnections and suitability to be installed also in urban area with nil visual impact after installation. Use of cable stretches in combination with overhead lines has proven to be […]
Services IEC/IEEE Testing Services and recent updates
IEC 62271-103 – Testing Services – Alternating current switches for rated voltages up to and including 52 kV
IEC 62271-103 revised in 2021 – The standard for alternating current switches IEC 62271-103 has been updated to align with other related product standards (for example IEC 62271-102 for earthing switches/disconnectors) for the kinematic chain and test on the position indicating device, making tests more uniform and have more clear acceptance criteria for the test […]
Physical agents
Electromagnetic fields
CESI provides consultancy on occupational health and safety related to electromagnetic fields. We assess the exposure of workers and the public to EMF through measurement and modelling. We design mitigation studies, including shielding and other technical actions that can reduce low frequency fields. We assess electrical and magnetic fields with 2D and 3D calculation models. […]
Technical papers
Ferroresonance in Inductive Voltage Transformers Or Power Voltage Transformers: analysis, laboratory tests and solutions
A ferroresonance analysis related to HV Inductive Voltage Transformers (IVT) and power Voltage Transformers or Station Service Transformers (PVT/SST) was addressed to develop models based on EMT formulation, enabling detailed ferroresonance risk analyses in specific HV station conditions and helping in the equipment technical specifications (including anti-ferroresonance remedial provisions). The research relied on a comparison […]
High RES penetration impact on Operations
​The development of Renewable Energy Sources (RES) is rapidly growing worldwide and they will play an increasingly important role in electricity power systems in the coming years. The majority of this is expected to be from Variable Non-Synchronous Renewable (VNSR) generation sources. According to the 2020 targets, significant volumes of VNSR generation are estimated across […]
Volatile RES & Thermal Plants flexibility
IntroductionWith the aim of reducing CO2 emissions and dependency from fossil fuels, in various countries the sharp increase of electrical RES (Renewable Energy Sources) as a result of policies of substantial subsidies is creating problems to an efficient and reliable operation of the electrical power system. Both transmission and distribution systems have to face an […]
Technical papers
Maximum feasible penetration of non-programmable RES generation in power systems
​The large-scale development of renewable sources, with particular reference to wind, in the generation mix might introduce several problems for a secure management of the power system, due to a higher generation uncertainty, thus requiring careful investigations by the responsible for planning and the involved system operators. In this context, CESI has developed a thorough […]