DQ0-transformation: calculate active and reactive power from instantaneous voltage and current signals

DQ0-transformation: calculate active and reactive power from instantaneous voltage and current signals

The DQ0-transformation, or direct-quadrature-zero transformation, is a very useful tool for electric power engineers to transform AC waveforms into DC signals. In particular, for three-phase systems, the use of DC signals simplifies the calculations immensely. The DQ0-transformation is the product of the Clarke and Park transformation. The Clarke transformation converts the abc-phase-components to αβγ-components while…

An approach to determine generation shift keys (GSKs) for defined market areas

An approach to determine generation shift keys (GSKs) for defined market areas

Generation shift keys (GSKs) describe how a change of the net position of a market area affects the power outputs of the generation units within the area. In other words, the GSK describes how the change of the net position is mapped to the different generation units. Transmission system operators (TSOs) use GSKs for various…

Load model identification in electric power systems: a linear least-squares approach

Load model identification in electric power systems: a linear least-squares approach

Load modeling is one of the most important aspects when it comes to the stability analysis of electric power systems. The way we model loads significantly impacts the results of the analyses. The so-called ZIP model considers the voltage dependency of loads and serves this purpose very well. ZIP stands for the three defined load…

How to create a measurement file for DIgSILENT PowerFactory from a CSV, TXT, or XLSX file?

How to create a measurement file for DIgSILENT PowerFactory from a CSV, TXT, or XLSX file?

Many times when you model time-domain simulations in DIgSILENT PowerFactory you want to use time-series data stored in CSV, TXT, or XLSX files. In PowerFactory you can integrate these time series by means of measurement files (*.ElmFile). These measurement files are simple ASCII files with a column for each variable including the time. The time…

How to check the consistency of PMU data?

How to check the consistency of PMU data?

The first thing before analyzing phasor measurement unit (PMU) data is to check its consistency. PMU data shall be checked for missing samples and consistency of the measurements. Missing samples are timestamps, for which no measurement value was recorded. The definition of data consistency is not as easy because there are many possible inconsistencies. For…

Analysis of frequency measurements of the Nordic, Continental European, and Japanese-50-Hz power systems

Analysis of frequency measurements of the Nordic, Continental European, and Japanese-50-Hz power systems

When my former colleagues from the Center for Electric Power and Energy (CEE) at DTU published the data of their frequency measurements of the Nordic, Continental European, and Japanese-50-Hz power systems, I thought I need to analyze the data and publish some insights. The frequency measurements are publicly available here (thanks for that): Nordic Power…

How to query data from the ENTSO-E transparency platform using Python?

How to query data from the ENTSO-E transparency platform using Python?

A step-by-step guide to install the Python API for the ENTSO-E transparency platform and sample code on how to query data. Most of the people working in the energy field know the ENTSO-E (European network of transmission system operators for electricity) transparency platform, which is an open-source collection of electricity generation, transportation, and consumption data…

Peak shaving with energy storage: peak shaving level as a function of the energy storage capacity for a given load profile

Peak shaving with energy storage: peak shaving level as a function of the energy storage capacity for a given load profile

Background Peak shaving has been around for many years and it still has some interesting applications. One obvious application is the reduction of high load peaks of industrial processes in order to reduce the demand charge which is determined by the maximum load that occurred within a given time frame, i.e. the lower the peak…