Challenges and practical experiences in power quality and electrical connection of distributed energy resources for certification laboratories

Recently, new standards dealing with power quality or connection requirements of distributed energy resources to the electrical network have been or are being published. For example, the prEN50438 standard about the connection of microgenerators, the P.O. 12.3 stating requirements to be complied by wind farms not to disconnect from the electrical network after a certain voltage dip, or the IEC 61000-3-11 or IEC 61000-3-12 about the limitation of flicker or harmonics emissions, respectively, can be mentioned among others. As a consequence, also new standards about measurement techniques or requirements that must be complied by measurement equipment have appeared or are appearing like the IEC 61000-4-7, that providing guides for harmonic and interharmonic measurements, the IEC 61000-4-34 about measurement techniques for voltage dips, short interruptions and voltage variations immunity test, or the IEC 61000-4-30 concerning Power Quality measurement methods. In consequence, laboratories have new challenges in order to continue being accredited certification bodies in the electrical sector, more concretely in the case of distributed energy resources connection, power quality and EMC. However, great investment efforts to purchase new measurement equipment and personnel training are needed. This paper describes concrete experiences and gives technical examples of the efforts being done by one of these accredited certification entities. The paper starts with a new laboratory specification, design and investment, analyzes the first experimental tests and results to show the capabilities of the laboratory against some of the standards mentioned above, and finishes with a description of an accreditation process.