[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"doc-detail-85993-en":3,"doc-seo-85993-105":29,"detail-sidebar-cat-0-en-105":82},{"code":4,"msg":5,"data":6},0,"success",{"doc_id":7,"user_id":8,"nickname":9,"user_avatar":10,"doc_module":4,"category_id":11,"category_name":12,"doc_title":13,"doc_description":14,"doc_content":15,"file_id":16,"file_url":17,"file_type":18,"file_size":19,"view_count":4,"is_deleted":4,"is_public":20,"is_downloadable":20,"audit_status":20,"page_count":21,"language":22,"language_code":23,"site_id":24,"html_lang":23,"table_of_contents":25,"faqs":26,"seo_title":13,"seo_description":14,"update_tm":27,"read_time":28},85993,1374391975076,"Riley","https://ap-avatar.wpscdn.com/avatar/14000253ca4ec9f6853?x-image-process=image/resize,m_fixed,w_180,h_180&k=1783305029341752051",6,"Technology","Open-Source Python Tool for Grid Converter Output Admittance Identification","Frequency-domain analysis using converter output admittance is crucial for evaluating converter-driven stability in power grids. The paper introduces a Python identification tool built on a fully open-source simulator under an MIT license, avoiding commercial MATLAB or PSCAD licensing. A steady-state sinusoidal frequency sweep injects signals at the PCC and measures current responses, then computes admittance via DFT from time-domain simulations. Analytical output-admittance models are derived for both grid-forming and grid-following control and verified against a PSCAD-based approach.","Open-Source Python Tool for Grid Converter Output Admittance Identification  \nJuho Mtt  \nSchool of Electrical Engineering Aalto University Espoo, Finland [juho.k.maatta@aalto.fi](juho.k.maatta@aalto.fi)  \nJarno Kukkola  \nABB Oy Drives Helsinki, Finland [jarno.kukkola1@fi.abb.com](jarno.kukkola1@fi.abb.com)  \nJanne Seppnen  \nSchool of Electrical Engineering Aalto University Espoo, Finland [janne.seppanen@aalto.fi](janne.seppanen@aalto.fi)  \nMarko Hinkkanen  \nSchool of Electrical Engineering Aalto University Espoo, Finland [marko.hinkkanen@aalto.fi](marko.hinkkanen@aalto.fi)  \narXiv :2607 . 10653v1 [ ee ss . SY] 12 Jul 2026  \nAbstract—Frequency-domain analysis based on converter output admittance is a key tool for studying converter-driven stability in power grids. This paper presents a Python-based identification tool built on a completely open-source simulator, eliminating the need for commercial licenses such as MATLAB or PSCAD and improving configurability through an MIT-licensed stack. The identification method uses steady-state signal injection with a sinusoidal sweep, deriving frequency-domain admittance from time-domain simulations. Analytical output-admittance models are developed for both grid-forming (disturbance-observer-based) and grid-following (phase-locked-loop-based) control to verify the numerical results. The tool’s results are compared against a commercial PSCAD-based alternative, demonstrating accurate admittance identification across control methods. Code and examples are available online to support reproducibility.  \nIndex Terms—Admittance, grid converters, identification, impedance, open-source, Python, time-domain simulations.  \nI. INTRODUCTION  \nConverter-based generation is rapidly increasing, and converter-driven stability has become a key concern, e.g., because converters can excite or amplify resonances in the grid [1]. To analyze such interactions, frequency-domain methods based on converter output admittance are widely used [2],[3] . When the converter output admittance and grid impedance are known, stability can be assessed using the multivariable Nyquist criterion [4] . Alternatively, passivity-based conditions can be applied using the converter output admittance alone [5] . The converter output admittance can be obtained either analytically, if the white-box model of the converter is available, or numerically from time-domain signals. Numerical identification can be performed either using simulation data or  \nThis project was supported by ABB Oy. The authors acknowledge the use of the EPE infrastructure of Aalto University School of Electrical Engineering.©2026 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.  \nexperimental measurements. The advantages of the numerical method are that tedious analytical calculations can be avoided and that the output admittance can also be obtained for a blackbox converter model.  \nSeveral tools have been developed for numerical outputadmittance identification and frequency-domain analysis in simulations. Commercial options include the AIM Toolbox [6] and Grid Impedance Scan Tool [7], both relying on PSCADas the simulation engine. Open-source projects have also been presented, such as Simplus Grid Tool [8] and Z-tool [9] . However, they still depend on commercial platforms, MATLAB and PSCAD, respectively. In some applications, the use of these commercial platforms may be beneficial due to their adoption in the industry. For example, Fingrid, the transmission system operator in Finland, requires PSCAD models to be submitted for certain power generating facilities and grid energy storage systems [10], [11] . However, licensing costs and the ","cbCaiblvZGCJ1lZW","https://ap.wps.com/l/cbCaiblvZGCJ1lZW","pdf",599799,1,8,"English","en",105,"# Introduction\n# Converter Output Admittance\n## Large-Signal Model","[{\"question\":\"How is the tool validated against existing approaches?\",\"answer\":\"The paper develops analytical output-admittance models for grid-forming and grid-following control and compares numerical results to a commercial PSCAD-based identification alternative, showing accurate admittance identification.\"}]",1784207646,20,{"code":4,"msg":30,"data":31},"ok",{"site_id":24,"language":23,"slug":32,"title":13,"keywords":33,"description":14,"schema_data":34,"social_meta":77,"head_meta":79,"extra_data":81,"updated_unix":27},"open-source-python-tool-for-grid-converter-output-admittance-identification","",{"@graph":35,"@context":76},[36,53,67],{"@type":37,"itemListElement":38},"BreadcrumbList",[39,43,47,50],{"item":40,"name":41,"@type":42,"position":20},"https://docshare.wps.com","Home","ListItem",{"item":44,"name":45,"@type":42,"position":46},"https://docshare.wps.com/document/","Document",2,{"item":48,"name":12,"@type":42,"position":49},"https://docshare.wps.com/document/technology/",3,{"item":51,"name":13,"@type":42,"position":52},"https://docshare.wps.com/document/open-source-python-tool-for-grid-converter-output-admittance-identification/85993/",4,{"url":51,"name":13,"@type":54,"author":55,"headline":13,"publisher":57,"fileFormat":60,"inLanguage":23,"description":14,"dateModified":61,"datePublished":61,"encodingFormat":60,"isAccessibleForFree":62,"interactionStatistic":63},"DigitalDocument",{"name":9,"@type":56},"Person",{"url":40,"name":58,"@type":59},"DocShare","Organization","application/pdf","2026-07-16",true,{"@type":64,"interactionType":65,"userInteractionCount":4},"InteractionCounter",{"@type":66},"ViewAction",{"@type":68,"mainEntity":69},"FAQPage",[70],{"name":71,"@type":72,"acceptedAnswer":73},"How is the tool validated against existing approaches?","Question",{"text":74,"@type":75},"The paper develops analytical output-admittance models for grid-forming and grid-following control and compares numerical results to a commercial PSCAD-based identification alternative, showing accurate admittance identification.","Answer","https://schema.org",{"og:url":51,"og:type":78,"og:title":13,"og:site_name":58,"og:description":14},"article",{"robots":80,"canonical":51},"index,follow",{"doc_id":7,"site_id":24},{"code":4,"msg":5,"data":83},[84,88,92,96,101,104,109,113,117,120,124],{"id":20,"doc_module":4,"doc_module_name":45,"category_name":85,"show_sort_weight":86,"slug":87},"Story & Novel",90,"story-novel",{"id":46,"doc_module":4,"doc_module_name":45,"category_name":89,"show_sort_weight":90,"slug":91},"Literature",80,"literature",{"id":52,"doc_module":4,"doc_module_name":45,"category_name":93,"show_sort_weight":94,"slug":95},"Exam",70,"exam",{"id":97,"doc_module":4,"doc_module_name":45,"category_name":98,"show_sort_weight":99,"slug":100},5,"Comic",60,"comic",{"id":11,"doc_module":4,"doc_module_name":45,"category_name":12,"show_sort_weight":102,"slug":103},50,"technology",{"id":105,"doc_module":4,"doc_module_name":45,"category_name":106,"show_sort_weight":107,"slug":108},7,"Healthcare",40,"healthcare",{"id":21,"doc_module":4,"doc_module_name":45,"category_name":110,"show_sort_weight":111,"slug":112},"Research & Report",30,"research-report",{"id":114,"doc_module":4,"doc_module_name":45,"category_name":115,"show_sort_weight":28,"slug":116},9,"Religion & Spirituality","religion-spirituality",{"id":28,"doc_module":4,"doc_module_name":45,"category_name":118,"show_sort_weight":28,"slug":119},"World Cup","world-cup",{"id":121,"doc_module":4,"doc_module_name":45,"category_name":122,"show_sort_weight":121,"slug":123},10,"Lifestyle","lifestyle",{"id":125,"doc_module":4,"doc_module_name":45,"category_name":126,"show_sort_weight":97,"slug":127},19,"General","general"]