{"id":1456,"date":"2025-04-14T12:11:20","date_gmt":"2025-04-14T16:11:20","guid":{"rendered":"http:\/\/localhost:10003\/dsa-tools-module\/dynred-dynamic-reduction\/"},"modified":"2025-08-24T14:50:21","modified_gmt":"2025-08-24T18:50:21","slug":"dynred-dynamic-reduction","status":"publish","type":"dsa-tools-module","link":"https:\/\/powertechlabs.com\/dsa-tools-module\/dynred-dynamic-reduction\/","title":{"rendered":"Dynamic Reduction"},"content":{"rendered":"\n\n\t<h3>DYNRED Dynamic Reduction<\/h3>\n<p>DYNRED is a software program developed by Powertech for EPRI in 1990s for creating dynamically equivalenced models of large power systems.<\/p>\n\t\t\t\t<img decoding=\"async\" src=\"https:\/\/powertechlabs.com\/wp-content\/uploads\/2025\/04\/image_2025-04-15_175414128.png\" alt=\"image_2025-04-15_175414128\" itemprop=\"image\" title=\"image_2025-04-15_175414128\" onerror=\"this.style.display='none'\" loading=\"lazy\" \/>\n\t\t\t\tApplication Scope\n\t\t\t\t<p>DYNRED starts with a set of models for a power system: powerflow and dynamics. For a specified set of system reduction creiteria, DYNRED reduces the system in the external region by replacing it with static and dynamic equivalents. The result is a smaller system model that allows fast computations for system performance analysis.<\/p>\n<p>DYNRED can be used for:<\/p>\n<ul>\n<li>Development of base models for system planning.<\/li>\n<li>Building models for on-line dynamic security assessment.<\/li>\n<li>Construction of appropriate models for control system design and tuning.<\/li>\n<\/ul>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/powertechlabs.com\/wp-content\/uploads\/2025\/04\/image_2025-04-15_173716979-300x251.png\" alt=\"\" width=\"300\" height=\"251\" \/><\/p>\n\t\t\t\tProduct Features\n\t\t\t\t<ul>\n<li>Reduction of large power system models for static and dynamic performance analysis<\/li>\n<li>Choice of reduction algorithms<\/li>\n<li>Compatibility in data formats with industry practices<\/li>\n<li>Performance benchmarking tools for reduced model validation<\/li>\n<li>Graphical user interface<\/li>\n<\/ul>\n\t\t\t\tReduction Criteria and Methods\n\t\t\t\t<p>To achieve the required reduction objectives, a set of criteria and methods can be specified:<\/p>\n<ul>\n<li>Regions of the system to be retained and to be reduced (&#8220;retained system specification&#8221;).<\/li>\n<li>Grouping of generators in the external region (&#8220;coherency identification&#8221;). Choices can go from the simple weak link method to more advanced tolerance-based method.<\/li>\n<li>Handling of the coherent generators in the system (&#8220;generator aggregation&#8221;). Either classical or hybrid method can be used.<\/li>\n<\/ul>\n\t\t\t\tModel Validation\n\t\t\t\t<p>A reduced model created can be validated by using the performance metrics computed by DYNRED from various types of applications, including:<\/p>\n<ul>\n<li>Basic powerflow performance.<\/li>\n<li>Extended powerflow performance at post-contingency conditions.<\/li>\n<li>Time-domain performance from no-fault simulations and simulations for specified contingencies.<\/li>\n<li>Frequency-domain performance from comparison of dominant modes in the system.<\/li>\n<li>Stability limit comparison subject to voltage and transient criteria.<\/li>\n<\/ul>\n\t\t\t\tApplication example\n\t\t\t\t<p>This example shows a dynamic reduction done using DYNRED for a large power system model. The following table gives the details on the full and reduced models.<\/p>\n<table>\n<tbody>\n<tr>\n<td>\u00a0<\/td>\n<td># of Buses<\/td>\n<td># of Generators<\/td>\n<\/tr>\n<tr>\n<td>Full Model<\/td>\n<td>54,735<\/td>\n<td>7,887<\/td>\n<\/tr>\n<tr>\n<td>Reduced model<\/td>\n<td>25,941<\/td>\n<td>3,099<\/td>\n<\/tr>\n<tr>\n<td>Reduction Ratio<\/td>\n<td>47.4%<\/td>\n<td>39.3%<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>Using the reduced model, the time it takes to complete a typical time-domain simulation is only 25.8% of the time for the full model. The figure below shows the quality of the reduced model.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/powertechlabs.com\/wp-content\/uploads\/2025\/04\/image_2025-04-15_175049262-300x283.png\" alt=\"\" width=\"300\" height=\"283\" \/><\/p>\n<p><em>Comparison of the time-domain simulation results for the rotor angle response of the same generator following a contingency.<\/em><\/p>\n\t\t\t\tSpecifications and Requirements\n\t\t\t\t<ul>\n<li>Processing power systems of up to 100,000 buses and 15,000 generators.<\/li>\n<li>Runs on MS Windows 7\/10\/server 2012 R2\/server 2016<\/li>\n<\/ul>\n\n","protected":false},"featured_media":1672,"template":"","application-type":[],"audience":[28,33],"compliance-standard":[],"module-type":[34],"class_list":["post-1456","dsa-tools-module","type-dsa-tools-module","status-publish","has-post-thumbnail","hentry","audience-for-modelers","audience-for-planners","module-type-other-dsa-tools"],"acf":[],"_links":{"self":[{"href":"https:\/\/powertechlabs.com\/wp-json\/wp\/v2\/dsa-tools-module\/1456","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/powertechlabs.com\/wp-json\/wp\/v2\/dsa-tools-module"}],"about":[{"href":"https:\/\/powertechlabs.com\/wp-json\/wp\/v2\/types\/dsa-tools-module"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/powertechlabs.com\/wp-json\/wp\/v2\/media\/1672"}],"wp:attachment":[{"href":"https:\/\/powertechlabs.com\/wp-json\/wp\/v2\/media?parent=1456"}],"wp:term":[{"taxonomy":"application-type","embeddable":true,"href":"https:\/\/powertechlabs.com\/wp-json\/wp\/v2\/application-type?post=1456"},{"taxonomy":"audience","embeddable":true,"href":"https:\/\/powertechlabs.com\/wp-json\/wp\/v2\/audience?post=1456"},{"taxonomy":"compliance-standard","embeddable":true,"href":"https:\/\/powertechlabs.com\/wp-json\/wp\/v2\/compliance-standard?post=1456"},{"taxonomy":"module-type","embeddable":true,"href":"https:\/\/powertechlabs.com\/wp-json\/wp\/v2\/module-type?post=1456"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}