IEEE Std 946-2020 pdf download – IEEE Recommended Practice for the Design of DC Power Systems for Stationary Applications.
4. Organization of this recommended practice Stationary dc power systems appear in many applications and industries. All have certain commonalities, while some have some unique requirements. It should be noted that these commonalities or unique requirements are derived from variance in environmental conditions, reliability expectations, and importance of application. That translates to specific feature requirements or technology differences (thyristor versus high-frequency switched mode chargers, or lead-acid versus Ni-Cd batteries) that can provide an engineering approach to the selection/design of dc power systems. For example, a substation charger can be used in a telecom application and vice versa as long as it can meet the requirements. Describing every application is beyond the scope of this document, therefore the three dominant applications are generation, substations, and telecommunications. Large telecommunication carriers may have their own internal dc power system standards that examine dc power systems and their requirements in detail. This is also beyond the scope of this document, but is worthy of a mention. In this recommended practice, each section includes subparagraphs reserved for these three applications when there are unique requirements. For other industrial applications, one can use the recommendations—in part or as a whole—of one of the three dominant applications. For example, substation application recommendations may be used, where applicable, for the design of an industrial process control dc power system. It is not the intent of this recommended practice to exclude other industrial applications. Lead-acid and nickel-cadmium batteries are the types of batteries primarily used in these applications. Some other battery technologies may be used but are not fully addressed in this document. 5. Description and operation DC power systems provide reliable power to critical loads.
5.1.1 Power generation Specific design guidance for dc power systems for nuclear generating plants are discussed fully in numerous design standards listed in Annex A. 5.1.2 Substation For additional guidance refer to IEEE Std 1818.