IEEE 946-2020 pdf free.IEEE Recommended Practice for the Design of DC Power Systems for Stationary Applications.
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 arc 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 selectionldesign of dc power systems. For example, a substation charger can be used in a telecom application and vice rersa 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 au 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.
DC power systems provide reliable power to critical loads. Examples of critical loads include auxiliary motors, circuit breakers and switchgear, relays, solenoids, SCADA, telecommunications equipment, inverters, emergency lighting equipment, fire suppression equipment, etc.
A dc system normally consists of one or more battery strings, one or more battery chargers/rectifiers and one or more distribution panels. If a batery isolation/protective device is used, refer to the battery protection guidelines of IEEE Std 1375. Refer to simplified typical connection in Figure 1 for the line of demarcation that limits the application of IEEE 946 versus IEEE 1375.IEEE 946 pdf free download.