Basically, a power substation is a part of a system which is designed to ensure that the effects of an outage will result in minimum disruption. If any component of the system fails, it often forces a greater load to be carried by other components of the system. Thus, it is quintessential for power substation manufacturers to consider all such contingencies to incorporate in planning and design criteria. In this blog, you will have an overview of general design considerations.
1. Initial and Ultimate Requirements
Short as well as long-range plans are required to take into account for the physical and financial integrity of electrical systems and offering adequate service to customers. The long range plan requires identifying requirements of a power substation for initial as well as future use. Ultimate requirements are also considered in the initial design.
Besides, economic comparison is also performed to find out what provisions are essential for ease of addition. Design plan should be in line with standard equipment, operation, and protection before construction is started. Otherwise, it may jeopardize the operation of the system.
2. Site Considerations
Failure to consider location and site of a substation can result in excessive investment. Thus, power substation manufacturers and/or clients who need substations are required to evaluate the following factors while selecting a site:
• Place of present and future load center
• Place of existing and future power sources
• Suitable right-of-way and access site for overhead/underground transmission and distribution circuits
• Location of existing distribution lines
• Proximity to all-weather highway and railroad siding
• Objections regarding noise, appearance, electrical side-effects and impact on private or public facilities
• Site maintenance requirements
• Soil resistivity, drainage and soil conditions
• Cost of earth removal, earth addition, and earthmoving along with cleanup of contaminated soils or buried materials
• Atmospheric conditions including salt and industrial contamination
• Topographical features of the site and surrounding area such as avoidance of earthquake fault lines, floodplains, wetlands, etc.
• Public safety and concern such as avoidance of schools and playgrounds
• Adverse effects on neighboring communication facilities and so on.
3. Environmental Considerations
Substations that require more than 5 acres of new physical disturbance need an Environmental Assessment (EA) and those that require less need an Environmental Report (ER).
Here are some of the factors that need to be considered before designing phase:
General
• Policies and Procedures
• Appearance
• Public Safety
• Audible Noise
• Site selection
• Layout design
• Level
• Transformers
• Electrostatic and Electromagnetic Effects
• Effluent
Weather
• Temperature
• Wind and Rain
• Ice and Snow
• Electrical Storms
• Humidity
Altitude
• Dielectric strength of air
• Current ratings of conductors operated in air
• Ambient temperatures
Earthquake
• Seismic design practices for areas with higher or frequent seismic activities
Others
• Wildlife and Livestock
• Airborne foreign material
4. Interfacing Considerations
For locating a substation, it is necessary to coordinate the location, design and construction with other utilities in the area such as telecommunications, water and sewer, gas, radio and television stations. Besides, timely planning should be made so that mutual agreements can be made between substation engineer and various other line engineers working in the project. In addition to this, a power substation engineer should also specify the line tension that will result in maximum load.
5. Reliability Considerations
The prime objective is to offer reliable service within acceptable voltage limits.
6. Operating Considerations
Substation arrangements, electrical connections, signs, and nameplates should be as clear as possible for ease of maintenance and simplicity.
7. Safety Considerations
A substation must be safe for the general public and for operating and maintenance personnel. This involves training of qualified personnel, suitable working rules and procedures, proper design, and accurate construction.
8. Maintenance Considerations
The design of a substation should be in such a way that allows maintenance by imparting minimum impact on substation’s operation. Assignment of proper and enough working space is also essential.
All these factors need to be taken under consideration by power substation manufacturers and concerned entities. Violating any rule or compromising with necessary considerations can be hazardous and/or illegal.