By FrÃ©dÃ©ric LÃ©onard, Paul Lembo and Guy CÃ´tÃ©, Hydro-Quebec
Three-dimensional computer-aided design (CAD 3-D) modeling software is widely used in the automobile and aircraft industry. Lately, Hydro-Quebec has adopted that same type of software for the design of new power stations and substations.
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Hydro-Quebec generates, transmits and distributes electricity, mainly using renewable energy sources, in particular hydroelectricity. It also conducts research in energy-related fields and takes an active interest in energy efficiency. The company has been testing CAD 3-D modeling software for the last two years for electrical substation design. During this time, 24 electrical substations (out of approximately 500 substations on Hydro-Quebec’s network) were modeled in whole or in part in 3-D.
The technical deliverables for an electrical substation consists of numerous drawings from several departments (electrical, civil, architecture, etc). Using CAD tools, all the engineering of the various departments can be joined together in a unique 3-D model. The software automatically generates 2-D drawings from the 3-D model. This ensures coherence between the various 2-D drawings, reduces the cost and the time of engineering and allows for better flexibility when simulating design alternatives.
Advantages of CAD
Hydro-Quebec’s main objectives in implementing 3-D models are improvement in the quality of the deliverables as well as improvement in the design’s efficiency. The advantages of a three-dimensional model when compared to two-dimensional drawings are:
- 3-D models facilitate communication and collaboration between the various stakeholders (engineering, customer, purchasing, management, contractors) and is particularly useful during public hearings. Substations are often located in urban areas. The neighboring populations are naturally worried about the disturbance that a substation may cause to their life quality. When we use 3-D models, concerns are quickly dissipated in most cases. The general public can appreciate more easily how the project can be implemented harmoniously in the existing environment.
- The 3-D model allows the utility to store attributes for each piece of installed equipment. It is therefore possible to automatically generate a bill of materials for purchasing.
- 3-D models facilitate interdisciplinary integration. Electrical clearances can be easily validated in 3-D. In consequence, the early detection of conflicts decreases the number of engineering change requests and prevents most on-site problems.
- Major suppliers are already using CAD tools for the design of their equipment. It is therefore possible to exchange information and to consult the 3-D models from these suppliers. These models are also very useful for the operator for consultations purposes throughout the lifespan of the equipment.
- A 3-D model allows better optimization of construction sequences and eases the work follow-up at the building site.
By using 3-D models, Hydro-Quebec can store attributes for each piece of installed equipment, making it possible to automatically generate a bill of materials for purchasing.Click here to enlarge image
Future of CAD Tools
Currently, Hydro-Quebec uses 3-D modeling only for the design of new substations and major additions to existing installations. However, the majority of substation projects consist of minor additions or modifications (equipment replacement, additions of feeders, etc.). Thus, up to now, most projects are still elaborated using traditional 2-D drawing tools in spite of the availability of 3-D CAD tools.
Creating a complete model for an existing installation from the 2-D as-built drawings remains a relatively long and complex operation. Minor projects do not require the availability of a 3-D model of the whole installation to complete the required engineering. It is still much faster to modify the existing 2-D drawings. Unfortunately, merely modifying existing 2-D drawings does not allow minor projects to benefit from the advantages inherent to 3-D modeling. A solution which would allow average-scale projects to benefit from these advantages is therefore required.
3-D scanning is an automated process of measurements using a laser scanner. This technology quickly and effectively collects a great quantity of three-dimensional points with a very high accuracy. The result is a point cloud representing the surrounding area in 3-D. Technological advances in this field are very fast and the possible applications for existing installations are highly interesting.
This technique is presently being investigated to determine the best approach (software and methodology) to digitize existing installations in 3-D.
CAD tools allow designers to detect errors upstream in the design process and to evaluate the quantities more precisely. This technology has proved advantageous for project teams since it eases collaboration, communication and three-dimensional visualization.
Thus, all stakeholders involved in project development have access to the numerical model. Information is readily available to everyone. CAD tools avoid misunderstanding, save time and reduce costs.
FrÃ©dÃ©ric LÃ©onard, is an electrical engineer at Hydro-Quebec. He specializes in software and CAD 3-D.
Paul Lembo, has been an electrical engineer at Hydro-Quebec for more than 25 years. He is the head of the electrical substation design group.
Guy CÃ´tÃ©, is an electrical engineer at Hydro-Quebec. He is the electrical substation design manager.