Content area
Full text
Open access and deregulation are having quite an impact on the power-delivery system and the way in which we think about electricity. In fact, electricity is being treated more like a commodity than an engineered product, which is changing the marketplace.
Today there is more volume and volatility but no corresponding increase in transmission and distribution assets. As a result, utilities and transmission operators are scrambling to find ways to increase capacity of existing transmission lines rather than follow the traditional method of placing more wire in the air. Politically, environmentally and financially, there is a great deal of resistance to adding new lines, equating to much longer project time frames and added expense.
Adding more lines is not always the best solution, either. One thing much of the nontechnical world forgets is the simple fact the flow of power follows the laws of physics and not economics, or where they wish the power to go. By the simplest definition, the grid consists of transmission and distribution lines interconnected to form networks for getting electricity to the customer.
There is an interaction between power lines that governs power-transfer limits that can trigger power-system constraints in the form of bottlenecks, congestion and loop flows. These constraints can be significant enough to actually reduce the network's overall ability to deliver power to the end user.
This continued worldwide increasing demand for electricity is reducing operational margins and can lead to thermal overload, short-circuit limits, transient stability limits, voltage instability and other performance issues. Fortunately, there are several technological developments that have the promise to solve or at least moderate these problems. It is not that utilities have not been using mitigation technologies to diminish these problems, they have, but today's technologies are far advanced from conventional practices.
Smarter Is Better
Utilities, regional transmission organizations (RTOs) and independent system operators (ISOs) base power-transfer limits on computer simulations that predict how their networks should behave under different system events and loadings. Based on very conservative computer model predictions, these operating authorities reinforce their systems at strategic locations and hope for the best. The modeling does a pretty good job of simulating the spiderweb that is the grid, but, in the final analysis, it is still just a simulation.
The...