Most people only think of a power center if they happen to pass one as they're driving somewhere else. For electric companies and some industrial companies, they are far more than a landmark; they're essential parts of business that are made up of many different components. All of these components must work well and last for a long time to avoid disruptions in operations. Here are some of the most important aspects of power centers:
Automatic Voltage Regulators
These machines, also known as step autotransformers, smooth out the flow of voltage to other components. They are especially useful in areas where the incoming voltage is often uneven. Many US embassies in foreign countries use these regulators, but they are also useful in domestic areas.
Voltage regulators are installed prior to the transformers that are connected to loads, or devices which draw power. This protects the transformers from voltage spikes and other anomalies that would otherwise cause damage.
Transformers aren't just for movies. In power centers, step-up transformers increase voltage so it can be sent over long distances. This makes up for the loss of power caused by the resistance inherent in electrical wiring. These devices can range from thumbnail size all the way up to hundreds of tons. The size that is needed depends on how much current is involved and how far it has to be sent before it reaches its destination. Power that has come through the wider grid almost always has gone through several transformers before reaching its destination, but energy that is generated on-site at industrial locations may only travel through one or two of these devices before it is used.
Not all voltage needs to be increased before it is used. Step-down transformers are also used by power distribution centers. In these cases, they are used to lower voltage coming in from high-tension wires. They are also used where the lines enter homes and offices, where they transform the high voltages of neighborhood lines into the 120- or 240-volt levels found in standard outlets.
These banks improve the efficiency of appliances and motors connected to the power centers they are part of. They remove reactive current and improve the power factor of circuits. When properly installed and set up, the voltage level at the load is increased, voltage regulation is improved, overloads are relieved, and power losses are reduced. Other benefits are obtained as well.
If you've ever driven by power centers and had a horrible buzz or howl come over your radio, you've heard electrical harmonics. Harmonics filters are installed into power centers to reduce this problem and several others. By lowering or eliminating harmonics, excessive fuse failures, overheating equipment, transformer failure, voltage distortion, and other issues are resolved; therefore, every power center should have a harmonics filter.
In most cases, a power center will be run by a local electric company or municipality. These companies often operate several centers, so they require many instances of all of the equipment used therein. By keeping extra equipment on hand, they can quickly restore service in the case of a storm or other cause of failure.
Large industrial installations such as mines may run their own power centers instead of relying on municipal power. This can be done to save money, to provide themselves with power levels that the main electrical company can't supply, or simply to ensure that they can keep their power going even if there is a failure of the wider grid. While these companies usually don't need the number of pieces of equipment that an electric company does, they should still keep plenty of spare parts handy. This will ensure that they can get back online quickly in the case of any problems.
20 December 2013