YAW CONTROL The yaw control continuously orients the rotor in the direction of the wind. It can be as simple as the tail vane, or more complex on modern towers. Theoretical considerations dictate free yaw as much as possible. However, rotating blades with large moments of inertia produce high gyroscopic torque during yaw, often resulting […]
YAW CONTROL AND SPEED CONTROL OF WIND TURBINE Read More »
Transformers are susceptible to damage by secondary short-circuit currents having magnitudes that can be many times rated load current. The damage results from the following effects: >> The I2R losses in the winding conductors are increased by the square of the current. This increases the temperature rise of the windings. >> Because protective devices limit the duration of
EFFECTS OF SHORT CIRCUITS ON TRANSFORMERS Read More »
The design of new substations has the advantage of starting with a blank sheet of paper. The new substation will typically have many IEDs for different functions, and the majority of operational data for the SCADA system will come from these IEDs. The IEDs will be integrated with digital two-way communications. The small amount of
NEW VERSUS EXISTING SUBSTATIONS Read More »
The following additional design trade-offs are available to the system engineer: NUMBER OF BLADES This is the first determination the design engineer must make. Wind machines have been built with the number of blades ranging from 2 to 40 or more. The high number of blades was used in old low, tip-speed ratio rotors for
WIND POWER SYSTEM DESIGN FEATURES Read More »
The wind power system is comprised of one or more units, operating electrically in parallel, having the following components: The tower. The wind turbine with two or three blades. The yaw mechanism such as the tail vane. The mechanical gear. The electrical generator. The speed sensors and control. The modern system often has the following
WIND POWER SYSTEM COMPONENTS Read More »
Electric power is one of the mainstays of our lives and the life of our nation. It differentiates advanced societies from third world nations. It touches almost every facet of our lives: our homes, our businesses, our schools, our transportation, and our leisure time. It is there when we are born, and it is there
SOCIETAL BENEFITS OF ELECTRICITY Read More »
An electrical power substation is a conversion point between transmission level voltages (such as 138 KV) and distribution level voltages (such as 11 KV). A substation has one or more step-down transformers and serves a regional area such as part of a city or neighborhood. Substations are connected to each other by the transmission ring
DIFFERENCE BETWEEN GRID STATION AND SUB STATION Read More »
MEASUREMENT: The set of operations having the object of determining the value of a quantity. MEASURAND: A quantity subject to measurement. METROLOGY: The field of knowledge concerned with measurement. This term covers all aspects both theoretical and practical with reference to measurement, whatever their level of accuracy, and in whatever field of science or technology
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Generally, Fixed Shunt Reactors are designed and located in a way to be connected to the network most of the time. However, lately it is often required by the electrical utilities to perform automatic switching in/out operations on Switchable Fixed Shunt Reactors by monitoring the bus-bar voltage level. Figure 8-1 illustrates a typical Switchable Fixed
CONTROL OF FIXED SHUNT REACTORS Read More »
Compared to shunt reactors with a fixed rating, Variable Shunt Reactors provide several benefits to the operators. Customer values and applications of VSRs are as follows. To reduce voltage spikes in the network resulting from switching in and out the Fixed Shunt Reactors; especially in networks with low short circuit power. Generally, switching Fixed Shunt
APPLICATIONS OF VARIABLE SHUNT REACTOR VSR Read More »