Power Electronics

Definition: On-line UPS abbreviated as OUPS is a type of UPS that uses a combination of rectifier and inverter circuits in order to provide continuous power to the load from the supply source without any interruption. From continuous power here we mean that power is supplied to the load in case of availability from the source and power outage as well with zero transfer time. On-line UPS is sometimes also known as double-conversion system. The reason for calling it so because, within an online … [Read more...] about On-line UPS

Dielectric Heating is a process of electric heating by which the temperature of a dielectric (non-conducting) material is raised by the application of an alternating electric field (high voltage ac signal). The increase in temperature results in heating the substance which is in contact with the external field. Dielectric heating is sometimes called high frequency or radio-frequency heating, capacitive heating. This process allows uniform heating of non-metallic materials which are unable to … [Read more...] about Dielectric Heating

A small amount of dc or ac voltage is required to charge the battery. Thus, to charge any battery, suppose ac input is required then initially the input ac signal must be limited, then filtered for the removal of noise and regulated so that the voltage achieved after doing this can be used to charge the battery. However, not only this, after the battery gets fully charged, the circuit must get turned off so that no further unwanted charging takes place. A battery charger acts as a source … [Read more...] about Battery Charger Circuit using SCR

Thyristor Controlled Reactor abbreviated as TCR is a device used in power systems that offers fast reactive power and voltage limiting characteristics to the lightly loaded system. It majorly deals with controlling the temporary overvoltage condition and voltage collapse condition when there is an increase in transient stability and a decrease in system oscillations. A TCR typically has two inverse thyristors connected in parallel configuration along with a reactance in series with … [Read more...] about Thyristor Controlled Reactor

Parallel operation of thyristors deals with the requirement of parallelly connecting multiple thyristors, the operation of SCRs in a parallel configuration and the factors to be considered when multiple thyristors are to be included. Need for parallel connection of SCR We have already discussed while discussing the series operation of thyristor that presently available thyristor ratings are 10 kV and 3 kA for voltage and current respectively. But sometimes even such high values of individual … [Read more...] about Parallel Operation of Thyristor

The series operation of thyristor explains why the serial connection of multiple thyristors is required, how the thyristors operate when serially connected and how can we deal with the drawbacks associated with the circuits that include multiple thyristors. Need for series connection of SCR After the introduction of SCR in 1957, the proposed rating of the thyristors has shown considerable improvement in recent years. At present, the thyristors are available with voltage and current ratings of … [Read more...] about Series Operation of Thyristor

Definition: The compensation of reactive power of the circuit is quite important as it is associated with the value of the power factor. The reactive power compensation corresponds to the controlling of reactive power to increase the performance characteristics of the AC system. There are some methods by which the power factor of the system can be improved and hence these are regarded as methods of reactive power compensation. On a practical basis, it is said that the value of the load power … [Read more...] about Methods of Reactive Power Compensation

Switching characteristics of thyristor sometimes called dynamic or transient characteristics correspond to the representation of dynamic behavior of the thyristor. Basically, the dynamic behavior of the device is associated with its turn-on and turn-off characteristics. We know that in general terms, that a switch is used to connect or disconnect an electrical circuit and the connection and disconnection cause the device to get turned on or off. In a similar way, when the switching … [Read more...] about Switching Characteristics of Thyristor

Definition: Insulated Gate Bipolar Transistor is a voltage-controlled ideal switching device formed by the combination of BJT and MOSFET. The IGBT utilizes the best qualities of BJT and PMOSFET to generate a transistor that possesses input characteristics of MOSFET and output characteristics of BJT. It is regarded as an advancement of power MOS technology and is abbreviated as IGBT but sometimes called as MOSIGT i.e., Metal Oxide Semiconductor Insulated Gate Transistor, COMFET i.e., … [Read more...] about Insulated Gate Bipolar Transistor (IGBT)

Definition: Static Induction Thyristor generally abbreviated as SITH is a self-controlled device similar to a gate turn-off thyristor. A SITH has three terminals namely cathode, anode, and gate. It was developed in the year 1960 by a Japanese engineer and commercially introduced in the year 1988. The commercial use of SITH was promoted by Japanese Universities and Industries. The key feature possessed by static induction thyristor is that it offers the capability of conducting a large … [Read more...] about Static Induction Thyristor