Experimental research of the influence of a ferromagnetic core on the speed of an induction-dynamic release with turning anchor type

Circuit breakers for overcurrent protection of semiconductor converters limit the duration and amplitude of the overcurrent at such a level that its thermal effect does not exceed the maximum allowable thermal protection index of the protected semiconductor device. The limitation of the thermal action of the short-circuit current is achieved by reducing the operation time of the circuit breaker. The design of the circuit breaker is changed in such a way that instead of the basic electromagnetic release is used an induction-dynamic release, which consists of an inductor with a ferromagnetic core and a rotary armature in the form of a copper disk. The electrodynamic force producing by the induction-dynamic release for quick operation is determined by the coefficient of mutual inductance of the inductor coil and the armature. Using of a ferromagnetic core entailed an increase in the coefficient of mutual inductance of the coil and armature, therefore, an increase in the electrodynamic force producing by the release, and a decrease in own tripping time of the circuit breaker. On a prototype, an experimental study of the proper operation time of the release was carried out at various values of the electrical parameters of the capacitor bank of the inductor power supply, the winding parameters of the inductor coil and the disk dimensions. The research results have proved both a decrease in the tripping time of the circuit breaker while conserving the energy of the capacitor bank of the inductor, and a decrease in the required energy of the capacitor bank to power the inductor while maintaining the minimum tripping time of the circuit breaker. Reducing the energy of the capacitor bank of the inductor made it possible to reduce the capacity and voltage of the capacitor bank of the supply of the release, and, consequently, its dimensions.

Analisis Perencanaan Capacitor Bank Untuk Perbaikan Faktor Daya Pada Pusat Perbelanjaan Blitar Square

Power factor is the ratio between active power (W) and apparent power (VA). In an electrical installation, the quality of electric power can be said to be good if the value of the power factor is above a predetermined standard of 0.85 according to the Minister (ESDM) Number 30 of 2012 [1]. From the research that has been done at the Blitar Square Shopping Center, it was found that the power factor value is still below the standard with an average value of 0.711. With the low power factor value, this shopping center gets a penalty from PT. PLN (Persero) due to the use of reactive power. Therefore, it is necessary to make efforts to improve the power factor by installing a capacitor bank. The installation of this capacitor bank is expected to be able to increase the power factor value with a power factor target of 0.98 and reduce the charge for reactive power usage penalties. The calculation results show that global compensation requires 12 capacitor banks with a rating of 10.4 kVAR, while sectoral compensation on the chiller load panel requires 7 capacitor banks with a rating of 10.4 kVAR and the foodmart load panel requires a capacitor bank with a rating of 10. 4 kVAR is 6 pieces. In simulating the installation of a capacitor bank using the ETAP application, it is known that the installation of a capacitor bank can increase the power factor value. In addition, the installation of a capacitor bank also results in an increase in the voltage value in the system, this voltage increase is still below the permissible standard of ± 5%. The simulation of installing a capacitor bank on global compensation can improve the power factor value from 72.99% to 96.97%, with a voltage increase of 0.479% from the initial value of 397 V to 398.9 V, and a decrease in the current value of 24.645% from the initial value. 330.7 A to 249.2 A. While the simulation of installing a capacitor bank in sectoral compensation can improve the power factor value from 72.99% to 93.57%, with a voltage increase of 0.401% from the initial value of 397 V to 398.6 V , and a decrease in the value of current by 21.593% from the initial value of 330.7 A to 258.1 A. The cost of installing a capacitor bank in global compensation was Rp. 189,897,500 while the sectoral compensation is Rp. 211.305.600. It can be concluded that the installation of a capacitor bank using the global compensation method is more effective.

An efficient Capacitor Bank Operating System for Single Phase Power Factor Correction using Neural Network Estimations

Wastage of electricity occurs in all places starting from a small house electrical loading to a heavy industrial electrical loading. KiloVolt-Ampere Reactive (KVAR) power metering devices are employed in industrial applications for measuring the energy utilization which measure the energy wastage along with it. This urges a consumer to pay for the unutilized or wasted energy as well. To avoid this, certain capacitor bank units are connected to the industrial application motor units. The right choice of capacitor rating are helpful in minimizing the wasted power observation in the KVAR meters. The selection of capacitor rating is analysed with respect to the power factor calculation. The power factor is a derivation of working power to the apparent power in an electrical system. An optimum power factor to be maintained in an electrical system is 1. The motive of the proposed work is to maintain the power factor by selecting an optimum capacitor bank on the operation of an electrical system at various load conditions. The requirement of capacitor bank values get changed with respect to the load given to an electrical system. A neural network based prediction model is employed in the work for estimating the right choice of capacitor bank. The efficiency of the proposed work is verified and found satisfied with a traditional capacitor bank operating system.

Method of Switching on and Off a Power Transformer with a Capacitor Bank in an Electrothermal Installation

The article is devoted to issues related to increasing the energy efficiency of industrial electrothermal installations, both in starting and stationary operating modes due to the use of capacitors and thyristor starters with special control. The results of a significant reduction in the duration of the transient process, elimination of surges and asymmetry of starting currents and voltage drawdowns are presented. The results of full compensation of the reactive power of the network in the steady-state mode are also presented. It is shown that the starting currents do not exceed their steady-state values and that the shutdown of the electrothermal installation is performed without the occurrence of an arc and switching losses at the contacts of the switches. Researches of an electrothermal installation with a capacity of 750 kV⋅A and a voltage of 380 / 80 V are made on the model in the Matlab environment.