Cascaded transformerless DC-DC voltage amplifier with optically isolated switching devices

A very high voltage amplifier is provided in which plural cascaded banks of capacitors are switched by optically isolated control switches so as to be charged in parallel from the preceding stage or capacitor bank and to discharge in series to the succeeding stage or capacitor bank in alternating control cycles. The optically isolated control switches are controlled by a logic controller whose power supply is virtually immune to interference from the very high voltage output of the amplifier by the optical isolation provided by the switches, so that a very high voltage amplification ratio may be attained using many capacitor banks in cascade

RANCANG BANGUN PFC YANG DILENGKAPI METERING DENGAN PENGONTROLAN CAPASITOR BANK UNTUK BEBAN DINAMIS

Power Factor Corection (PFC) will be needed by the industries that use motors for the process industry. When using the motor as well as the industry bears the burden of reactive power required by the motor to rotate. With inductive loads such as motors properties causing low power factor (θ Cos). State Electricity Company (PLN) to determine Cos θ as low as 0.85, if under 0.85, the enterprises will get a fine. To anticipate the company use capacitor banks to improve cos θ above 0.85. Method for soft switches SCR capacitor bank is highly recommended. By using soft-switch SCR will improve cos θ as well eliminate the charging capacitor bank inrush currents which can reach 150-300 times nominal current of charging capacitor bank. In the dynamic motor load using a step-capacitor used in accordance with what is needed so that cos θ can be closer to the value set of points. Set point hysteresis value of cos θ of ± 0.01 to minimize fluctuations in the step of switching capacitor banks. With soft-switch SCR method for multiple step capacitor bank will increase the efficient of resources and economic factors of the capacitor bank equipment. Microcontroller is very important in applying the SCR method, the soft switch as a trigger SCR controller. Power factor improvement in motor load cos θ = 0.2 Laging become cos θ = 0.9839 to the setting points cos θ = 0.98. Based on simulation data for each step capacitor bank, a step capacitor bank made the cos θ = 0.265, two step capacitor bank made the cos θ = 0.382, 3 step method to make banks capsitor cos θ =0 .639, and four step capacitor bank made the cos θ = 1. Keywords: PFC, power factor, SCR soft switch, inrush current, microcontroller

Methodology for characterizing electric power system response and locating the energized capacitor banks using conventional power quality data

textA relatively small harmonic current with frequencies near or at the power system parallel resonant frequencies could excite the power system into a resonance condition. While a capacitor bank is not the root cause of the condition, it facilitates and helps cause the problem. This is because when the capacitor bank is energized, the system resonant frequency could shift closer to existing harmonic frequencies produced by nonlinear loads. Therefore, the objective of this dissertation is to quantify the power system characteristics corresponding to the parallel resonant frequencies and system damping. Additionally, since a capacitor bank actively facilitates the resonance condition, the relative or exact location of the involved bank must be determined. This dissertation first presents a practical and accurate methodology to estimate system parallel resonant frequencies by performing spectral analysis of the voltage and current transient data immediately after the capacitor bank switching. The proposed method is also robust in that the accuracy of the resulting estimates is not affected by prevalent harmonics in the system. This dissertation provides two efficient algorithms for estimating the system damping parameters using the Hilbert and analytic wavelet transforms. These algorithms take advantage of the principle of an asymptotic or weaklymodulated signal, for which the signal phase varies much more rapidly than the amplitude. The zero-input voltage response or free response of the capacitor bank energizing can be categorized into these asymptotic signals, and one can assign a unique time-varying amplitude with the system damping information and phase pair by building analytic signals. System model reduction theory also allows us to interpret or quantify this damping as an effective X/R ratio. This dissertation defines two fundamental signatures of shunt capacitor bank energizing. It demonstrates that these two signatures can be utilized to accurately determine the relative location of an energized capacitor bank whether it is upstream or downstream from the monitoring location. This dissertation also presents an efficient and accurate methodology for finding the exact location of an energized capacitor bank. Once a PQ monitor is found to be upstream from the capacitor bank by the relative location finding algorithm, the proposed algorithm can further determine the exact location of the switched capacitor bank by estimating the distance between the PQ monitor and the energized capacitor bank. Thus, one can pinpoint the energized capacitor bank causing the resonance.Electrical and Computer Engineerin

PERANCANGAN HMI (HUMAN MACHINE INTERFACE) SEBAGAI PENGONTROL DAN PENDETEKSI DINI KERUSAKAN KAPASITOR BANK BERBASIS PLC

Progammable Logic Controller (PLC) is a user friendly, microprocessor-based equipment that contains control functions of various types and levels of complexity. The control system is designed to be able to monitor the value of the power factor to remain stable and can determine the indication of early damage to the capacitor bank. In this research, an automatic control system is designed that can turn on the capacitor bank when the power factor value ≤ 0.95 and turn off the capacitor bank when the power factor value ≥1. HMI can provide data indication of early breakdown of capacitor banks based on the current value of each capacitor. This system utilizes PLC GE, and CE Digital Transducer so that the condition of the capacitor bank can be known in case of damage and decreased efficiency. Based on the test, when the power factor value is 0.95, the program will turn on the capacitor bank to meet the set point value of 0.95 and turn on the alarm indication that the power factor value is not sufficient, when the power factor value exceeds ≥1, the program will turn off the capacitor bank that works longer. The HMI system is able to provide data to perform preventive maintenance activities on a regular basis in order to maintain the efficiency and reliability of capacitor banks

Dynamic capacitor bank

Low power factor systems run inefficiently and cause power companies to lose thousands of dollars with wasted power. Correction systems currently implement static capacitor solutions to offset this power factor; however, companies where the power factor varies significantly need a better solution. In this paper, we discuss a reactive power factor correction system that could greatly benefit companies with this problem. The system is in its prototype state, which comprises of a capacitor bank, sensing circuit, a switching circuit and a microprocessor; we named it the Dynamic Capacitor Bank. During our project, we were able to get a sensing circuit to sense load voltage and current, as well as design a switching circuit and an inductive load for testing of the system. Our system performed the necessary steps to correct a power factor; however, we were limited by the power levels allowed for a senior design project and could not show precise information. Overall, a Dynamic Capacitor Bank could greatly benefit systems with varying power factor

Optimal Location of a Capacitor Bank in a Primary Feeder to Load up Linearly

A capacitor bank is not only used to improve the power factor, but also can be used to reduce losses in the power system network, such as its placement on the primary feeder. The position of the capacitor bank will be affected by the compensation factor and the sharpness of increase loads linearly in a primary feeder. This paper is aimed to determine an optimal location of the capacitor bank in the primary feeder which their loads increasing linearly in order to get maximum loss saving. Mathematical model to determine the optimal location of the capacitor bank has been clearly derived in this paper. Simulation results show that the maximum loss reduction occurs in compensation between 50% and 100%, with get loss saving about 52%. In these conditions, optimal locations lay between 75% and 100%. These results were influenced by the sharpness of the increase loads and the compensation factor. For loads increasing sharply, the position of the capacitor banks will be further away from the substation; whereas for greater compensation factor, the position of the capacitor bank will be getting closer to the substation

High Voltage Charging of a Capacitor Bank

We have demonstrated the feasibility of charging a capacitor bank to a high voltage using an autonomous ultra-compact explosively driven source of prime power. The prime power source is a longitudinally driven shock wave depolarization of a ferroelectric ceramic. The energy-carrying elements of the shock wave ferroelectric generators (FEGs) were poled Pb(Zr52Ti48)O3 polycrystalline ceramic disks with 0.35 cm3 volume. FEGs charged 9 nF, 18 nF, and 36 nF capacitor banks and provided pulsed-power with peak amplitudes up to 0.29 MW. The maximum efficiency of electric charge transfer from shocked Pb(Zr52Ti48)O3 elements to a capacitor bank was 46%. We demonstrated experimentally that the FEG-capacitor bank system can perform as an oscillatory circuit. A methodology was developed for numerical simulation of the operation of the FEG-capacitor bank system; the simulation results were in a good agreement with the experimental results

Radioisotope thermal generator (RTG) power conditioner

New regulator: (a) permits operation with high-impedance radioisotope thermal generators at conversion efficiencies typically above 90%; (b) does not require input filtering; (c) eliminates current spiking; and (d) is simple, efficient, and reliable. Converter-charger pair could be adapted for other power levels by changing transistor, diode, capacitor bank, and inductor

Compact 20-kiloampere pulse-forming-network capacitor bank

Bank uses commercially available high-energy-density capacitors for energy storage and silicon-controlled rectifiers for switching. Low voltage design employing solid-state switching is utilized in lieu of conventional gas discharge switching

Effects of Capacitor Bank Installation in a Medium Voltage (MV) Substation

Several medium voltage  substations, often called 33/11kV injection substations in Nigeria, are being run in electric utility companies without installing capacitor banks. Research has shown that the inclusion of capacitor bank improves system power factor and efficient running of the power system.This paper presents a brief description of the theory of power factor and its importance in achieving power system control and stability. Possible implications of substations without capacitor bank installations were also itemised. A schematic diagram of Ajangbadi 2X15MVA 33/11kV injection substation in Eko Electricity Distribution Company, Nigeria, is presented as a case study. A flowchart of the algorithm used to determine substation and network load parameters was developed and implemented. All results obtained and the necessary conclusions are presented. Keywords: Medium voltage, Injection Substation, Capacitor Bank, Power factor, Load parameters