Working Safely With Hazardous Capacitors: Establishing Practical Thresholds for Risks Associated With Stored Capacitor Energy

Scott, Mark

doi:10.1109/mias.2018.2875130

Cited by 8 publications

(6 citation statements)

References 8 publications

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“…With Equation (11) and with the data from Table 1, the (theoretical) capacities of the capacitors (on a branch of the wye-connected bank) that must be inserted in parallel with the inductive consumers were determined as follows: In the following tables i represents the inductive character, and c represents the capacitive character of the loads.…”

Section: Resultsmentioning

confidence: 99%

“…The main methods of improving power factor correction depend on the position of the capacitors banks, as follows: the distribution power factor correction, the group power factor correction, the central power factor correction, the combined power factor correction, and the automatic power factor correction. According to the literature, improving the power factors in power engineering can lead to cost savings of 10 to 30% [7][8][9][10][11].…”

Section: Introductionmentioning

confidence: 99%

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An Experimental Analysis of Three-Phase Low-Voltage Power Factor Controllers Used in a Deforming Regime

Diniș,

Popa

2024

Energies

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In industry, to improve the power factor in low-voltage power substations, a power factor controller (the most used method) can be installed which connects capacitors banks (connected, or not, with coils) in the electrical installation. The most important parameters of power engineering are the power factors that indicate the efficiency of energy use. Currently, many non-linear consumers (more single-phase than three-phase) are used on low voltages. Harmonics (currents and/or voltages) are the most important dynamic component of power quality, affecting electrical equipment performance and also reducing power factors. The purpose of this analysis is to increase the displacement power factor and to decrease the total harmonic distortion (for the current) in the conditions where there are linear and non-linear consumers, where the power factor must be improved with capacitors banks. Relevant different consumers have been selected for both the industry and the home sector, as follows: inductive motors that are linear, inductive consumers, compact fluorescent lamps that are non-linear, and capacitive consumers. This analysis was carried out depending on the number of steps used for the power factor controller, the values of the capacitors banks, the AC reactor (connected in series with all consumers), and the LC shunt filters. For a slight deformation regime, a large number of capacitors banks with different values ensure a finer adjustment of the displacement factor. The maximum number of steps that regulators can command should not necessarily be used (the reliability of the installation decreases with the increase in the number of capacitors banks), but a reduced number of steps can be used, which can lead to higher values of displacement power factors. To improve the deforming regime and to increase the displacement power factor, the use of LC shunt filters, connected to a small number of steps, will also increase the displacement power factor (over 0.9) and decrease the total harmonic distortion (up to 7–10%) for the current. Weaker results were obtained with AC reactors connected to the power supply phases of consumers and, if a larger number of stages were used, to which LC shunt filters were connected, these filters become difficult to calibrate (resonances occur).

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

An Experimental Analysis of Three-Phase Low-Voltage Power Factor Controllers Used in a Deforming Regime

Diniș,

Popa

2024

Energies

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“…This technology has a strong dependence on subjective experience and makes it difficult to meet certain requirements. For example, single-tuned PPFs must adjust their frequency slightly lower than the harmonic frequency to be eliminated, as aging, atmospheric conditions, or faults in the element can change the initial adjustment frequency of PPFs and reduce the role of long-term filters [24,[27][28][29].…”

Section: Of 37mentioning

confidence: 99%

Aspects Regarding of Passive Filters Sustainability for Non-Linear Single-Phase Consumers

Diniș,

Popa,

Cunțan

et al. 2024

Sustainability

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The efficient use of electrical energy (an important component of sustainability) has become increasingly important for electrical consumers (industrial and non-industrial) as we face the challenges of climate change and the need to protect the environment. This theme is essential for guaranteeing a secure and sustainable future for both present and future generations. The power quality and the efficiency of electrical energy are connected to each other. Some power quality problems are caused by natural and unpredictable events, but many disturbances affecting power quality are caused by suppliers and consumers. One of the most important parameters in power engineering is the power factor, which indicates the degree of efficient use of electrical energy. Harmonics is the most important dynamic component of power quality, which affects the operation of electrical equipment and, at the same time, reduces the power factor. Harmonic sources in power systems are generally associated with nonlinear loads. To analyze the operating of passive filters (series L, shunt LC, T type LCL), two groups of experiments (relevant consumers were chosen for the industry as well as from the household sector) were carried out with single-phase nonlinear consumers: in the first group of experiments, a variable-frequency drive is used to supply a three-phase induction motor with variable load; in the second group of experiments, compact fluorescent lamps and LED lamps were used. Following the experiments, it was found that the difficulty of calibrating coils (to size a filter), especially the coils with a core, and the change in electrical properties over time for capacitors. For a certain type of consumer, the improvement of the current waveform depends on the type of filter used, the possibility of improving the power factor (to use electrical energy efficiently), and the role of the source impedance, which is particularly important to improve the efficiency of passive filters. Through the appropriate choice of the passive filter, a decrease in the deforming regime is obtained, with a slight decrease in the active power, and by increasing the power factor, a decrease in the losses of electrical energy from the electrical networks is obtained, with direct implications for the emission of greenhouse gases.

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“…This should include a shock and arc flash risk assessment so the correct PPE may be chosen and boundaries that define safe approach distances from exposed energized electrical conductors or circuit parts can be established. Consider and seek to answer the following questions as an outcome of the analysis and assessment: Is a capacitor stored energy hazard present? Note: Evaluation of equipment manuals, schematics, or drawings will be necessary. How much stored energy, in joules, could be present? How long may it take to adequately discharge a capacitor? What testing and grounding methods are most suitable for the stored energy that could be present? What are the limited, restricted, and arc flash boundaries? What personal protective equipment is needed when entering a boundary? …”

Section: Capacitors and Capacitor Safety Basicsmentioning

confidence: 99%

Section: ■ Capacitors and Capacitor Safety Basicsmentioning

confidence: 99%

Electrical Shock During Phone Assisted Troubleshooting of Laboratory Equipment

Wright

Rodriguez

Clark

et al. 2023

ACS Chem. Health Saf.

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Researchers have the potential to be exposed to a wide variety of hazards inherent to the equipment they use and maintain. When equipment does not function as expected, researchers sometimes reach out to their vendors for assistance. Early diagnostic or troubleshooting interactions between researcher and vendor are often conducted over the telephone and can lead to researchers performing work outside of their area of expertise and exposure to unknown hazards. This type of interaction significantly contributed to an incident where during diagnostic activities a researcher accidentally contacted, and discharged, a capacitor in an X-ray diffraction instrument. While this incident did not produce a serious injury, if the capacitor discharge path had occurred hand-to-hand across the heart, a serious injury may have been possible.

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Working Safely With Hazardous Capacitors: Establishing Practical Thresholds for Risks Associated With Stored Capacitor Energy

Cited by 8 publications

References 8 publications

An Experimental Analysis of Three-Phase Low-Voltage Power Factor Controllers Used in a Deforming Regime

An Experimental Analysis of Three-Phase Low-Voltage Power Factor Controllers Used in a Deforming Regime

Aspects Regarding of Passive Filters Sustainability for Non-Linear Single-Phase Consumers

Electrical Shock During Phone Assisted Troubleshooting of Laboratory Equipment

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