• Journal of the Korean Society of Safety
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• v.27 no.3
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• pp.49-56
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• 2012

The purpose of this paper is to present a model for operating an emergency power system(EPS) that can secure a sufficient power supply used in case of a fire by analyzing the status of power supplies for emergency and firefighting operations. Investigations on the one of the causes of the operational failure of firefighting systems show evidence of EPS. Generally, when power to a building is interrupted, EPS supplies the emergency load(excepted firefighting load) first. When a power outage and a fire occur simultaneously, the EPS must be able to supply both the emergency load and the firefighting load, especially the firefighting load to the end. However, in order to save construction costs, emergency power generators in apartment, commercial, and business buildings can satisfy only one of the required loads. In cases like this, when a power outage and a fire occur simultaneously, there is a danger of firefighting equipment not operating due to insufficient power supply from the emergency generator. Therefore, an EPS must have a reserved firefighting power that can supply both the firefighting and the emergency load. Such EPS, when faced with a danger of an overload, will shut down the supply to all or part of the emergency load, thus securing a continuous power supply to the firefighting equipment. The generator power system with reserved firefighting power (RFP) will also have an indicator to show that the selective control is being used. General power generation systems for emergency load and firefighting load were found to have a demand factor of 50-60% with a lump. However, when installing an EPS, the builders must choose the higher demand factor suggested according to the official approval demand factor of the building.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.8
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• pp.40-48
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• 2015

In this paper, battery charging and discharging circuit with a single voltage power supply is proposed. The proposed circuit has the separated current path and charging-monitoring sequence control scheme. In the charging sequence, the proposed 2-level comparator combined with control signal of the micro-processor can control the constant charging current to protect the over current of the battery. Furthermore, the proposed circuit uses a periodic main power switch control to detect the discharging characteristics to estimate the approximated battery life-time. In the experiments, the proposed emergency power supply for emergency call system has 89% efficiency with 98% power factor. And the proposed sequence control scheme is well operated in the designed emergency power system.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.11a
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• pp.252-253
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• 2005

This paper describes a improvement of power control characteristics of ship's emergency lighting power supply(SELPS), that power factor(PF) is improved and electric power is controlled extensively, and power ON-OFF is controlled and system parameter monitored in remote distance by PC serial communication.

• Fire Science and Engineering
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• v.26 no.3
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• pp.29-34
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• 2012

The purpose of this study is to propose an effective operating method of a power generator used by the Emergency Power System in case of a simultaneous fire and of the limitations of the interlock system the power supply from the emergency power generator. On the Emergency Power System with Reserved Fire-fighting Power (RFP), in case of an overload, the collective control Emergency Power System signals the main circuit breaker to shut off the supply to the emergency load, leaving the supply to the firefighting load uninterrupted to the end. The sequential control Emergency Power System signals the firefighting power supply to shut off the fire stage of the emergency load and continues to monitor the power supply. If an overload happens again from increased firefighting load, the sequential control Emergency Power System sends a secondary signal to shut down the second stage of the emergency load.

• Journal of Power System Engineering
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• v.11 no.3
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• pp.3-8
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• 2007

The emergency AC power supply system of the nuclear power plant is designed to supply the power to the nuclear reactor at the emergency operating condition. The safety function of the diesel generator at the nuclear power plant is to supply AC electric power to the plant safety system whenever the preferred AC power supply is unavailable. The reliable operation of onsite emergency diesel generator should be ensured by a conditioning monitoring system designed to maintain and monitor and forecast the reliability level of diesel generator. To do this kind of diesel generator condition monitoring we reviewed several operating factors and history of the wolsong unit 3 diesel generator and selected the proper conditioning monitoring operating factors.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.11a
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• pp.129-133
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• 2005

While everyone who uses electric power desires perfect frequency, voltage, stability, and reliability at all times, this cannot be realized in practice. The supplying utility cannot be expected to provide a perfect power supply because many of the causes of power supply disturbances are beyond the control of the utility. The outage happens but due to many reason. The electricity equipment requires consequently the emergency power supply. We classify the subordinate for quick supply of the emergency power supply and must grope the supply plan. We will find out in this paper through the case study about the emergency power efficient operation plan.

• Journal of Navigation and Port Research
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• v.28 no.8
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• pp.667-671
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• 2004

This paper describes an development of digital power supply for ship's emergency lighting system(SELS). Proposed system is composed of emergency power supply system(EPSS), half bridge(HB) inverter, fluorescent lamp(FL) starting circuit and microprocessor control system. Experimental works using proposed system confirm that speedy and stable power to be supplied when main power source cut-off, compared with conventional analog type, and control input power up to 35.0［%］ by adjusting pulse frequency of the HB inverter.

• Journal of Power System Engineering
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• v.17 no.4
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• pp.31-35
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• 2013

The emergency AC power supply system of the nuclear power plant is designed to supply the power to the nuclear power plant at the emergency operating condition. The safety function of the diesel generator at the nuclear power plant is to supply AC electric power to the safety system whenever the preferred AC power supply is unavailable. The reliable operation of onsite standby diesel generator should be ensured by a condition monitoring system designed to maintain, monitor and forecast the reliability level of diesel generator. The purpose of this paper is to improve the existing ultrasonic sensor used for condition diagnosis of engine fuel pump and cylinder head for the accurate diagnosis in actual engine condition of emergency diesel generator(EDG). As a result of this study, we could design and develop much more reliable ultrasonic sensor than existing ones.

• Journal of Navigation and Port Research
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• v.29 no.10 s.106
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• pp.859-863
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• 2005

This paper describes the improvement of power control characteristics of ship's emergency lighting power supply(SELPS), by which electric power is controlled extensively, and power ON-OFF is controlled and system parameter monitored in remote distance by PC serial communication. Proposed system is composed of step-down converter(SDC), emergency power supply circuit(EPSC), half bridge(HB) inverter, fluorescent lamp(FL) starting circuit, microprocessor control and multi communication circuit. Experimental works confirm that relative system stops when over current is detected and speedy and stable emergency power is supplied when main power source cut-off, and controls input power up to 35[$\%$] by adjusting pulse frequency of the HB inverter, and ON-OFF control of multiple SELS, real time transmission and monitor of parameters as to voltage, current, and power values are performed appropriately by PC communication.

• The Transactions of the Korean Institute of Power Electronics
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• v.21 no.4
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• pp.302-311
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• 2016

This paper proposes a hybrid ESS that integrates an energy storage system (ESS) with an uninterruptible power supply (UPS). The hybrid ESS has a demand management and emergency power supply function while increasing the battery utilization of the UPS, which has just been used in a power failure. In addition to the critical load, the proposed system augments the capacity of emergency generation using an additional load, which has voltage and frequency-dependent characteristics to the grid side. The control algorithm of the AC-DC converter and bidirectional DC-DC converter is proposed for demand management and emergency power supply. Furthermore, seamless and autonomous transfer methods to alleviate the transient during mode transfer are proposed. To validate the proposed control scheme, experimental results from a 5 kW prototype are provided.