• International Journal of Aerospace System Engineering
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• v.9 no.1
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• pp.1-15
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• 2022

Pyrotechnic initiators provide a source of pyrotechnic energy used to initiate a variety of space mechanisms. Pyrotechnic systems build in electromagnetic environment that may lead to critical or catastrophic hazards. Special precautions are need to prevent a pulse large enough to trigger the initiator from appearing in the pyrotechnic firing circuits at any but the desired time. The EMC verification shall be shown by analysis or test that the pyrotechnic systems meets the requirements of inadvertent activation. The MIL-STD-1576 and two range safeties, AFSPC and CSG, require the safety margin for electromagnetic potential hazards to pyrotechnic systems to a level at least 20 dB below the maximum no-fire power of the EED. The PC23 is equivalent to NASA standard initiator and the 1EPWH100 squib is ESA standard initiator. This paper verifies the two safety margins for electromagnetic potential hazards. The first is verified by analyzing against a RF power. The second is verified by testing against a DC current. The EMC safety margin requirement against RF power has been demonstrated through the electric field coupling analysis in differential mode with 21 dB both PC23 and 1EPWH100, and in common mode with 58 dB for PC23 and 48 dB for 1EPWH100 against the maximum no-fire power of the EED. Also, the EMC safety margin requirement against DC current has been demonstrated through the electrical isolation test for the pyrotechnic firing circuits with greater than 20 dB below the maximum no-fire current of the EED.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.10a
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• pp.239-242
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• 2009

Power Control and Distribution Unit (PCDU) plays roles of power generation control for solar array panel, power storage control for battery system, power conversion for unregulated and regulated primary bus and power distribution to bus and payload system. The selection and design of the proper auxiliary power interface for PCDU depending on various mission is one of the most important step for electrical power subsystem design. In this paper, the general design approach of auxiliary power interface for PCDU which can be used for small-sized LEO satellites application is given. And, the auxiliary power design concept for always alived modules such as solar array regulator and house keeping module is also suggested.

• Proceedings of the KIEE Conference
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• 2001.07a
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• pp.377-379
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• 2001

When a wide area blackout occurres, reenergizing transmission lines should be done at first. The KEPCO(Korea Electric Power Corporation) divides whole power system grid into seven subsystem, and each subsystem has one of two blackstart power plants which are usually hydro or combined-combustion type, one priority power plant which should be first supplied with electric energy, and transmission lines between them. Voltage rising, line charging, and operation stability problem should be considered when these lines are reenergized. In this paper, building-up process for primary transmission system that should be energized at first is analyzed.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.4
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• pp.404-409
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• 2009

A DC power system has many loads with various functions. In particular, these sizable loads take the form of power electronic converters. When they are tightly regulated, the loads appear as constant power loads and result in negative incremental input impedance. Under certain conditions the effect of such loads on the power system is causes instability. In this paper, converter with a large storage capacitor and a lag compensator is proposed as a DC bus conditioner to mitigate the voltage transients on the bus. In addition, the proposed control approach has the advantage of performing both the functions of mitigating the voltage bus transients and maintaining the level of energy stored. Simulation and experimental results showed that the proposed control method was operated well in a small-scale DC power system that contained subsystems with constant power characteristics, such as DC/DC converters and electrical drives.

• Aerospace Engineering and Technology
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• v.1 no.1
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• pp.72-83
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• 2002

Required power and solar array sizing of KOMPSAT-2 have been analyzed by ASTRIUM and KARI in November, 2000. There are Electrical Power Subsystem(EPS) design discrepancies between ASTRIUM and Korea Aerospace Research Institute(KARI) according to heritage program, EPS operation concepts, power source and the characteristic of the electrical boxes. To design the power system of KOMPSAT-2, ASTRIUM has used the EPS design of the CHAMP and GlobalStar program. But SSTI, TOMS-EP and KOMPSAT-1's design concepts has been used for KOMPSAT-2 EPS design by the KARI. To get the design conclusion, there are many trade-off meetings for the EPS sizing using each sides' heritage program and EPS operation concept. And the EPS design factors and approaching methods have been reviewed and discussed. In addition the EPS design results from ASTRIUM and KARI are summarized in this paper.

• Proceedings of the KSRS Conference
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• v.1
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• pp.220-223
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• 2006

The COMS(Communication, Ocean and Meteorological Satellite) EPS(Electrical Power Subsystem) is derived from an enhanced Eurostar 3000 EPS which is fully autonomous operation in normal conditions or in the event of a failure and provides a high level of reconfiguration capability and flexibility. This paper introduces the COMS EPS preliminary design result. The COMS EPS consists of a battery, a solar array wing, a PSR(Power Supply Regulator), a PRU(Pyrotechnic Unit), a SADM(Solar Array Drive Mechanism) and relay and fuse brackets. This can offer a bus power capability of 3 kW. The solar array is made of a deployable wing with two panels. One type of solar cells is selected as GaAs/Ge triple junction cells. Li-ion battery is base lined with ten series cell module of five cells in parallel. PSR associated with battery and solar array generates a power bus fully regulated 50 V. Power bus is centralised protection and distribution by relay and fuse brackets. PRU provides power for firing actuators devices. The solar array wing is routed by the SADM under control of the AOCS(Attitude Orbit Control Subsystem). The control and monitoring of the EPS especially of the battery, is performed by the PSR in combination with on-board software.

• Proceedings of the KIPE Conference
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• 1998.07a
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• pp.138-142
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• 1998

This paper has been analyzed, modeled, designed, fabricated, and tested for solar cell simulator which has solar array characteristics. The main purpose is the development of solar cell simulator to test electrical power subsystem for GEO Communication Spacecraft. The maximum power of the simulator is about 5 ㎾, which is consist of 12 independent simulator modules with 420 W power rating. The 12 simulator modules are independently controlled like as real solar array system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.12
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• pp.2119-2126
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• 2016

In this paper, we developed a smart black box that can monitor and record the information of the sensor from subsystem in the smart grid system. The plant is the complex power system which is integrated by solar power system, grid-connected power systems, and BESS(battery energy storage system). The black box with the web-server application can connect and synchronize to an external monitoring system and a smart phone. We hope that this system is to contribute to improve operational efficiency, reliability, and stability for the smart grid power system.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.2
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• pp.150-157
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• 2014

Li-Ion battery is used in the most satellites now due to advantages such as weight, thermal dissipation and self discharge compared to the previous generations of electrochemical batteries. The performance analysis model of the Li-Ion battery is needed to aid the design of new satellite electrical power subsystem. This paper develops the performance analysis model of the Li-Ion battery to apply to the electrical power subsystem design and energy balance analysis on geostationary orbit. The analysis model receives the satellite bus power, solar array power and battery temperature and gives the battery voltage, charge and discharge currents, taper index, state of charge and power dissipation. The results from the performance analysis are compared and analyzed with the flight data to verify the model. The compared results show satisfactory without significant difference with the flight data.

• Journal of the Korean Society of Propulsion Engineers
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• v.2 no.3
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• pp.80-89
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• 1998

Propulsion subsystem transfers KOMPSAT into mission orbit and controls its attitude. Design factor consists of structure safety, electrical circuit design, consumable power estimation of thermal hardwares, damping device design of fuel transient pressure, and system configuration design by considering plume effect from thruster firing. System level analysis should be performed for verification of system design under launch vehicle and orbital environment. Electrical functional test of thermal control hardware, proof pressure test, cleanliness verification test, and internal/external leakage test of fuel feeding system should be carried out for performance estimation of propulsion system. Design and assembly process of propulsion subsystem was depicted and reliability of system was verified by test analysis in this paper.