• Journal of Power Electronics
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• v.11 no.4
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• pp.533-541
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• 2011

The redundant operation of a parallel AC to DC converter via a serial communication bus is presented. The proposed system consists of three isolated CUK power factor correction modules. The controller for each converter is a dsPIC30F6010 microcontroller while a RS485 communication bus and the clock signal are used for synchronizing the data communication. The control strategy of the redundant operation relies on the communication of information among each of the modules, which communicate via a RS485 serial bus. This information is received from the communication checks of the converter module connected to the system to share the load current. Performance evaluations were conducted through experimentation on a three-module parallel-connected prototype, with a 578W load and a -48V dc output voltage. The proposed system has achieved the following: the current sharing is quite good, both the transient response and the steady state. The converter modules can perform the current sharing immediately, when a fault is found in another converter module. In addition, the transient response occurs in the system, and the output voltages are at their minimum overshoot and undershoot. Finally, the proposed system has a relatively simple implementation for the redundant operation.

• Proceedings of the KIPE Conference
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• 2016.07a
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• pp.479-480
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• 2016

This paper introduces a master and slave control algorithm for parallel operation of UPS system. If each module of UPS system control the output voltage and filter inductor current in parallel operation, it occur unbalanced output power each module. To operate UPS system parallel, it need a algorithm that control output power of modules. A master and slave control algorithm is helpful to balance output power of modules by controlling output current. The effect of a master and slave control algorithm is proved by simulations.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.10
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• pp.1672-1681
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• 2016

This paper proposes a wireless parallel operation method of three-phase modular UPS inverter using resistive droop control. Furthermore, it applies a virtual resistor to droop control so that the output impedance of UPS inverter gets closer to resistive. It makes resistive droop control effective. The simulation using PSIM was performed in order to verify the validity of proposed algorithm. After consisting two-parallel system with three-phase modular UPS inverter, the experiment according to resistive load was conducted. It demonstrated the performance of current sharing and power sharing.

• The Transactions of the Korean Institute of Power Electronics
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• v.5 no.4
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• pp.409-416
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• 2000

In case of operating two converters in parallel with ZCT operation method using one current sensor for fault tolerance by system characteristics, identifying fault detection and isolation is difficult of which converter is fault since the ZCT output is a difference of two converters' supply current when a converter has fault. This thesis suggest a fault detection and isolation method of converter in case of operating two converters in parallel for fault tolerant system and verified this suggested method through an experiment.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2358-2361
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• 2003

In this paper, parallel control method that enables coordinating operations of multiple mini ice storage air conditioner is proposed based on LonWorks system. The proposed parallel control method is a kind of master/slave control method based on LonTalk network communication. In the control method, master controller leading whole system operations is determined by date to avoid the disproportion of outdoor unit operations. In addition to the above, duty shift control method is proposed to avoid redundant operations of outdoor units and to equalize the operation frequencies of them. Through some simulation tests, the proposed parallel control method and the duty shift control method are evaluated and the efficiencies of them are validated by comparing with existing methods.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.22 no.2
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• pp.53-59
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• 2014

Simultaneous parallel approaches in all weather conditions should be applied to manage efficiently increasing volume of air traffic flow and solve the problem of delayed arrivals. But All of the airports which have closely-spaced parallel-runways in Korea don't meet the interval-standards for IFR parallel approaches. In that regard, more accurate and safer System should be applied for the Korean airports. GNSS was adopted as an international standard of the next-generation navigation system and many studies and master plans have been activated by stages in Korea. In this paper, the current state of the domestic airports will be analyzed focusing on the interval of parallel runways and future specification of both flight operation system and air-side management will be recommended.

• Journal of Information Processing Systems
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• v.20 no.1
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• pp.24-37
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• 2024

To address the requirement for high-speed encryption of large amounts of data, this study improves the widely adopted cipher block chaining (CBC) mode and proposes a controllable parallel cipher block chaining (CPCBC) block cipher mode of operation. The mode consists of two phases: extension and parallel encryption. In the extension phase, the degree of parallelism n is determined as needed. In the parallel encryption phase, n cipher blocks generated in the expansion phase are used as the initialization vectors to open n parallel encryption chains for parallel encryption. The security analysis demonstrates that CPCBC mode can enhance the resistance to byte-flipping attacks and padding oracle attacks if parallelism n is kept secret. Security has been improved when compared to the traditional CBC mode. Performance analysis reveals that this scheme has an almost linear acceleration ratio in the case of encrypting a large amount of data. Compared with the conventional CBC mode, the encryption speed is significantly faster.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.65-68
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• 2008

This paper proposes the parallel operation control algorithm of a power conditioning system (PCS) for a distributed Fuel Cell power generation system. A proposed control algorithm is made good a drawback of the conventional control algorithm. The controller must also supervise the total PCS operation while communicating with the fuel cell system controller. Simulation results are presented to performance of a proposed control algorithm for the PCS.

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.282-284
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• 1988

In this paper, a method for constructing parallel-in, parallel-out multipliers in GF($2^{m}$) is presented. The proposed system is composed of two operational parts by using shift register. One is a multiplicative arithmetical operation part capable of the multiplicative arithmetic and modulo 2 operation to all product terms with the same degree. And the other is an irreducible polynomial operation part to outputs from the multiplicative arithmetical operation part. Since the total hardware is linearly m dependant to an GF($2^{m}$), this system has a reasonable merit when m increases. And also this system is suited for VLSI implementation due to simple, regular, and concurrent properties.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.172-176
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• 2000

The paper presents the fault detection and isolation of two DC-DC converters parallel operation by ZCT method. Two experimental prototype converters were designed and implemented for evaluation of fault tolerant system. The experimental results show that fault detection and isolation circuit works very well.