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[en] In recent years the maximum level of induced interference current which can normally be expected in instrumentation systems has been found to be in the region of 100mA rms. However, in the course of investigating interference problems abnormally high levels, of as much as 20A peak, have been found to originate from relay circuit interruption. A likely coupling mechanism for this source of interference is discussed and analysed and it is concluded that proper suppression of relays is practical, safe and beneficial. (author)
[en] It is about a relay for power protection. It describes the definitions of structure, a point of contact protection of contact, reclosing, relay scheme and input circuit. It explains normal use condition, special use condition, rated frequency, rated voltage and rated current, fluctuation range of permission of incoming relay. It deals with general structing outer case, correction device, operation indicator and outer terminal condition sort and method of the test. It adds the marks and pictures about currents
[en] This paper builds a system based on FPGA, which is used for USB 2.0 data monitor, simulate and verify system. To build the system, and construction of hardware experimental platforms and logical module programming with HDL are both required. The core of the system is FPGA and ULPI peripherals, which extend two external USB ports for FPGA. By using HDL to package ULPI core, generate data buffer and relays module, and build the connection between ULPI data transceiver. And the function of data monitor and collection will be accomplished. The cooperation simulations by using ISE and ModelSim is using for system analyzation, modification, and verification. (paper)
[en] This book gives description of protective relay. The contents of the first part are protective relay on general introduction, explanation of the terms and characteristic, classification of protective relay, structure of protective relay, operating of protective relay, short-circuit fault, earth fault and analyze of fault area, right using of protective relay. The last parts consist of current relay and voltage real y with over current relay, connection of wire of CT and over current relay and changing of current tap of OCR on using, over voltage relay and under voltage relay and voltage suppressor relay short-circuit relay for current compensation ground relay, directional relay, selective relay, directional relay and indication relay, distance relay, balance relay, TR relay, power control relay and another protective relay.
[en] The insulation level of DC control circuits is an important safety-critical factor and, thus, should be subject to continuous and periodic monitoring. The methods used for monitoring the insulation in live circuits may, however, disturb the reliable operation of control relays. The risks of misoperation and failure to reset of relays posed by the operation of various insulation monitoring and fault location systems are evaluated.
[en] This book is divided into two chapters, which deals with protective relay. The first chapter deals with the basic knowledge of relay on development of relay, classification of protective relay, rating of protective relay general structure of protective relay, detecting of ground protection, about point of contact, operating relay and trip relaying. The second chapter is about structure and explanation of relay on classification by structure such as motor type and moving-coil type, explanation of other relays over current relay, over voltage relay, short voltage relay, relay for power, relay for direction, test of over voltage relay, test of short voltage relay and test of directional circuit relay.