g`b`�� �� 06��c��x\b��+w��wܙ=����,�ya�z-~9$�X���A����@���Ao@� ��� endstream endobj 79 0 obj 83 endobj 73 0 obj << /Type /Page /MediaBox [ 0 0 614.39999 792 ] /Parent 69 0 R /Resources << /XObject << /Im1 77 0 R >> /ProcSet [ /PDF /ImageB ] >> /Contents 74 0 R /CropBox [ 0 0 614.39999 792 ] /Rotate 0 >> endobj 74 0 obj << /Filter /FlateDecode /Length 75 0 R >> stream 3,018,416. Preferably the reset control circuit 48 consists of an operational amplifier 50 whose non-inverting input is connected to common by resistor 52 and whose inverting input is connected to pick-up control circuit 32 via the resistor 44 and the diode 46 and to a suitable negative voltage source 54 by a resistor 53. The preferred embodiment of such a function generator is more fully described in my copending application mentioned above. using thermal images, Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions, Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for dynamo-electric generators; for synchronous capacitors. A protective relay as defined in claim 9 in which said accumulator comprises a capacitor the charge on which increases with time whenever the accumulator is operative, said accumulator being in its quiescent state whenever the charge on said capacitor is near zero and attaining its trip state when said charge increases to a preselected level. Where this is so, a current magnitude device can be used, such as a fuse or an instantaneous relay or trip device and selectivity can be obtained by grading current. In this manner the accumulator 2 is returned to its quiescent state at a substantially linear rate. The operating time of high-speed relays is usually expressed in cycles based on the power-system frequency; for example, "one cycle" would be 1/60second in a 60-cycle system. The Canadian Electrical Code permits 300% overcurrent on the primary for this option. It will be apparent to those skilled in the art that other types of electrical apparatus (e.g., motors, transformers or the like) requiring protection from heat damage could also be protected by use of my relay. This relay has to be installed straight only and away from magnetic field. The relay is then always activated with the same time lag.Definite time overcurrent relays are used for protecting supply lines in high and low voltage networks, (overhead power transmission lines as well as cables). APPARATUS REQUIRED: Microcontroller based overcurrent relay, VPL 01 THEORY: Static relays are those relays which consist of electronic circuitry to develop all those characteristics achieved by moving parts in an electro-magnetic relay. The directional relay is nothing but a directional power relay which operates when the power in the circuit flows in a particular direction. US3942074A US05/509,879 US50987974A US3942074A US 3942074 A US3942074 A US 3942074A US 50987974 A US50987974 A US 50987974A US 3942074 A US3942074 A US 3942074A Authority US US Patent References: 3849706: LOGARITHMIC COMPUTING CIRCUIT: 1974-11-19: Johnson et al. Di Musiani Franco & C. Detector device for overcurrents and the loss of one or two phases, Static overcurrent trip device to operate a circuit breaker in response of fault conditions in an alternating current net system, Process and device for monitoring overloads adaptive to the load, Temperature-compensating overcurrent detection circuit for DC motor, Temperature compensated square function generator, Protection system and method for an electrical variable speed doubly fed induction machine, Negative-phase-sequence responsive apparatus, Phase-sequence network for eliminating response failure upon positive and negative sequence cancellation, Electronic motor protection relay with current-dependent release action, Approach based on a single sensor microcontroller for ground fault circuit breakers, A system and method for controlling load dump voltage of a synchronous machine, Minimum size, integral, A.C. overload current sensing, remote power controller with reset lockout, Protective circuit arrangement for surge protectors, Device for detecting unbalanced conditions in a polyphase equipment bank, Overcurrent protection circuit for AC systems, Arc fault detection in ac electric power systems, Ground fault circuit interrupter utilizing a single transformer, Solid-state trip device comprising an instantaneous tripping circuit independent from the supply voltage, Motor protection circuit and automatic restart control system, Circuit breaker with digitized solid-state trip unit with inverse time tripping function, Electronic circuit breaker with protection against sputtering arc faults and ground faults, Method and means for damping subsynchronous oscillations and DC offset in an AC power system, Circuit breaker with protection against sputtering arc faults, Method and system for reconnecting inverter to rotating motors, Three phase system monitoring and control circuit, Motor control circuit including motor current limiting means, Automatic surge suppressor disconnect protection system. Over the past decades, static relays were used, while nowadays microprocessor relays are used. 2. A protective relay as defined in claim 1 in which said integrating means comprises a capacitor, the charge on which determines the magnitude of said output signal, and in which said control means comprises a discharge path including a constant current source effective whenever said resetting action occurs to remove said charge from said capacitor at said substantially linear rate. chosen for electromechanical relays and 0.30 seconds for static relays to allow coordination with the motor relays that are typically set with a 0.05 second delay. CO Circuit Opening Overcurrent Relay The overcurrent unit contacts are in the contactor switch coil circuit and when they close, the solenoid plunger moves upward to open the de-ion contacts which normally short circuit the trip coil. 3,262,017), the accumulator 2 could be either an analog RC integrator as shown or a digital counter as is suggested in U.S. Pat. Gravitational force can affect the relay. The means 1 of my relay includes more specifically a signal sensor 14 which is coupled to the line 10 and which typically comprises a symmetrical component segregating network capable of producing a voltage proportional to the negative phase sequence current in the stator windings of the protected generator. H�*��234�31P AsK#=39��K�3�P�%��+�� � ��� endstream endobj 75 0 obj 44 endobj 76 0 obj 7217 endobj 77 0 obj << /Type /XObject /Subtype /Image /Name /Im1 /Width 2560 /Height 3300 /BitsPerComponent 1 /Decode [ 1 0 ] /Filter /CCITTFaxDecode /DecodeParms << /K -1 /Columns 2560 /Rows 3300 /BlackIs1 true >> /ColorSpace /DeviceGray /Length 76 0 R >> stream Thus, it has a adjustable time setting as well as a pick up adjustment. No. SGC12A/B Static Negative Sequence Time Overcurrent Relay for Generator Protection Author: GE Multilin Subject: Instruction Manual Keywords: SGC, SGC12A, … Thus, the output voltage developed at terminal 21 is normally a slightly negative quiescent magnitude equal to the forward drop of diode 28, as mentioned above. 3. Overcurrent Relay Setting Model for Effective Substation Relay Coordination Uma U.Uma, I.K.Onwuka Akanu Ibiam Federal Polytechnic Unwana Micheal Okpara University Umudike Abstract: - Relay protection setting of substation plays a very vital role for power system safe operation. data:image/svg+xml;base64,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, data:image/svg+xml;base64,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, GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER, EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS, Emergency protective circuit arrangements responsive to undesired changes from normal non-electric working conditions using simulators of the apparatus being protected, e.g. This current may be expressed by the relationship I = V/R58 , where V is the output voltage of the reset control circuit 48 (e.g., + 0.2 volts) and R58 is the ohmic value of resistor 58 (e.g., 1 megohm). 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