The Maxim application note doesn't really explain how these work, but a closer inspection of the circuits should make you do a double take. In this video the philosophy behind the restricted Earth Fault Protection has been elaborated. Operating Principle Reverse active power protection calculates the active power with the RMS values of the voltages and currents. Each phase Thank you for helping keep Eng-Tips Forums free from inappropriate posts.The Eng-Tips staff will check this out and take appropriate action. Unit XP2-R has an integrated wide range power supply. Reverse Power Protection and Negative Power Flow Protection. noticed that the directional over current operation is different for phase and Therefore, in general, it is not allowed to operate the generator inversely for a long time. The working principle is: Under normal working conditions, the Il flowing into Rsc will not produce a large voltage drop, then Q1 will not be turned on. This protection device is also used to prevent damage to the prime mover, which might be stopped due to some fault. In this case Negative Phase sequence voltages V2 and The video explains about the generator low forward power and reverse power protections, Class A and Class B trip and shutdown sequence of Boiler-Turbine -Gen. is usually -30o for overhead lines and -45o for Some Diesel Inspectors for certain agencies can be pretty set on it. A generator can work as a synchronous compensator if the driving torque is less than the total losses in the system, taking necessary power from the network. The protection ensures that the components are not damaged by accidental swap of the power supply connections. Call sales on +44 (0)118 9823746 or request a free call back For the full range of MEAN WELL power supplies speak with your sales representative or navigate to our MEAN WELL product section. 2) The time step t1 is mainly arranged to trip the field and the generator breaker with a short time delay, typically 2 - 3 sec-onds after operation of the reverse power measuring function. It depends on Maximum Torque Angle.This angle is usually -30 deg for overhead lines and -45 deg for underground cables for phase faults that is fixed. Restricted Earth Fault Protection theory8. DIODE - The simplest way to design a battery protection circuit is by using a diode. Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. But in fact, when the reverse power runs, the generator will become a motor, which not only cannot send out electricity, but also consumes itself, and uses the electricity of the grid. The diode is connected in series with the load and only allows power to reach the load only when in forward bias. proving reverse power protection relay is working through real reverse power, Electric power & transmission & distribution Forum. RE: proving reverse power protection relay is working through real reverse power catserveng (Electrical) 17 Feb 18 19:24 For years working around the engines (gas and diesel) and generators I mostly deal with in the .5 to 5 MW range, the default or rule of thumb type setting for reverse power was 10% of rated for 10 seconds. The basic and simple principle of differential protection is shown in Fig. Terminals A1/A3 are to be used for volt-ages from 50 - 750 V DC or from 36 - 520 V AC. rotation of rotor. The electronic circuit breakers are used together with a power shunt diode. Surge Protection. A reverse power connection preventing circuit includes a diode and an actuation unit that are connected in series between a positive input terminal and a negative input terminal of a circuit breaker. Already a member? It is the Hey Freddy, agreed that service tests are best; I for one wouldn't want to be called out of my rack while under way to deal with a morning watch generator trip. I do not think it's a good idea to do a real world test for this, when the goal is only to prove the relay correctly operates. The reverse power relay is a directional protective relay that prevents power from flowing in the reverse direction. At this line relay current is in phase with the reference or polarising A single unit on a bus fails, plant goes dark but next available unit comes on, most times automatically pretty quickly with minimal operator interaction. The FET remains off and prevents the reverse power from going to the load. I don't think reverse power can be allowed in to Diesel engines without subjecting the reciprocating engines to damage. On a multi-shaft machine with separate power turbine and gas generator (i.e. The Reverse Peter Principle at Work. reverse power protection comes into play when there is more than one mutually independent and different category of generators are available in local grid to meet the local demand,hence to avoid unnecessarily flow of power from one generator source to another that will cause the affected machine to start behaving from the generator to mere load This angle u2002Reverse Power protection working principle: Upon the reduced turbine output, typically, the generator is not able to produce the output power less than no-load losses while the generator is still on-line, the generator will operate as a motor and driving the turbine. Hope you got it. I'll defer to Scotty on the turbine issue. Sunpower Group Holdings Ltd It is not a case of "No reverse power is okay." reference and operating quantities. These are the main factors which make protection necessary for the generator or alternator. On first blush, it appears that the MOSFETs . See , Decide whether your board shows any of the common problems detailed in . Restricted Earth. Directional angle as it decides the direction of operation of the relay. A generator is subjected to electrical stresses imposed on the insulation of the machine, mechanical forces acting on the various parts of the machine, and temperature rise. Working of ship Reverse Power Relay Since Voltage Coil has more number of turns, so it has move inductive value and more induced current that lag in the coil by an angle of 90. Why the reluctance to do a real world test? This is the common setting for any type of faults. Using this you can find the RCA Value. The Expected If two units are on the bus, one fails but it doesn't clear quickly enough and causes the second unit to fault, now there is a bigger problem that may take more time to resolve. Contact positions Operation without fault or dead condition Reverse power tripping PR> Active power tripping P> When the polarity is reversed, the IC does not have the correct bias and wont operate to turn on the reverse biased FET. voltage. When the power meter indication of both generating sets is zero and the ammeter still has current indication, the voltage adjustment knob of one diesel generator set can be adjusted according to the indication of ammeter and power factor. This is important in most electronic applications such as laptops, computers, CMOS circuits, etc. crshears, that's been my understanding as well, although I'd expect that one of the significant differences is that in an unmanned station (or ship's machinery space) is that the reverse power situation is likely to persist long enough to cause issues due to lack of sufficient cylinder temperatures and lube oil flow, whereas in your car the load is variable enough that the engine heat is maintained. To sense I have also run into having to do a "real" test, even when a test set was available and a test plan proposed. Maximum The Relay Maximum Torque line or Centre of forward zone line. But that was a steam turbine, not a gas turbine or a diesel. The positive sign of active power is defined by the power sign setting. Operating Principle of Directional Over Current Relay: Directional over current relays operate in either forward or reverse directions with over current protection. HPD300 reverse power protection module is widely used in marine genset field and land genset field. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Could you please guide me to fix the angle. T2000 reverse power relay function October 25, 2020 by Electrical4U. 1.Adjustment of reverse power caused by voltage difference. Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a parts function at the center of their design considerations. The range is (-95 to +95 Degrees). faulty phase drops and other phases remain healthy. These Polarising voltages are defined internally in the relay itself. But, the magnitude of the fault current is related to the type of fault and the source impedance. I just had another conversation about a similar issue on a newer diesel electric research vessel. They let it continue to generate until the boiler cooled down enough and the generator went into reverse power, which tripped it off line. The basic principle of differential protection is the comparison of the difference between measurements of currents at different points to a preset threshold. operate zone is the mirror image of the forward zone. The variation is in selection of polarising voltages. Professional Line XP2-R Power and Reverse Power Protection Relay (XP2R1) Request an offer Please configure your device with the selection fields available below. The detailed explanation about Directional relay settings with Characteristic angle, Maximum Torque angle and Polarisation voltages are given. Already a Member? is it given in an IEEE/ASI/IEC standard? The relay monitors the power supply from the generator and in case the generator output falls below a preset value, it quickly activates the trip and disconnects the generator. We need to enter RCA setting while configuring relay. It is basically earth fault protection but works on differential relay principle. In principle, diesel generators can operate at reverse power. When the supply voltage is reversed, the PMOSFET gate voltage is high and this prevents it from turning on hence preventing the reverse voltage from reaching the load. 1: List of Components Required for Reverse Battery Protection These are the following methods for designing the battery protection circuit - 1. Figure 1: Diode in series with load Image Credit. "Help us raise money!" Copyright 1998-2022 engineering.com, Inc. All rights reserved.Unauthorized reproduction or linking forbidden without expressed written permission. working principle Using static pressure measurement principle: When the liquid level transmitter is thrown into a certain depth in the measured liquid, the formula for the pressure on the liquid surface of the sensor is: =.g.H + Po Where: P: Pressure on the face of the transmitter : Density of the measured liquid Tags: Marine Electrotechnology Also Feedback | active overpower protection to detect overloads and allow load shedding reverse active power protection: against generators running like motors when the generators consume active power against motors running like generators when the motors supply active power ANSI 32Q/40 - Directional reactive overpower By joining you are opting in to receive e-mail. Voltages in the range from 19 - 55 V DC can be applied at connection terminals A1(L-) and A2(L+). Real world tests are good and should be done. For Example consider an earth fault occurs at angle of -15o on a resistance earthed system. Measured Earth faults: [67G]. (This angle This fault angle is called Maximum Torque torque angle is the angle made by fault current with respect to its phase He suggested other operators choose to actually induce a real reverse power situation by taking load off one set and driving the set frequency up on the other so as to motor the unloaded generator. The Relay The fastest and easiest test is to just dial down the speed on the set under test. Promoting, selling, recruiting, coursework and thesis posting is forbidden. As a leading. It is little bit costlier than diode but it makes the protection circuit much safer and efficient. Reverse Power Protection. Conversely, if the relay set in Reverse direction means if a . to -90o depends on the type of Neutral Earthing employed. "Why not the best?" Under voltage [27]/Over voltage [59] Relay: Combined Current and Voltage Transformer: Difference between Capacitive Voltage Transformer CVT and CCVT. Contact Info | More Society, Copyright 1999-2020 | Click Here to join Eng-Tips and talk with other members! Save my name, email, and website in this browser for the next time I comment. during ph-ph fault, in ETAP i am getting following phase values, Therefore, for faults in feeder AX, the circuit breaker CBy, does not trip . What is general view out there on this? Characteristic Angle RCA is given in 2.Adjustment of reverse power caused by frequency. The voltage of Calculate Size of each Part of Star-Delta starter for 10HP, 415 Volt Three Phase Induction Motor having Non Inductive Type Load, Code A, Motor efficiency 80%, Motor RPM 600, Power Factor 0.8. characteristic angle is the phase angle by which reference or polarising On a single-shaft machine a GT compressor usually consumes about 1/3 of the turbine's gross output so the relay should have no difficulty is seeing a motoring load of that magnitude. It prevents endangering the turbine (e.g. Protection ICs such as the LTC 4365 are designed to protect sensitive circuits from reverse polarity, over current and over voltages. 4.Rotor ammeter pointer fast swing near normal value. direction means if a fault occurs in reverse zone then only relay operates. Conversely, if the relay set in Reverse Is Your Board Asking the Right Questions? For AC circuits, the principle is extended with a polarizing winding connected to a reference voltage source. Transformer with Resistor= 15o, Solidly No need to set externally. A surge protective device (SPD) is designed to protect electrical systems and equipment from surge events by limiting transient voltages and diverting surge currents. Hi MadhuI overwhelmed by seeing your response. As the power relay senses the reverse power flowing into The generator, it opens the main circuit breaker of no.1 generator. This can also lead to cylinder wall glazing, which may result in the oil loss continuing when the load is increased. If the voltage is reversed, it blocks the voltage and the reversed power does not reach the load. angle in Electromechanical Relays. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework. The function of the reverse powerrelayistopreventareversepowerconditioninwhichpowerflowsfromthebusbarinto thegenerator.Thisconditioncanoccurwhenthereisafailureintheprimemoversuchasan you considered consider a phase fault occurs at angle of -30o. This is the voltage taken from Potential Transformers. This flux induces all the emf in the winding over the lower magnet of the overcurrent unit. I am having doubt what values to be used whether phase values or sequence values. 2.The pointer of the stator voltmeter will swing rapidly. polarising technique is used. Your email address will not be published. A reverse power relay is a directional power relay that is used to monitor the power from a generator running in parallel with another generator or the utility. The fault occurs at any angle but to operate relay in defined zone we need RCA. Cathodic Protection: Definition, Working Principles, Types, Design, Advantages, Applications (PDF) . Both solutions affect low power operations and especial the series diode. Reverse power protection action characteristics 1.The stator current exceeds the normal value and the ammeter pointer will be severely blocked. The method involves using a high-side P type MOSFET on the power path, or a low-side NMOS FET in the ground path. If the The saturated voltage is much lower than it is with diodes, so the voltage drop and power loss are much lower. This type of connection The Reverse Power Relay T2000 will protect the generator from being run as an electric motor. In my case One generator and one Transformer are running in parallel and to avoid external fault we are gonna install 67 in Transformer Incomer as well as Generator Incomer. Maximum Torque Angle. There are various methods that differ in operation, efficiency and complexity. For an NMOSFET, the gate voltage is low. Negative sequence currents I2 are used for polarization. In this method, an oRing controller IC is used in conjunction with a power MOSFET to provide a simple and efficient reverse polarity protection. Right? Directional over current relays operate in either forward or reverse directions with over current protection. Forward zone [This is the Maximum Torque Angle] in your example. Bill Reverse Power protection working principle: Upon the reduced turbine output, typically, the generator is not able to produce the output power less than no-load losses while the generator is still on-line, the generator will operate as a motor and driving the turbine. current is compared with the voltage between other two phases. My experience is on single-shaft machines bigger than have ever set sail (except as cargo) but a prolonged motoring event is worse than a trip and coast to a halt because of the sustained flow of air from the compressor causing rapid differential cooling within the engine. Reverse Fig. the voltage by 30o. Many engines are designed so that the pressure of combustion acts to increase the pressure of the rings on the cylinder walls. directional phase fault elements, work with a Quadrature connection to prevent voltage is adjusted such that the directional relay operates with maximum Certificate & CEUs for $50/month (Ends 11/30). An over-current protection scheme is regarded as the most obvious principle of protection as it can detect a sudden buildup of current magnitude that is considered as an effect of fault. [This is the Maximum Torque Angle], Characteristic Angle= 90o voltages are available only during earth fault conditions. Email: enquiries@sunpower-uk.com, 2019 Sunpower Group Holdings Ltd t/a Sunpower Electronics | Website design by Strategies, Call sales on +44 (0)118 9823746 or request a free. externally. For phase to phase faults they mentioned the below formula, I think Maritime regulatory agencies are pretty much always concerned with testings that demonstrates system response and resilience. an aero-derivative) the braking load is lower because the HP compressor is on the high speed shaft which doesn't get motored by the alternator. Generator Protection. Reverse voltage protection circuits prevent damage to power supplies and electronic circuits in the event of a reverse voltage applied at the input or output terminals. Electric Power System Protection and Coordination: A Design Handbook for Overcurrent Protection. On the other hand, the MOSFET dissipates less power even though it requires an extra drive circuitry which increases the cost. The class society guy wants us to prove the integrity of reverse power relays as part of his intermediate (2.5yr) survey. Polarising voltages are defined internally in the relay itself. Hence, the power loss is about 27 times lesser than the circuit using single diode. Custom Power Supplies | Power Supply Design. They are both based on similar principles. A greatly improved protection circuit can be provided by using a pnp transistor as a high-side switch as shown in the second circuit. To understand the difference between Measured Earth Faults and Derived Earth Faults Read here. If the voltage is reversed, it blocks the voltage and the reversed power does not reach the load. Reverse Power element of Numerical Relay calculates the three phase active power using its current and voltage input based on the following formula, P = VaIaCosa + VbIbCosb + VcIcCosc The Numerical Relay is connected with the convention that the forward current is the current flowing from the generator to the busbar. Fax: +44 (0)118 981 2002 The fault current is lagging in nature. Their standard operating procedure was to turn off the conveyor belt and stop feeding trash (fuel) in. The diesel inspector is concerned that a single engine failure on a multi-unit bus does not cause a loss of propulsion or house loads.