Reverse Power Relay Research Articles

Generator protection system with reverse power relay on 1000 KVA 'Cummins' diesel generator at Cepu Human Resources Development Center

Generator protection system with reverse power relay on 1000 KVA 'Cummins' diesel generator at Cepu Human Resources Development Center

Distributed generation adverse impact on the distribution networks protection and its mitigation.

Integration of Distributed Generation (DG) generates problems for the protection of Distribution Networks (DNs) in power systems. When DG is integrated into a power distribution system (DS), the radial nature of the network is altered and the power starts to flow in a reverse direction. In addition to the reverse flow of power, the DG upsurges the fault current level and affects the existing time intermission coordination of the protective overcurrent relay. This study proposes a reverse power relay (RPR) and Fault Current Limiter (FCL) to mitigate the fault current level and reverse power flow in a Distribution Network (DN) by the use of DG. The FCL works only as a unidirectional fault current limiter (UFCL) by restricting the flow of fault current that occurs in the main grid (MG) of the DG. However, FCLs can protect the flow of fault currents from the MG by affecting the operational flexibility and reliability of the DG. To overcome the flow of fault current of the DG, this study proposes RPR to monitor the power flow to the DG. Collectively the study focuses on the protection of radial DS by using RPR and UFCL. The analysis and the modeling were conducted on the 15KV DN of the radial feeder in Debre Markos DN. The 3Φ fault analysis (which is more severe than others) was performed to validate the protection capability of the mitigation techniques which were proposed in this study.

Design of Digital Reverse Power Relay Model for Generator Protection

Abstract: Generators are one of the most important parts of the power system. Faults at the generator lead to severe failures and fatal accidents. Hence, generators’ protection is a major concern, especially from faults – voltage and current fluctuations, short circuit faults, frequency variations, over-fluxing, flow of reverse power, etc. In this project, a protection scheme is presented for power flow in opposite direction that is flow of power from grid to the generator, due to which the generator starts consuming and acts as a load. Modelling tools are important to have a basic idea of power system. These tools aid an engineer to modify the system under all circumstances. This paper contains the simulation and modelling of digital reverse power relay in MATLAB/ Simulink®. The libraries in MATLAB offer Power System Analysis Toolbox which are simulation based, for power system engineering projects. Keywords: Reverse power relays, Relay Modelling, Digital relays.

Generator protection system with reverse power relay on 1000 KVA 'Cummins' diesel generator at Cepu Human Resources Development Center

Each generator is designed to create a certain amount of electricity. However, there are situations when the generator cannot handle the current load. The solution is to employ two or more generators to produce as much power as the number of generators operating simultaneously or synchronizing (parallel generator). Several parameters must be configured throughout the synchronization process, including the phase sequence, voltage, frequency, and phase angle, which must be the same. An operation failure can occur if one of the prerequisites is not fulfilled, resulting in reverse power. The motoring condition is a condition that occurs when the primary mover of a parallel generator fails. A reverse power protection mechanism is required to prevent this motoring. When one of the generator's prime movers fails or the operation fails, the voltage and load will drop. The other generator then feeds another generator. The reverse power relay instructs the generator's main circuit breaker to open the circuit so that no additional equipment is harmed. This research aims to investigate and comprehend the reverse power relay protection system's use.

Enhancing the Performance of Reverse Power Relay for Generator Protection

The generator is the most important component in energy generation, and it needs to be protected from both internal and external disturbance. Reverse power relays (RPR), with the directional relay being the most commonly utilized as the principal safeguard, are used to trip the turbine generators to minimize the damage of prime mover. Modeling tools are helpful for learning the basics of a power system, especially for newbie engineers. These tools assist novice engineers in modulating the system in both normal and abnormal situations. This paper demonstrates how to model and simulate a digital RPR on MATLAB. Different conversions of data processes involved in signal digitization are also explored. Electromechanical relays were previously popular, but fast and very accurate digital relays have now surpassed them. Fast relay functioning is recommended, especially in the case of system faults that might cause a blackout. Digital relays provide a number of advantages, including several changeable settings and a small size. The performance of test relay in this article is tested by connecting a synchronous generator of 11kV to 220kV via a step-up transformer.

Integrated Battery Energy Storage into an Optimal Low Voltage Distribution System with PV Production for an Urban Village

The feed-in tariff for rooftop photovoltaic (PV) systems has not yet been adopted in Cambodia, the utility thus does not purchase excess power by reverse power flows from PV production, and only unidirectional energy meters are used even in the capital. The power distribution systems are expanded in recent years due to load demand increase, and this issue makes the distribution system designers perform the planning. The design of a low voltage distribution system and suitable solutions are proposed to handle these issues. This paper purposes of designing an optimal low voltage distribution topology with the integration of PV and three different proposed solutions of reverse power relay (RPR), solar hybrid inverter (SHI) and battery energy storage (BES) in an urban village, which consists of improving a balanced load and existing PV production usage. Firstly, the repeated phase ABC is applied to minimize the power loss and unbalanced load in the three-phase distribution system. Next, the integration of RPR, SHI, and BES into household grid-connected PV production systems have been proposed as solutions. To confirm a proposed method, the urban village in Phnom Penh, Borey Mungkul Phnom Penh, Sangkat Veal Spov, is chosen and modelled for a case study. Simulation results allow concluding that the integrated battery energy storage into the optimal low voltage distribution topology provides the best solution to design the grid connection PV system.

MODELING TO IMPROVE THE PERFORMANCE OF REVERSE POWER RELAY IN GENERATOR

The generator is the primary component in electricity generation and requires a protection system from internal and external interference that occurs. This study considers how to improve the performance of relays in power plants. A model of a generator that is executed in a fault condition to reset the protective equipment, namely Reverse Power Relay (RPR). The study is intended to model the state of internal and external fault on the generator by applying a working principle of RPR. The model is designed to anticipate the actual fault in the generator. The simulation results obtained output such as; active power, current and time delay relay. The RPR reset of the generator system is applied to the generator in Riau Power. The RPR is installed on the generator is -612 kW, equivalent to 30%, the relay delay time is 0.2 seconds. Based on standardization, the return of power reaches a maximum of -12.66 MW, which is captured 50% with a maximum replacement of 30 seconds. Results of the RPR simulation have been validated with the IEEE standard at a time delay that corresponds to the percentage of reverse power settings installed at 6% and a time delay of 0.6%. Finally, to maximize the protection system on the generator, adjust 50% to 95% of the installed settings. It can be said that the system is able to increase generator protection and minimize the impact of internal or external fault.

Enhancing the coordination of reverse power, overcurrent, under-frequency, and under-voltage relays using transient stability analysis in real plant applications

Abstract In order to achieve the optimization of the production process, power continuity is needed. The most important is the protection system, overcurrent relays are widely used as a primary relay to protect overload and short circuit. However, in some cases due to the nonlinearity pattern of the system, overcurrent relays does not grant the protection system. To overcome this problem, under-frequency and under-voltage relay are installed as a backup relay, but it also do not give the best result. This paper focused on the addition of reverse power relay to improve the system performance. Transient stability analysis is necessary to set reverse power relay because optimal power flow analysis cannot give proper parameter when a failure in grid happen. By arranging the delay time between those relays according to IEEE 242-2001, adequate coordination can be done. Moreover, the frequency and the voltage of the system stable at 100.04%, and 100.01%.

ANALISIS GANGGUAN REVERSE POWER DAN UNDER FREQUENCY PADA GENERATOR 153,75 MVA UNIT GAS TURBINE 3.1 DI PLTGU GRESIK

Generator unit GT 3.1 at PLTGU Gresik which is operating in parallel with Sub Krian Gresik System failed at fuel supply on 06 October 2015 at 10:08 pm so that reverse power protection worked. The disruption resulted in the GT 3.1 unit stopped in operating for 2.21 hours. This research was conducted to find out how the disturbance and setting of reverse power relay in GT 3.1 unit and then the relationship between reverse power with under frequency and counter measures so that the reverse power interference on GT 3.1 unit does not happen again. In manual book settings applied, reverse power relay type 7RM3410 has a limit setting of 16% (16MW). Meanwhile, according to IEEE standard number 242 of 2001 reverse power relay setting of ∠ 50% and on generator unit GT 3.1 is still in the category allowed. When the 76.6% decline occurs due to disruption of the fuel supply, the value of EA = 1735.9 ∠ 31.98 ° V, and IA = 5750.26 ∠ 154.78 ° Ampere, the terminal voltage drops to 1035.88V while the system voltage is 10.5kV resulting in a reverse 17.2 MW. The power exceeds the applied setting, therefore the trip generator because reverse power relay work on setting time 1 second. At the time of interference, the rotation value of 702 rpm with a frequency value of 11.7 Hz. Setting the relay under frequency is 47.5 Hz lag time 10 seconds

Impacts of Embedded Generation on Distribution Network Behavior

This paper explores the impacts of multiple embedded generators penetration on distribution system behavior. For this rationale, a IEEE-13 bus distribution feeder was modeled and investigates by assimilating different types of embedded generation (EG) sources. Different scenarios were implemented in which WIND, SOFC FUEL CELL, SOLAR and MICRO TURBINE plants were modeled with high variability of load and generation to observe their impacts on system’s protection, unsymmetrical faults also consider observing impacts effectively. To eradicate the impacts on distribution system with presence of EG’s and distribution system undergone in the event of faults, in this paper primarily reverse power due to EG integration is estimated and sensed with reverse power relay, Further two types of Superconducting Fault Current Limiters Passive resonance CB (PRCB) SFCL and Inverse current injection CB (I-CB are proposed and results are compared for amended solution in mitigating fault current magnitude and over voltages, Finally penetrations levels are computed mathematically and All the modeling and simulations were carried out using MATLAB SIMULINK tool.

A Novel Method of Protection to Prevent Reverse Power Flow Based on Neuro-Fuzzy Networks for Smart Grid

This paper addresses the energy challenges related to the weak protection of renewable energy from reverse energy flow and expanding access to high-quality energy at the same time. Furthermore, this paper focuses on participation in the global transition to clean and low-carbon energy systems. Moreover, the increased demand for renewable energy seems to likely depend on whether it will be possible to greatly accelerate rates of progress toward increased efficiency, de-carbonization, greater generating diversity and lower pollutant emissions. This paper focuses on the protection of renewable energy technologies because they can be particularly attractive in dispersed areas and therefore, represent an important option for rural areas that lack electrical energy and distribution infrastructure. This paper proposes an improved protection device for a reverse power protection system using a new intelligent decision support system (IDSS). The IDSS is a support system for decision making, which makes extensive use of artificial intelligence (AI) techniques. The new method integrates the powerful specification for neural networks and fuzzy inference systems. The main advantage of this method is that it causes a decrease in the steady state oscillation for the reverse power relay. In addition, the proposed method has the ability to monitor extreme environmental conditions. The generator can be converted into a motor when the steam supply to a turbine is interrupted while the generator is still connected to a grid (or operates in parallel with another generator). As a result, the generator will become a synchronous motor and will actually cause significant mechanical damage. The reverse energy protection device should be included in the generator protection scheme. Smart grids use communication networks with sophisticated algorithms to ensure coordination between protection systems. ZigBee is a newly developed technology that can be used in wireless sensor networks (WSNs) to comply with the IEEE 802.15.4 standard. Low data rates, low power consumption and low cost are key features of ZigBee. The execution of star, tree and mesh topologies as well as support comparison is based on end-to-end delay, throughput, medium access control load in addition to sent and received traffic parameters. The use of star topology obtained a delay of 0.2 s. The simulation results show that this method is superior to the traditional method in terms of speed and steady-state oscillation.

Fast predictive technique for reverse power detection in synchronous generator

Reverse power relays are utilised to trip turbine generators to avoid prime mover damage and directional relay is most widely used as the main protection for these conditions. An intentional time delay is ordinarily utilised to overcome the possible maloperation of these relays. However, the intentional time delay to prevent maloperation is not an ideal solution. As this time delay increases the reverse power relay operation time, which means that the motoring action of the synchronous generator persist for a longer time, making the prime mover more vulnerable to active power drawn by the generator. This study proposes a new flux-based approach to detect reverse power condition in the synchronous generators. The proposed scheme uses the analysis of angular velocity and acceleration data that are calculated from the estimated magnetic flux at the machine stator terminals. The basic idea of the technique stems from the principle that the stator and rotor magnetic fluxes rotate together at synchronous speed and will not be affected by system disturbances for a short interval according to highly inductive characteristics of the synchronous machine. The main advantage of this predictive algorithm is its speed, security and sensitivity to detect the reverse power conditions.

Reducing the impact of DG on distribution networks protection with reverse power relay

The assimilation of distributed sources in to existing distribution networks (DN’s) will bring up the several technical, economical and regulatory questions. Conventional distribution system is radial in nature, characterized by a single source feeding a network of downstream feeders. Therefore the voltages decrease towards the end of the feeder from the source, The incidence of distributed generators (DG) in the distribution networks alter the radial nature of distribution, causes the power flow in reverse direction in the event of DG is added in a system, or any fault in the feeding source/end, the DG exceed the local load, that is, towards the high voltage grid, it causes the existing protection system fails to protect the distribution networks against these changes.To solve this problem reverse power relay (RPR) is proposed to protect the system voltage fluctuations, power reversals condition. The proposed Reverse power relay is a directional power relay it monitor the power flow from a generator (centralized) running in parallel with another generator (DG) or the utility. The reverse power relay prevents a reverse power in the network by disconnect the DG from the distribution network under faulted condition. It also estimates the reverse power and proposes corresponding adjustment value to provide solution to protect distribution network as per the relay settings and distribution system changing scenario. The simulations have been performed using mat lab/simulink.

Underfrequency Protection of Power Systems for System Relief Load Shedding-System Splitting

1. It appears that regardless of the characteristics of an actual load, the dumping of appreciable overload on a generating station is likely to cause the frequency to drop too rapidly to permit manual switching to be effective, and automatic relays are necessary to prevent swamping of generators and to permit rapid restoration of even limited service. 2. Unnecessary line and generating station switching should be avoided. A combination of frequency and reverse power relays may be of assistance in reducing the probability of unnecessary switching, as the arrangement prevents breaker operation unless the load carried by the breaker is at least partially responsible for the underfrequency. 3. Selected loads may be dropped by frequency-sensitive relays. Loads that are likely to stall, causing damage to equipment such as ore crushers, rolling mills, etc., should be prevented from being recharged during the period of serious underfrequency. 4. An analysis is presented which permits consideration of both the normal and rotational power of both generators and loads. This may be useful in establishing settings for under frequency protection equipment.

Relays for High-Tension Lines

The author considers the following arrangements desirable: For radial feeders not in parallel?inverse-time-limit overload relays, with selective ground relays. Radial feeders in parallel?reverse-power relays in combination with reverse-time-element relays, or the balanced system. Single lines in tandem?definite and inverse-time-limit relays with progressively longer time settings near the generating station. Two or more parallel lines in tandem?inverse-time-limit relays at the points where the power leaves the station or substation, and overload relays in combination with reverse-power relays at the points where the power enters the substation; also, the balanced system preferable, when possible. Single line ring systems?inverse-time-limit relays, combined with reverse-energy relays, or, preferably, the balanced system. Parallel line ring systems?inverse-time-limit relays on the outgoing feeders at the generating stations, and a balanced interconnected combination of reverse-energy and inverse-time-limit relays at the receiving ends of the supply feeders. Tie lines?some balanced arrangement. Generator relays seldom used, but arrangements are suggested. Transformers?differential relays. Special grounding relays for extra high-tension cable feeders. Appendices A, B, C describe connections of reverse-power relays, relay testing and a special installation.