An Adaptive and Scalable Protection Coordination System of Overcurrent Relays in Distributed-Generator-Integrated Distribution Networks

Integration of distributed generators (DGs) into a distribution network (DN) can cause coordination challenges of overcurrent relays (OCRs) because of different fault-current contributions of DGs as well as the directional change in fault currents. Therefore, the OCRs should be properly coordinated to maintain their adaptability and scalability to protect the DG-integrated distribution network. In this study, an adaptive and scalable protection coordination (ASPC) approach has been developed for the OCRs in a DG-contained distribution network based on two implementation stages. At the first stage, the reliability improvement of fault-current calculation results is performed by determining the min-max confidence interval of fault current for each different fault type, which is the basis for properly selecting tripping and pick-up thresholds of definite-time and inverse-time OC functions in the same OCR. At the second stage, optimization algorithms are used for calculating protection-curve coefficients and Time-Dial Setting (TDS) multiplier for the inverse-time OC functions in the OCR. A real 22 kV DG-integrated distribution network which is simulated by ETAP software is considered a reliable test-bed to validate the proposed ASPC system of OCRs in the multiple-DG-contained distribution network. In addition, the coordination results of OCRs can be obtained by three common optimization algorithms, Particle Swarm Optimization (PSO), Gravitational Search Algorithm (GSA), and Genetic Algorithm (GA). These relay coordination results have shown an effective protection combination of the definite-time OC functions (50P and 50G) and the inverse-time OC functions (51P and 51G) in the same OCR to get the adaptable and scalable DN protection system.

Optimal setting of DOC relay in distribution system in presence of D-FACTS

The process of selecting optimal settings for directional over-current relays (DOC relays) is a selection of time dial setting (TDS) and IP (backup current), So that changes in the system of electrical power distribution. In this work, a breeder genetic algorithm (BGA) has been applied to optimal settings of DOC relays with multisystem D-FACTS devices. The simulation consists of two network operation scenarios, scenario without D-FACTS which consisting of coordination of DOC relays against three phase faults, and the second scenarios with multi TCSC. In general, had been verified on optimal settings of relays that the impacts of TCSC insertion in 33-bus distribution system on DOC relays.

Study on a protection coordination approach for over-current relays in distribution generator-integrated distribution networks

Sự hiện diện của nguồn phân tán DG (Distributed Generator) đã gây ra những thách thức đến việc duy trì độ tin cậy của những OCPR quá dòng OCPR (Over-current Protection Relay) khi hoạt động để bảo vệ lưới điện phân phối (LĐPP). Trong quá trình vận hành để đảm bảo cung cấp điện cho LĐPP, những đặc tính vận hành của nguồn DG đã làm thay đổi đáng kể giá trị dòng điện sự cố và đây là nguyên nhân chính dẫn đến những hiện tượng OCPR hoạt động không tin cậy, chẳng hạn như mất tính chọn lọc, giảm độ nhạy, hoạt động vượt cấp hoặc hoạt động đồng thời. Do đó, việc điều phối những OCPR thuộc hệ thống bảo vệ trên LĐPP có xem xét đến những đặc tính vận hành của nguồn DG nhằm đảm bảo tính phối hợp khi hoạt động là cần thiết. Trong nghiên cứu này, nhóm tác giả sẽ giới thiệu về một phương pháp điều phối bảo vệ OCPCO (Over-current Protection Coordination Optimization) dành cho hệ thống bảo vệ của LĐPP có tích hợp nguồn DG. Cụ thể, phương pháp OCPCO này được phát triển dựa vào việc sử dụng kết quả phân tích ngắn mạch kết hợp với giải thuật tìm kiếm GSA (Gravitational Search Algorithm) để xác định các hệ số điều phối A, B, C và TDS (Time Dial Setting) phù hợp với từng trạng thái vận hành của LĐPP có tích hợp nguồn DG, đặc biệt là sau khi LĐPP đã được tái cấu trúc để cách ly sự cố và khôi phục cung cấp điện. Thông qua hàm mục tiêu về tổng thời gian đảm bảo phối hợp CTI (Coordination Time Interval) cho phép giữa những OCPR liền kề nhau, phương án điều phối trị số chỉnh định sẽ được đề xuất và cập nhật đến từng OCPR thông qua hạ tầng mạng truyền dẫn thông tin. Mô hình LĐPP có tích hợp nguồn DG được nhóm tác giả xây dựng dựa vào LĐPP thực tế bằng phần mềm ETAP, để phục vụ cho việc phân tích ngắn mạch và kiểm tra tính khả thi của phương pháp OCPCO đề xuất. Hơn nữa, kết quả điều phối bảo vệ bằng giải thuật GSA sẽ được so sánh với những kết quả xuất ra từ giải thuật PSO&GSA và GA nhằm làm cơ sở kiểm tra tính phù hợp khi điều phối những OCPR trên LĐPP có tích hợp nguồn DG.

Security-Constrained Optimal Protection Coordination for Dual-Setting Digital Directional Overcurrent Relays in the Distribution Network Including Non-Renewable/Renewable Synchronous Distributed Generation

In this paper, the security-constrained optimal protection coordination (SCOPC) is introduced for dual setting digital directional overcurrent relay (DDOCR) in distribution network, which including renewable and non-renewable synchronous distributed generation (SDG). The SCOPC minimizes the total operation time of DDOCRs in primary and backup protection operating to achieve a fast protection coordination. Also, to improve the flexibility in DDOCRs setting, the allowable limits of A and B coefficients, pickup current (PC) and time dial setting (TDS) in both reverse and forward directions are considered as constraints. Another constraint is the Coordination Time interval (CTI). To consideration of the mentioned scheme security, the SCOPC mechanism considered the unavailability of DDOCRs due to their failure, so the stochastic method is used to modelling of this parameter. To calculate the fault current, network variables are proportional to the daily stochastic operation results of distribution network. Moreover, the proposed problem is implemented on the standard distribution networks, and then the optimal solution is obtained with hybrid algorithm of grey wolf optimization (GWO) and training and learning optimization (TLBO). The numerical results illustrate that the proposed algorithm is able to achieve a reliable and fast protection coordination that has a low standard deviation.

Um algoritmo baseado em evolução diferencial para coordenação ótima de relés de sobrecorrente

É desenvolvida uma meta-heurística baseada no método de otimização Differential Evolution Algorithm para se obter os melhores ajustes dos relés de sobrecorrente direcional. O trabalho tratou o Time Dial Setting como variável de decisão, enquanto que o tipo de curva e a corrente de sensibilização foram considerados pré-definidos, caracterizando assim um problema linear. Para avaliar a eficácia do algoritmo utilizou-se dois sistemas radiais e um malhado. Os resultados obtidos pelo algoritmo foram comparados com outros métodos consolidados na literatura, e conclui-se que o método proposto obteve resultados idênticos aos melhores ajustes reportados na literatura.

An Improved Inverse-Time Over-Current Protection Method for a Microgrid with Optimized Acceleration and Coordination

This paper presents an improved inverse-time over-current protection method based on the compound fault acceleration factor and the beetle antennae search (BAS) optimization method for a microgrid. The proposed method can not only significantly increase the operation speed of the inverse-time over-current protection but also improve the protection coordination by considering the possible influential factors in terms of microgrid operation modes, distributed generation (DG) integration status, fault types, and positions, which are marked as the most challenging problems for over-current protection of a microgrid. In this paper, a new Time Dial Setting (TDS) of inverse-time protection is developed by applying a compound fault acceleration factor, which can notably accelerate the speed of protection by using low-voltage and short-circuit impedance during the fault. In order to improve the protection coordination, the BAS algorithm is then used to optimize the protection parameters of the pick-up current, TDS, and the inverse time curve shape coefficient. Finally, case studies and various evaluations based on DIgSILENT/Power Factory are carried out to illustrate the effectiveness of the proposed method.

Studi Koordinasi Pengaman Motor Arus Bolak-Balik

Sejalan dengan perkembangan teknologi dalam bidang sistem tenaga listrik dan penggunaan mesin mesin listrik sebagai penggerak industri. Motor arus bolak balik (AC) berperan penting dalam dunia industri sebagian besar penggerak yang terdapat didalam pabrik menggunakan motor – motor listrik tersebut, baik dengan supply tiga fasa maupun satu fasa. Berdasarkan hasil penelitian yang telah dilakukan mengenai studi koordinasi pengaman motor arus bolak balik maka diperoleh setting rele untuk beban lebih sebesar 0.08 dari arus nominal dan setting waktu 20 detik, setting rele untuk arus lebih sebesar 0.58 dari arus nominal dan setting waktu 0.1 detik, setting rele untuk tegangan lebih sebesar 0.7 dari tegangan nominal, setting arus untuk rele gangguan tanah 5A sampai 20A dengan setting waktu 1 time dial, setting rele panas lebih untuk CB pada suhu 171.95 oC dan setting sinyal alarm 162.9 oC. Untuk menjaga kehandalan dari sistem pengaman maka perlu digunakan rating dan setting arus serta waktu yang tepat pada rele pengaman. Hal ini perlu diperhatikan karena jika menggunakan setting yang keliru akan mengakibatkan arus gangguan yang besar timbul melewati motor dimana akan mengakibatkan kerusakan motor.

Desarrollo del algoritmo genético heurístico para la coordinación de protecciones

The coordination of overcurrent relays is an easy task when dealing with a radial distribution line. However, when directional units are in place to protect meshed networks, the problem becomes very complex. This is because the protection device must offer primary and backup operation for the same or multiple lines using the same protection setting. Moreover, considering two parameters namely the time dial setting and the current pickup setting make the coordination problem even more complex to be achieved manually. Therefore, in this article, the protection coordination study is formulated as an optimization problem to be solved using a heuristic Genetic Algorithm. This not only saves time for the protection engineer; it also transfers the burden to a computer using artificial intelligence and guarantee that the results are close to optimal.

Perhitungan TDS Overcurrent Relay Menggunakan Adaptive Modified Firefly Algorithm

Pertamina RU V Balikpapan will be integrated with electricity sources with PT. PLN. Then there will be a change in the generator operating pattern on the system so that it needs to be analyzed again. The protection system aims to isolate the interference quickly, selectively, and coordinatively so that damage to the system can be minimized and the continuity of electric power can be maintained properly. The important thing that must be considered from protection coordination, especially in overcurrent relays, is filling the TDS (Time Dial Setting) parameter. TDS regulates the relay operation time in securing a disturbance. Generally the TDS value is determined using a manual calculation to obtain a minimum TDS value. However, to get the right TDS value in coordinating with other relays it still uses trial and error methods. In this final project, we will discuss how to calculate the time dial overcurrent relay inverse setting with the adaptive modified firefly algorithm method in the electrical system at PT. Pertamina RU V Balikpapan considers integration with PLN to obtain a minimum TDS value. The result of this final project is to obtain a minimum TDS value in some cases typical types such as the longest channel, consideration of LVCB operating time, and short channels so that it can be well coordinated with the long lines installed on the same bus.