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Implementacja algorytmów pomiarowych i decyzyjnych zabezpieczeń elektroenergetycznych

Nowak W., Tarko R., Makuch A.

Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej

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2012

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Nr 31

109-112

PL

Jednym z najgroźniejszych zakłóceń występującym w systemie elektroenergetycznym są zwarcia wielkoprądowe, które jeżeli nie są szybko wyłączone, mogą doprowadzić do poważnych w skutkach awarii. W celu eliminacji zakłóceń stosuje się szybkie urządzenia do odłączenia obwodów zwartych oraz automatykę zabezpieczeniową, której zadaniem jest wykrycie, rozpoznanie oraz wyłączenie zwarcia w określonym czasie. Sprawdzenie poprawności działania algorytmów decyzyjnych zastosowanych w zabezpieczeniach elektroenergetycznych jest możliwe na drodze obliczeniowej. Dzięki wykorzystaniu programu symulacyjnego EMTP ? ATP, możliwe jest wyznaczenie przebiegów przejściowych oraz interpretacja wyników osiągniętych za pomocą modeli cyfrowych. W artykule przedstawiono wyniki analizy działania algorytmów decyzyjnych, mających istotny wpływ na funkcjonowanie modelu matematycznego zabezpieczeń elektroenergetycznych. Zostaną również przedstawione realizacje algorytmów pomiarowych wielkości kryterialnych i procesów decyzyjnych dla modeli zabezpieczenia nadprądowego zwłocznego oraz zabezpieczenia odległościowego.

EN

One of the most dangerous disturbances occurring in the power system are short-circuit high current, which if not quickly turned off, can lead to serious consequences of failure. In order to eliminate distortions shall be quick disconnect device and compact circuit protection automatics, whose task is to detect, identify and turn off the circuit as soon as possible. Through the use the EMTP-ATP, it is possible transient determination and interpretation of results obtained using digital models. The publication will be presented the results of the analysis of decision algorithms implemented in the EMTP-ATP, which have a significant impact on the functioning of the mathematical model of power protection. It will also be presented realization algorithms for measuring the size criterion and decision-making models and the time delay overcurrent and distance protection. The above analysis requires the selection of appropriate electric quantities corresponding to the correct measurement of the amplitude of the current in case of the time delay overcurrent protection and impedance in case of distance protection.

2

Precyzyjny przetwornik czas-liczba z powielaniem i uśrednianiem czasu trwania impulsu

Szplet R., Poteralski M.

Pomiary Automatyka Kontrola

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2012

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R. 58, nr 7

569-571

EN

This paper describes the design and test results of a time-to-digital converter with 1.9 ps resolution and measurement uncertainty below 12.2 ps (Fig. 4). The time-to-digital conversion is based on time width averaging. Information about the measured time interval is contained in the width of a pulse that circulates in a closed delay loop and its width is measured by the counting method with use of a high frequency multiphase clock (Fig. 1). The converter resolution is directly proportional to the number of cycles of the measured pulse in the delay loop, the number of phases and frequency of a clock used (2). However, increase in the number of loop cycles causes growth in the jitter of circulating pulse edges that finally leads to deterioration in the measurement precision. Therefore, in order to obtain the highest precision of conversion, the number of cycles for which the converter provides the smallest measurement uncertainty was experimentally determined. In addition, to minimize a disadvantageous impact of unequal propagation times of the loop elements for the rising and falling pulse edges on the value of the measured time interval, the information about the measured time interval is contained between the rising edges of the pulse-pair instead of the opposite (rising and falling) edges of a single pulse (Fig. 2). The converter was implemented in a programmable device Spartan-6 manufactured by Xilinx. (Xilinx).

3

A comparison method for identifying operating conditions for ship roll stabilization

Koshkouei A. J., Burnham K. J., Roberts G. N.

Systems Science

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2005

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Vol. 31, no 4

75-85

EN

Ship roll stabilisation may be improved by utilizing a set of parallel controllers in which individual controllers are activated in pairs for roll control via actuation of rudder and fins. To this end, it is necessary to identify the ship's operating conditions for facilitating the activation of the appropriate controller pair. Operating conditions depend mainly upon ship speed, wave height and wave encounter angle and, whereas only the ship speed is known to the system, the other conditions need to he identified. An approach has been designed to detect the actual seagoing condition via roll frequency detection. Two different methods are illustrated and discussed in this paper.

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Averaged equations for developing flow of a fluid-solid mixture

Massoudi M.

International Journal of Applied Mechanics and Engineering

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2001

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Vol. 6, no 2

1025-1049

EN

A mathematical description of a mixture of a Newtonian fluid infused with particulate solids is presented within the context of Mixture Theory. In the absence of any thermal effects, the balance of mass and balance of linear momentum equations for each component are averaged over the cross section of the flow to obtain ordinary differential equations describing developing flow between parallel plates. The resulting coupled equations describe the variation of the average velocities and volume fraction in the direction of flow, and represent a simplified approximate set of equations which are used in engineering applications.