Measurements, Models, Systems and Design

531 s.

Methods for checking a circuit with energy meter and current transformer

W artykule opisano specyfikę sprawdzania układów półpośrednich dla potrzeb oceny dokładności systemów pomiarowych stosowanych w rozliczeniach energii elektrycznej. Opisano i porównano dwie metody: dwufunkcyjną i proponowaną jednofunkcyjną sprawdzania układów półpośrednich. Przedstawiono teoretyczne podstawy stosowania obu metod oraz schematy aplikacyjne z zastosowaniem opracowanych testerów.The paper presents methods for checking an energy measuring circuit including an energy meter and current transformer (Fig. 1). In Paragraph 2 there are described and compared two methods: a double and single function method. Circuits for measuring the errors of the energy meter with a current transformer (Fig. 2), energy meter (Fig. 3) and current transformer (Fig. 4) are presented in Paragraphs 3-5. The analysis of the discussed methods is given in Table 1. The double function method makes it possible to check the accuracy of the circuit with an energy meter and current transformer and full diagnostics of this scheme. The double function method is dedicated to multifunction (double function) testers of energy meters with additional function of an instrument current transformer tester. Double function testers Calport 100 Plus accuracy class 0,1 and 0,2 and Caltest 300 accuracy class 0,05 and 0,1 have been produced in Poland since 2009. The single function method is dedicated for single function energy meter testers - these popular testers, for example Calport 100, have been manufactured in Poland for 10 years

Checking analog meters with use of a multifunction calibrator

W artykule opisano możliwości wykorzystania kalibratora uniwersalnego do sprawdzania mierników analogowych. Kalibrator wykorzystywany jest przy sprawdzaniu urządzenia wskazującego oraz przy wyznaczaniu błędów podstawowych. Do wprowadzania wartości wielkości wyjściowej kalibratora można wykorzystać pulpit sterujący lub komputer. Do sterowania kalibratorem z komputera opracowano dwa programy, których podstawowe właściwości opisano w artykule.The algorithm for checking an analog meter [1] has to test the measurement instrument indicator and the measurement accuracy. Measurement errors are tested for all marked points of the meter scale and for all ranges of the meter. A measuring system with a multifunction calibrator of type C101 [2] shown in Fig. 1 can be used for testing analog meters. The multifunction calibrator can be programmed by means of the calibrator keyboard presented in Fig. 2 or by a computer. In order to check the measurement instrument indicator there can be used special keyboard functions [4] which enable the repeated change of the calibrator output value. A program generating a modulated signal at the calibrator outputs [3] can also be used. One part of this program is a rising function whose window is presented in Fig. 3. For testing measurement errors of the meter there can be used the keyboard or program Calpro-C101. This program allows: starting entering information about the testing meter and selecting the method of testing, preparing tables of testing points and improving the measurement. The hypothetical table of the testing points is shown in Fig. 4. This table can be written as a computer file, exported to Excel sheet or save in a computer memory. It can be done before or after realising the measuring procedure for checking the analog meter. The result can be presented in the form of a chart on the monitor screen, printed or saved in the computer memory. From the comparison of the keyboard with computer method, one can draw a conclusion that the computer method is better. It is less laborious and more reliable but needs a special software

Innovative Engineering Solutions and Best Practices to Mitigate Coastal Risk

Engineering solutions are widely used for the mitigation of flood and erosion risks and have new challenges because of the expected effects induced by climate change in particular sea level rise and increase of storminess.This chapter describes both active methods of mitigation based on the reduction of the incident wave energy, such as the use of wave energy converters, floating breakwaters and artificial reefs, and passive methods, consisting of increase in overtopping resistance of dikes, improvement of resilience of breakwaters against failures, and the use of beach nourishment as well as tailored dredging operations

Innovative engineering solutions and best practices to mitigate coastal risk

Engineering solutions are widely used for the mitigation of flood and erosion risks and have nowadays to face new challenges due to the expected effects induced by climate change in particular sea level rise and increase of storminess. This Chapter describes both active methods of mitigation based on the reduction of the incident wave energy, such as the use of wave energy converters, floating breakwaters and artificial reefs, and passive methods, consisting of increase in overtopping resistance of dikes, improvement of resilience of breakwaters against failures, and the use of beach nourishment as well as tailored dredging operations