مطلوب مساعدة لحل أسئلة عن الكهرباء……. Transformer

واحد من ربعي عتده برجيكت عن الكهرباء،،، و حاولت أحل الأسئلة لكن طلعت مب من تخصصي،،، و جربت في النت لكن على ما أظن ان الاسئلة مب محددة و ما كانت واضحة على الأقل بالنسبة لي،،،، أرجو المساعدة من أصحاب الخبرة في الكهرباء،،، مطلوب حل الأسئلة يوم الأربعاء الظهر……………….

تحياتي…………. مرفق الاسئلة

Project Paper
1. Investigate Instrument Transformers using internet resources. Some good sites are:
Current Transformers (CTs)
Current Transformers page, The Electricity Forum
Electric Power eTool: Illustrated Glossary: Current Transformers
Current Transformers –Product Information
Potential Transformers – Product Information
2
. A. What is the normal maximum output(s) of a current transformer (CT)
B. What is the normal maximum output(s) of a potential transformer (PT)
C. What is the difference in operation between a PT and a Capacitive Voltage Transformer (CVT)

3
. The transformer shown in the above diagram is protected by a protection system using three CTs and one PT. Calculate the primary and the secondary Currents of the transformer using the formula for 3-phase power

4. CT’s are available with ratios as followings:
25:5, 50:5, 100:5, 200:5, 400:5, 600:5, 800:5, 1200:5, 1600:5 and 2000:5
Chose the CT ratio you would use for each of the CT’s shown in your diagram. Assume a maximum transformer neutral current of 80A.

5. PT’s are available with ratios following:
15k:120, 25k:120, 50k:120, 100k:120, 200k:120, 300k:120, 600k:120, 800k:5
Chose the PT ratio you would use for the CT shown in your diagram. Assume a maximum transformer neutral current of 80A.

6. If the system in the diagram is operating at full load, what will be the outputs of the CTs and the PT?

7. The metering package shown on the following page can read 3-phase current if it connected in a Y configuration. To get a Y connection, we need to use 3 single-phase current transformers (CTs) as shown on the following page. Each CT has a CURRENT IN set of terminals. These are the CT Primary terminals and connect in series between the power supply and the motor. The CT CURRENT OUT terminals are the Secondary terminals and connect to the metering current terminals.
Show how you would connect the CTs and metering pack to measure the line current and voltage in the system shown.