Asenkron motor kontrol ünitelerinin zaman serisi analizi

Abstract

ÖZET Bu tez çalışmasında, asenkron motor hız kontrol ünitelerinin Türkiye pazarında faaliyet gösteren iki büyük firmanın satışları incelenmiş ve bu doğrultuda zaman serisi analizi yapılarak İ990 yılı için satış rakamları belirlenmeye çalışılmıştır. Birinci bölümde, asenkron motor hız kontrol ünitesi ihtiyacının ortaya çıkışı açıklanmış, mevcut pazar gelişimiyle ilgili bilgi verilmiştir. Pazar gelişiminin en önemli sebebi asenkron motorların kullanım kolaylığı ve bakım gerektirmemesidir. ikinci bölümde, asenkron motor ve asenkron motor hız kontrol ünitesinin tanımı yapılmış ve kullanım alanları üzerinde durulmuştur. Yarı iletken malzeme sanayiindeki gelişimler asenkron motor hız kontrol ünitelerinin üretimini olanaklı kılmış ve böylece dünyada mekanik kontrolün yerini elektronik kontrol almıştır. Türkiye'de bu sektörde faaliyet gösteren firmalar tanıtılmıştır. Üçüncü bölümde, faaliyet gösteren firmaların izlediği satış organizasyonu ve sistemi üzerinde durularak, reklam usulleri, stok politikaları ve ambalaj koşullarından söz edilmiştir. Üretim girdilerinin büyük bir kısmı ithal edildiğinden temin zamanı uzun ve maliyeti yüksektir. Bu yüzden üretim yapan firmalar stoklu çalışmamaktadır. Dördüncü bölümde, talep tahminiyle ilgili genel bilgi verildikten sonra Samel, Eka ve toplam pazar için zaman sersi analizi yapılmış ve pazar için 1990 yılı satışları tahmin edilmiştir. Bu sektörde üretim siparişe göre yapıldığından, firmaların önceki yıllardaki satışlarının pazarın o yıllar için talebine eşit olduğu varsayılmıştır. Beşinci bölümde, yapılmış olan zaman serisi analizi yardımıyla pazar büyümesi tahmin edilmeye çalışılmıştır.

SUMMARY MARKET TIME SERIES ANALYSIS FOR THE ASYNCHRONOUS MOTOR CONTROL UNITS The subject of this thesis is the market demand of the asynchronous motor control units. The thesis consists five chapters which are as follows : Chapter 1 : Introduction Chapter 2 : Motor Control Industry In Our Country Chapter 3 : General Status Of Firms Acting In This Sector Chapter 4 : Market Time Series Analysis For Asynchronous Motor Control Units ^ Chapter 5 : Conclusions 1. INTRODUCTION The more than half of the electrical energy produced in the world are used in the operating of centrifugal or flow loads such as pumps, fans, blowers and compression. Most of these machines use constant frequency asynchronous motors. Asynchronous motors are the most commonly used electrical machines in industry, being economical, reliable, and easily maintained. Asynchronous motors are manufactured to operate at constant frequencies. However, customer need operation at variable speeds. This can be accomplished by mechanical or electronic frequency control. Mechanical frequency control is the oldest method which causes time loss. Electronic frequency control wasn't possible untill recent years because of technology. Electronic frequency control systems which can change the output frequency of asynchronous motors within wide ranges have been developed after the beginning of semi-conductor applications. In this thesis, firstly the market capacity of asynchronous motors market is studied, then the firms who manufacture asynchronous motor control units is introduced. Market capacity of the asynchronous motor control units has been estimated by extrapolating the production figures of firms in recent years.2. MOTOR CONTROL INDUSTRY IN OUR COUNTRY While direct current motors was only used in the most critical applications, asynchronous motors rapidly began to be used in different conditions and places in the world. Although the rate of the use of asynchronous motors in our country has risen rapidly, this is less than the rate in developed countries, According to the market research, Gamak A. Ş. and Abana Elektromekanik San. ve Tic, A, Ş. produce 90 % of the asynchronous motors in this market. Gamak has 60 % and Abana has 30 %; market share. The remaining 10 X of the market is shared between Arçelik, Elsan and some importer companies. Gamak has aimed at producing 500.000 units and Abana has aimed at producing 100. 000 units in 1990. Control units for three phase asynchronous motors have been manufactured first, approximately ten years ago by Sama Sanayii Mamulleri Tic. A. Ş. in Izmir. This firm had a monopoly position for five years from the beginning. Eka A.Ş. and Enko Endüstriyel Kontrol Müh. San. ve Tic. Ltd. Şti. have been manufacturing these units since 1985. Although the former firm produce them by Westinghouse know-how agreement, the letter's units are produced by local technology. As a result of this production ways, Eka has caught considerable slice from market, but Enko hasn't been successful like Eka. Elpaş Elektrik Malzemeleri Sanayi ve Pazarlama A. Ş. has begun to be seen in asynchronous motor control units market since 1987 by Electrical Southing Company licence agreement. ABB Elektik A. Ş., and Enel Endüstriyel Elektronik San. ve Tic. Ltd. Şti. have followed them since 1988. Simko Tic. ve San. A. Ş., Telemecanique ve Elektrik Cihazlar San. A.Ş. which are multinational companies began to sell asynchronous motor control units in 1989. In recent years, multinational agents have been catching the local prices due to the reorganization customs regulations. And this situation is an important problem for local firms. But still multinational agents haven't established satisfactory maintenance facilities. Another problem for local firms is that some of the multinational agents who have decided to enter this market with a big lost budget. Electronic speed drive units have the following viiadvantages : a) Light weight-compact design, b) Soft start, c) Soft stop, d) Motor protection, e) Line protection, f) Self protection systems, g) With low harmonics electronics components producing steeples smooth speed variation, h) Wide range applications, i) Easy maintenance, j ) Logic control facilities, k) Easy mechanical assembling, 1) Easy adaptation to energy control systems, m) Remote control, n) High efficiency, o) Wide speed range ( 2 x Nominal motor speed). Operational life of asynchronous motor control units vary according to the sectors in which they are used. This period is roughly 4-15 years. 3. GENERAL STATUS OF FIRMS ACTING IN THIS SECTOR Manufacturing firms in this sector, usually work without goods stocks, since the main input in the production of this units are imported material, and they are costly. Marketing policy is usually the same for all of firms in this sector. On one hand, the market is very small now, but on the other hand there is a potential market. There are lots of asynchronous motors in Turkey as well as around the world, that are in operation. Until recently, direct current motors have been used more then asynchronous motors. After the rapid development in semi-conductor technology the use of variable speed drives have been on the increase for a number of years. Since asynchronous motor contol units are electronic units, packing is very important. Sufficient precautions should be taken to protect them from environmental conditions such as dust, humidity, etc., and care should be taken for gentle handling. Advertisements are done through fairs and some special magazines about electronic equipments. 4. MARKET TIME SERIES ANALYSIS FOR ASYNCHRONOUS MOTOR CONTROL UNITS In preparing a forecast with a quantitative technique one almost always has a number of historical observations or observed values. These observations may represent viiimany things, from the actual number of units sold, to the cost of producing each unit. Since these observed values vary over time, they are generally represented by a variable such as x. Although x or some other symbol generally identifies the actual (historical) observed values of a variable, a different symbol (y) is often used to represent the forecasted value of the variable. The fact that some forecasting techniques are much more appropriate for making short-term forecasts, whereas others can handle long-term forecasts effectively, is due to the characteristic of time horizon, which can be identified for any forecasting method. This characteristic is closely related to the way in which a forecasting technique prepares its forecast and to the amount of data required. There are different types of demand analysis as follows $ 1. Demand analysis for new goods, 2. Demand analysis about different sector of industry, 3. Demand analysis about factories 4. Total demand analysis about future of a company, 5. Demand analysis about special goods. There are different types of demand methods as follows : 1. Demand analysis depending on experience and estimation, 2. Demand analysis depending on economic parameters, 3. Demand analysis by the use of mathematical and statistical methods. For this thesis time series analysis have been employed due to the characteristics of data available for market of asynchronous motor control units. First of all the trend functions are choosen for Samel, Eka and total market. These functions as follows: Samel' s trend function is : Y = -75.0145 + 114.9733 x - 4.80082 x* Rffl = 0.584229 Standart error of estimations : 146. 9892 Standart error of b : 23. 98375 Standart error of c : 1. 109360 <Y - Y') = 367299.2026 Eka' s trend function is : Y = 14.97552 + 8.927902 x ixRffi = 0.321802 Standart error of estimations : 78. 77844 Standart error of b : 3. 05489S (Y - Y' ) = 168673.3 Total market's trend function is : Y - - 119.106 + 140.0105 x - 5.56793 xe R« = 0.634275 Standart error of estimations : 174. 5833 Standart error of b : 28. 48618 Standart error of c : 1.317619 (Y - Y' ) = 518148.66 Then season indexes and conjecture indexes are calculated. According to the these values, sale values are estimated for 1990 (For Samel, Eka and total market). 5. CONCLUSION There is a potential market for asynchronous motor control units. But units are not well known, because the product is at the beginning of its life curve. And prices of units are more than expensive than their alternatives which are mechanical control units. It is assumed that the total market was shared by Eka and Samel between 1985 and 1987 years. In this market, market shares of Eka and Samel have been decreasing since the second half of 1987. According to the season values, sales are the most in the 4. tree months.