The Fifth International Conference on Technological

Conference Title

The Fifth International Conference on Technological Advances in Electrical, Electronics and Computer Engineering (TAEECE2018) Conference Dates

July 05-07, 2018

Conference Venue

Avrasya University, Trabzon, Turkey ISBN:

ISBN: 978-1-941968-47-5 ©2018 SDIWC

Published by

The Society of Digital Information and Wireless Communications (SDIWC) Wilmington, New Castle, DE 19801, USA www.sdiwc.net

Table of Contents

TAEECE2018 Design of Modular Multi-level Converter and Permanent Magnet Synchronous Generator-based Wind Energy Conversion System …………………………………………………………….……………………………………. 1 Performance Evaluation of Underwater Acoustic Communication using Trigonometric Chirp Modulation …………………………………………………………………………………………………………..……………………... 7 Multi-keyword Search Employing Identity-Based Encryption Technique (MKS-IDE) ……………………... 13 Image Processing Based Anti-Sleep Alarm System for Drowsy Drivers ………………………………………….. 19 Design and Implementation of Energy Management System for Buildings ………………………………….. 23

Proceedings of the Fifth International Conference on Technological Advances in Electrical, Electronics and Computer Engineering (TAEECE2018), Turkey, 2018

Design of modular multi-level converter and permanent magnet synchronous generator-based wind energy conversion system Hakam H. Abdul Hakeem Department of Electrical and Electronics Engineering Gaziantep, Turkey [email protected]

Ahmet Mete Vural Department of Electrical and Electronics Engineering Gaziantep, Turkey [email protected]

Abstract—In this paper, a back-to-back (BTB) modular multi-level converter (MMC) is designed for a permanent magnet synchronous generator (PMSG) based wind energy conversion system (WECS). The switching of power semiconductors of BTB-MMC is based on phase-shifted carrier pulse width modulation (PSC-PWM). Capacitor voltage balancing issue of the BTB-MMC is realized with a control system working in accordance with PSC-PWM technique. The designed PMSG based WECS is verified through case studies using PSCAD/EMTDC.

PSC-PWM technique [11]. Combining the averaging control with capacitor voltage balancing control enables capacitor voltage balancing issue without any external balancing circuit.

Keywords: Permanent magnet synchronous generator; Wind energy conversion system; Modular multi-level converter; Back-to-back converter. I. INTRODUCTION With the quick exhaustion of conventional fossil fuels, many renewable energy sources have emerged as substitutions for conventional sources [1]. In recent years, the wind energy has become the fastest expanding renewable source [2], [3]. The permanent magnet synchronous generator (PMSG) is one of the growing trend in wind energy conversion system (WECS) design because of many advantages such as no need for gearbox and rotor excitation, brushless structure, low maintenance cost/weight, and wide range of speed control [4],[5],[6]. It is necessary to use a power converter in WECS to control real/reactive power efficiently [7], [8]. Consequently, PMSG needs full-scale back-to-back (BTB) converter for gridconnection. In recent years, multilevel converters such as diode-clamped, flying-capacitor, cascaded Hbridge, and modular multilevel converter (MMC) have gained popularity in almost all voltage and power levels due to advantages such as low harmonic content, small filtering requirement, and no need for a coupling transformer [9]. The MMC was first proposed by Marquardt, R. for high voltage direct current transmission [7]. MMC is very suitable for medium voltage/high power WECS applications due to modular circuit topology and independent control capability of each MMC [10], [11]. In this paper, a back-to-back (BTB)-MMC topology is applied to a PMSG based WECS. On the basis of the works realized in [4], the control strategy of the BTB-MMC is realized based on

ISBN: 978-1-941968-47-5 ©2018 SDIWC

II. PMSG BASED WECS DESIGN Two MMCs can be connected from their DC link to form a BTB arrangement. Thus, BTB-MMC can be used in a WECS. The MMC near wind generator operates as an AC-DC converter, while the other one is connected to AC grid and operates as a DC-AC converter. By this way, the real power generated by the wind turbine is transferred to the AC grid in a controllable way. The sub-module (SM) or cell is the fundamental building block of an MMC. Each SM can be constructed by a half-bridge (HB) having two power semiconductors (IGBT) and a capacitor [12], [13]. Fig. 1 shows the switching states of a SM. Table 1 lists the SM capacitor cases. The PMSG based WECS design using a BTB-MMC arrangement is shown in Fig. 2. Each MMC has three legs and each leg contains an upper and a lower arm [12], [14]. Four sub-modules (SM) or cells are connected in series in each arm. With this design, line-to-line AC voltage of each MMC has 2n+1=17 levels, where n is the number of cells per arm).

S1

D1

S1

D1 +

+ C

+

Vcmp

C

+

-

Vmp

S2

Vmp

-

S2

D2

-

(a) Case 1 (i>0) S1

(b) Case 2 (i>0) S1

D1

Vcjp

C

+

D1 +

+

C

+

-

Vjp

-

Vcmp -

D2

S2

D2

Vjp

S2

D2

(d) Case 4 (i 0) (𝑖𝑛𝑣 < 0)

(6)

The voltage command of every sub-module 𝑣∗ 𝑚𝑣 is shown below for positive-arm and negative-arm commands: 𝑣∗ 𝑚𝑣 = 𝑣∗ 𝐴𝑣 + 𝑣𝐵𝑣𝑚𝑔 𝑣∗ 𝑚𝑣 = 𝑣∗ 𝐴𝑣 + 𝑣𝐵𝑣𝑚𝑔 +

𝑣∗

𝑣

4

𝑣∗ 𝑣 4

+ +

𝐸

8 𝐸 8

(m: 1 ~ 4)

(7)

(m: 5 ~ 8)

(8)

ISBN: 978-1-941968-47-5 ©2018 SDIWC

Rated active power Rated frequency DC-link voltage arm inductance SM capacitor voltage Carrier frequency Coupling inductance

5 MW 50 Hz 9 kV 3 mH (6.4%) 2.25 kV 2 kHz 6 mH

Table 3. Wind turbine parameters.

Wind speed Frequency Rotor radius Active power

12 m/m 50 Hz 35 m 5 Mw

3


Table 4. AC grid parameters.

Frequency Rated voltage L-L rms

50 Hz 5.5 kV

In this work, the controllers of the WECS are examined under two cases: under steady-state rated conditions and under dynamic state when DC-link voltage is dropped. A. Case 1: Under Rated Conditions Fig. 4 shows the simulated waveforms of line-toline voltages, phase currents, and line-to-neutral voltages of AC-DC MMC under rated conditions, respectively.

Fig. 5 (a) Active and reactive power output of PMSG, (b) DC-link voltage of BTB-MMC, (c) Circulating current.

Fig. 5 shows the active and reactive power output of the PMSG, DC-link voltage of BTB-MMC, and circulating current, respectively. As shown, the circulating currents are minimized. Fig. 6 shows the active and reactive power of DC-AC MMC and lineto-line voltage of DC-AC MMC, respectively. From these waveforms, we can see that the DC-AC MMC side is able to output 17 levels at the line-to-line voltage converted from the DC-link voltage that has been delivered by AC-DC MMC.

(a)

(a)

(b) Fig. 6 (a) The active and reactive power of DC-AC MMC, (b) Lineto-line voltage of DC-AC MMC. (b)

(c) Fig. 4 (a) Line-to-line voltage of AC-DC MMC, (b) Phase currents of AC-DC MMC, (c) Line-to-neutral voltage of AC-DC MMC.

In order to generate high quality AC voltage, the DC capacitor voltage of SM per each arm must be equal. Fig. 7(a) shows the DC capacitor voltages of eight SMs in MMC1. As observed, DC capacitor voltages in phase-u of MCC1 has no ripples. Fig. 7(b) shows the DC capacitor voltages of eight SMs in phase-w of MMC2. Theoretically, DC capacitor voltage of each SM is 2.25 kV. This value can be calculated as: 𝑣∗ 𝑐 =

DC supply voltage number of SM in upper arem or lower

=

9 4

(9)

(a)

(a) (b)

(c)

ISBN: 978-1-941968-47-5 ©2018 SDIWC

(b) Fig. 7 (a) DC capacitor voltages of AC-DC MMC, (b) DC capacitor voltages DC-AC MMC.

4


B. Case 2: Under Dynamic Case

has returned to their nominal values after some disturbances.

In this case study, the dynamic performance of the control scheme is examined when DC link voltage set point is dynamically changed for a duration of 0.05s as shown in Fig. 8(a). As observed from the simulated waveforms presented in Fig. 8, the control system of the WECS was able to ride through these dynamic states smoothly. (a)

(a) (b)

(b) (c) Fig. 9 (a) DC-capacitor voltages of MMC1, (b) DC-capacitor voltage of MMC2, and (c) voltages of AC three phase voltage source

(c)

(d)

(e) Fig. 8 (a) DC link voltage set-point change, (b) Line to line voltage of MMC1, (c) Active and reactive power of DC/AC side, (d) Phase currents of MMC2, (e) Active and reactive power of PMSG.

After the drop of DC link voltage, three-phase AC voltage of both MMCs are also diminished. Since, the DC link voltage is used as reference voltage in the controller for both MMCs. Thus, the supplied and absorbed active power of MMC1 and MMC2 are respectively decreased. Fig. 9(a) shows the voltages of eight SMs in phase-w of MMC1 when DC link voltage set-point change is applied. The voltages of each SM

ISBN: 978-1-941968-47-5 ©2018 SDIWC

V. CONCLUSION The design and control of the power converters in a WECS is still challenging. The design and simulation of BTB-MMC based PMSG WECS is proposed in this work. BTB-MMC arrangement brings many advantages to WECS design such as being flexibility and modularity. Moreover, MMC is able to generate higher voltages with diminished voltage stress on each power electronic semiconductor. Harmonic levels can also be significantly decreased thanks to the increased number of voltage levels. As a result of this, filtering requirements are becoming less. MMCs have also better fault ride through capabilities. PSC-PWM method is used to trigger power semiconductors in each SM. Balancing and average control methods are designed to achieve the balancing of capacitor voltage in each SM in both MMCs. In order to verify the efficiency of the proposed control scheme, two cases studies were performed in this work. As observed from the simulation results, the dynamic performance of the proposed control scheme is satisfactory. REFERENCES [1]

Yaramasu, Wu, Sen, Kouro, and Narimani, "High power Wind Energy Conversion Systems: State-of-the-Art and Emerging Technologies, " IEEE. Vol. 103, No. 5, May 2015, pp. 736739

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[2]

[3]

[4]

[5]

[6]

[7]

[8]

[9]

[10]

[11]

[12]

[13] [14]

[15]

[16]

Henk, P., Jan Abraham, "Trends in Wind Turbine Generator Systems,” IEEE Jornal of emerging and selected topics in power electronmics Vol. 1, No. 3, Sep 2013, pp. 174-185 Yaramasu, Wu, Sen, Kouro, and Narimani, "High-Power Wind Energy Conversion Systems: State-of-the-Art and Emerging Technologies,” Proceedings of the IEEE., Vol. 103, No. 5, May 2015, pp. 736-739 Mian, W., Yaowei, H., Wenjian, Z., Yue W, Guozhu C, "Application of modular multi level converter in meduim voltage high power permanent magnet synchronous generator wind energy conversion system,” IET Power. GEN. Distrib.,Mar 2016, pp. 1–10 M.S. Camara, M.B. Camara, B. Dakyo and H. Gualous, "Permanent Magnet Synchronous Generators For Offshore Wind Energy System Linked To Grid Modeling And Control Strategies", IEEE, 16th International Power Electronics and Motion Control Conference, PEMC2014, Antalya/Turkey, September, 2014 Tan Luong, Thanh Dung, Thanh Trang, and Huy Dung "Advanced Control Strategy of Back-to-Back PWM Converters in PMSG Wind Power System,” Power Engineering and Electrical Engineering. Vol. 13, June, 2015, pp. 81-95 A. Lesnicar and R. Marquardt, "An innovative modular multilevel converter topology suitable for a wide power range," in Proc. 2003 Power Tech Conference Proceedings, 2003 IEEE Bologna W. Abd Halim, S. Ganeson, M. Azri, T.N.A. Tengku Azam, “Review of Multilevel Inverter Topologies and Its Applications,” Journal of Telecommunication, Electronic and Computer Engineering, Vol. 8 No. 7, pp. 51-56 Makoto Hagiwara, Kazutoshi Nishimura, and Hirofumi Akagi, “A Medium-Voltage Motor Drive With a Modular Multilevel PWM Inverter,” IEEE Trans. Power Electronic., Vol. 25, No. 7, Jul 2010, pp. 1786-1799 Ahmed, N.; Haider, A.; van Hertem, D.; Zhang, L.; Nee, H.P. Prospects and challenges of future HVDC Super Grids with modular multilevel converters. In Proceeding s of the 14th Conferenceon Power Electronics and Applications (EPE 2011), Birmingham, UK, 30 August–1 September 2011; pp. 1–10. M. Hagiwara and H. Akagi, “Control and experiment of pulse width modulated modula rmultilevel converters,” IEEE Trans. Power Electron., vol. 24, no. 7, Jul. 2009, pp. 1737–1746 H. Vahedi and K. Al-Haddad, "Half-bridge based multilevel inverter generating higher voltage and power," in Electrical Power & Energy Conference (EPEC), 2013 IEEE, 2013, pp. 1-6. Makoto Hagiwara, and Hirofumi Akagi, “Control and Experiment of Pulsewidth-Modulated Modular Multilevel Converters,” IEEE Trans. Power Electron., Vol. 24, No. 7, Jul 2009, pp. 1737–1746 R. H. Baker, "Switching circuit," ed: US Patent 4,210,826, 1980 Pracha Khamphakdi, Kei Sekiguchi, Makoto Hagiwara, , and Hirofumi Akagi, “Design and Experiment of a Back-To-Back (BTB) System Using Modular Multilevel Cascade Converters for Power Distribution Systems” IEEE Trans. Power Electron, 2013, pp. 311-317 Debnath, S., Qin, J., Bahrani, B., et al.:‘Operation, control, and applications of the modular multilevel converter: a review’, IEEE Trans. Power Electron., 2015, 30, (1SI), pp. 37–53 Manish V. Kurwale ,Palak G. Sharma , Gautam Bacher, “Performance Analysis of Modular Multilevel Converter (MMC) with Continuous and Discontinuous Pulse Width Modulation (PWM) ,” International Journal of Advanced Research in Electrical, Electronics and Instrumentation Engineering., Vol. 3, Issue 2, February 2014, pp. 7463-7474

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[17] Suman Debnath, Jiangchao Qin, Behrooz Bahrani, Maryam Saeedifard, and Peter Barbosa, “Operation, Control, and Applications of the Modular Multilevel Converter: A Review,” IEEE Transactions on Power Electronics., vol. 30, Jan. 2015, pp. 37–53 [18] Hirofumi Akagi, Shigenori Inoue, and Tsurugi Yoshii, “Control and Performance of a Transformerless Cascade PWM STATCOM With Star Configuration,” IEEE Transactions on industry Application, VOL. 43, NO. 4, July/August 2007, pp. 1041-1049

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Performance Evaluation of Underwater Acoustic Communication using Trigonometric Chirp Modulation Ali Emadi

Ali Jamshidi

School of Electrical and Computer Engineering Shiraz University Shiraz, Iran [email protected]

School of Electrical and Computer Engineering Shiraz University Shiraz, Iran [email protected]

Abstract—In this paper, we propose an underwater acoustic communication based on trigonometric chirp modulated waveforms. We show that a usual system with linear chirp modulation requires wide bandwidth. Therefore, a Doppler resilient and robust underwater digital communication system based on a non-linear frequency modulation as trigonometric chirp technique has been presented. To evaluate the performance of trigonometric chirp modulation technique over AWGN channel, Rayleigh fading and Rician channels with and without Doppler effect, we have conducted some simulations. It is demonstrated that the performance of proposed method, even in lower spreading factors gives better performance than an LFM chirp modulated system in terms of bit error rate. Keywords—Underwater Acoustic Communication, Linear frequency Modulation (LFM), Trigonometric Chirp, Doppler Shift, Rayleigh Fading, Rician Fading.

I. I NTRODUCTION Over past decades, many underwater wireless communication technologies have been proposed and applied as ocean exploration, oceanography data collection, control over autonomous underwater vehicles, undersea navigation and etc. When studying problems of sending data from transmitter to receiver, the distortion induced by the channel lead us to analyze for then being able to choose a right signal waveform. A reliable underwater acoustic communication is challenging because of some channel characteristics such as; small bandwidth, high power attenuation, fast time variation of the channel response, fading along of multipath propagation and Doppler effect due to relative speed between the receiver and the transmitter. Actually in UWA communication, due to the low velocity of acoustic waves (roughly 1500 m/s) Doppler shift is larger than terrestrial radio frequency communication. But this is not the only impact of Doppler in acoustic waves. Unlike the case of radio transmission which Doppler shift is usually modeled as a frequency offset, the effect of Doppler shift on the symbol duration cannot be neglected. Significant Doppler

ISBN: 978-1-941968-47-5 ©2018 SDIWC

shift results loss of information and frame desynchronization, as well. In addition to relative speed between the source and the receiver, different sampling frequencies also yield to signal compression-expansion. This means that for example, if our DAC is not accurate, we have to consider this problem in the system. Recently, there have been considerable attempts to design robust receivers which prosperously equalize the channel and also increase transmission rate. Chirp spread spectrum (CSS) techniques use chirp signals for data transmission. Chirp is a sinusoidal signal whose frequency decreases or increases over a specified time duration. Chirps as another spread spectrum signals are commonly used in radar applications and many years later in sonar due to its good temporal resolution of auto correlation function and also, considerable processing gain obtained from correlation measurement in the receiver [1]–[9]. In march 2007, IEEE introduced CSS physical layer in its new standard as 802.15.4 a, allowing CSS to be used in various application such as industrial control, sensor networking, real time location systems and medical devices [10]. Some characteristics of chirp modulations make it robust to multipath with low Doppler sensitivity. We know that linear frequency modulation (LFM) is the simplest chirp waveform. It has some advantages in comparison to non-linear chirps such as easy generation by different technologies, mostly simple to process by a matched filter or similar techniques. Accordingly, more applications for the CSS system based on linear chirps have been developed than that for non-linear types. But the main drawback is obtaining orthogonality between two LFM signals. A large time-bandwidth product, known as spreading factor, is needed. Either considerable symbol duration or wide bandwidth causes large spreading factor. The time-bandwidth product of a linear CSS should be more than 70 to achieve relatively acceptable orthogonality between its symbols for binary signaling. As we know, significant bit rate is more preferable [11]. Thus, by necessity a classical LFM signal will occupy undesirable large bandwidth especially at high speed data rate. So it is important to choose a pair of chirp signals

7


which will be sufficiently orthogonal in small spreading factors to sending information. Nevertheless, non-linear chirps have not attained high prevalent like linear type, so far. Probably it is because of limited availability of non-linear-FM generation and processing devices, more complexity of system, derivation of performance evaluation can be troublous, as well. By accepting these issues, desired performance can be achieved with considerable reduction in bandwidth. Better performances due to some intrinsic properties of non-linear chirps were motivation of our research. In this paper, we use trigonometric chirp signals to modulate binary data. To obtain a better performance, it is preferable to consider two orthogonal chirp signals. At the receiver, we consider a matched filter to correlate the received signal with a known signal. We illustrate that a trigonometric chirp modulated system has better performance over AWGN and different fading channels in contrast with a system based on LFM chirp. The remainder of this paper is organized as follows. In section II, the orthogonality of LFM and trigonometric chirp as a type of non-linear frequency modulation have been investigated. In section III, performances over additive white gaussian noise (AWGN) and two fundamental fading channels for underwater acoustic systems as Rayleigh and Rician have been evaluated. In section IV, a real analytical measurement is given which predicts our simulated results. Finally, section V concludes this paper. s * (t ) 0

☎0

Ts

dt

✁

i = 0, 1

(2)

Where kh∗, ∗ik is the absolute value of the inner product between observation r and transmitted signal si . So, we can consider the hypothesis test as follows H0 : r = s0 + n (3) H1 : r = s1 + n According to the non-coherent maximum a posteriori (MAP) detector, the decision rule will be H0

khr, s0 ik − khr, s1 ik>