Wind System

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Applied Energy Symposium and Forum, Renewable Energy Integration with Mini/Microgrids, Applied Energy Symposium and Forum, Energy Integration REM 2017, 18–20 Renewable October 2017, Tianjin, China with Mini/Microgrids, REM 2017, 18–20 October 2017, Tianjin, China

Analysis of MISO Super Lift Negative Output Luo Converter with 15th International Symposium on District Heating andConverter Cooling Analysis ofThe MISO Super Lift Negative Output Luo with MPPT for DC Grid Connected Hybrid PV/Wind System MPPT for DC Grid Connected Hybrid PV/Wind System Assessing the feasibility of using the heat, Prabhu. demand-outdoor Kumar. Kaa, Ramji Tiwariaa, Ramesh Babu. Nb* K.Raa b* Kumar. K , Ramji , Ramesh Babu. N ,heat Prabhu. K.R temperature function forTiwari a long-term district demand forecast a a

School of Electrical Engineering, VIT University, Vellore, India; bM.Kumarasamy College of Engineering,Karur, India. School of Electrical India; bM.Kumarasamy College of Engineering,Karur, India. c a,b,c Engineering, VIT a University, Vellore, a b c

I. Andrić

*, A. Pina , P. Ferrão , J. Fournier ., B. Lacarrière , O. Le Corre

a Abstract IN+ Center for Innovation, Technology and Policy Research - Instituto Superior Técnico, Av. Rovisco Pais 1, 1049-001 Lisbon, Portugal b Abstract Veolia Recherche & Innovation, 291 Avenue Dreyfous Daniel, 78520 Limay, France c This paper proposes a multi-input single output super -lift negative output converter for DC grid France connected hybrid Département Systèmes Énergétiques et (MISO) Environnement IMT Atlantique, 4 rueLuo Alfred Kastler, 44300 Nantes, This paper proposes a multi-input singleThe output (MISO) super liftis negative output Luo converter for DCcapacitor grid connected hybrid wind and photo voltaic (PV) system. proposed converter developed by sharing the charging and DC link wind and between photo voltaic The proposed converter is developed by sharing the Therefore, charging capacitor DC link capacitor the two(PV) supersystem. lift negative output Luo converters to form a hybrid system. it has the and advantage of capacitor two super lift negative outputcomponents. Luo converters form a hybrid system. Therefore, has the advantage of the simplebetween structuretheand reduced converter passive Thetoproposed converter is designed anditthen analyzed for the the simple structure and reduced passive components. The proposed converter is designed then PV analyzed forwith the DC grid connected hybrid wind converter and PV system. This study considers a 500W wind system and aand 560W system Abstract DC grid connected hybrid wind(MPPT) and PV algorithms system. This study considers 500W method wind system andwind a 560W maximum power point tracking of perturb& observea (P&O) for both and PV system system. with The maximum power point tracking (MPPT) algorithms of perturb& observe (P&O) method for both wind and PV system. proposed converter effectiveness has been validated and compared with the proportional integral (PI) and P&O control District heating networks are commonly addressed in the literature as one of the most effective solutions for decreasingThe the proposed converter effectiveness beenBased validated compared withhigh the investments proportional integral (PI) P&O usage control algorithms bygas using the simulation results. on These theand availability of the wind and PV energy sources, the and converter is greenhouse emissions from thehas building sector. systems require which are returned through the heat algorithms by using the simulation results. Based on the availability of the wind and PV energy sources, the converter usage is presented. sales. Due to the changed climate conditions and building renovation policies, heat demand in the future could decrease, presented. prolonging the investment return period. Copyright 2018ofElsevier Ltd.isAll rights reserved. The main© scope thisAuthors. paper to assess the feasibility of using the heat demand – outdoor temperature function for heat demand Copyright © 2018 The Published by Elsevier Ltd. Copyright and © 2018 Elsevier Ltd. All rights reserved. Selection peer-review under responsibility of the (Portugal), scientific committee of the Applied Symposium and Forum, forecast. and Thepeer-review district of under Alvalade, located inofLisbon was used a case study.Energy The district is consisted Selection responsibility the scientific committee of theas Applied Energy Symposium and Forum, of 665 Selection and peer-review under responsibility of the scientific committee of the Applied Energy Symposium and Forum, Renewable Energy Integration with Mini/Microgrids, REM 2017. Renewable Energy with Mini/Microgrids, 2017 Three weather scenarios (low, medium, high) and three district buildings that varyIntegration in both construction period andREM typology. Renewable Energy Integration with Mini/Microgrids, REM 2017. renovation scenarios were developed (shallow, intermediate, deep). To estimate the error, obtained heat demand values were Keywords: super lift Luo converter; wind; Photo Voltaic; MPPT; hybrid system. compared with results from a dynamic heat demand model, previously developed and validated by the authors. Keywords: super lift Luo converter; wind; Photo Voltaic; MPPT; hybrid system. The results showed that when only weather change is considered, the margin of error could be acceptable for some applications (the error in annual demand was lower than 20% for all weather scenarios considered). However, after introducing renovation 1.scenarios, Introduction the error value increased up to 59.5% (depending on the weather and renovation scenarios combination considered). 1. Introduction The value of slope coefficient increased on average within the range of 3.8% up to 8% per decade, that corresponds to the Due to energyofcrises andhours environmental pollution, renewable energy sources used of in weather domestic, decrease in vast the number heating of 22-139h during the heating season (depending onare the widely combination and Due toelectric vast energy crises and environmental renewable energy sources areavailable widely used in The domestic, industrial, vehicles and other applications whereintercept the regular mainfor grid is not [1,2]. most renovation scenarios considered). On the other hand, pollution, function increased 7.8-12.7% per decade (depending on the industrial, electricsources vehicles and other where the regular main gridand is solar not [1,2]. The most promising energy among all theapplications renewable energy sources the wind to meet the load demand, coupled scenarios). The values suggested could be used to modify the are function parameters for available the scenarios considered, and promising energy sources among all the renewable energy sources are the wind and solar to meet the load demand, but these sources are uncontrollable and unpredictable in nature, so it is quite difficult to meet the demand improve the accuracy of heat demand estimations.

but these sources individually [3-6]. are uncontrollable and unpredictable in nature, so it is quite difficult to meet the demand individually [3-6]. Published by Elsevier Ltd. © 2017 The Authors.

* Peer-review N Ramesh Babu. Tel.:+91-9443030636. under responsibility of the Scientific Committee of The 15th International Symposium on District Heating and address: [email protected] *E-mail N Ramesh Babu. Tel.:+91-9443030636. Cooling. E-mail address: [email protected]

Keywords: Heat demand; Forecast; Climate change 1876-6102 Copyright © 2018 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility the scientific 1876-6102 Copyright © 2018 Elsevier Ltd. All of rights reserved. committee of the Applied Energy Symposium and Forum, Renewable Energy Selection and peer-review under responsibility Integration with Mini/Microgrids, REM 2017. of the scientific committee of the Applied Energy Symposium and Forum, Renewable Energy Integration with Mini/Microgrids, REM 2017. 1876-6102 © 2017 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the Scientific Committee of The 15th International Symposium on District Heating and Cooling. 1876-6102 Copyright © 2018 The Authors. Published by Elsevier Ltd. Selection and peer-review under responsibility of the scientific committee of the Applied Energy Symposium and Forum, Renewable Energy Integration with Mini/Microgrids, REM 2017 10.1016/j.egypro.2018.04.062

Kumar. K et al. / Energy Procedia 145 (2018) 345–350 Kumar K/ Energy Procedia 00 (2018) 000–000

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However, this can be defeat by integrating the different renewable energy sources with power electronic converters to form a hybrid system. The most promising renewable energy sources to form a hybrid system are the wind and solar, due to its availability and complement in its nature [7]. The benefit of integration of hybrid renewable energy sources with the grid increase the sustainability, effective peak hour management, electric market up-gradation and reduces the impact on customers during the grid failure. As of June 30th, 2017, the total grid tied installed capacity of wind is 32,508.17MW and the PV is 13,114.82MW. [8] The voltage generated by these two sources is unstable and too low. So it requires DC-DC converters with high step-up gain to meet the required rating of the system [9,10]. The basic boost converter can increase the voltage gain by operating in its extreme large duty cycle [11,12]. As consequences, stress on the power semiconductor devices increases and decreases the overall conversion efficiency of the system. From the past few decades, several multiinput DC-DC power converter configurations are derived from the traditional buck, boost and buck-boost converters are available and are detailed in the literature [13-17]. In this paper, a new converter topology of MISO super lift negative output Luo converter is proposed for the application of the wind and solar energy sources integration. The advantage of the proposed converter is to operate in both individual and simultaneous modes of operation. The wind energy system is regulated by the switch S1 with perturb and observer method to extract maximum power and PV energy system is regulated by the switch S2 with perturb and observer method to extract maximum power. 2.

Analysis of super lift negative output Luo converter

The schematic diagram of super lift negative output Luo converter is shown in Fig. 1. It steps up the DC output voltage in geometric progression stage by stage, the converter circuit has one switch, one inductor, two capacitors and two diodes. The transfer gain (G) [18] is given in Eq. (1). The Luo converter voltage transfer gain, G 

Vo 1  Vs 1 k

(1)

Where, Vs: Source voltage (V), k: Duty cycle, VO: Output voltage (V), G: Gain value S Vs

L

C1 D1

C2

Vdc +

Vo +

D2

Fig. 1. Super lift negative output Luo converter

2.1 Proposed converter The schematic diagram of proposed MISO converter is shown in Fig. 2. It is designed from the traditional super lift negative output Luo converter. In order to make a multi-input single output system, two super lift negative output Luo converters are integrated together by sharing the charging capacitor, C1 and DC link capacitor, C2 between the two Luo converters as shown in the Fig. 2. It operates in four different modes based on the availability of the energy sources by operating switches S1 and S2, as shown in Fig. 3 and are explained in the following subsection.



Kumar. K et al. / Energy Procedia 145 (2018) 345–350 Kumar K/ Energy Procedia 00 (2018) 000–000 Vw Iw

Vpv

P&O Method

P&O Method

MPPT-1

347 3

Ipv

MPPT-2

S1

S2

L1

C1 D3

D1 Wind source

L2

C2 Vdc + D2

PV source

Vo + D4

Fig. 2. Block diagram of proposed MISO Luo converter

2.2 Modes of operation Mode-1: S1: ON, S2: ON (Both wind and PV sources are available) The sharing capacitor C1 is charged by the both wind and PV source voltages Vw and Vpv respectively. iL1 is the current flowing through the inductor L1, increases with the voltage Vw during the availability of wind source and similarly current iL2 through inductor L2, with the voltage Vpv during the availability of PV source. The Dc link capacitor, C2 supplies power to the load. The mathematical current equations ofi L1 and iL2 are expressed in Eq. (2).

iL1  I w 

Vw  Vc1 t L1

and

i L 2  I pv 

Vpv  Vc1 L2

(2)

t

Mode-2: S1: ON, S2: OFF (wind source alone is available) When S1 is ON, the sharing capacitor C1 is charged by the voltage Vw of the wind source and iL1is the current flowing through the inductor L1 increases with the voltage Vw during the availability of the wind source. When PV source not available, S2 is OFF, then both C1 and L2 are in a discharging state in C2, to get the boosted voltage across the load. The mathematical current equations of iL1 and iL2 are given in Eq. (3). V V  Vc1 iL 2  I dc  c1 t (3) iL1  I w  w t L2 and L1 The summary of modes of operation of proposed converter with switching states is listed in Table 1 Table 1. Summary of modes of operation of the converter Diode conduction states Wind PV source Mode source D1 D2

Charging and discharging D3

D4

L1

L2

1

Available (S1-ON)

Available (S2-ON)

Forward bias

Reverse bias

Forward bias

Reverse bias

Wind source

PV source

2

Available (S1-ON)

Unavailable (S2-OFF)

Forward bias

Reverse bias

Reverse bias

Forward bias

Wind source

Capacitor, C1

3

Unavailable (S1-OFF)

Available (S2-ON)

Reverse bias

Forward bias

Forward bias

Reverse bias

Capacitor, C1

PV source

4

Unavailable (S1-OFF)

Unavailable (S2-OFF)

Reverse bias

Forward bias

Reverse bias

Forward bias

Capacitor, C1

Capacitor, C1

Mode-3: S1: OFF, S2: ON (PV source alone is available) When wind source is not available, then S1 is OFF, then both C1 and L1 are in discharging state to C2, to get the boosted voltage across the load. When PV source is available, S2 is ON, then the sharing capacitor C1 is charged by the Vpv of the PV source and the current iL2 flowing through the inductor L2, increases with the voltage Vpv during

Kumar. K et al. / Energy Procedia 145 (2018) 345–350 Kumar K/ Energy Procedia 00 (2018) 000–000

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the availability of the PV source. The mathematical current equations of i L1 and iL2 are given in Eq. (4).

iL1  I dc 

Vc1 t L1

iL 2  I pv 

and

V pv  Vc1

(4)

t

L2

Mode-4: S1: OFF, S2: OFF (Both wind and PV sources are not available) When both sources are not available, then S1 and S2 are OFF, then the sharing capacitor and inductor L1 and L2 are in discharging state to the DC link capacitor C2, to get the boosted voltage at the load side. The mathematical current equations of iL1 and iL2 are given in Eq. (5). iL1  I dc 

Vw Iw

Vc1 t L1

iL 2  I dc 

and

P&O Method

P&O Method

MPPT-1

Vw

Vpv

Iw

Ipv

(5) P&O Method

MPPT-1

MPPT-2

S1 iL1

Vc1 t L2

S2

L1

C1

C1

Wind source

PV source

D4

(a)Mode-1: S1: ON, S2: ON (Both wind and PV sources are available) P&O Method

D2

(b) Mode-2: S1: ON, S2: OFF (wind source alone is available)

Ipv

S1

S2

L1 S2

L1

C1

C2 Vdc + D2

C1

Wind source

C2 Vdc +

PV source

Vo +

D2

D4

L2 D3

D1

L2 D3

D1 Wind source

+ D4

Vpv

MPPT-2

S1

PV source

Vo

C2 Vdc +

+

D2

L2 D3

D1

Vo

C2 Vdc +

S2

L1

D3

D1 Wind source

S1

iL2

L2

Vo

PV source

+ D4

(d)Mode-4: S1: OFF, S2: OFF (Both sources are not available) (c) Mode-3: S1: OFF, S2: ON (PV source alone is available) Fig. 3. (a)-(d) Modes of operation of proposed MISO Luo converter

3.

Simulation result analysis

The performance of the proposed MISO Luo converter is validated by considering the availability of wind speed as constant 12m/sec for the period of 0 to 0.4 sec and the solar irradiation is 1000 w/m2 for the period of 0.4 to 0.8 sec. The proposed hybrid system parameter specifications are listed in Table 2. Table 2. Hybrid system parameter specifications Description

Ratings

PV rating Wind rating Luo converter-1 Luo converter-2 Sharing capacitor DC link capacitor Load resistance Switching frequency

24 V, 23.4 A, 560 W 24 V, 21 A, 500 W L1=3e-3 H L2=3e-3 H C1=1e-3 F C2=5e-3 F R=110 Ω fs=15 kHz



Kumar. K et al. / Energy Procedia 145 (2018) 345–350 Kumar K/ Energy Procedia 00 (2018) 000–000

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Power(W)

Current(A)

Voltagr(V)

In region (0 to 0.4 sec), the wind is the only source available energy source, it varies continuously as per the availability of energy source. In this region wind system with Luo converter-1 is in operating state and step up the available 24V wind source to 240V DC by operating at its voltage transfer gain of 10 as shown in Fig.4. 30 20 10 0 30

0

0.2

0.4

0.6

0.8

0

0.2

0.4

0.6

0.8

0

0.2

0.4 Time(Sec)

0.6

0.8

20 10 0

500 250 0

Fig. 4. Wind system output voltage, current and power

Power(W)

Current(A)

Voltage(V)

In region (0.4 to 0.8 sec), PV is the only available energy source; it varies continuously as per the availability of energy source. In this region, PV source with Luo converter-2 is in operating state and step up the available 24 V PV source to 240 V DC by operating at its voltage transfer gain of 10 as shown in Fig. 5. 30 20 10 0 30

0

0.2

0.4

0.6

0.8

0

0.2

0.4

0.6

0.8

0

0.2

0.4 Time(Sec)

0.6

0.8

20 10 0

500 0

Fig. 5. PV system output voltage, current and power

Voltage(V)

Fig. 6 shows that the output voltage of the hybrid system is kept constant despite the variation in the input sources. During the period 0 to 0.4 sec, wind source will provide input to the converter and PV source provides for the period 0.4 to 0.8 sec. the MPPT control algorithm used in this paper are P&O and PI. The comparison of the both the control algorithms for the proposed converter are shown in Fig. 6. 300 200 100

Current(A)

0 3

PI MPPT Output

0

0.2

0.4

0.6

0.8

0

0.2

0.4

0.6

0.8

0

0.2

2 1 0

Power(W)

P&O MPPT Output

750 500 250 0

0.4 0.6 Time(Sec) Fig. 6. DC link voltage, current and power

0.8

Kumar. K et al. / Energy Procedia 145 (2018) 345–350 Kumar K/ Energy Procedia 00 (2018) 000–000

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Table 3, compute the results obtained by the proposed converter while using P&O and PI control algorithms. From the table, it is seen that the P&O based MPPT algorithm with proposed converter gives the average maximum power of 516W, while the PI controller gives the only 468W. Thus the proposed converter along with the P&O based MPPT algorithm provides the better performance. Table 3. Comparison of MISO hybrid system with MPPT

Voltage (V) Current (A) Power (W)

4.

Wind system output

PV system output

240 2.1 500

240 2.34 560

Average output with MPPT PI 235 1.98 468

P&O 240 2.15 516

Conclusion

The analysis of MISO Luo converter with MPPT has been presented for DC grid connected wind and PV hybrid system. In this paper, two super lift negative output Luo converters are integrated together to minimize the converter components and for the application of renewable energy sources integration. Based on the availability of energy sources, control switches S1 and S2 decides the mode of operation of the proposed converter. MPPT P&O method has been realized for the both PV and wind system and the results are compared with the PI-based MPPT technique. The proposed converter with the P&O algorithm as an MPPT shows the better performance by making the use of complementary nature of renewable energy sources and maintains constant 240 DC throughout the period. References: [1] Haitham AR., Malinowski M., and Kamal AL.,. Power electronics for renewable energy systems, transportation and industrial applications. John Wiley & Sons. 2014. [2] Saravanan, S., Babu NR. Analysis and implementation of high step-up DC-DC converter for PV based grid application. Appl Energy. 2017; 190: 64-72. [3] Tiwari R, and Babu NR. Fuzzy Logic Based MPPT for Permanent Magnet Synchronous Generator in wind Energy Conversion System. IFAC-Papers OnLine. 2016; 49(1): 462-467. [4] Erdinc O., Uzunoglu M. Optimum design of hybrid renewable energy systems: Overview of different approaches. Renew. Sustain. Energy Rev. 2012; 16(3): 1412-1425. [5] Tiwari R, Babu NR. Recent developments of control strategies for wind energy conversion system. Renew. Sustain. Energy Rev. 2016; 66 : 268-285. [6] Kumar K., Babu NR, Prabhu KR. Design and Analysis of an Integrated Cuk-SEPIC Converter with MPPT for Standalone Wind/PV Hybrid System. Int. J Renew Energy Research. 2017; 7(1): 96-106. [7] Kumar K., Babu NR., Prabhu KR. Design and Analysis of RBFN Based Single MPPT Controller for Hybrid Solar and Wind Energy System. IEEE Access.2017; 5: 15308 - 15317. [8] Cumulative development of various renewable energy system/ devices in country. Retrieved from http://mnre.gov.in/mission-and-vision2/achievements. 30 June 2017. [9] Wu .G, Xinbo Ruan, and Zhihong Ye. Nonisolated high step-up dc–dc converters adopting switched-capacitor cell. IEEE trans indus electron. 2015; 62(1): 383-393. [10] Liang, Tsorng-Juu, Jian-Hsieng Lee, Shih-Ming Chen, Jiann-Fuh Chen, and Lung-Sheng Yang. Novel isolated high-step-up DC–DC converter with voltage lift. IEEE trans indus electron. 2013; 60(4): 1483-1491. [11] Saravanan, S., Babu NR. RBFN based MPPT algorithm for PV system with high step up converter. Energy Convers Manag. 2016; 122: 239251. [12] Saravanan, S., Babu NR. Non-Isolated DC-DC Converter for Renewable Based Grid Application. Energy Procedia. 2016; 103: 310-315. [13] Zhang, Neng, Danny Sutanto, and Kashem M. Muttaqi. A review of topologies of three-port DC–DC converters for the integration of renewable energy and energy storage system. Renew. Sustain. Energy Rev. 2016; 56: 388-401. [14] Akar, Furkan, et al. A Bidirectional Nonisolated Multi-Input DC–DC Converter for Hybrid Energy Storage Systems in Electric Vehicles. IEEE Trans Vehicular Technol. 2016; 65(10): 7944-7955. [15] Liu, Fuxin, Zhicheng Wang, Yunyu Mao, and Xinbo Ruan. Asymmetrical half-bridge double-input DC/DC converters adopting pulsating voltage source cells for low power applications. IEEE Trans Power Electron. 2014; 29(9): 4741-4751. [16] Chen, Yen-Mo, Alex Q. Huang, and Xunwei Yu. A high step-up three-port dc–dc converter for stand-alone PV/battery power systems. IEEE Trans Power Electron. 2013; 28(11): 5049-5062. [17] Khosrogorji, S., M. Ahmadian, H. Torkaman, and S. Soori. Multi-input DC/DC converters in connection with distributed generation units–A review. Renew. Sustain. Energy Rev.. 2016; 66: 360-379. [18] Rashid, Muhammad H. Power electronics handbook: devices, circuits and applications. Academic press, 2010.