EGLM06: 23-24 Assignment-1: Solar energy battery charger circuit design The objective of this assignment is to design a solar energy battery charge circuit to charge a 48V, 100 Ah Lithium-Ion battery with maximum power from PV array for given conditions. The reference charging circuit is shown in Figure 1. Under standard condition, the PV array need to output voltage around 150 V and output current around 15 A. PV Array Ipe MPPT IGBT/MOSFET Module data Module: A10Green Technology A101-M60-220 Maximum Power (W) 219.876 Open circuit voltage Voc (V) 36.06 Vpr Voltage at maximum power point Vmp (V) 30.12 Temperature coefficient of Voc (%/deg.C) -0.3624 L Diode PWM PV voltage controller C₂ 18at Vat Figure 1 Green Technology A10J-M60-220 solar modules are employed for the PV array. The PV module parameters are shown in Table below: (MATLAB Library) The battery parameter is shown in Table below (MATLAB Library) 48 V Battery Bry Cells per module (Ncell) 60 Short-circuit current Isc (A) 7.95 Current at maximum power point Imp (A) 7.3 Temperature coefficient of Isc (%/deg.C) 0.054805/nNominal voltage (V) 48 Rated capacity (Ah) 100 Initial state-of-charge (%) 50 Battery response time (s) 30 1: PV array electrical characteristics analysis 1.1 Determine PV array configurations and the number of PV modules required. 1.2 Based on the function provided in "Display-V and P-V characteristics" (double clicking the PV array symbol). (1) Plot the I-V and P-V curves of the PV array under different solar irradiance: S = 200W/m², 600W/m², and 1000W/m², respectively. (The cell temperature remains at constant temperature of 25 °C) (2) Use the Data Cursor to record Voc Is Vmax Pmax, for each solar irradiance and fill Table-1 (3) Comment on the effect of solar irradiance on short circuit current Isc and open- circuit voltage Voc as well as Pmax. Irradiation (W/m²) 200 600 1000 Table-1 Isc (A) Voc (V) Temperature (°C) 25 45 65 Vmax (V) (1) Plot the I-V and P-V curves of the selected PV panel under different cell temperature: T= 25°C, 45°C and 65°C, respectively. (The solar irradiance remains at constant irradiance of 1000W/m²). Ise (A) Voc (V) Imax (A) (2) Use the Data Cursor to record VoccVmaxPmax for each s and fill Table-2. (3) Comment on the effect of temperature on short circuit current Ise and open-circuit voltage Voc as well as Pat constant irradiation of 1000(W/m²). Table-2 Vmax (V) Pmax (W) Imar (A) Pmax (W)/n2: Design the solar energy battery charger circuit. The battery charging circult specification and operating conditions are shown in the Table 2.1 below: PV array rated output voltage PV array rated output current Peak to peak value of the battery ripple voltage Peak to peak value of the battery ripple current Buck converter PWM switching frequency C₁ Battery rated voltage 150.6 V 14.6 A 60 mV 2 A 20kHz 100 μF 48V Table 2.1 Initial Battery state of the charge Duration of charging Solar irradiance between 0 to 1 second Solar irradiance between 1 to 2 second Solar irradiance between 2 to 3 second 50%. 3 seconds 200 (W/m²). 1000 (W/m²). Ambient temperature of 25 °C solar array 600 (W/m²). 2.1 Based on the specification and operating conditions specified in Table 2.1. (1) Design a suitable inductance of the output inductor of the buck dc-dc converter so that maximum peak-peak value of inductor output ripple current less than 2A. (2) Design suitable capacitance value for output capacitor C₂ so that the Peak-to- peak value of the battery ripple voltage less than 60 mV. (3) Specify suitable control parameters for the MPPT and controller. (4) Present all above circuit and circuit description. 2.2 Based on above specification and conditions, design and develop the simulation circuit of solar energy battery charger so that the maximum possible solar energy from the PV array can be charged into the battery for the given solar irradiance conditions. (1) Design and develop the buck dc-dc converter circuit for the PV charger system. (2) Design a maximum power point tracking (MPPT) algorithm, voltage controller as well as the PWM generation circuit for the buck dc/dc converter charging circuit so that the PV array can always output at its maximum power for the given conditions. 2.3 The solar irradiance is set as: from 0 to 1 second - 200 (W/m²), 1 to 2 second - 600 (W/m²), from 2 to 3 second - 1000 (W/m²), carry out the simulation for 3 seconds./n2.5 Simulation results and analysis: (1) Present the output voltage, output current and output power waveform of the PV Array. Comment on PV array output voltage, current and power. Is the PV array output voltage, current and power expected? (2) Comment on the performance of MPPT controller and effect on the PV output voltage, current and power. Estimate the MPPT efficiency by comparing the theoretical values in Task-1. (3) Present the duty cycle as well as PWM waveforms and estimate the duty cycle in steady-state operation of the buck converter. (4) Present the battery input voltage and current waveforms. Comment on the value and quality of battery charging voltage and current. is simulated voltage and current waveforms of the battery expected? 2.6 If the IGBT switch is implemented by using IKW30N60H3 IGBT device (Data sheet uploaded in canvas/Assignment Overview), estimate the IGBT power loss under solar irradiance of 1000 (W/m2) condition and calculate the percentage of this power loss against the power delivered. (Estimation method should be provided). 3. Conclusion 4. Reference Report Submission: A coursework report based on the work in Task 1 and 2 is needed to submitted after you complete the circuit design and simulation. The report should be typed and submitted as a portable document in PDF format. The report should not be more than 15 pages in single column format. Clearly state your student number on the cover page of your report. Submission method: The assignment report should be uploaded in a single document in PDF to the EGLM06 Energy and Power Electronics Laboratory on Canvas.

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