PV Systems - Components and Concepts Maximum Power Point Tracking - PowerPoint PPT Presentation

PV Systems - Components and Concepts Maximum Power Point Tracking (MPPT) Week 7.3 Arno Smets

Generic I-V curve of a solar cell P MPP I SC Current I Power P Maximum Power Point (MPP) V OC Voltage V

PV cell, module and array Connection in series Connection in parallel A v  voltages add up  currents add up v 3I SC A 9 Cells current (A) Cells current (A) 8 3 2I SC 7 6 2 5 1 I SC 4 V OC 2V OC 3V OC 3 2 0.4 0.8 1.2 1.6 2.0 0 V OC 1 Cell voltage V (V) 0 0.1 0.2 0.3 0.4 0.5 0.6 Cell voltage V in V

Generic I-V curve of a PV module Irradiance G I SC Temperature T Current I V OC Voltage V

PV module – operating point I SC (I,V) Temperature T Irradiance G Current I V OC Voltage V

PV module – PV curve P MAX (I,V) I SC   Current I Power P P V I (P,V) V OC Voltage V

PV curve - MPPT P MPP I mpp Current I Power P Maximum Power Point (MPP) V mpp Voltage V

PV module – Need for MPPT P MPP I mpp P’ MPP Current I Power P V mpp Voltage V

Fixed Voltage MPPT Techniques Method Indirect Fractional Open Circuit Voltage MPP Method Tracking Perturb and Observe Method Current I Power P Incremental Direct Conduction Method Voltage V

MPPT – Fixed Voltage Method P MPP winter P MPP summer Current I Power P Constant irradiance Voltage V

MPPT – Fractional Open Circuit Voltage P MPP I mpp P’ MPP Current I I’ mpp Power P   V k V mp p oc V mpp V OC V’ mpp V’ OC Voltage V

Addition of a pilot PV cell P MPP I mpp P’ MPP Pilot cell Current I I’ mpp Power P Module V mpp V’ OC V OC V’ mpp Voltage V   V k V mp p oc

MPPT – Perturb and Observe P MPP Current I Power P Voltage V

MPPT – Perturb and Observe - Drawback P MPP P’ MPP A Current I Power P B P A > P B Voltage V

MPPT – Incremental Conductance d P d P I SC dV  dV  0 0 I mpp Current I Power P d P dV  d P 0 dV  0 V OC I  V mpp Conductance V Voltage V

MPPT – Incremental Conductance    d P d I V ( ) I I  At MPP  dV d V V V   I I  d P V d I   I To the left of MPP  V V dV dV   I I  To the right of MPP V V

MPPT – Incremental Conductance   I SC I I    I I V V I mpp  V V   Current I I I Power P  V V V OC V mpp Voltage V

Incremental Conductance Algorithm V(t), I(t), V ref (t) Δ I = I t -I t-1 Δ V = V t -V t-1 < >  Increase Decrease I I  ?  V ref V ref V V = Maintain V ref RETURN

MPPT – Incremental Conductance   I SC I I    I I V V I mpp  V V   Current I I I Power P  V V V OC V mpp Voltage V

MPPT – Hardware Implementation BUCK BOOST DC-DC CONVERTER

MPPT – Products Steca Solarix MPPT Charge Controller Steca Grid 500 MPPT Inverter

MPPT – Summary P MPP I SC Current I Power P Maximum Power Point (MPP) V OC Voltage V

Thank you for your attention!