1. Photovoltaic Systems Engineering Session 11
SEC598F18
Photovoltaic Systems Engineering
Session 11
Electronic Control Devices (ECDs), Part 2
Inverters
October 03, 2018

2. Session 11 content Inverters Purpose, utility
Operation, reliability, failure mechanisms

3. Learning Outcomes
Introduction to the power electronics used in PV systems
Recognition of the importance of controllers and inverters to the operation of certain PV systems

4. PV Systems - MPPT
Representative electrical loads

5. PV Systems - MPPT An approach to assuring a better match is the use of
Maximum Power Point Tracking (MPPT) – an electronic technique
that moves the operating point along the maximum power
hyperbola (I * V = constant) associated with the PV array until it
intersects the electronic load I-V characteristic

6. PV Systems - MPPT
IMPPT
Imp
VMPPT
Vmp

7. PV Systems - MPPT
Imp
IMPPT
MPPT
Vmp
VMPPT

8. PV Systems - MPPT Perturb and Observe
PV operating points from P&O algorithm
N.Fermia et al., Power Electronics and Control Techniques for Maximum
Harvesting in PV Systems

9. PV Systems - MPPT Perturb and Observe Time domain behavior
N.Fermia et al., Power Electronics and Control Techniques for Maximum
Harvesting in PV Systems

10. PV Systems - MPPT
Perturb and Observe
P&O flowchart

11. PV Systems - MPPT Perturb and Observe
N.Fermia et al., Power Electronics and Control Techniques for Maximum
Harvesting in PV Systems

12. PV Systems - Inverters
The inverter is the essential electronic system that converts the DC electrical output from the PV array into the AC electrical input for the residence, national electrical grid, and so on
INVERTER
DC input
AC output

13. PV Systems - Inverters
Heart of the inverter – the “H-bridge”

14. PV Systems - Inverters
The H-bridge in operation

15. PV Systems - Inverters The output of the inverter is controlled
by pulse width modulation (PWM)

16. PV Systems - Inverters State of the Art Inverters:
High efficiency – 98% or higher
Dual independent MPPT systems
Integrated DC disconnect and combiner inputs
No fans or electrolytic capacitors

17. PV Systems - Inverters
J.M.Jacob, Power Electronics: Principles and Applications