STEVAL-ISV003V2

250 W microinverter for plug-in PV panels (60 Hz version)

Data brief

Features

•

Input voltage range from 18 V to 45 V

•

Output voltage range from 110 V to

240 V AC, 60 Hz

•

Grid connection algorithm and MPPT

capability

•

Digital control section managed by the

STM32

•

RS-232 for communication

•

RoHS compliant

Description

The STEVAL-ISV003V2 is a demonstration board

which implements the microinverter concept and

is designed to optimize the power production of

each single solar panel by means of DC-AC

conversion. The conversion system is capable of

both grid synchronization and maximum power

point tracking (MPPT) thanks to the use of an

advanced control algorithm implemented on a

32-bit STM32 microcontroller. The MPPT function

is based on the perturb and observe (P&O)

concept which seeks the best operating point of

the panel, thus maximizing the energy produced

in every environmental condition. The grid

synchronization algorithm has the advantage

over standard solutions of a decoupled control of

active and reactive power. The STEVAL-

ISV003V2 demonstration board uses a high-

frequency (HF) isolated DC-DC converter with

interleaved current and an optimized full-bridge

DC-AC inverter. The typical solar panel voltage is

first stepped up to about 400 V and then

converted into AC to create a sinusoidal output.

An LED display provides a user-friendly interface

for the end user and allows monitoring and/or

modifying some of the main operating

parameters. Two modes of operation are

available and can be selected for the STEVAL-

ISV003V2 to allow either open-loop or closed-

loop operation in synchronization with the grid. In

open-loop mode the sinusoidal reference is

created internally by means of a standard lookup

table, while in closed-loop mode a sinusoidal

voltage feedback proportional to the gird voltage

is used. Finally, the RS-232 interface can be

used for serial data transfer of specified voltage,

current, and current signals.

April 2014

DocID025856 Rev 1

1/4

For further information contact your local STMicroelectronics sales

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