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April 2012

Doc ID 023149 Rev 1

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STEVAL-ISV018V1

300 W PV converter to be integrated into a photovoltaic panel based

on SPV1020 and bypass diodes SPV1001N30 and SPV1001N40

Data brief

Features

0.2% accuracy

protection

improved efficiency at low solar radiation

Description

The STEVAL-ISV018V1 demonstration board

contains three SPV1020s in the same PCB and is

suitable for distributed PV panels with 3 isolated

strings. The outputs of the SPV1020s can be

connected in parallel or in series, despite the

pairs of independent inputs.

The STEVAL-ISV018v1 default setting is output

series connection.

The SPV1020, is a monolithic DC-DC boost

converter designed to maximize the power

generated by photovoltaic panels independent of

temperature and amount of solar radiation.

The optimization of the power conversion is

obtained with an embedded logic which performs

the MPPT (max power point tracking) algorithm

on the PV cells connected to the converter.

One or more converters can be housed in the

connection box of PV panels, replacing the

bypass diodes and, thanks to the fact that the

maximum power point is locally computed, the

efficiency at system level is higher than that of

conventional topologies, where the MPP is

computed in the main centralized inverter.

For a cost effective application solution and the

meeting of miniaturization needs, the SPV1020

embeds the power MOSFETs for active switches

and synchronous rectification, minimizing the

number of external devices. Furthermore, the 4

phase interleaved topology of the DC-DC

converter allows the use of electrolytic capacitors

to be avoided, which could severely limit the

lifetime.

It works at fixed frequency in PWM mode, where

the duty cycle is controlled by the embedded logic

running a Perturb and Observe MPPT algorithm.

The switching frequency, internally generated and

set by default at 100 kHz, is externally tunable,

while the duty cycle can range from 5% to 90%

with a step of 0.2%.

Safety of the application is guaranteed by

stopping the drivers in the case of output

overvoltage or overtemperature.

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