基于SPV1020设计的太阳能电池DC-DC电源转换方案

SPV1020是ST 公司的内置了MPPT算法的PWM模式DC/DC升压转换器，能最大化太阳能电池板所产生的能量，不受温度和太阳辐射的影响。MPPT算法精度在0.2%，工作电压0-36V，具有过压，过流和超温保护，内置了软起动，效率高达98%。本文介绍了SPV1020主要特性，方框图和应用电路。

Interleaved DC-DC boost converter with built-in MPPT algorithm SPV1020 is a monolithic DC-DC boost converter designed to maximize the power generated by photovoltaic panels independently 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 will be higher than the one of conventional topologies, where the MPP is computed in the main centralized inverter.

For a cost effective application solution and miniaturization needs, 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 to avoid the use electrolytic capacitors, which would 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&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 case of output over-voltage or overtemperature.

SPV1020主要特性：

■ PWM mode DC-DC boost converter

■ Duty cycle controlled by MPPT ALGORITHM with 0.2% accuracy

■ Operating voltage range 0-36 V

■ Overvoltage, overcurrent, overtemperature protections

■ Built in soft-start

■ Up to 98% efficiency

■ Automatic transition to burst mode for improved efficiency at low solar radiation

■ SPI interface

SPV1020应用：

■ Photovoltaic panels

图1。SPV1020简化方框图

图2。SPV1020应用电路