ST公司的STEVAL-ISV008V1是采用SPV1020的300W光伏电池转换器,是PWM模式的DC/DC升压转换器,工作电压0-40V,效率高达98%,MPPT算法占空比控制精度0.2%,内置软起动,具有过压,过流和过温保护,RoHS兼容.本文介绍了SPV1020主要特性,方框图,应用电路以及STEVAL-ISV008V1评估板主要特性,方框图,电路图和材料清单.

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 overvoltage 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 0-45 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应用电路图

The STEVAL-ISV008V1 demonstration board contains 3 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 (STEVAL-ISV008v1 default setting) or in series, despite the pairs of independent inputs. For the STEVAL-ISV008v1 only the output parallel connection is allowed.

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 embedded logic which performs the MPPT (maximum power point tracking) algorithm on the PV cells connected to the converter.

One or more converters can be housed in the connection box of the PV panels, replacing the bypass diodes and, because 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 miniaturized system, 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 avoids the use of electrolytic capacitors, which would severely limit the lifetime.

The SPV1020 operates 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 adjustable. The duty cycle can range from 5% to 90% with a resolution of 0.2%. Safety of the application is guaranteed by stopping the drivers in the case of output overvoltage or overtemperature.

STEVAL-ISV008V1主要特性:

■ PWM mode DC-DC boost converter

■ Duty cycle controlled by MPPT algorithm with 0.2% accuracy

■ Operating voltage range 0-40 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

■ RoHS compliant

图3.STEVAL-ISV008V1评估板外形图

图4.STEVAL-ISV008V1方框图

图5.STEVAL-ISV008V1评估板电路图

STEVAL-ISV008V1评估板材料清单:


详情请见:
http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/DATASHEET/CD00275733.pdf
和
http://www.st.com/internet/com/SALES_AND_MARKETING_RESOURCES/MARKETING_PRESENTATIONS/PRODUCT_PRESENTATION/stforsolarenergy_marketing_pres.pdf