ST公司的STEVAL-ISV008V1是采用SPV1020的300W光伏電池轉換器,是PWM模式的DC/DC升壓轉換器,工作電壓0-40V,效率高達98%,MPPT算法占空比控制精度0.2%,內置軟起動,具有過壓,過流和過溫保護,RoHS兼容.本文介紹了SPV1020主要特性,方框圖,應用電路以及STEVAL-ISV008V1評估板主要特性,方框圖,電路圖和材料清單.
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應用:
Photovoltaic panels
圖1. SPV1020簡化方框圖
圖2. SPV1020應用電路圖
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
圖3.STEVAL-ISV008V1評估板外形圖
圖4.STEVAL-ISV008V1方框圖
圖5.STEVAL-ISV008V1評估板電路圖
STEVAL-ISV008V1評估板材料清單:
詳情請見:
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
