Interleaved DC-DC boost converter with built-in MPPT algorithm
Description
The SPV1020 is a monolithic 4-phase interleaved DC-DC boost converter designed to maximize the power generated by photovoltaic panels independent of temperature and amount of solar radiation.
Optimization of the power conversion is obtained with 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 the PV panels, replacing the bypass diodes. As 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 to minimize size, the SPV1020 embeds power MOSFETs for active switches and synchronous rectifiers, minimizing the number of external devices. In addition, the 4-phase interleaved topology of the DC-DC converter obviates the need to use electrolytic capacitors, which may severely limit system 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 from 50 kHz to 200 kHz, while the duty cycle can range from 5% to 90% with a step of 0.2%.
The safety of the application is guaranteed by stopping the drivers in the case of output overvoltage or overtemperature.
Multiple SPV1020s can be used in a panel array with one SPV1020 per panel. Panels can be connected in series, in parallel, or series/parallel combinations.
Features
■ PWM mode DC-DC boost converter
■ Duty cycle controlled by MPPT algorithm with 0.2% accuracy
■ Operating voltage range 6.5 - 40 V
■ Overvoltage, overcurrent, overtemperature protection
■ Interleaved 4-phase topology
■ Built-in soft-start
■ Up to 98% efficiency
■ Power capability 320 W at 40 V output
■ Automatic transition to burst mode for improved efficiency at low solar radiation
■ SPI interface
Applications
■ Photovoltaic panels
■ Battery charging with a CVCC controller
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