19-01-2016, 02:26 PM
ABSTRACT
TI’s comprehensive solar energy harvesting portfolio can deliver the entire solar system solution. A broad selection of analog, power management and microcontroller ICs are targeted at grid-tied central inverters, micro-converters and micro-inverters, as well as off-grid battery charging solutions, to maximize the power point and provide the highest possible system efficiency. DSP- and ARM®-based MCUs also provide system control and support communication technologies including power line communications (PLC), Ethernet, CAN bus, and low-power RF solutions such as ZigBee®. A variety of power management ICs can provide auxiliary bias supplies from either the DC or AC power rails.TI’s portfolio of high-performance analog ICs also provide ideal front ends for MPPT power sensing and power line communications; isolation to sensitive communications electronics; and relay drivers or power switches for islanding in systems requiring UL1741 compliance.
Central Inverter Solutions
Central, or “traditional”, inverters are centralized power control units that convert DC power from a string of 72-cell solar panels to AC power for use on the electrical utility grid. These are usually large scale commercial or residential systems producing in excess of 1 kW of power. Maximum power point tracking for the entire string is done only at the inverter box, which may also include relays to “island” the solar system from the grid.
Micro-Inverter Solutions
Central Inverter Solutions
Central, or “traditional”, inverters are centralized power control units that convert DC power from a string of 72-cell solar panels to AC power for use on the electrical utility grid. These are usually large scale commercial or residential systems producing in excess of 1 kW of power. Maximum power point tracking for the entire string is done only at the inverter box, which may also include relays to “island” the solar system from the grid. Micro-inverters operate similarly to central inverter systems, but are installed on each individual panel and handle much less
power, typically 300 W. Micro-inverters provide the benefit of scalability for those who want to start small, yet have full DC/AC conversion with MPPT, and expand later
Micro-Converter Solutions
Micro-converters maximize the DC power point of a single solar panel and convert (down or up) the DC voltage to be transported downstream to a centralized AC (grid-tied) inverter. Being located on each panel, these systems are lower power (typ. 300 W) than centralized converters. These are sometimes called “optimizers” because they optimize the power of each
panel, increasing the overall efficiency of the system.
Battery Charging Solutions
Off-grid solar power systems often need to charge a battery, or array of battery cells, that provide continuous power to the load when solar energy is no longer present. Often cost sensitive, in order to optimize the size, cost and usable power of the storage elements, off-grid systems also require that the power point be maximized. However, this can be done by employing, lower power and less complex MCUs than grid-tied systems or by employing a simple fixed power point – often set at 76% of VOC. Loads such as LED lighting and motors may require additional power boosting and/or control.