Short-string parallel-DC optimizer for photovoltaic systems

#This disclosure relates generally to optimized photovoltaic systems. More specifically, the system disclosed herein relates to optimizing a short-string of photovoltaic panels to produce a consistent, reliable, and efficient source of power on residential rooftops.

#Photovoltaic systems convert solar energy into direct current electricity. A simple photovoltaic system may include a solar panel and a power inverter. As the solar panel in the simple photovoltaic system absorbs solar energy, the solar panel creates direct current electricity. The solar panel is typically connected to a power inverter to convert the direct current electricity into alternating current electricity to power electrical devices.

#Conventional photovoltaic systems have several drawbacks. First, conventional photovoltaic systems require that each solar panel in a string of solar panels maintain the same azimuth. For example, in the United States, each solar panel in a string of solar panels should face south to absorb the maximum amount of solar energy available. However, on a residential rooftop, for example, space on south facing portions of a roof may be limited such that a homeowner cannot install a meaningful number of solar panels on a rooftop. For example, a rooftop on a residential home may be constructed with a hip roof (or a variant thereof), gables, or other vertical sides that prevent installation of one or more solar panels on a south facing portion of a rooftop. Homeowners with rooftops that limit solar panel installation on the desired azimuth are unable to efficiently take advantage of conventional photovoltaic technology.

#The accompanying drawings illustrate several embodiments of the short-string parallel DC optimizer for photovoltaic systems and constitute a part of the specification. The illustrated embodiments are exemplary and do not limit the scope of the disclosure.

#FIG. 1 illustrates a traditional string topology for a photovoltaic system.

#FIG. 2 illustrates an optimized string topology for a photovoltaic system.

#In the following description, for purposes of explanation and not limitation, specific techniques and embodiments are set forth, such as particular techniques and configurations, in order to provide a thorough understanding of the device disclosed herein. While the techniques and embodiments will primarily be described in context with the accompanying drawings, those skilled in the art will further appreciate that the techniques and embodiments may also be practiced in other similar devices.

#Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used throughout the drawings to refer to the same or like parts. It is further noted that elements disclosed with respect to particular embodiments are not restricted to only those embodiments in which they are described. For example, an element described in reference to one embodiment or figure, may be alternatively included in another embodiment or figure regardless of whether or not those elements are shown or described in another embodiment or figure. In other words, elements in the figures may be interchangeable between various embodiments disclosed herein, whether shown or not.

#FIG. 5 illustrates an exemplary optimized short-string topology photovoltaic system 500. Photovoltaic system 500 includes a plurality of solar panels 505a, 505b, 505c, 505d, 505e, 505f, 505g, 505h, 505n-3, 505n-2, 505n-1, and 505n. Solar panels 505a-505n are organized into n short-strings of four solar panels each. Although twelve solar panels and three short-strings are shown in FIG. 5 for convenience of explanation (four solar panels per short-string), photovoltaic system 500 could implement any number of solar panels and any number of short-strings including more or fewer than what is shown in FIG. 5. A short-string is defined herein as meaning a string of between two and four solar panels connected in a series electrical connection.