{"id":117648,"date":"2023-08-16T13:58:41","date_gmt":"2023-08-16T11:58:41","guid":{"rendered":"https:\/\/www.velasolaris.com\/handbuch\/systems\/"},"modified":"2025-10-14T17:34:04","modified_gmt":"2025-10-14T15:34:04","slug":"systems","status":"publish","type":"handbuch","link":"https:\/\/www.velasolaris.com\/en\/handbuch\/polysun-designer\/electric-components\/systems\/","title":{"rendered":"Systems"},"content":{"rendered":"\n
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Photovoltaic System Design: Grid & Off-Grid Solutions<\/h1>\n\n\n\n

A photovoltaic system is a key component of modern energy supply, whether as a grid-connected PV system with feed-in capabilities or as a standalone off-grid PV system. Polysun supports planners and engineers with realistic simulations that reflect the specific characteristics of both system types. The focus is on precise photovoltaic system design, including the sizing of PV modules, inverters, and the integration of energy storage and consumers. This enables Polysun to provide critical insights for optimizing self-consumption, grid feed-in, and supply reliability across various application scenarios.<\/p>\n\n\n\n

Grid-Connected PV Systems<\/h2>\n\n\n\n

The project can be started from the menu Project \u2013 New project or by means of the Wizard.<\/p>\n\n\n\n

In the Wizard first the location has to be defined either from the map or from the database. After the location has been defined, in the next step you can choose the criteria for the PV grid-connected system and the corresponding system template.<\/p>\n\n\n\n

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Figure: choosing a PV system template<\/figcaption><\/figure>\n<\/div>\n\n\n\n

In the drop-down menus, you can first choose in the upper left side of the dialog window what kind of energy providers you would like to have in your project. Here you can choose one or more types of providers.<\/p>\n\n\n\n

\u2018Yes\u2019 means this energy provider must be in the system.<\/p>\n\n\n\n

\u2018No\u2019 means this energy provider must not be in the system.<\/p>\n\n\n\n

\u2018N\/a\u2019 (not applicable) means that this type of energy provider is not a criterion for the selection of the system (the list will show systems with and without this component).<\/p>\n\n\n\n

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Figure: choosing photovoltaics as an energy provider<\/figcaption><\/figure>\n<\/div>\n\n\n\n

Next you will have to define the type of energy consumers\/loads available for your project:<\/p>\n\n\n\n

As a next step, the system specification can be defined as follows:<\/p>\n\n\n\n

Table: Photovoltaic systems specification<\/p>\n\n\n\n

System specification<\/strong><\/td>Types<\/strong><\/td><\/tr>
System size<\/strong><\/strong><\/td>Residential system
Commercial system<\/td><\/tr>
Collector\/Generator field<\/strong><\/td>Single field
Several fields<\/td><\/tr>
Template source\/company<\/strong><\/strong><\/td>All standard templates
All company templates<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
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Figure: choosing system specification<\/figcaption><\/figure>\n<\/div>\n\n\n\n

Then the templates will be shown on the right side of the dialog window filtered in accordance to the defined parameters. The pre-view of the template is available, when you hover the mouse cursor over the template name. You can choose the most appropriate template by double-clicking on it. If there aren\u2019t any templates which meet all the requirements of your system, then you can choose the closest one and change it accordingly.<\/p>\n\n\n\n

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Figure: selection of the template<\/figcaption><\/figure>\n<\/div>\n\n\n\n

When the template is chosen, in the next step the appropriate grid configuration, nominal voltage and nominal frequency can be defined from the catalog.<\/p>\n\n\n\n

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Figure: selection of the electrical grid from the catalog<\/figcaption><\/figure>\n<\/div>\n\n\n\n

Then the \u2018Maximum phase-load imbalance\u2019 according to the local parameters as well as \u2018cos \u03c6\u2019 shall be determined. The maximum phase-load imbalance is important for 1-phase and 2-phase inverters, when the load must be balanced.<\/p>\n\n\n\n

\u2018Cos \u03c6\u2019 is the ratio between real power and apparent power (called also power factor) to a constant value. The default value is cos \u03c6 = 1 which means no reactive power. The usable power is an active power. A certain degree of reactive power cannot be avoided in AC grids. The grid operator may demand to set cos \u03c6 between 0.95 and 1 in order to avoid high additional load, which cannot be used to power electrical devices. Reactive power leads also to greater conduction losses.<\/p>\n\n\n\n

\u2018Maximum real power\u2019 is a limitation of active power related to the peak power. The photovoltaic power station may feed into the grid not more real power than the indicated peak power fraction. The purpose of the power limitation is to avoid feed in high midday peaks.<\/p>\n\n\n\n

\u2018Limitation type\u2019 can be \u201cbefore consumption\u201d and \u201cafter consumption\u201d. \u201cBefore consumption\u201d means limitation of the inverter power independently from self-consumption or battery charging. \u201cAfter consumption\u201d means limitation of the inverter power taking into account self-consumption or battery charging. In this case the charge controller has to be used for power limitation.<\/p>\n\n\n\n

If the \u2018Unlimited\u2019 option is ticked, then it is not important for the system.<\/p>\n\n\n\n

In the next step of the Wizard the PV Generator can be specified. You can find more detailed information about photovoltaic modules and their parameters in the section PV Modules<\/a> and Parameters PV Modules<\/a> of this User Guide.<\/p>\n\n\n\n

The module type can be chosen from the catalog.<\/p>\n\n\n\n

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Figure: selection of the PV module from the catalog<\/figcaption><\/figure>\n<\/div>\n\n\n\n

The important parameters for PV module disposition are as follows:<\/p>\n\n\n\n