How to determine and configure voltage: The new process

In this support article, you will find an in-depth description of the significance of the parameter voltage in energy management services. Additionally, it provides insights into the adjustments required for configuring voltage and highlights the differences from the previous approach. 

TLDR: To ensure the proper functioning of charge points with diverse energy services, the voltage parameter is essential. Previously, voltage configuration was performed at a group-level in EnergyUI. However, in the new process within the Virta Hub, voltage will be configured at a pool-level. Until the pool-level voltage value has been set (automatic for countries that have only one grid voltage, otherwise has to be set by a user) for the associated charge points, the Virta Hub will persist in using the group-level values.

Why is this relevant & what is voltage used for?

There are some variables to consider when subjecting charging points to energy management services. These variables may differ from site to site or from country to country. In many cases, the charging points themselves are not able to provide the needed information, thus preventing the automatic configuration of the charging points. 

The user can specify parameters that are specific to the charging point, including setting the maximum power of a single charging point and determining whether the installation is 1-phase or 3-phase. Furthermore, the user can also configure the voltage, which is a parameter specific to the site. By making the before-mentioned parameters configurable by the user, the energy management services provided by Virta can be dynamically localized from country to country and from site to site.

• Voltage: The voltage range changes from country to country. Some countries may even have several voltage ranges in their electricity infrastructure.
• The number of connected phases: Some sites may consist of 1-phase installations, some of 3-phase installations, and some may consist of both. The number of installed phases will have a significant effect on the power output of a station (especially in terms of AC stations). 
• Maximum power: In most cases, the only option to control an AC charging point’s power is by configuring the maximum allowed current. Therefore, the maximum power (defined in Old Admin Panel) is first converted to current, and then a request is sent to a charging point to adjust its maximum allowed current. It's important to note that in OCPP 1.6, it is not possible to control the electric current individually per phase. Hence, the current adjustment is applied uniformly across all phases.

When subjected to energy services, the backend’s conversion logic will always use these parameters in calculating new payloads to charging points, e.g., when restoring them back to “full” power.

-- This article focuses specifically on voltage, and how users can determine the pool voltage and, in certain scenarios, configure it -- 

Configuring voltage is not a new thing - What has changed?

Previously, the parameter "voltage" was configured for a group of charging points in EnergyUI. However, as we gradually migrate our energy services to the Virta Hub, we will disable this parameter in EnergyUI and introduce it instead in Virta Hub as a configurable parameter of a pool. The key difference is that an energy group in EnergyUI is different from a pool. For instance, there could be an energy group in EnergyUI that consists of charging points from several pools in the Virta Hub. Therefore, one must ensure that the "voltage" parameter is correctly configured for all relevant pools. 

Another important distinction is that the voltage options that are available depend on the country where the organization is located, and in some countries, there may only be a single option to select from. If the pool is situated in a country that operates solely on a particular voltage range, the pool will be automatically assigned that value. The voltage options that are specific to each country are obtained from IEC; a database maintained by the International Electrotechnical Commission.

Determining the pool voltage and configuring it in 

• After logging in, navigate to the pool view of the pool you want to configure.
• Scroll down until you see a section called Technical installation.
• You will see the applied voltage in the field called Pool voltage.

Countries with one option for voltage: 

In case the country where the pool is located only has one option for voltage, the parameter appears as “locked”: The user cannot change it. 

Countries with several options for voltage: 

In case the country where the pool is located operates on several voltage ranges, the user must choose the proper option.