Achieving Power System Balance

A small utility in Tennessee installed a complete automated power factor balancing system without complex SCADA. The integrated power balancing system includes capacitors, a capacitor bank controller, circuit breakers, and a controlling RTU.

All monitoring, control, visualization, and security of the integrated utility power balancing system is provided by the OrionLX Substation Automation Platform by NovaTech Automation, a substation automation company that has served the power transmission and distribution market for over 30 years. The OrionLX is a communication and automation processor that can be integrated with practically any equipment, usually microprocessor-based relays, meters, and other IEDs as well. It can connect to SCADA system or itself be a basic SCADA system.

The system uses open-source web technologies and pre-configured template pages. This simplifies the building of interactive SCADA and local HMI screens to view data from connected IEDs and RTUs using standard web browsers. Engineers can open multiple browsers to have graphical interfaces for the different substations and key remote monitoring features on different tabs, which eases network monitoring. Multiple users can be logged in simultaneously.

“With the substation automation platform, the utility did not need a dispatcher for PF balancing, only a supervisor to oversee the facility,” says Ryan McAuliffe, NovaTech Sales Engineer. 

The platform’s System Balance scheme helps to ensure that each substation maintains a 1.000 power factor. The scheme will initialize values and then load all previous retentive values or default values if there are no retentive values. With the scheme, an overall leading power system state will turn off one or more capacitors, and an overall lagging power system state will turn on one or more capacitors, providing alerts and control.

To ensure that individual feeders are in balance and within tolerance, a second logic scheme has been proposed for Individual Feeder Balance that will run every five minutes after completion of the primary scheme. This is needed due to the configuration of the utility’s distribution network assets. Although total substation power factor can be balanced, it is possible to have two feeders out of balance in the condition of one lagging and one leading. The second scheme looks at individual feeder power factor tolerance and makes corrections as needed. 

Together, the primary and secondary balancing schemes provide integrated Volt-VAR regulation and optimization. The schemes automatically switch capacitor banks in and out to maintain power factor very close to balance, summing PF on each feeder and comparing it with the metered value reported to the power provider. The automation includes features to reduce wear and maintenance such as never switching the same capacitor bank twice in a row.

The system maintains the ability to manually control all capacitor banks and provides web-based HMI for monitoring and control of breakers and IEDs in substations.

For the utility, the power balancing schemes are extremely beneficial. The schemes have reduced the labor required to monitor the distribution grid, and the utility has maintained almost full power factor compliance with the Transmission Network Operator.

For more information on SCADA solutions from NovaTech Automation, visit:

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