Capacitor Bank Monitoring and Control

Remote control of distribution capacitors can be used to better optimize the system power factor, release system capacity and improve voltage regulation.

Telemetric offers two options for capacitor bank monitor and control:

• The TC012 for basic monitoring and control;
  
• The DNP-RTM (Remote Telemetry Module) for communication with a capacitor bank control such as the EnergyLine 1000 or IntelliCAP PLUS.

The Telemetric TC012 MicroRTU is specifically configured to monitor and control fixed or switched capacitor banks. One of several application-specific configurations of the general purpose T646, the TC012 provides capacitor bank control through two 30 Amp relays and capacitor bank monitoring through an analog input sensor that converts the 0-100 Amp capacitor bank neutral current to a 0-10 Volt AC signal. It is designed for outdoor environments, and operates from AC power.

The Telemetric DNP-RTM is a communication solution for remote monitoring and control of Intelligent Electronic Devices (IEDs) that support the DNP3 protocol. The DNP-RTM continuously polls the connected IED through a local serial connection. When a reportable change is detected, the DNP-RTM transmits an event report via the cellular network. This minimizes communication costs while providing near real-time information. The user can also send commands to the RTM, which are transferred to and immediately carried out by the IED. The RTM sends back an acknowledgement that the IED received and responded to the command.

Telemetric currently offers DNP-RTM integration kits for the EnergyLine 1000 series and the Energyline IntelliCAP PLUS. Click here to see a complete list of DNP-RTM integrations.

Many remote capacitor bank controls are based on one-way pager or radio systems and do not provide direct confirmation that the control signal was received or implemented. In these systems, the resulting VAR must often be monitored at the substation in an effort to confirm that the correction was made.

The Telemetric products offer several functional advantages over other products:

• System reliability is improved by a direct, positive confirmation that the capacitor bank was actually switched on or off line.
  
• A two-way communications path provides valuable feedback when a local voltage-based override condition exists.
  
• The TC012 neutral current monitoring feature provides additional valuable data about the cap bank. For example, a neutral current of zero indicates that the installation is switched out of service. Normal neutral current (a nominal value above zero) when the bank is closed indicates the bank is switched in service and the installation is operating as expected. A neutral current that is higher than average but below a predefined limit indicates the presence of high harmonic current or resonant conditions, which may indicate a partial pack failure. A higher, pre-defined level of current indicates a blown fuse or other serious problem.
  
• Communication coverage provided by the analog cellular coverage exceeds that of any other wireless network in North America.