Customer service and satisfaction may be impacted when a utility has to rely on trouble calls from its customers to notify them of power disturbances. This was the situation at Kansas City Power & Light (KCP&L) where they use a 34-kV subtransmission system to deliver power to approximately 50 rural 34/12-kV substations. These substations and associated distribution lines had no automation and no communication infrastructure. KCP&L (Kansas City, Missouri, U.S.) operators typically relied on trouble calls from customers on circuits with particular equipment such as reclosers or regulators to diagnose the extent of their problems. Consequently, KCP&L began researching solutions with Telemetric (Boise, Idaho, U.S.) that would provide low-cost communication to widespread areas of its rural system.

Telemetric uses the digital control channel of the cellular network to provide reliable, secure, cost-effective wide-area coverage. The company's solution uses existing cellular towers and radio systems, reducing utility infrastructure investment and maintenance cost.

Telemetric was in the design stages of this project and welcomed KCP&L's efforts to co-fund the initiative. KCP&L's project assisted Telemetric in the development and enhancement of the following:

• A low-cost remote telemetry module (RTM) for monitoring and control of any DNP 3.0-compliant intelligent electronic device (IED).

• A low-cost capacitor monitor/control device with a self-contained radio.

• A Web-based graphic user interface (GUI).

• A secure virtual private network (VPN) link to SCADA.

KCP&L also provided engineering, testing and support for the product application. Telemetric provided a flexible base product and a path for technology advancement. KCP&L influenced the product development and ensured its needs and the needs of the utility industry were satisfied.

Development of the RTM

The RTM frequently polls the IED locally through a local serial connection. The RTM is configured to read selected analog and digital values and provide control functions. Telemetric embeds digital and analog data into a 25-digit cellular packet. For digital points, up to 69 digital status values fit in a single packet. The RTM can automatically initiate a call (unsolicited report by exception) when a digital or analog value changes for a configurable magnitude and amount of time. Therefore, the RTM uniquely supports features such as analog dead-band reporting, even if the IED does not.

The RTM development for each IED included the design of a hardware integration kit to facilitate the communications connection. This kit includes provisions for mounting the RTM in the IED, providing 12 Vdc to the RTM, a communications cable to pass the DNP protocol between the RTM and the IED, and the antenna connection. Integrations were developed for S&C capacitor controls, Siemens regulator controls and Nu-Lec recloser controls.

By installing the RTM within the existing enclosure of the IED, issues such as surge suppression and environmental integrity were minimal.

KCP&L soon learned the configuration of these devices was effectively “plug-and play.” KCP&L was able to quickly configure the controls and deploy them without needing comprehensive understanding of DNP protocols for these devices. This allowed KCP&L to gain valuable operating experience with the automated controls early in the project. KCP&L discovered a few anomalies in the IED control software before many were deployed.

The RTM solution uses the Telemetric website to display information from each device in summary and individual format. Multiple levels of access with passwords enable KCP&L to securely manage authorized users, including control functionality such as opening and closing devices through the DNP-related commands.

Appropriate personnel are automatically notified by e-mail or pager when alarms occur.

RTM Solution Promptly Put to Use

KCP&L used the RTM to satisfy the needs of the city of Baldwin, Kansas, U.S., which funded a project to provide an alternate 34-kV feed into its substation. The project called for reclosers with the ability to automatically isolate the normal feed and reconfigure the alternate feed if no fault was detected between the reclosers.

The city of Baldwin authorized the purchase of two Nu-Lec reclosers equipped with automatic changeover software. Fiber-optic cable was installed between the two reclosers to enable the exchange of information and commands to support automatic reconfiguration. KCP&L equipped both devices with RTMs (Fig. 1) to provide two-way communication to its distribution control center. The RTMs allow the KCP&L dispatcher to know the controls are in the automatic state and are ready to reconfigure. The RTMs monitor the health of the fiber-optic cable and send an alarm if communication is interrupted. Dispatchers also have remote control capability for use during planned switching.

A few months after installation, an insulator tie-wire failed on the normal feed causing a temporary loss of power to Baldwin. The automatic changeover performed flawlessly to restore power and properly report the status to KCP&L dispatchers.

KCP&L also used the RTM to automate all 18 capacitors on its 34-kV system. This project used S&C IntelliCAP PLUS controls (Fig. 2) and was completed in May 2004. Since then, three incidents of blown fuses were successfully reported from these capacitors.

KCP&L currently has a total of 55 RTMs installed on capacitors, reclosers and regulators.

Radio Issues Identified and Resolved

KCP&L performed a detailed radio site survey and discovered the Telemetric radio solution provided nearly 100% coverage in their outlying areas. However, as more radios were deployed, some challenging radio communications issues were identified and resolved.

The most serious challenge arose when KCP&L noticed that certain installations experienced regular communications interruptions. Telemetric and KCP&L observed that communications initiated by the radios in the field devices were being received, but some user requests for data were not getting out to the device. Telemetric worked with its communications aggregator Aeris (San Jose, California, U.S.) to resolve this problem by developing tools to routinely monitor and test all connected devices to locate where these issues exist.

The Low-Cost, Self-Contained Capacitor Control

KCP&L has experience justifying successful capacitor automation projects in the Kansas City metropolitan area. The utility applied the cost justification model to the rural application. Several metropolitan and rural circuits were modeled with an engineering software program to show how capacitor application affected the circuit-voltage profile and losses.

Due to longer rural circuits having smaller wire size, the effect of capacitors on voltage drop and system losses was much more dependent upon capacitor bank size in the rural applications. Therefore, it was more appropriate to assess automation costs in relation to the total effect on the system rather than on the kVAr basis.

KCP&L had difficulty keeping fixed (non-switched) rural capacitors in service due to blown fuses, periodic high-voltage complaints and the fact the capacitors were in isolated areas.

Anticipated costs of the equipment, communications charges, installation costs and engineering costs were compared to the various benefits (Figs. 3 and 4). This study showed the development of a low-cost communicating capacitor control was justified. Therefore, KCP&L began an additional project to develop a low-cost capacitor monitor with remote control capability.

Of particular interest is the “capacitor bank installations, avoided cost” component (Fig. 3). KCP&L had already proven that capacitor automation along with a timely repair plan results in needing fewer capacitor banks in service to maintain the desired voltage profile and MVAr support. Therefore, for the same number of capacitors in the field, more MVAr would be available during peak loading with automation in place.

Table 1. TC012 Analog Input Table for Capacitor Neutral Current

	Open	Closed	Blown Fuse	Defective C.T.
Capacitor Bank Size (kVAr)	Range 1 (A)	Range 2 (A)	Range 3 (A)	Range 4 (A)
Option 1 - 300	0-0.249	0.25-9.9	10-94.9	≥95
Option 2 - 600	0-0.249	0.25-19.9	20-94.9	≥95
Option 3 - 900	0-0.249	0.25-34.9	35-94.9	≥95
Option 4 - 1200	0-0.249	0.25-49.9	50-94.9	≥95

TC012 Development

KCP&L initially used an off-the-shelf Telemetric device to demonstrate that capacitor neutral current and line voltage could be detected and monitored. Nashville Electric Service (NES; Nashville, Tennessee, U.S.) visited KCP&L and began support of this capacitor monitor/control development.

KCP&L and NES worked with Telemetric to integrate this product into a four-jaw configuration, so that it could be used interchangeably with other capacitor controls already used at utilities. KCP&L and NES developed a specification and worked with Telemetric to design and manufacture a low-cost device (Telemetric TC012) with a self-contained radio to allow monitoring and remote control of capacitor banks. This device, which sells for less than the cost of most controls or radios alone, sends alarms for blown fuses, loss of power and low or high voltage.

KCP&L and Telemetric worked together to create a dynamic configuration table for the device software (Table 1). This table electronically links the capacitor neutral current under various conditions against the installed capacitor bank size. This table allows users to configure values into the TC012 to determine whether a capacitor bank is open, closed with normal neutral current, has a blown fuse or has a defective current sensor.

Success Stories

KCP&L linemen coordinated repairs or replacement of oil switches and defective capacitor units when they installed the monitoring devices, which helped limit the number of trips to the capacitor controls. KCP&L noticed significantly improved power factor in regions where these capacitor devices were installed. The utility no longer has to patrol and inspect these capacitors periodically because operating problems can be reported through the Telemetric radio.

The battery-backed Telemetric TC012 reports power outages before the first customer calls in. In addition, various abnormal distribution system voltages have been reported when circuits were rearranged during a switching contingency. This notifies KCP&L to proactively respond to customer problems. The configuration table is loaded into the TC012 such that one setpoint change allows the various ranges to be enabled for the entire row.

In addition, the TC012s successfully reported 10 capacitor neutral current alarms due to blown fuses after they were installed.

TC012 Website Applications

Control actions can be set up to switch a capacitor automatically through the website due to high or low voltage, or neutral current imbalance. Status reports, which can be time scheduled in advance or requested on demand, are used to check the communications health to the device occasionally. In addition, the TC012 will report digital changes and analog variances via unsolicited report by exception and display them on the webpage (Fig. 5). Therefore, the status report for the TC012 is done once every 10 days.

As an added convenience, many TC012 operating parameters can be changed remotely. These include the alarm setpoints for the neutral-current sensor, alarm points for low and high line voltage, and parameters to detect power outages. As a result, KCP&L linemen simply install the TC012, and call in when the installation is complete and report the bank size, station number and installation location.

KCP&L engineers complete a simple website configuration for a device and remotely program the control using the special configuration table previously described. The alarm points of this table can be configured through the Telemetric website. This function was important to KCP&L to mitigate trips to the field to program the device with a laptop computer.

Technical Device Issues Resolved

Telemetric, KCP&L and NES also worked together closely to identify and resolve several mechanical issues during their initial field trial. Design changes identified and implemented included enhanced device grounding and surge suppression. In addition, based on field experience, a more reliable product from a different manufacturer replaced the original NEMA 4 enclosure. Water ingress also was discovered through the hole in the enclosure for the antenna exit. This was resolved by better drilling specifications and the addition of silicone sealant as added insurance.

Analog reading accuracy and resolution was one major area identified and improved. Early tests showed the current readings on the neutral of some 300-kVAr capacitor banks were less than 0.5 A. The analog input board of this device had to be re-engineered to provide resolution down to 0.25 A of neutral current.

In order to provide the analog accuracy necessary for the project, KCP&L worked with Telemetric to develop a dual range analog reading that uses two scales to measure neutral current. Also, KCP&L encouraged Telemetric to improve the 120 Vac accuracy reading of the TC012 to ensure the voltage reading was within plus or minus 1.5% of true RMS. KCP&L now uses this voltage reading to help ensure the primary voltage on the distribution system is within an acceptable range. After these issues were resolved, KCP&L began a rollout of this product to all the fixed capacitor banks in the East and South Districts. KCP&L currently has 85 Telemetric TC012 devices installed (Fig. 6).

SCADA-Xchange Project

The SCADA-Xchange project involved integrating the communications with Telemetric products into KCP&L's SCADA and EMS. The Telemetric SCADA-Xchange service acts as a gateway protocol converter that enables access to any Telemetric connected device from KCP&L SCADA or EMS. KCP&L also uses the Telemetric secure Web application to monitor devices. The information from the Telemetric packet is recreated to a full DNP message at the Telemetric network-operating center and forwarded to KCP&L through a secure connection. KCP&L also uses the Bow Network proxy server as part of its communication solution. The long-term plan is to integrate both portions into the KCP&L OMS platform.

Benefits to KCP&L and the Industry

This KCP&L/Telemetric project has introduced economic automation options for North American electric utilities that previously could not justify the high capital costs of a communication infrastructure for deploying larger numbers of automated devices. The solution is creative, economical, scalable and ideal for control, alarming and receiving analog and digital values.

The RTM integration now includes 16 suppliers with 28 products. More than 40 utilities now use this RTM solution and there are 19 utilities using SCADA-Xchange. The list of utilities embracing this solution is growing. The project demonstrates an effective way for any utility to use a Web-based solution to test or apply new automation. It also provides a migration path for DNP-protocol data and a way to perform control using its SCADA systems.

Future Considerations

This project has given KCP&L new communication and control options for distribution automation. This solution also has practical applications in the metropolitan area. KCP&L is beginning two projects where this Telemetric solution will provide immediate benefit in the pilot stages or possibly a long-term communications solution.

KCP&L has begun a project to automate its grid and spot networks within its metropolitan coverage area. The RTM along with a Richards Manufacturing Co./ETI microprocessor network protector relay can be easily deployed. Engineers, dispatchers and cable splicers can gain early experience with the automation of the network relay.

KCP&L also is studying automatic reconfiguration for its 34-kV system. The RTM can be used as a temporary way to quickly and economically provide remote control to the operating devices. Depending on the communications solution required for the project, the Telemetric device could be used temporarily or permanently.

KCP&L is a beta site for Telemetric's enhanced digital communications device. Testing will include the digital control channel and SMS (small messaging service) through the digital network in the coming months. The digital communication network has more bandwidth and will provide an additional communication solution.

Carl R. Goeckeler is the Distribution Automation project leader for Kansas City Power & Light, where he has worked for the past 29 years. He initiated KCP&L's Power Quality program and authored a syndicated PQ publication used by electric utilities and customers for PQ training. Goeckeler led the Distribution Automation portion of the overall projects that won the “DistribuTECH Utility Automation Innovation Award” and the “Ultra Award for Innovative Technology” in 1997. KCP&L was awarded the “T&D Automation Project of the Year Award” at DistribuTECH 2004. Goeckeler received a BSEE degree from the University of Missouri at Rolla in May 1975. He is a registered professional engineer in Missouri and a member of IEEE.
Carl.Goeckeler@kcpl.com