MERLIN II® AHVC Program Upgrade

This upgrade involves changing the existing versions of the Program and Parameter Chips to FMDK’s Version 5.0x on each of the AHVC’s. No other changes to the AHVC components are required for this upgrade.  

 Features of the Version 5.0x Program

  • Simplified Parameter Listings with Plain English Descriptions.
  • Operational Access for T-R Nameplate Data, Spark Display Mode and Control and Advanced Back Corona Detection and Control.
  • Setup/Controls Configuration Access for Alarms, Trip Settings, SCR Phasing, Spark Profiles and Communications.
  • 6 User Lists switch able from the Keypads and/or the WIN-CMS Software installed on the Station’s PC.

 Operational Access and Selected Program Updates

This updated access list organizes the Parameters normally needed for the Station in an easy to read and understand 0 through 11 numbers.  T-R primary and secondary voltages and currents, spark per minute limit, output bushing selection and undervoltage KV trip is included with this level of access for parameters normally adjusted by the user.  The SCR conduction angle limit has been revised to a better-understood 0 to 100% as compared to previous program versions.

The newly included Parameters incorporate Merlin’s exclusive spark rate control and display.  Two modes of operation and three modes of displaying sparks are now available.  The first spark operation mode and display is based upon our Opposite Half Cycle Spark Recovery (U.S. Patent 4,2900,003) where program algorithms samples sparks during the last two ˝ cycle occurrences and averages them forward as “This is what I will see” or “Future Mode”.

The second display mode indicates true sparks per minute, updated every 60 seconds while operating in the “Future Mode”. The third operational mode is based upon the true sparks per minute display mode and controls on that basis or “Past Mode” similar to other High Voltage Controls. The display and operational modes are installed in one parameter by entering one-digit values that are user selectable.

 The next incorporation is Merlin’s advanced back corona detection and avoidance bases upon our Digital Signal Processing and Waveform Analysis (U.S. Patent 4,996,471) where our exclusive Dynamic VI curve is processed to detect and automatically adjust the AHVC to a different operating level below the onset of back corona. This differs from all other High Voltage Controls due to the Dynamic VI curve being accomplished over one half cycle of SCR Firing thus not disturbing the power levels of the operating set as with conventional VI curves.

Setup Access

This 19 Parameter List is used to setup specifics, alarms and control trip points that may differ from set to set. Communications identification, baud rate and interface computer type are also included.  Our SCR phasing parameter has been incorporated in this list to aid in troubleshooting during SCR change outs.

The updated Chips incorporate factory parameters for spark rate control and prediction and are arranged as “Spark Profiles” that can be user changed with a single parameter. Once finalized by our Technical Service Representative at the site the AHVC’s operate completely automatically without intervention.

Benefits with Version 5.0x upgrade include:

Ease of training with simplified, easy to understand parameters.

Access lists allow modification of T-R set nameplate values, from the norm, when internal problems arise by changing one or two parameters from the Operational Access List.

Simplified troubleshooting, fewer parameter values to scroll through.

Incorporated Soft Start Algorithms gradually apply power to user-selected levels with a “Slow Ramp”.  Minimizes current in-rush and extends the life of existing control components.

The latest technology back corona detection and avoidance based upon U.S. Patents.

  • Merlin’s exclusive “Spark Profiles”
  • Completely compatible with current Merlin AHVC hardware.
  • A fraction of the cost of AHVC replacement.
Merlin® Controls -  FMDK Technologies, Inc.