//******************************************************************************************************//  AngleDifferenceCalculator.cs - Gbtc////  Copyright © 2016, Grid Protection Alliance.  All Rights Reserved.////  Licensed to the Grid Protection Alliance (GPA) under one or more contributor license agreements. See//  the NOTICE file distributed with this work for additional information regarding copyright ownership.//  The GPA licenses this file to you under the MIT License (MIT), the "License"; you may//  not use this file except in compliance with the License. You may obtain a copy of the License at:////      http://opensource.org/licenses/MIT////  Unless agreed to in writing, the subject software distributed under the License is distributed on an//  "AS-IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. Refer to the//  License for the specific language governing permissions and limitations.////  Code Modification History://  ----------------------------------------------------------------------------------------------------//  10/26/2016 - J. Ritchie Carroll//       Generated original version of source code.////****************************************************************************************************** using System;using System.Collections.Generic;using System.ComponentModel;using System.Linq;using System.Text;using GSF;using GSF.Collections;using GSF.TimeSeries;using GSF.TimeSeries.Adapters;using GSF.Units.EE;using PhasorProtocolAdapters; namespace PowerCalculations{    /// <summary>    /// Calculates a composed angle difference.    /// </summary>    [Description("Angle Difference Calculator: Safely calculates a difference between two angles, unwrapping source angles as needed")]    public class AngleDifferenceCalculator : CalculatedMeasurementBase    {        #region [ Members ]         // Constants        private const int ValuesToShow = 4;        private const double PhaseResetAngle = 720.0D;         // Fields        private double[] m_lastAngles;        private double[] m_unwrapOffsets;        private List<double> m_latestCalculatedAngles;        private IMeasurement[] m_measurements;         #endregion         #region [ Properties ]         /// <summary>        /// Gets or sets flag indicating whether or not this adapter will produce a result for all calculations. If this value is true and a calculation fails,        /// the adapter will produce NaN for that calculation. If this value is false and a calculation fails, the adapter will not produce any result.        /// </summary>        [ConnectionStringParameter]        [Description("Defines flag that determines if adapter should always produce a result. When true, adapter will produce NaN for calculations that fail.")]        [DefaultValue(false)]        public bool AlwaysProduceResult { get; set; }                /// <summary>        /// Returns the detailed status of the <see cref="AngleDifferenceCalculator"/> calculator.        /// </summary>        public override string Status        {            get            {                StringBuilder status = new StringBuilder();                 status.AppendFormat("  Last " + ValuesToShow + " calculated angles:");                 lock (m_latestCalculatedAngles)                {                    if (m_latestCalculatedAngles.Count > ValuesToShow)                        status.Append(m_latestCalculatedAngles.GetRange(m_latestCalculatedAngles.Count - ValuesToShow, ValuesToShow).Select(v => v.ToString("0.00°")).ToDelimitedString(", "));                    else                        status.Append("Not enough values calculated yet ...");                }                 status.AppendLine();                status.Append(base.Status);                 return status.ToString();            }        }         #endregion         #region [ Methods ]         /// <summary>        /// Initializes the <see cref="AngleDifferenceCalculator"/> calculator.        /// </summary>        public override void Initialize()        {            base.Initialize();             // Validate input measurements            List<MeasurementKey> validInputMeasurementKeys = new List<MeasurementKey>();            SignalType keyType;             for (int i = 0; i < InputMeasurementKeys.Length; i++)            {                keyType = InputMeasurementKeyTypes[i];                 // Make sure measurement key type is a phase angle                if (keyType == SignalType.VPHA || keyType == SignalType.IPHA)                    validInputMeasurementKeys.Add(InputMeasurementKeys[i]);            }             // Make sure only phase angles are used as input            if (validInputMeasurementKeys.Count == 0)                throw new InvalidOperationException("No valid phase angles were specified as inputs to the angle difference calculator.");             if (InputMeasurementKeyTypes.Count(s => s == SignalType.VPHA) > 0 && InputMeasurementKeyTypes.Count(s => s == SignalType.IPHA) > 0)                throw new InvalidOperationException("A mixture of voltage and current phase angles were specified as inputs to the angle difference calculator - you must specify one or the other: only voltage phase angles or only current phase angles.");             if (validInputMeasurementKeys.Count != 2)                throw new InvalidOperationException($"Expected exactly two phase angles as inputs to the angle difference calculator, got {validInputMeasurementKeys.Count}.");             InputMeasurementKeys = validInputMeasurementKeys.ToArray();             // Validate output measurements            if (OutputMeasurements.Length < 1)                throw new InvalidOperationException("An output measurement was not specified for the angle difference calculator - one measurement is expected to represent the \"Calculated Angle Difference\" value.");             Dictionary<string, string> settings = Settings;            string setting;             if (settings.TryGetValue("AlwaysProduceResult", out setting))                AlwaysProduceResult = setting.ParseBoolean();                        // Initialize member fields            m_lastAngles = new double[2];            m_unwrapOffsets = new double[2];            m_latestCalculatedAngles = new List<double>();             // Set last angles as uninitialized            m_lastAngles[0] = double.NaN;            m_lastAngles[1] = double.NaN;        }         /// <summary>        /// Calculates an angle difference.        /// </summary>        /// <param name="frame">Single frame of measurement data within one second samples</param>        /// <param name="index">Index of frame within the one second samples</param>        protected override void PublishFrame(IFrame frame, int index)        {            Measurement calculatedMeasurement = Measurement.Clone(OutputMeasurements[0], frame.Timestamp);            double angle, deltaAngle, angleDifference, lastAngle, unwrapOffset, angle1 = double.NaN, angle2 = double.NaN;             // Attempt to get minimum needed reporting set of composite angles used to calculate angle difference            if (TryGetMinimumNeededMeasurements(frame, ref m_measurements))            {                // Get both phase angles, unwrapping as necessary                for (int i = 0; i < m_measurements.Length; i++)                {                    // Get current angle value                    angle = m_measurements[i].AdjustedValue;                     // Get the unwrap offset for this angle                    unwrapOffset = m_unwrapOffsets[i];                     // Get angle value from last run, if there was a last run                    lastAngle = m_lastAngles[i];                     if (!double.IsNaN(lastAngle))                    {                        // Calculate the angle difference from last run                        deltaAngle = angle - lastAngle;                         // Adjust angle unwrap offset if needed                        if (deltaAngle > 300)                            unwrapOffset -= 360;                        else if (deltaAngle < -300)                            unwrapOffset += 360;                         // Reset angle unwrap offset if needed                        if (unwrapOffset > PhaseResetAngle)                            unwrapOffset -= PhaseResetAngle;                        else if (unwrapOffset < -PhaseResetAngle)                            unwrapOffset += PhaseResetAngle;                         // Record last angle unwrap offset                        m_unwrapOffsets[i] = unwrapOffset;                    }                     // Pick off unwrapped angles                    if (i == 0)                        angle1 = angle + unwrapOffset;                    else                        angle2 = angle + unwrapOffset;                }                 // We use modulus function to make sure angle is in range of 0 to 360                angleDifference = (angle1 - angle2) % 360.0D;                 // Record last angles for next run                for (int i = 0; i < m_measurements.Length; i++)                    m_lastAngles[i] = m_measurements[i].AdjustedValue;            }            else            {                angleDifference = double.NaN;                calculatedMeasurement.StateFlags |= MeasurementStateFlags.BadData;            }             // Convert angle value to the range of -180 to 180            if (angleDifference > 180)                angleDifference -= 360;             if (angleDifference <= -180)                angleDifference += 360;             if (double.IsNaN(angleDifference) && !AlwaysProduceResult)                return;             calculatedMeasurement.Value = angleDifference;             // Expose calculated value            OnNewMeasurements(new IMeasurement[] { calculatedMeasurement });             // Track last few calculated reference angles            lock (m_latestCalculatedAngles)            {                m_latestCalculatedAngles.Add(angleDifference);                 while (m_latestCalculatedAngles.Count > ValuesToShow)                    m_latestCalculatedAngles.RemoveAt(0);            }        }         #endregion    }}