자기부상 열차 고온초전도 선형동기전동기(HTS-LSM) 자속 분포 & 1,000Hz 0-Alloc C# 인버터 역기전력 동기화 서보 엔진

using System;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;

namespace ZeliDesk.Stem.MaglevControl
{
    /// <summary>
    /// 3상 전류 및 전압 측정 구조체 (스택 할당 0-Alloc)
    /// </summary>
    [StructLayout(LayoutKind.Sequential, Pack = 8)]
    public readonly struct ThreePhaseData
    {
        public readonly double PhaseA;
        public readonly double PhaseB;
        public readonly double PhaseC;

        public ThreePhaseData(double a, double b, double c)
        {
            PhaseA = a;
            PhaseB = b;
            PhaseC = c;
        }
    }

    /// <summary>
    /// d-q축 회전 좌표계 물리량
    /// </summary>
    public ref struct DqCoordinates
    {
        public double D;
        public double Q;

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public DqCoordinates(double d, double q)
        {
            D = d;
            Q = q;
        }
    }

    /// <summary>
    /// 1,000Hz 무할당 HTS-LSM 인버터 동기 제어 엔진
    /// </summary>
    public ref struct HtsLsmInverterEngine
    {
        private const double PolePitchTau = 0.45; // 극간격 (m)
        private const double FluxLinkagePsi = 1.85; // HTS 코일 유효 자속 연계 (Wb)
        private const double StatorResistance = 0.12; // 지상 코일 저항 (Ohm)
        private const double InductanceD = 0.0035; // d축 인덕턴스 (H)
        private const double InductanceQ = 0.0038; // q축 인덕턴스 (H)
        private const double InvSqrt3 = 0.5773502691896257;

        private double _integratedIdError;
        private double _integratedIqError;
        private double _filteredTheta;

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void ExecuteControlCycle(
            in ThreePhaseData measuredCurrent,
            double vehiclePositionX,
            double vehicleVelocityV,
            double targetThrustForce,
            out DqCoordinates voltageCommand,
            out double electricalAngle,
            out double actualThrust)
        {
            // 1. 전기적 위상각 계산 (라디안)
            electricalAngle = (Math.PI / PolePitchTau) * vehiclePositionX;
            electricalAngle = electricalAngle - (2.0 * Math.PI * Math.Floor(electricalAngle / (2.0 * Math.PI)));
            _filteredTheta = electricalAngle;

            double cosTheta = Math.Cos(electricalAngle);
            double sinTheta = Math.Sin(electricalAngle);
            double omegaE = (Math.PI / PolePitchTau) * vehicleVelocityV;

            // 2. Clark & Park 변환 (3상 -> d-q축 전류 변환)
            double iAlpha = measuredCurrent.PhaseA;
            double iBeta = (measuredCurrent.PhaseB - measuredCurrent.PhaseC) * InvSqrt3;

            double id = iAlpha * cosTheta + iBeta * sinTheta;
            double iq = -iAlpha * sinTheta + iBeta * cosTheta;

            // 3. 목표 전류 산출 (i_d = 0 제어 기법으로 최대 추력 효율 달성)
            double targetIq = targetThrustForce / ((1.5 * Math.PI / PolePitchTau) * FluxLinkagePsi);
            double targetId = 0.0; // 무효자속 최소화

            // 4. PI 전류 제어기 루프
            double errId = targetId - id;
            double errIq = targetIq - iq;
            _integratedIdError += errId * 0.001;
            _integratedIqError += errIq * 0.001;

            double kpCurrent = 15.0;
            double kiCurrent = 350.0;

            // 5. 비간섭 역기전력 피드포워드 전압 보상
            double vCompD = -omegaE * InductanceQ * iq;
            double vCompQ = omegaE * InductanceD * id + omegaE * FluxLinkagePsi;

            double vd = (kpCurrent * errId + kiCurrent * _integratedIdError) + vCompD;
            double vq = (kpCurrent * errIq + kiCurrent * _integratedIqError) + vCompQ;

            voltageCommand = new DqCoordinates(vd, vq);

            // 6. 실시간 발생 추력 계산 (N)
            actualThrust = (1.5 * Math.PI / PolePitchTau) * (FluxLinkagePsi * iq + (InductanceD - InductanceQ) * id * iq);
        }
    }
}