CEC Model

CEC Model - Current Energy Converter (Hydrokinetic Turbine)

This directory contains the complete Current Energy Converter (CEC) model, also known as a Hydrokinetic Turbine (HKT), with grid integration capabilities.

Overview

The CEC/HKT model is a comprehensive Simulink implementation that simulates a tidal or river current energy converter with permanent magnet synchronous generator (PMSG), power electronics, and grid connection. The model captures the hydrodynamic-to-electric energy conversion process for marine current energy systems.

Model Files

• HKT_grid_dyn_final.slx - Complete hydrokinetic turbine model
• river_model_w_IM_250418_23a.slx - Alternative river current model with induction machine
• HKT_grid_dyn_Bladerunner.fmu - Pre-compiled FMU for co-simulation with PowerFactory or other tools
• HKT_Params.txt - Model parameters and configuration settings
• Velocity.mat - Sample current velocity profile data

System Components

1. Hydrokinetic Turbine

• Input: Water current velocity (m/s)
• Function: Extracts kinetic energy from flowing water
• Characteristics:
  • Blade radius: 0.5 m
  • Optimal tip-speed ratio (λ_opt): 3.4
  • Maximum power coefficient (Cp_max): 0.46
  • Number of turbines: 1
  • Rated power: 11 kW

2. Permanent Magnet Synchronous Generator (PMSG)

• Type: Direct-drive PMSG (10:1 gear ratio)
• Specifications:
  • Pole pairs: 5
  • Flux linkage: 1.9 Wb
  • Resistance: 0.069 Ω (including filter)
  • Inductance: 2.06 mH (including filter)
  • Combined inertia: 21.46 kg⋅m² (turbine + generator)

3. Power Electronics

• Rectifier: Converts variable-frequency AC from generator to DC
• DC-link: Energy storage and voltage regulation
• Inverter: Grid-connected inverter for power injection

4. Control System

• Maximum Power Point Tracking (MPPT): Optimizes power extraction across varying current speeds
• Grid synchronization: Maintains proper voltage and frequency alignment
• Power quality control: Ensures compliant grid operation

Key Features

• ✅ Physics-based hydrodynamic model
• ✅ Realistic turbine Cp-TSR characteristics
• ✅ PMSG model with generator dynamics
• ✅ Maximum power point tracking
• ✅ Grid-connected operation
• ✅ FMU export capability for co-simulation

Model Parameters

Key parameters (from HKT_Params.txt):

• Water density (ρ): 1023 kg/m³
• Blade radius (R): 0.5 m
• Gear ratio (Ng): 10:1
• Rated power: 11 kW
• Simulation time step (Ts): 100 μs

Performance Characteristics

The model includes validated performance curves:

Power coefficient vs tip-speed ratio characteristics

Turbine, generator, and grid power profiles

DC bus and grid-side electrical characteristics

Tip speed and current velocity with TSR tracking

Using the Model

Standalone Simulation (Simulink)

1. Open HKT_grid_dyn_final.slx in MATLAB/Simulink
2. Load parameters: run('HKT_Params.txt')
3. Configure current velocity input (or use Velocity.mat)
4. Run simulation
5. Analyze turbine performance and power output

FMU Co-simulation (with PowerFactory)

1. Use the pre-compiled HKT_grid_dyn_Bladerunner.fmu file
2. Import into PowerFactory (see FMU Method guide)
3. Connect to grid model at designated bus
4. Configure current velocity profile as input
5. Run co-simulation

Exporting Your Own FMU

1. Open HKT_grid_dyn_final.slx
2. Use Simulink FMU export functionality
3. Follow the FMU Method guide for configuration

Model Inputs

• Current Velocity (m/s) - Water current speed
• Grid Voltage - Three-phase grid voltage (when connected)

Model Outputs

• Active Power (W) - Power injected to grid
• Reactive Power (VAr) - Reactive power exchange
• DC-link Voltage (V) - Intermediate DC voltage
• Generator Speed (rad/s) - Rotational speed
• Tip-Speed Ratio (TSR) - Operating point indicator
• Power Coefficient (Cp) - Efficiency metric

Notes

• Current velocity profiles can be customized in Velocity.mat
• The model is designed for tidal/river current applications
• Power output scales with current velocity cubed (P ∝ u³)
• See HKT_figures/ directory for detailed performance curves