Grid-Connected Bidirectional Single-Phase Inverter

Table of contents

1. 1. Introduction
   • What the course covers
   • Learning outcomes
   • Prerequisites
   • Notation used throughout
   • Control structure in the stationary (abc) and rotating (dq) frames
2. 2. The Inverter
   • Topology (fast leg and slow leg)
   • Simplified model of the inverter
   • Control structure
3. 3. PWM strategy
   • Gate signal derivation (fast-leg duty cycle, slow-leg gate signal)
   • Numerical example in Python (sinusoidal reference → S_SL and D_FL waveforms)
4. 4. Control in the abc frame
   • Current control: PI + feedforward, with numerical example
   • Power calculation: the simple method (P = LPF(v_ac · i_c), Q from the power triangle)
   • Pure active power control (PFC-style), with numerical example
   • Pros and cons of each method
5. 5. Control in the dq frame
   • Motivation for dq control
   • Clarke and Park transformations
   • Phase-locked loop (PLL), with numerical example
   • Park transform for single-phase: Simple OSG and SOGI
   • Power control in dq (P-axis and Q-axis decoupled), with numerical example
   • Current control in dq with decoupling terms, with numerical example
6. 6. Comparison of control methods
   • Control variables, complexity, sensitivity, reactive-power control
   • When abc is enough, when dq is preferable
7. Appendix
   • Hand calculation of the Park transform