Inverter Course

Lesson 1 • Passive Components in Power Circuits

Examines resistors, capacitors, and inductors in power contexts. Connects component behavior to filtering and energy storage in inverter stages.

Lesson 2 • Heat Management and Thermal Ratings

Explains thermal resistance, junction temperature, and heat sink design. Ensures students can evaluate component derating and cooling requirements.

Lesson 3 • AC and DC Signal Characteristics

Distinguishes AC and DC waveforms, defining amplitude, frequency, and phase. Provides the signal vocabulary needed to analyze inverter outputs.

Lesson 4 • Basic Electrical Quantities and Laws

Covers voltage, current, power, and energy relationships using Ohm's and Kirchhoff's laws. Establishes the mathematical language used throughout the course.

Lesson 1 • Single-Phase Full-Bridge Inverter

Extends the half-bridge to a four-switch H-bridge for full output swing. Demonstrates unipolar and bipolar PWM modulation strategies.

Lesson 2 • Three-Phase Voltage Source Inverter

Covers the six-switch three-phase bridge producing balanced three-phase AC. Connects phase-leg operation to line-to-line voltage generation.

Lesson 3 • Single-Phase Half-Bridge Inverter

Analyzes the two-switch half-bridge circuit producing a bipolar AC output. Establishes the switching-leg concept used in all subsequent topologies.

Lesson 4 • Current Source and Z-Source Inverters

Introduces current-fed and impedance-source topologies as alternatives to voltage-source designs. Highlights shoot-through immunity and boost capability.

Lesson 1 • Overvoltage and Thermal Protection

Addresses DC bus overvoltage clamping and junction temperature monitoring. Integrates protection signals into the control system for coordinated fault response.

Lesson 2 • Gate Drive Requirements for MOSFETs and IGBTs

Defines gate charge, threshold voltage, and drive current needed for fast, loss-efficient switching. Sets design targets for the gate drive stage.

Lesson 3 • Isolated Gate Drive Topologies

Compares transformer-coupled, optocoupler, and digital isolator gate drive architectures. Addresses isolation voltage, propagation delay, and power supply design.

Lesson 4 • Overcurrent and Short-Circuit Protection

Implements desaturation detection and current sensing to protect switches during fault conditions. Defines safe operating area and soft-shutdown procedures.

Lesson 1 • Selective Harmonic Elimination

Uses pre-calculated switching angles to eliminate specific low-order harmonics. Reduces filter size while maintaining output quality at low switching frequencies.

Lesson 2 • Dead-Time Compensation

Addresses voltage distortion caused by blanking time inserted between complementary gate signals. Implements feed-forward correction to restore output accuracy.

Lesson 3 • Space Vector PWM

Introduces the space vector plane and sector-based switching sequences for three-phase inverters. Achieves higher DC bus utilization than carrier-based SPWM.

Lesson 4 • Hysteresis and Deadbeat Control

Covers bang-bang hysteresis and predictive deadbeat current control as alternatives to carrier-based PWM. Connects response speed to switching frequency variation.

Lesson 1 • Pre-charge and Inrush Control

Designs pre-charge resistor circuits and active inrush limiters to protect capacitors at startup. Defines pre-charge timing and bypass relay sequencing.

Lesson 2 • DC Bus Voltage Ripple Analysis

Calculates current ripple injected into the DC link by switching and load. Connects ripple magnitude to capacitor size and switching frequency.

Lesson 3 • Battery and Supercapacitor Integration

Covers bidirectional DC-DC converters that interface energy storage to the DC bus. Addresses state-of-charge management and power sharing strategies.

Lesson 4 • Capacitor Technology Selection

Compares electrolytic, film, and ceramic capacitors for DC bus applications. Evaluates ESR, ESL, ripple current rating, and lifetime under thermal stress.

Lesson 1 • Inverter Control Architecture Overview

Maps the control hierarchy from inner current loops to outer voltage and power loops. Establishes bandwidth separation rules that ensure stable cascaded control.

Lesson 2 • Proportional-Resonant Controllers

Introduces PR controllers that achieve zero steady-state error for sinusoidal references without dq transformation. Extends to selective harmonic compensation.

Lesson 3 • dq Reference Frame Control

Transforms three-phase AC quantities to a rotating DC frame for simplified PI control. Covers Park and Clarke transformations and phase-locked loop synchronization.

Lesson 4 • PI Controller Design and Tuning

Derives PI controller parameters from plant transfer functions using frequency-domain methods. Applies gain and phase margin criteria to guarantee stability.

Lesson 1 • Power Quality and Harmonic Standards

Evaluates inverter output against grid harmonic injection limits and power quality standards. Designs LCL filters to meet compliance requirements.

Lesson 2 • Anti-Islanding Detection and Prevention

Implements passive and active anti-islanding methods to detect loss of grid and disconnect safely. Addresses detection time and non-detection zone minimization.

Lesson 3 • Low-Voltage Ride-Through Capability

Designs control strategies that keep the inverter connected during grid voltage dips per grid codes. Manages reactive current injection and DC bus overvoltage.

Lesson 4 • Grid Synchronization Techniques

Implements phase-locked loops and frequency-locked loops to track grid voltage angle and frequency. Evaluates performance under unbalanced and distorted grid conditions.

Lesson 1 • Functional and Performance Testing

Executes no-load, partial-load, and full-load tests to verify output voltage, frequency, and efficiency. Validates control loop behavior and protection trip points.

Lesson 2 • Pre-Commissioning Inspection and Testing

Defines visual inspection, insulation resistance, and continuity checks before energization. Prevents damage caused by wiring errors or component defects.

Lesson 3 • Preventive Maintenance Programs

Establishes scheduled maintenance tasks including capacitor health checks, cooling system cleaning, and firmware updates. Extends inverter service life and reduces downtime.

Lesson 4 • Fault Diagnosis and Troubleshooting

Applies systematic fault isolation to common inverter failures including gate drive faults, overcurrent trips, and sensor errors. Uses fault codes and waveform analysis.