The Mitsubishi FR-E820S-0030-4-60 is a 3-phase 200V, 0.75kW inverter from the FR-F720P series. When using the inverter, the motor's starting current is limited to below 150% of rated current (typically 125%–200% depending on model), and starting torque is controlled accordingly. The inverter generates a three-phase modulated waveform by approximating an ideal circular rotating magnetic field using an inscribed polygon method. It includes frequency compensation to eliminate speed control errors, estimates magnetic flux amplitude to reduce stator resistance effects at low speeds, and uses voltage and current closed-loop control for improved dynamic accuracy and stability. However, it lacks torque regulation, limiting overall system improvement. The inverter converts AC to DC (rectification) and then DC to variable-frequency AC (inversion), enabling soft start, variable speed control, improved power factor, and protection functions for AC induction motors. The output is a simulated sine wave for motor speed control. For applications requiring high-precision sine waves, a dedicated variable-frequency power supply (15–20 times the cost) is used.