This review covers load-based compensation and active power filters for electrical system power quality improvements. Shunt or series compensating devices at the load terminal improve reactive power control, voltage stability, and power transfer. Active power filters inject compensatory currents or voltages to reduce harmonic distortion and reactive power use. Power quality can be improved with shunt, series, or hybrid APFs. Voltage-oriented control provides sinusoidal references for current or voltage control loops using voltage signal phase information. The authors investigate sliding mode control, which uses discontinuous control signals for fast dynamic response and durability. Although it has disadvantages, PI control is commonly utilized in speed control. Fuzzy logic and neural networks enable adaptive and intelligent APF control, which we investigate. With active power filters and load-based modifications, reactive power regulation and harmonic reduction improve power system performance and stability.