Research Of Active Power Filter Based On Multilevel Inverter

High voltage&high power power-electronic device centralizes modern technologies in electrical engineering. Active power filter, the dynamic harmonic control equipment, makes it as its core component. The combination of them makes sense in electrical engineering field, sepecially in the application of wind farm, electrical viecal, etc. The thesis discusses the active power filter based on multilevel inverter.The thesis compares different multi-level topologies, then choose the most widely used one, diode-clamped three-level inverter, as the topology of active power filter. The operating principle of APF, its mathematical model, as well as its control algolithm, are discussed in detail. The algolithm of SVPWM under system of rectangular coordinates is simplified to SVPWM under system of60-degree coordinates. The simulation result of Simplorer confirms that this topology can decrease the voltage endurance capability of IGBT while applied in the APF, thus can save cost of equipment.The thesis design the prototype based on ARM embedded system, including power circuit, sampling circuit, controller circuit and dual-chip communication circuit; then complete the embedded program, including data sampling, calculation of instruction current and reference voltage, SVPWM controlling under system of60-degree coordinates, etc.The experiment result shows that three-level APF can compensate the harmonic of distrubition network in a great extent.The performance of three-level APF is also better than two-level APF in tradition.