STACKED VOLTAGE SOURCE INVERTER WITH SEPARATE DC SOURCES

摘要

A stacked voltage source inverter having separate DC sources is described herein. This inverter is applicable to low or medium voltage, low to medium power applications such as photovoltaic utility interface systems, battery storage application such as peak shaving with renewables, motor drive applications and for electric vehicle drive systems. The stacked inverter consists of at least one phase wherein each phase has a plurality of low voltage full bridge inverters equipped with an independent DC source. This inverter develops a near sinusoidal approximation voltage waveform with fast switching and small low pass AC output filter. A system controller controls operating parameters for each inverter. The inverter may have either single-phase or multi-phase embodiments connected in either wye or delta configurations.

主权项

1. A multiple direct current (DC) voltage source inverter to supply power to an alternating current (AC) power system, comprising:
a plurality of full bridge inverters, each having a primary node and a secondary node, each of said full bridge inverters having positive and negative node, each of said full bridge inverters having a voltage supporting device electrically connected in a parallel relationship between said positive node and said negative node and a direct current (DC) source connected between the positive and negative nodes; at least one stacked inverter phase, each stacked inverter phase having a plurality of said full bridge inverters, each of said full bridge inverters in each stacked inverter phase interconnected in a series relationship with said secondary node of one of said full bridge inverters connected to said primary node of another full bridge inverter, said series interconnection defining a first full bridge inverter and a last full bridge inverter, each phase having an input node at said primary node of said first full bridge inverter and an output node at said secondary node of said last full bridge inverter; a local controller coupled to each full bridge inverter providing the control signals to each full bridge inverter to output an approximate nearly sinusoidal voltage waveform; and a system controller which communicating with each local controller; the system level controller generating a system control signal for configuration, activation, deactivation and operating mode selection of said local controller.