Buildings´ power quality regulator based on advanced Static Var Generator

Widespread applications of power electronic-based loads and single phase loads in buildings, such as PCs, TVs, printers, air-conditioners, refrigerators, elevator, etc., cause serious power quality problems, such as reactive power, unbalance current, and harmonic current. To deal with the unbalance and non-linear loads in buildings, this paper developed an advanced SVG (Static Var Generator), which is based on improved TTA (Time-domain Transform Algorithm) current detection method. First, the basic operation principle and steadiness characteristic of the device are discussed, then the improved TTA is proposed further and applied into three-phase four-wire power system. The main circuit topology is the four-leg configuration to eliminate exactly the zero sequence current. Dual-DSP strategy is adopted to increase the control speed and precision. At last, some experimental and locale running results are obtained. The results show that this SVG has the perfect performance, not only largely decreases the THD, which will meet the IEEE-519 standard recommendations on harmonic levels, but also effectively compensates the reactive and unbalance current.