GROUP OF CONVERTER SUBSTATIONS Russian patent published in 2006 - IPC H02M7/08 

FIELD: electrical engineering; power supply systems for aluminum electrolysis lines at aluminum works.

SUBSTANCE: proposed group of m converter substations characterized in that all its converters handle equal load currents has at least two converters incorporating at least one step-down power transformer whose high-voltage winding is connected to supply mains and low-voltage winding is split in two parts; first of two mentioned converter substations has n₁ converters and second one, n₂ converters; each converter has converter transformer with bushings a, b, c and at least one bridge rectifier; each converter transformer has winding connected to supply mains and rectifier winding, as well as at least one winding affording shift angles between rectifier winding voltage and supply voltage; two design alternates of converters distinguished by phase shift angle of converter transformer are used; converter transformers k₁ of first of mentioned converter substations are connected to network formed by one part of step-down power transformer low-voltage winding and converter transformers of remaining (n₁-k₁) converters are connected to network formed by other part of step-down transformer low-voltage winding; converter transformers k₂ of second mentioned converter substation are connected to network formed by one part of step-down transformer low-voltage winding and remaining converter transformers (n₂-k₂) are connected to network formed by other part of step-down transformer low-voltage winding; at least one of converter transformers is connected to respective phases of power network formed by one part of step-down power transformer low-voltage winding. Novelty is that transformer bushings a, b, c are connected to supply mains phases a, b, c, respectively, and that at least one of converter transformers is connected to other phases of power network formed by one of low-voltage winding parts of step-down power transformer; another novelty is that one of transformer bushings is connected to respective phase of this network and two other ones, to other phases of this network; still another novelty is that each of two mentioned converters k₁ and k₂ whose transformers are connected to one part of step-down transformer low-voltage windings is proposed to be made of one design alternate with respect to angle of phase shift and each of (n₁-k₁) and (n₂-k₂) converters whose converter transformers are connected to other parts of step-down transformer low-voltage windings, of other design alternate with respect to angle of phase shift; converter transformers in one of two mentioned substations made of one design alternate are proposed to be connected to phase leads of network formed by one of parts of step-down power transformer low-voltage winding; converter transformers of same design alternate in other substation are proposed to be connected differently to phase leads of power network formed by one part of step-down transformer low-voltage winding, where m is total number of converter substations, natural number, 4 ≤ n₁ ≤ 16; 4 ≤ n₂ ≤ 16; 2 ≤ k₁ ≤ 8; 2 k₂ ≤ 8.

EFFECT: reduced number of converters, supply voltage distortion factor, capital outlays for converter substation construction, and provision for dispensing with additional filtering and compensating devices.

1 cl, 3 dwg