The characteristics of the State Grid low-voltage standardized cabinet: "Safe and reliable, durable, unified standard, universal interchangeable, reasonable classification, widely applicable", extensively absorbing the operating experience and design results of various operating units and manufacturing enterprises, in full On the basis of research and seminars, unified standards, streamlined classification, advanced pilots, and taking into account differences to achieve the goal of simplifying operation and maintenance and improving efficiency.
In terms of the scheme design of the standardized low-voltage switchgear, the structural scheme, primary interface, secondary interface, civil engineering interface, and main component parameters of the low-voltage switchgear have been standardized and unified. This design simplifies the cabinet type, cancels the fixed cabinet, and simplifies the bus current specification to 1 250 A, 2 000 A, 2 500 A. The feeder scheme is classified into four types according to the function; Simplify the system scheme and configuration requirements, realize the unification of functional configuration and cabinet combination, and meet the requirements of interchangeability; standardize the secondary principle, secondary interface, and secondary identification, so that on-site personnel can perform construction wiring and operation and maintenance operations Safer and more efficient;
Unified the technical parameters of the main components, realized functional improvements, and reserved interfaces for future intelligent management of low-voltage distribution networks.
In terms of test and detection of standardized low-voltage switchgear, combined with relevant national standards and CCC certification requirements, comprehensive, strict and detailed specifications have been carried out for various tests of standardized low-voltage switchgear, and the test indicators, test methods and judgment basis have been unified , further strengthened the quality control of the standardized low-voltage switchgear production process, components/raw materials, and laid a good foundation for the safe and reliable operation of the equipment.
1 typical structural scheme
In order to facilitate equipment management, the product name code of the standardized low-voltage switchgear of State Grid Co., Ltd. is set as "SLVA", SLVA is the initials of Standardized Low-Voltage Assemblies, hereinafter referred to as "SLVA low-voltage switchgear" .
The typical structural scheme of SLVA low-voltage switchgear is divided into 4 categories and 8 subcategories. Among them, the four categories are incoming line cabinets, bus coupling cabinets, feeder cabinets, and reactive power compensation cabinets. The 8 subcategories are 1 category for incoming line and bus coupler cabinets; 4 categories for feeder cabinets; 2 categories for reactive power compensation cabinets.
1.2 Inlet Cabinet (Option 1)
The incoming line cabinet (Scheme 1) is divided into two schemes: left incoming line and right incoming line. See Figure 1-1.
Figure 1-1 Inlet Cabinet (Scheme 1)
(a) left incoming line; (b) right incoming line
1.3 Bus coupler cabinet (plan 2)
Bus coupler cabinet (plan 2) is divided into two schemes: left bus coupler and right bus coupler. See Figure 1-2.
Figure 1-2 Bus coupler (Scheme 2)
(a) Left Bus Tie ;(b) Right Bus Tie Low-Voltage Switchgear Standardized Design Scheme (2020 Edition)
1.4 Feeder Cabinet (Scheme 3～Scheme 6)
1.4.1 Feeder cabinet 1 (Scheme 3) is suitable for the left and right installation scheme of two-way frame circuit breaker (2×630A). See Figure 1-3.
Figure 1-3 Feeder Cabinet 1 (Scheme 3)
1.4.2 Feeder cabinet 2 (Scheme 4) is suitable for the upper, middle and lower installation scheme of three-way frame circuit breaker (3×630A). See Figure 1-4.
Figure 1-4 Feeder Cabinet 2 (Scheme 4)
1.4.3 Feeder cabinet 3 (plan 5) is applicable to the installation plan of six-way molded case circuit breaker (4×400A+2×250A). See Figure 1-5.
Figure 1-5 Feeder Cabinet 3 (Scheme 5) Low-Voltage Switchgear Standardized Design Scheme (2020 Edition)
1.4.4 Feeder cabinet 4 (Scheme 6) is applicable to the installation scheme of four-way molded case circuit breakers (4×630A). See Figure 1-6.
Figure 1-6 Feeder Cabinet 4 (Scheme 6)
1.5 Reactive Power Compensation Cabinet (Scheme 7～Scheme 8)
1.5.1 Reactive power compensation cabinet 1 (Scheme 7), in which SVG is selected according to the needs of each operating unit. See Figure 1-7.
Figure 1-7 Reactive Power Compensation Cabinet 1 (Scheme 7)
1.5.2 Reactive power compensation cabinet 2 (Scheme 8) adopts smart capacitors. See Figure 1-8.
Figure 1-8 Reactive Power Compensation Cabinet 2 (Scheme 8)