35KV New Energy Box-Type(Chinese-Style) Substation

Overview

The 35kV compact pre-installed substation, commonly known as the Chinese box-type substation, is a new type of box-type substation, and its products are widely used in wind farms and photovoltaic power plants. It mainly consists of the transformer body,high-voltage electrical part, low-voltage electrical part, box, etc. The transformer is a three -phase double-winding oil-immersed self-cooled non-exciting voltage-regulating power transformer; the high-voltage electrical part of the Huashi Box Transformer is mainly composed of 35kV high-voltage circuit breakers, 35kV isolating switches, 35kV current transformers, 35kV voltage transformers, 35kV lightning arresters , 35kV live displays,etc, the low-voltage electrical part of the Huashi Box Transformer is mainly composed of low-voltage frame circuit breakers, self-use systems (self-use transformers, feeder switches, etc.), surge protectors, etc.

Model Meaning

Product features

• Compact structure, small size, easy and flexible installation;
• Fully insulated, fully sealed structure, safe and reliable, maintenance-free, and reliably protect personal safety;
• The high-voltage side is protected by dual fuses. The plug -in fuse is a dual sensitive fuse (temperature, current), and the backup fuse is a current-limiting fuse, which reduces operating costs;
• High-voltage incoming lines adopt cable connector structure, which is fully insulated, safe and reliable, and easy to operate;
• It can be used for both ring networks and terminals. The conversion is very convenient and improves the reliability of power supply.
• The transformer is of three-phase three-pillar or three-phase five-pillar structure. The iron core adopts stepped joint process or rolled core process, which has low noise, low loss, and strong resistance to short circuit and overload.
• Using  special process of vacuum drying and vacuum oiling our company will extend this process used in 110kV products to 10kV products, providing a strong guarantee for improving product quality.
• The box can be designed with anti-corrosion and special painting treatment according to the requirements of the operating environment. It has “three prevention” functions, namely anti-condensation, anti-salt fog, and anti-mold functions, and can meet the anti-corrosion requirements in high temperature and high humidity environments.

Related standards&parameters

• GB 1094.1-2013 Power transformers Part 1: General principles
• GB/T 15164-2022 Load Guidelines for Oil-immersed Power Transformer
• DL/T 572-2010 Power Transformer Operation Regulations
• IEC 60076 series international standard for power transformers
• GB 2536-2011 Transformer Oil Standard

Technical Requirements For Chinese Substation

The Huashi box transformer consists of three parts: a high-voltage chamber, a transformer, and a low-voltage chamber. Each chamber is separated into independent compartments by separators, and a manhole is provided in the box for convenient installation and maintenance, Its internal layout is set in accordance with the requirements of standard design drawings. The box transformer adopts natural cooling method, and the temperature of the low pressure chamber is controlled below 60 ℃ through the cooling device in the cabinet to ensure a good operating environment for secondary equipment. A communication cabinet needs to be installed on the transformer cabinet (Install switches, optical fiber boxes and other equipment), UPS battery cabinets operate under continuous long-term overload at 1.1 times (the oil temperature shall not exceed 85℃ in the project environment), 1.2 times (the oil temperature shall not exceed 85 ℃ in the project environment, and the temperature rise under short-term overload operation at 1.5 times shall comply with the provisions of General Equipment for Power Transmission and Transformation Projects of State Grid Corporation of China ” (Typical Specifications for Power Transformation and Distribution Stations of 66kV and Below) and Table 3-2 relevant values.

Dehumidification, explosion prevention and condensation prevention measures should be taken inside the box transformer. Cable holes in high and low pressure rooms should be sealed with polymer flexible sealing material TS-68 on the basis of sealing with fireproof mud. Install sealing strips on the cabinet door of the box transformer.The sealing strip is made of ethylene propylene diene monomer rubber, which has good heat resistance, weather resistance, ozone resistance, corrosion resistance and aging resistance.Live parts such as high-voltage cable heads, busbars, and terminal terminals are fully insulated with flame retardant and thermally conductive silicone rubber insulating material TS-10, After insulation treatment, the high-voltage parts of 35kV shall be able to withstand the voltage withstand voltage of 40.5kV for 1 minute; After insulation treatment the low-voltage busbars shall be able to withstand the voltage withstand voltage of 2.5kV for 1 minute. High-voltage bushing porcelain bottles, insulating rods, insulators and other insulating devices are brushed with high self-cleaning anti-pollution flash coating SRTV,with a coating thickness of 0.4±0.1mm. The seller is responsible for modifying the added cooling fan and adopting external circulation ventilation for cooling. (Delete) The design service life of the box transformer should not be less than 30 years. Each compartment of the box transformer should be equipped with a combination configuration of low-power normally-powered heater and dehumidifier. Ventilation holes should be reasonably set according to the volume of the cabinet. The box transformer temperature and humidity signal should have remote transmission function and be uploaded to the box transformer through the communication interface. Measurement and control device.

Appearance and installation dimensions

Technical Parameters

Item		unit	High-Voltage Switch		Transformer		Low-Voltage Apparatus
Rated Voltage		kV	12	40.5	10.5/0.8	35/0.8	0.8
Rated Capacity		KVA			1000-3300
Rated Frequency		HZ	50		50		50
Rated Current		A	200	63
1 min Power Frequency withstand Voltage	Interphase And Ground	kV	42	95	35	85	5
	Isolate Fracture	kV	48	110
Lightning Impulse withstand Voltage	Interphase And Ground	kV	75	185	75	220	12
	Isolate Fracture	kV	85	215
Rated Short Circuit Breaking Current (Effective Value)		KA		31.5			50
Rated Short-Time Withstand Current (Effective Value)		KA	20(4S)	20(4S)			40(1S)
Rated Short-Circuit Closing Current (Peak)		KA	50	50
Rated Peak Withstand Current		kA	50	50
Protection Grade					IP33
Noise Level					≤55dB

Component Selection Table

Rated Capacity (KVA)	High Voltage Switch		High Voltage Fuse		High Voltage Lightning Arrester		Low Voltage Switch	Auxiliary Transformer
	12	40.5	12	40.5	12	40.5
1000	FZRN25-12 VTK-12	FT16-40.5	XRNT-12/100	XRNT-40.5/30	HY-5WZ-17/45	HY-5WZ-51/134	RDW1 Circuit Breaker KFW2 Circuit Breaker	Capacity can be determined on demand
1600			XRNT-12/160	XRNT-40.5/30
2000			XRNT-12/200	XRNT-40.5/60
2500				XRNT-40.5/80
3150				XRNT-40.5/100A
3300				XRNT-40.5/100A