SFTBBC high voltage reactive power compensation device, 10KV capacitor compensation cabinet

Overview

TBBC high-voltage shunt capacitor complete set (hereinafter referred to as the device) is mainly used in three-phase power systems with industrial frequencies of 6kV, 10kv, and 35kV to adjust and balance the substation network voltage, improve the power factor, reduce losses, and improve the power supply quality.

 Normal use conditions

◆Altitude: not higher than 1000m;

◆Ambient temperature: -25°C~ +55°C;

◆Relative humidity: no more than 85%;

◆No explosive media are allowed in the operating area, and the surrounding medium should not contain gases and conductive media that can corrode metals and destroy insulation.

 Features

1.The device can operate for a long time under a steady-state overvoltage of 1.1 times the rated voltage;

2.The device can operate continuously under overcurrent with a root mean square value not exceeding 1.3 times the rated current of the capacitor bank;

3.The device uses a high-voltage circuit breaker without heavy breakdown and is equipped with an oxide cast lightning arrester to limit the operating overvoltage generated when switching capacitor banks;

4.For 6KV and 10KV devices, vacuum load switches, vacuum circuit breakers or SF6 circuit breakers are used as switches for capacitor banks. For capacitor banks with small capacitance and group switching, vacuum contactors are used. For capacitor banks with large capacitance, vacuum circuit breakers or SF6 switches should be used.

5.The device uses dry-type air-core reactors connected to the power supply side of the device or dry-type iron-core reactors connected to the neutral point side of the device to limit the closing inrush current, suppress high-order harmonics, and improve the network voltage waveform. Reactors with a rated reactance of 0.5-1% are used to limit the closing inrush current; reactors with a rated reactance of 5-6% are used to suppress harmonics of the 5th order and above and limit the closing inrush current; reactors with a rated reactance of 12-13% are used to suppress harmonics of the 3rd order and above and limit the closing inrush current;

6.The device uses FDGR type discharge coil, which can reduce the residual voltage of the capacitor bank from the rated voltage peak to less than 0.1 times the rated voltage within 5s;

7.According to the needs of the system and users, the device can be controlled locally or in the main control room, centralized or automatically;

8.The device uses single capacitor fuse protection as the main protection, open triangle voltage, voltage differential, neutral line unbalanced current protection as backup protection, in addition, the device is also equipped with overcurrent, overvoltage, and undervoltage protection. The implementation of these protections can also use a better performance microcomputer capacitor protection monitoring device to meet the requirements for capacitor relay protection.

Structural features

1.The 6~10KV device consists of a high-voltage switchgear (including circuit breakers, high-voltage disconnectors, current transformers, relay protection, and measuring instruments), series reactors, discharge coils, oxide lightning arresters, grounding switches, fuses for single capacitor protection, parallel capacitors, and connecting busbars and steel structures. The double star type also includes a current transformer for neutral line unbalanced current protection.

2.The 6~10kV high-voltage switchgear is installed in the switch room. The layout of equipment such as capacitor groups and series reactors is divided into three types: indoor cabinet type, frame type, and collective type.

a.Indoor cabinet type

The capacitor bank is composed of one incoming line cabinet and several capacitor cabinets according to different capacity specifications. The incoming line cabinet is equipped with a discharge coil, a grounding switch and an oxide arrester. The capacitor cabinet includes parallel capacitors, fuses for single capacitor protection, and a transparent observation window on the door panel.

b.Frame type

The capacitor bank includes an incoming line rack and a capacitor frame. The entire device frame is divided into several sections and then assembled on site. The incoming line rack is equipped with a discharge coil, a grounding switch, an oxide arrester, and a current transformer for neutral line unbalanced current protection in double star connection. The capacitor frame includes parallel capacitors and fuses for single capacitor protection. A steel mesh fence can be set outside the frame or a steel mesh door can be set on the frame.

c.Collective

The collective type is a capacitor bank composed of collective parallel capacitors. The collective structure includes a series reactor, collective parallel capacitors and a discharge coil.

3.The 35kV device consists of a high-voltage switch cabinet (including high-voltage circuit breakers, current transformers, relay protection, measurement and indication parts), series reactors, discharge coils, oxide cast lightning arresters, single-unit protection fuses, parallel capacitors, etc. The double star connection also has a current transformer for neutral line unbalanced current protection, and the devices are all frame structures.

4.Wiring of series reactor

The air-core reactor is installed before the capacitor bank, i.e. on the power supply side, and the iron-core reactor is installed after the capacitor bank, i.e. on the neutral point side of the device.

TBBC high-voltage shunt capacitor complete set (hereinafter referred to as the device) is mainly used in three-phase power systems with industrial frequencies of 6kV, 10kV, and 35kV to adjust and balance the substation network voltage, increase the power factor, reduce losses, and improve the power supply quality.