BW-VKC
Voltage regulating high voltage reactive power automatic compensation device
Changes the compensation capacity of the capacitor group by changing the terminal voltage
Changes the compensation capacity of the capacitor group by changing the terminal voltage
The BW-VKC Voltage Regulating High Voltage Reactive Power Automatic Compensation Device uses fixed connection of capacitors, and changes the compensation capacity of the capacitor group by changing its terminal voltage. According to the principle of Q=ωCU², if the capacitor remains unchanged and the terminal voltage drops to 50% (or 40%, 60%) of Un, its output capacity can be adjusted between rated voltage and 25% (or 16%, 36%) of Qn, and the capacity adjustment difference can be changed by changing the voltage regulation differential.
The device mainly consists of secondary devices and their ancillary equipment, including high-voltage isolation switches, dry or oil-immersed voltage regulators, series reactors, high-voltage parallel capacitors, discharge coils, surge arresters, compensation controllers, and on-load tap changer controllers.
Precise adjustment: The device uses fixed connection of capacitors and does not adjust reactive power by switching capacitors. Instead, it adjusts the reactive power output by changing the terminal voltage of the capacitor through the voltage regulator.
No charging and discharging: The capacitor can solve the problems of charging and discharging caused by switching capacitors during operation, and the adjustment can be made at any time as the system reactive power changes.
No overvoltage: There is no overvoltage during the adjustment process of the voltage regulator, which ensures the safety of the capacitor and prolongs its service life.
Suppress surge current: The capacitor uses a suitable low-voltage closing, effectively reducing the impact of the capacitor closing surge current on the system and the capacitor itself.
Safe and reliable:It can automatically recognize the gear signal, call up the current setting parameters of different gears, and avoid protection dead angles.
Strong applicability: It can be used in new substation projects, or with the addition of voltage regulators to existing fixed compensation capacitors in substations to achieve automatic compensation function.
No. | Comparison | Fixed Compensation | Group Switching | Voltage Regulation Type |
1 | Main Features | Capacitors are fixedly connected, with simple structure and low cost | Capacitors are automatically switched in multiple groups to achieve automatic tracking compensation and improve power factor | Capacitors can be adjusted without switching, with highly stable power factor, no inrush current or overvoltage during adjustment, long service life, and maintenance-free |
2 | Compensation Level | 1 | 2~6 | 9 |
3 | Voltage at Start-up | Un | Un | 0.5Un |
4 | Capacitor Inrush Current at Start-up | ≤20 Icn | ≤20 Icn | ≤5 Icn |
5 | Capacitor Adjustment Gradient | Qc | Determined by group capacity | 25%~rated capacity/9 gears |
6 | Compensation Method | Non-adjustable | Vacuum Switching | On-load switch for gear adjustment |
7 | Operational Safety | High | Low (switch has arc and requires maintenance) | High (switch has no arc and is maintenance-free) |
8 | Operational Impact | No impact | Capacitors frequently switch on and off, causing impact | Capacitors are continuously online in real time without impact |
9 | Capacitor Service Life | Long | Short (high frequency of surge impact) | Long (almost no surge impact) |
Rated Voltage | 6kV、10kV、35kV |
Rated Frequency | 50Hz |
Voltage Sampling | A-phase and C-phase line voltage, AC 100V |
Current Sampling | B-phase, AC 0-5A (secondary side of current transformer) |
Capacitor Wiring | Star connection |
Operating Power Supply | AC220V/380V |
Overvoltage Capability | 1.1Un |
Overcurrent Capability | 1.3In |
Voltage Regulation Range | 50%-rated voltage/40%-rated voltage |
Capacity Regulation Range | 25%-rated capacity/16%-rated capacity |
Regulation Gears | 9/11 |
Connection Group | Ya0, three-phase three-wire star connection |
Sampling Control | Single-bus single-sampling single-control, double-bus double-sampling double-control |
Installation Method | Indoor or outdoor |
Protection Function | Overvoltage, undervoltage, overcurrent, speed breaking, unbalanced voltage, lightning protection, harmonic over-limit, daily switching times, non-energy protection, etc. |
Applicable Range | It is suitable for centralized compensation of busbar in new substations of 35kV-220kV and the renovation of existing fixed capacitors in substations, which can effectively improve the power factor of the line, reduce line losses, and improve the voltage quality of the power supply line. |
Operating Environment | Environment temperature: -25℃~+40℃, altitude: ≤ 1000m, air humidity: 95% (at 25℃), no significant dust, corrosive or combustible gases, water vapor or salt spray pollution in the surrounding air. |