High voltage shunt capacitor

Main purpose and scope of application
High-voltage shunt capacitors are mainly used in 50Hz or 60Hz AC power systems to improve power factor. Reduce reactive power loss, improve voltage quality, and give full play to the efficiency of power generation and power supply equipment. It is an energy-saving product recommended by the country.
This product complies with: National Standard GB/T11024.1-2010 (our company is the main drafting unit of this standard)

Working conditions
1. The altitude does not exceed 1,000m, the ambient temperature is 40/B, and the maximum temperature of type B is +45°C.
2. There is no severe mechanical vibration, no harmful gas and steam, no conductive or explosive dust in the installation place.
3. The capacitor should be operated under well-ventilated conditions, and it is not allowed to operate under airtight and unventilated conditions.
4. The wiring of the capacitor should use soft wires, and the entire loop should be in good contact.

Model and meaning

Structural features
1. The capacitor is composed of a box shell and a core. The box shell is made of steel plate sealed and welded. The box shell is welded with an outlet porcelain sleeve. The two sides of the box wall are welded with hanging brackets for installation. Ground bolt.
2. The capacitor core is formed by stacking several elements and insulators. The element is formed by rolling and flattening two pieces of aluminum foil sandwiched with a film paper composite medium or a full film medium as a pole plate. The components in the core are connected in a certain series and parallel mode to meet the requirements of different voltages and capacities.
3. For capacitors with internal fuses, each component has a fuse in series. When a component breaks down, the intact component connected in parallel with it will discharge to it, so that the fuse will be blown quickly within milliseconds. The faulty component is removed, so that the capacitor continues to operate.
4. The three-phase capacitors are connected in star shape.
5. The liquid medium in the capacitor is used to impregnate the solid medium and fill the voids inside the capacitor. It has excellent electrical and physical properties and has good compatibility with other materials in the capacitor.

Main technical parameters
1. Rated voltage: 6.3kV, 6.6kV, 6.6/√3kV, 10.5kV, 11kV, 11/√3kV, 12kV, 12/√3kV, 19kV
2. Rated capacity: 30-334kvar, other voltage levels and The capacity can be specially ordered.
3. Capacity tolerance: -5~10%
4. Loss tangent value: film-paper composite medium tan δ≤0.O8%, full-membrane medium tan δ≤0.O5%
5. Withstand voltage: the capacitor should be able to Withstand AC 2.15 times or DC 4.3 times rated voltage, no breakdown or flashover for l0s.
   Insulation level: 6kV class 30kV, 10kV class 42kV AC test lasted 1min without breakdown or flashover.
6. Self-discharge performance: A capacitor with a discharge resistor is installed inside, and the residual voltage will drop from √2UN peak value to less than 75V within 10 minutes after the power is cut off.
7. The maximum allowable overvoltage: at 1.1 times the rated voltage, no more than 8 hours per 24 hours, at 1.15 times the rated voltage, no more than 30 minutes per 24 hours, no more than 5 minutes at 1.2 times the rated voltage, 1.3 times the rated voltage The voltage does not exceed 1 minute.
8. The maximum allowable current: the allowable current does not exceed 1.3 times the rated current for operation, the transient overcurrent takes into account the overvoltage, the positive capacitance deviation and the influence of harmonics shall not exceed 1.43 times the rated current.
9. Compliance with standards: The products comply with the national standard GB/T 11024.1-2010 and the international standard IEC60871-1:2005.

Main specifications

Ordering and use instructions
1. The capacitor rated voltage must be selected according to the network voltage, considering that the capacitor input will raise the voltage, so when choosing the capacitor rated voltage at least 5% higher than the network voltage; when a reactor is connected in series in the capacitor circuit At this time, the terminal voltage of the capacitor will increase with the reactance rate of the series reactor. Therefore, when selecting the rated voltage of the capacitor, it should be determined after calculation according to the reactance rate of the series reactor.
2. Capacitors are low-impedance channels for harmonics. Under the harmonics, a large number of harmonics will be injected into the capacitors to make the capacitors overcurrent or overvoltage. In addition, the capacitors will also amplify the harmonics, or even cause resonance, endanger the safety of the power grid and make the capacitors The service life is greatly shortened. Therefore, the capacitor must be used in series with a reactor that suppresses harmonics in the case of high harmonics.
3. The inrush current when the capacitor is closed can be as high as hundreds of times the rated current of the capacitor. Therefore, the switch of the switching capacitor should be a switch without heavy breakdown. In order to suppress the closing inrush current, a reactor that suppresses the inrush current can also be connected in series.
4. After the capacitor with internal discharge resistor is disconnected from the power supply, it can drop from the peak value of the rated voltage to below 75V within 10 minutes. If it is required to decrease the peak value of the rated voltage to below 50V within 5 minutes after the power supply is disconnected, it should be Specify when ordering.
5. The capacitor used for line compensation should be installed at 150-200kvar at one place, and be careful not to install the capacitor on the same platform with the transformer, and do not use the same set of drops to prevent the possibility of ferromagnetic resonance when the line is in non-full-phase operation. The over-current and over-voltage can damage the capacitors and transformers.
6. The zinc oxide surge arrester used to protect the operating overvoltage should be the zinc oxide surge arrester dedicated to the capacitor, and it is best to install it between the capacitor poles.
7. The fuse dedicated for capacitors should be selected for quick-break protection, and the rated current should be 1.43-1.5 times the rated current of the capacitor.
8. When the capacitor is directly connected in parallel with the high-voltage motor, in order to prevent self-excitation when the motor is disconnected from the power supply, causing the voltage of the capacitor terminal to rise above the rated value, the rated current of the capacitor must be less than 90% of the motor no-load current; When the motor adopts Y/△ wiring, it is not allowed to connect the capacitor directly to the motor, and a special wiring method should be adopted.
9. When the capacitor is used at an altitude higher than 1000 meters or the capacitor is used in a humid tropical zone, it should be stated when ordering.
10. Special specifications or special requirements for capacitors should be stated when ordering.