what does the actual power capacitor in electronic products look like

The concepts of physics knowledge in textbooks are often derived from ideal models, and are generally invisible and intangible, so many times we don’t know what this thing is after learning various knowledge points. Even if we encounter it in real life, we don't know what it is, so what does the actual power capacitor in electronic products look like?

Basic information about power capacitors

Power capacitors, capacitors used in power systems and electrical equipment. Any two metal conductors separated by an insulating medium form a capacitor. The size of the capacitance of the capacitor is determined by its geometric size and the characteristics of the insulating medium between the two plates. When the capacitor is used under AC voltage, its reactive power is often used to represent the capacity of the capacitor, and the unit is var or kvar.

Classification of power capacitors

Power capacitors can be divided into 8 types according to their uses:

①Parallel capacitor: formerly known as phase-shifting capacitor. It is mainly used to compensate for the reactive power of the inductive load in the power system to improve the power factor, improve the voltage quality and reduce the line loss.

②Series capacitor: connected in series in the power frequency high-voltage transmission and distribution lines to compensate the distributed inductance of the line, improve the static and dynamic stability of the system, improve the voltage quality of the line, lengthen the power transmission distance and increase the transmission capacity.

③Coupling capacitors: mainly used for high-frequency communication, measurement, control, protection of high-voltage power lines, and as components in devices for extracting electric energy.

④ Circuit breaker capacitor: formerly known as voltage equalizing capacitor. Parallel connection acts as a voltage equalizer on the fracture of the ultra-high voltage circuit breaker so that the voltage between each fracture is uniform during the breaking process and when it is disconnected and can improve the arc extinguishing characteristics of the circuit breaker and increase the breaking capacity.

⑤Electrothermal capacitors: Used in electrothermal equipment systems with a frequency of 40-24000 Hz to improve the power factor and improve the characteristics of the circuit voltage or frequency.

⑥Pulse capacitor: It mainly plays the role of energy storage, and is used as basic energy storage components such as impulse voltage generator, impulse current generator, and oscillation circuit for circuit breaker test.

⑦ DC and filter capacitors: used in high-voltage DC devices and high-voltage rectifier and filter devices.

⑧Standard capacitor: used in the power frequency high voltage measurement dielectric loss circuit, as a standard capacitor or as a capacitive voltage divider for measuring high voltage.

Performance characteristics of power capacitors

1. High-quality capacitor

The self-healing low-voltage compensation capacitor is adopted, and the capacitor has a built-in temperature sensor to reflect the internal heating degree of the capacitor and realize over-temperature protection.

2. Embedded switch module

The smart power capacitor has a built-in switch module. The switching switch module is composed of a thyristor, a magnetic latching relay, a zero-crossing trigger conduction circuit, and a thyristor protection circuit, which realizes "zero switching" of the capacitor and ensures that there is no inrush current impact and no operating overvoltage during the switching process. The switch module responds quickly and can be operated frequently.

3. Modular structure

The smart power capacitor has a modular structure, small size, simple on-site wiring, and convenient maintenance. The expansion of the reactive power compensation system can be realized only by increasing the number of modules.

4. Perfect protection design

Smart power capacitors have functions such as power failure protection, short circuit protection, voltage phase loss protection, and capacitor overtemperature protection, which can effectively ensure the safety of capacitors and prolong the life of the equipment.

5. Advanced control technology

The control physical quantity is reactive power and adopts reactive power flow prediction and delay multi-point sampling technology to ensure no oscillation in switching. When the load is heavy, the reactive power is fully compensated.

6. Anti-switching oscillation technology

The unique design principle is adopted to prevent non-compensation or over-compensation caused by the crash of the controller and to prevent capacitor switching oscillation.

7. Automatic compensation of reactive power

Intelligent power capacitors automatically switch according to the magnitude of the reactive power of the load, dynamically compensate the reactive power, and improve the power quality. Smart capacitors can be used alone or multiple units can be used online.

8. Friendly man-machine interface

Display current, voltage, reactive power, and other equipment operating parameters; display switching status, composite switch module fault status, and communication status; and can conveniently realize debugging/working status switching and manual/automatic operation functions.

Application Fields of Power Capacitors

The main application fields of power capacitors are factory power distribution systems, residential area power distribution systems, municipal commercial buildings, traffic tunnel power distribution systems, box transformers, complete cabinet, outdoor distribution boxes, etc.

power capacitor Summarize

Power capacitors are used a lot in real life, and a few words can only understand the tip of the iceberg. What is more important is to understand its characteristics and functions in actual use. Theoretical knowledge is often just a learning method when understanding a certain transaction. It will be more complicated, and it needs to be analyzed through theory and then corrected by practical experience.