Application Cases

Power capacitors serve as crucial reactive power compensation and overvoltage protection devices in electrical power systems. Throughout their decades-long operational lifespan, they frequently endure cumulative effects from various impulse overvoltages. Research indicates that some power capacitors withstand up to tens of thousands of impulse overvoltage events. The cumulative impact of these overvoltages leads to the degradation of solid insulating media, posing potential risks to equipment safety.

As essential components for reactive power compensation and overvoltage protection, power capacitors play a vital role in power systems and are widely deployed. Typically, a single converter station may utilize thousands of power capacitors. The failure of any single capacitor can potentially trigger system shutdowns, making their reliable operation critical to power system stability. Since power capacitors are energy storage devices operating at high internal electric field strengths, they are particularly sensitive to impulse overvoltages and high-frequency voltage surges during operation. Furthermore, their sealed internal construction makes them susceptible to internal overheating when line faults occur, potentially leading to capacitor ignition or explosion incidents that could cause significant losses to the power system.

Research Background
Significant research has been conducted internationally on the breakdown characteristics of polypropylene films used in power capacitors. Scholars have investigated the DC and AC breakdown characteristics of polypropylene films and proposed the trap theory of electrical breakdown. However, studies on the breakdown characteristics of polypropylene films under impulse voltage conditions remain limited. Researchers including M. Nagao from Nagoya University in Japan conducted withstand voltage tests on polypropylene films using DC voltage under different temperature conditions. Their findings revealed that in low-temperature regions, the electrical strength of polypropylene films remains largely independent of ambient temperature, electric field rise rate, and sample type, whereas in high-temperature regions, electrical strength decreases with increasing temperature.

Experimental System
In experiments, piezoelectric sensors function as acoustic signal transmitters, detecting and reflecting pressure waves that carry space charge distribution information. The weak voltage signals output by piezoelectric sensors are amplified and captured by oscilloscopes for testing. Signal generators produce excitation signals that are amplified by the ATA-67100 high-voltage amplifier to provide a DC polarization electric field for polypropylene film samples. This setup enables the study of internal space charge distribution under specific DC electric fields. Protective resistors serve to limit current and prevent damage to the high-voltage amplifier from excessive current in cases of insulation breakdown or surface flashover on samples.

Research Content
After cumulative exposure to impulse voltages, polypropylene films undergo a series of internal changes, potentially including alterations in their compositional structure. This research investigates the cumulative failure characteristics of polypropylene films used in power capacitors under different impulse voltage waveforms. Through experimental acquisition of breakdown characteristics and cumulative breakdown behavior under various impulse voltage waveforms, the study examines how waveform parameters influence these properties. It further explores the cumulative damage mechanisms in polypropylene films subjected to multiple impulse voltages and analyzes the underlying action mechanisms.

Figure: ATA-7000 Series High-Voltage Amplifier Specifications

The ATA-7000 series represents an ideal high-voltage amplifier capable of amplifying both AC and DC signals. With single-ended output of 20kVp-p (±10kVp) high voltage, it can drive high-voltage loads. Featuring digitally controlled adjustable voltage gain and one-touch settings storage, it provides users with convenient and straightforward operational options.

Application Scenarios of ATA-7000 Series High-Voltage Amplifiers:
Dielectric elastomer testing, EHD electrohydrodynamic printing, Ferroelectric testing, Plasma research, 3D printing, Material polarization, Electrospinning, Microfluidics.

Additional Applications:
Soft robotics, Electroactive polymers, Piezoelectric drive and control, Laser modulation, Semiconductor research, Electrostatic deflection, Electrorheological fluids, AC/DC biasing, Particle accelerators, Mass spectrometers, Material characterization, DBD plasma actuators, Atmospheric pressure plasma, Corona discharge, Dielectric breakdown testing, Ion beam deflection, Electron beam deflection, Electrophoresis, Dielectrophoresis, Ion engines, Particle accelerators, Material characterization, Electrostatic actuators, Electrostatic spraying, Electrostatic coating, Solar panel (photovoltaic cell) testing, Electro-optic modulation, Electrophotography, Corona generators, Electrostatic chucks, Electrostatic deflection of charged particle beams, etc.