DX8000 Differential Frequency Dielectric Loss Tester with High Precision ±1% Variable Frequency 50Hz-60Hz and Multiple Testing Modes

The DX8000 Variable Frequency Dielectric Loss Tester is a high-precision instrument designed for on-site or laboratory testing of dielectric loss tangent values and capacitance parameters in various high-voltage power equipment, widely used in power plants and substations. Featuring an integrated design, it incorporates a dielectric loss test bridge, variable-frequency voltage regulator, step-up transformer, and SF6 high-stability standard capacitors. The high-voltage supply is generated by the instrument's internal inverter and stepped up via a transformer for sample testing. It supports frequency settings including 50.0 Hz, 47.5 Hz/52.5 Hz, 45.0 Hz/55.0 Hz, 60.0 Hz, 57.5 Hz/62.5 Hz, and 55.0 Hz/65.0 Hz, employing digital notch filtering technology to eliminate interference from power-frequency electric fields and effectively address measurement challenges under strong electromagnetic interference conditions. The instrument is also suitable for testing under generator-powered conditions after complete power outages. Equipped with a temperature-controlled insulating oil cup, it enables comprehensive measurement of dielectric losses in insulating oils. The instrument primarily features the following characteristics:

• Super-large LCD display in Chinese
  The device features a user-friendly design with a high-end full-touch LCD display and an intuitive interface, ensuring clear guidance for every step without requiring additional training. A single tap completes the entire measurement process, making it the ideal intelligent dielectric loss measurement instrument available today.
• Massive Data Storage
  The instrument is equipped with a calendar chip and high-capacity storage, capable of storing 200 data sets. It can save test results in chronological order, allow instant access to historical records, and supports print output.
• Scientifically advanced data management
  Instrument data can be exported via a USB drive and viewed or managed on any PC.
• Multiple Testing Modes
  The instrument supports various testing methods including internal high voltage, external high voltage, internal standard, external standard, forward connection, reverse connection, and self-excitation mode. Under the external standard with external high voltage and forward connection configuration, it can measure dielectric loss at high voltages (greater than 10 kV).
• Measuring the CVT without disconnecting the high-voltage leads
  The instrument can accurately measure the dielectric loss and capacitance values of a CVT without removing its high-voltage leads.
• Measuring C0 using the CVT reverse-biased shielding method
  The instrument can employ the reverse-shielding method to measure the dielectric loss and capacitance values at terminal C0 of the CVT.
• High-speed sampling signal
  The inverter and sampling circuit inside the instrument are fully digitally controlled, with continuously adjustable output voltage.
• Multiple layers of protection ensure safety and reliability.
  The instrument features multiple protection mechanisms against input voltage fluctuations, high-voltage currents, output short circuits, power supply failures, overvoltages, overcurrents, and temperature extremes, ensuring its safety and reliability. It also includes a grounding detection function that prevents operation or testing of ungrounded devices. In case of incorrect connection to a 380 V power source, an alarm function activates to safeguard the instrument from damage.
• CVT testing completed in one step
  This instrument can also measure the dielectric loss and capacitance of fully sealed CVTs (capacitive voltage transformers) C1 and C2, enabling simultaneous testing of both components. It additionally measures the CVT's transformation ratio and voltage angle difference.
• LCR fully automatic measurement
  Fully automatic measurement of inductance, capacitance, and resistance with angle display.

Under the influence of alternating voltage, a dielectric material consumes part of its electrical energy, which is converted into thermal energy and resulting in losses. This energy loss is termed dielectric loss. When an alternating voltage is applied to a dielectric, a phase angle difference ψ exists between the voltage and current within the material; the complementary angle δ of ψ is called the dielectric loss angle, while its tangent tgδ is referred to as the dielectric loss tangent. The value of tgδ serves as a key parameter for quantifying dielectric losses. The measurement circuit consists of a reference circuit (Cn) and a test circuit (Cx), as illustrated in Figure 2-1. The reference circuit comprises a high-stability standard capacitor integrated with the measurement circuitry, whereas the test circuit includes the sample device and corresponding measurement components. The measurement circuit is composed of a sampling resistor, a pre-amplifier, and an A/D converter. By measuring the amplitude and phase difference of currents in both circuits, a digital signal processor employs real-time digitization and vector analysis to determine the capacitance value and dielectric loss tangent of the sample. The instrument incorporates built-in anti-interference measures to ensure accurate measurements even under external electric field disturbances. Figure 2-1 Measurement Principle Diagram

IV. Panel Description

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