PowerHV products

Insulated cylinder type: can be used in a single unit or cascaded, modular structure, easy to stack up. The insulated cylinder is made of epoxy reinforced glass fibers and filled with oil. Such a structure is suitable for indoor use, usually for short time operation (in accordance with IEC standard) at rated current. After running for the specified maximum time at certain current, the test transfromer needs to be cooled to ambient temperature, which means the usual pattern is intermittent operation.

The feed through transformer is designed as “?” shape iron core, one side of the core can be opened at 45°. This design makes it easy to install test object (cable). Considering the universality of the use of feed through transformer on site, the design for the capacity is in a unified and suitable range. Before testing we increase or decrease the quantity of feed through transformers according to different cross-section & length of the cable. There are two taps at the primary of feed through transformer. After calculation and verification, we take consideration of the DC resistance, reactance value, number of turns and insulation of the coil in the design of feed through transformer to ensure the safety & reliability for the operation of multiple units in parallel. The cross-section of the iron core which is leaning on one side is 1.4 times more than the area of iron core which is straight. This can decrease the magnetic resistance of magnetic circuit.

DC high voltage test system uses AC voltage multiplication and rectification. Selection of capacitor and number of stage is significant to the performance of DC generator. HV silicone stack uses hydraulic pressure for polarity changeover. It can be realized quickly by control system in long-distance. Grounding switch quickly & effectively releases the residual charge. SCR automatic tracking function keeps the voltage of test object stable.

PowerHV offers the high-precision measuring bridge and standard capacitor for the C & tan delta measuring. The QS87 is a high precision bridge particularly for use in laboratory. It mainly takes advantage of current comparison, which makes it extraordinary precise and reliable in measurement and distinguishes the bridge from Schering bridge and high voltage dielectric loss tester. The use of computer-aided data processing unit makes the measurement more intuitive and convenient. Using in conjunction with high voltage standard capacitors, the bridge is functioned to measure under high voltage capacitance and tgδ of high voltage products such power cables, bushings, power capacitors, reactors and transformers. It can also test dielectric constant and tgδ of solid/liquid insulating materials, or ratio error and phase error of power/instrument transformers.

High-voltage dividers are used to measure voltages and decouple partial discharges in high-voltage test systems. Depending on the specific type, they are used to measure alternating voltage (AC), direct voltage (DC), lightning impulse voltage (LI), and switching impulse voltage (SI) systems. High-voltage dividers by PowerHV comply with the relevant IEC standards 60060, 61083, and 60052. The systems are available for both indoor and outdoor use.

The impulse current shunts are designed for impulse current measurements on low inductive test objects. They are primarily used for impulse current measurements on power transformers (IEC 60076-3). Yet they can also be used for impulse current measurements with wave shapes 4/10 µs, 1/20 µs, and 30/80 µs on metal-oxide surge arresters according to IEC 62475. They are available with a rated resistance ranging from 0.1 ohms to 10 ohms and a rated current ranging from 100,000 A to 50 A.

Impulse Current Test Systems are manufactured for testing equipment applied in medium and high voltage transmission & distribution systems against the effects of lightning strokes (direct or indirect) or against electromagnetic interference effects.