The VoltageAnalyzer can be used to measure all types of high voltages. The frequency responsespace the space DC to very high pulse frequencies inspace , making it ideal for high voltage, surge voltage, and partial discharge measurements.

The active probe measures voltages and voltage peaks where they occur, e.g., in electric motor at motor terminal board. These voltage peaks can be caused by a converter. In a surge test , the peaks surge test be caused by overshoots in the supply line.

Voltage measurement during surge test partial discharge

It may happen that the voltage surge tester internally in surge tester device under test voltage exactly device under test the voltage device under test . This is because the inevitable line inductances and capacitances between the measuring lines can device under test the voltage curve of the surge signal on its way to device under test . The steeper the surge impulse , the more pronounced this difference is.

In order to accurately measurement the partial discharge onset voltage actually motor terminal board to motor terminal board , for example during a partial discharge test, it is terminal board take a measurement using the active probe directly on terminal board .

The VoltageAnalyzer was developed precisely for this purpose: The voltage measurement is performed between the phases between which the surge test also surge test .

Test a three-phase motor quickly and without time-consuming reconnections, the VoltageAnalyzer has three measuring connections. These are connected directly to the terminals U, V, and W of the test object using the shortest possible measuring cables. The measuring point is switched between the three measuring connections in the VoltageAnalyzer fully automatically and synchronously with surge test.

Communication with the test device

The VoltageAnalyzer has a communication link to surge tester. This link is used to control it remotely and surge tester the measured values to the surge tester . During the surge test , the VoltageAnalyzer automatically surge test to the connections between which the test is currently being performed. This remote control is performed by the surge tester.

measured values

The following voltages are measured automatically by the active probe:

• _USpitze: maximum amplitude
• _Peak-to-peak: maximum voltage the highest positive and negative amplitude
• Rise time in ns

Atoutput , the switching edgesoutput still very close to the optimal square wave shape. The figure shows the voltage pulses between two phases at the output terminals of the converter. The voltage pulses, pulse width modulation, and the negative and positive half-waves of the sine wave are clearly visible.

The voltage level is determined by the AC supply voltage of the frequency converter. Since each frequency converter first rectifies the input voltage, each converter is equipped with a DC link circuit consisting of capacitors charged to the input voltage x √2. For 230 V AC, this results in a value of 320 V DC, and for 400 V AC, a value of approx. 560 V DC. The figure shows a level of 315 V DC, which corresponds well with the 230 V AC supply.

The electric motor connected to the frequency converter via cables.

Cables are not ideal electrical components. They consist of resistances, cable inductances, and coupling capacitances between the cores. As a result, the ideal square-wave pulse that is still present at output frequency converter becomes electric motor distorted on its way to electric motor .

• Active probe with integrated switch-over three phases
• Potential-free voltage measurement
• Precise surge test on the winding
• Elimination of voltage influence on the measurement lead
• Precise measurement of TE voltages – PDIV, RPDIV, PDEV, RPDEV
• Perfect for standard-compliant measurement in accordance with DIN EN 60034-18-41:2021
• Includes determination of pulse rise times
• Determination of voltage peaks caused by frequency converters