Apparatus, system and method for measuring high voltage on high-voltage node

A system for measuring a high voltage signal on a high-voltage node, comprising:

• a high voltage divider connected with the high-voltage node, the high voltage divider comprising a high voltage arm and a low voltage arm;
• and
• a measuring apparatus provided in a terminal box coupled with the high voltage divider, the measuring apparatus comprising:
• a power electronic converter comprising a first AC-to-DC converter, a first DC-to-AC converter and a second AC-to-DC converter, the first AC-to-DC converter being connected with the low voltage arm to obtain a voltage measurement signal, the first DC-to-AC converter being configured to output a modulated signal of the voltage measurement signal, the second AC-to-DC converter being configured to output a demodulated signal of the voltage measurement signal;
• a high-frequency transformer comprising a primary coil connected with an output terminal of the first DC-to-AC converter to receive the modulated signal and a secondary coil connected with an input terminal of the second AC-to-DC converter;
• and
• a controller configured to provide control signals to control switching devices of the first DC-to-AC converter to control a turn-on sequence of each switching device such that the first DC-to-AC converter outputs the modulated signal, to calculate signal parameters including phase information and amplitude information of the high voltage on the high-voltage node, and to output the calculated signal parameters.

A method for measuring a high voltage signal on a high-voltage node using a measuring apparatus,

• the measuring apparatus comprising a power electronic converter, a high-frequency transformer and a controller,
• the power electronic converter comprising a first AC-to-DC converter, a first DC-to-AC converter and a second AC-to-DC converter, the first AC-to-DC converter being configured to obtain a voltage measurement signal of the high voltage on the high-voltage node, the first DC-to-AC converter being configured to output a modulated signal of the voltage measurement signal, the second AC-to-DC converter being configured to output a demodulated signal of the voltage measurement signal;
• the high-frequency transformer being coupled between the first DC-to-AC converter and the second AC-to-DC converter to transmit the modulated signal;
• the method comprising providing, at the controller, control signals to switching devices of the first DC-to-AC converter to control a turn-on sequence of each switching device such that the first DC-to-AC converter outputs the modulated signal;
• and
• the method further comprising calculating, at the controller, signal parameters of phase information and amplitude information of the high voltage on the high-voltage node, and outputting the calculated signal parameters.