Device and method for live detecting partial discharge of overhead line in distribution network and equipment along line

A device for live detecting a partial discharge of an overhead line in a distribution network and equipment along the line, comprising:

• a master detection unit, a slave detection unit, and a main control computer, wherein the master detection unit and the slave detection unit are respectively connected with the main control computer;
• wherein the master detection unit comprises:
• a master synchronous pulse transmitting module, master partial discharge sensor modules, master insulating handles, master communication optical fibers, and a master detection host;
• the master synchronous pulse transmitting module and the master partial discharge sensor modules are respectively connected with the master detection host through the master communication optical fibers;
• the master insulating handles are connected with the master synchronous pulse transmitting module and the master partial discharge sensor modules for live erecting the master synchronous pulse transmitting module and the master partial discharge sensor modules on the overhead line;
• wherein the slave detection unit comprises:
• a slave synchronous pulse transmitting module, slave partial discharge sensor modules, slave insulating handles, slave communication optical fibers, and a slave detection host;
• the slave synchronous pulse transmitting module and the slave partial discharge sensor modules are respectively connected with the slave detection host through the slave communication optical fibers;
• the slave insulating handles are connected with the slave synchronous pulse transmitting module and the slave partial discharge sensor modules for live erecting the slave synchronous pulse transmitting module and the slave partial discharge sensor modules on the overhead line;
• wherein the main control computer sends a clock calibration instruction, and the master detection unit and the slave detection unit receive a global positioning system (GPS) timing signal according to the instruction, and internal clocks of the master detection unit and the slave detection unit are updated according to the signal to complete clock calibration;
• a first synchronous pulse signal is transmitted by the synchronous trigger controlled by a microprocessor of the master detection unit, and is coupled to an overhead line;
• the first synchronous pulse signal transmitted by the master detection unit propagates along the overhead line to the slave;
• a partial discharge sensor module of the slave detection unit detects this pulse and triggers a synchronous pulse trigger in the slave detection host;
• a second synchronous pulse signal is transmitted by a synchronous pulse transmitter triggered by a slave synchronous pulse trigger, and is coupled to the overhead line,
• the second synchronous pulse signal transmitted from the slave detection unit propagates to the master detection unit along the overhead line,
• a partial discharge sensor module of the master detection unit detects the second synchronous pulse signal transmitted from the slave detection unit;
• the slave detection host and the main detection host collect partial discharge data;
• a propagation time T of a high-frequency pulse signal on the detected overhead line is obtained according to signal data collected by the master detection unit and the slave detection unit at two ends, and a calculation formula is as follows:
• T
• =
• (
• t
• 4
• -
• t
• 1
• )
• -
• (
• t
• 3
• -
• t
• 2
• )
• 2
• ,
• (
• 1
• )
• where t1 is a transmission time, namely a starting time of the first pulse signal, t2 is a time of receiving the first pulse signal from the slave detection unit, namely a receiving time, t3 is a starting time of the second pulse signal, and t4 is a receiving time of the second pulse signal;
• the starting time of the first synchronous pulse transmitted by the master detection unit is defined as a first reference zero t1, and a reference zero of partial discharge signal data collected from the slave detection unit is calculated as a second reference zero (t2−T), so detection data of the detection units at two ends are accurately synchronized, the partial discharge location is calculated as follows:
• l
• P
• ⁢
• D
• =
• L
• A
• ⁢
• B
• +
• v
• ·
• [
• (
• t
• A
• -
• t
• 1
• )
• -
• (
• t
• B
• -
• t
• 2
• +
• T
• )
• ]
• 2
• ,
• (
• 2
• )
• where IPD is a distance between the partial discharge location and the master detection unit, LAB is a total length of the overhead line, tA is a time taken for the partial discharge signal to reach the master detection unit, and tB is a time taken for the partial discharge signal to reach the slave detection unit;
• a total length LAB of the overhead line is calculated by a following formula:
• L
• AB
• =
• T
• ·
• v
• =
• [
• (
• t
• 4
• -
• t
• 1
• )
• -
• (
• t
• 3
• -
• t
• 2
• )
• ]
• ·
• v
• ,
• (
• 3
• )
• where T is a propagation time of the first synchronous pulse signal from the master to the slave, and v is a propagation speed of the first synchronous pulse signal;
• where the main control computer calculates a partial discharge location according to the first partial discharge information and the second partial discharge information based on a clock synchronization result.