CN208207047U - Double resistance multi-channel type high voltage direct current photoelectricity flow measuring systems - Google Patents

Abstract

A kind of double resistance multi-channel type high voltage direct current photoelectricity flow measuring systems designed by the utility model, it includes the first analog-to-digital conversion module, second analog-to-digital conversion module, third analog-to-digital conversion module, 4th analog-to-digital conversion module, high voltage direct current photo-signal, which receives, calculates equipment, first fiber optical transceiver, second fiber optical transceiver, third fiber optical transceiver, 4th fiber optical transceiver, 5th fiber optical transceiver, six fibers transceiver, 7th fiber optical transceiver, 8th fiber optical transceiver, the first resistor and second resistance being connected in a high tension loop of hvdc transmission line.The utility model can accurately measure the variation of transient current and the distortion situation of current waveform.

Description

Dual-resistor multi-channel high-voltage DC photocurrent measurement system

technical field

The utility model relates to the technical field of DC transmission power equipment maintenance, in particular to a dual-resistor and multi-channel high-voltage DC photocurrent measurement system.

Background technique

With the rapid development of my country's economy, a large number of EHV and UHV DC transmission projects have been put into operation, and current measurement methods have also been put into operation in large quantities. With the construction of intelligent substations and centralized control centers, the photocurrent measurement method has also become popular, and a new resistance-type high-voltage DC photocurrent measurement method that is easy to maintain, low in cost, simple and practical has also emerged. However, the existing resistive high-voltage DC photocurrent measurement methods all adopt the form of a single resistor, and there is no redundant module, which shows weak robustness in practical applications, resulting in problems such as low reliability. Once such a current measurement failure occurs, the protection and control device will fail to operate.

Utility model content

The purpose of this utility model is to provide a double-resistor multi-channel high-voltage direct current photocurrent measurement system, which can accurately measure the change of instantaneous current and the distortion of current waveform.

In order to achieve this goal, a dual-resistance multi-channel high-voltage DC photocurrent measurement system designed by the utility model is characterized in that it includes a first analog-to-digital conversion module, a second analog-to-digital conversion module, and a third analog-to-digital conversion module. module, the fourth analog-to-digital conversion module, high-voltage DC photocurrent signal receiving and computing equipment, the first optical fiber transceiver, the second optical fiber transceiver, the third optical fiber transceiver, the fourth optical fiber transceiver, the fifth optical fiber transceiver, the sixth The optical fiber transceiver, the seventh optical fiber transceiver, the eighth optical fiber transceiver, the first resistor and the second resistor connected in series in the primary high-voltage circuit of the high-voltage DC line, wherein the first analog-to-digital conversion module and the second analog-to-digital conversion module , the voltage analog measurement terminals of the third analog-to-digital conversion module and the fourth analog-to-digital conversion module are respectively connected in parallel with the first resistor and the second resistor connected in series, and the digital signal output terminal of the first analog-to-digital conversion module is connected to the first optical fiber transceiver The digital signal input end of the first optical fiber transceiver, the optical signal output end of the first optical fiber transceiver is connected to the optical signal input end of the second optical fiber transceiver through an optical fiber, and the digital signal output end of the second optical fiber transceiver is connected to a high voltage DC photocurrent signal receiving computing device The first digital signal communication interface;

The digital signal output end of the second analog-to-digital conversion module is connected to the digital signal input end of the third optical fiber transceiver, the optical signal output end of the third optical fiber transceiver is connected to the optical signal input end of the fourth optical fiber transceiver through an optical fiber, and the fourth optical fiber The digital signal output end of the transceiver is connected to the second digital signal communication interface of the high-voltage DC photocurrent signal receiving computing device;

The digital signal output end of the third analog-to-digital conversion module is connected to the digital signal input end of the fifth optical fiber transceiver, the optical signal output end of the fifth optical fiber transceiver is connected to the optical signal input end of the sixth optical fiber transceiver through an optical fiber, and the sixth optical fiber The digital signal output end of the transceiver is connected to the third digital signal communication interface of the high voltage DC photocurrent signal receiving computing device;

The digital signal output end of the fourth analog-to-digital conversion module is connected to the digital signal input end of the seventh optical fiber transceiver, the optical signal output end of the seventh optical fiber transceiver is connected to the optical signal input end of the eighth optical fiber transceiver through an optical fiber, and the eighth optical fiber The digital signal output end of the transceiver is connected to the fourth digital signal communication interface of the high-voltage direct current photocurrent signal receiving computing device.

The dual-resistor and multi-channel high-voltage DC photocurrent measurement system of the present utility model utilizes the basic principle of voltage u=current i*resistance r, converts the primary current into a voltage model, and sends it to the high-voltage DC photocurrent signal to receive and calculate by optical fiber equipment. Because the resistance is fixed, the size of the voltage u changes proportionally with the change of the current, and can reflect the change of the instantaneous current and the distortion of the current waveform.

The utility model has the advantages of:

(1) Compared with the traditional current measurement method using electromagnetic current transformer, this utility model does not have electromagnetic saturation phenomenon, and can more accurately reflect the change of fault current waveform. The traditional electromagnetic current transformer exists outside the area Failure will lead to electromagnetic coil saturation, causing differential protection malfunction;

(2) Because the utility model uses optical fiber as the transmission medium, there is no defect of an insulation flashover, and there are no failures such as oil leakage, air leakage, and current transformer explosion;

(3) The utility model is equipped with redundant backup equipment, and it is not necessary to perform a power outage of the equipment when troubleshooting, which greatly reduces the number of power outages of the equipment.

Description of drawings

Fig. 1 is the structural representation of the utility model;

In the figure, 1—the first resistor, 2—the second resistor, 3—the primary high voltage circuit of the high voltage DC line, 4—the first analog-to-digital conversion module, 5—the second analog-to-digital conversion module, 6—the third analog-to-digital conversion Module, 7—the fourth analog-to-digital conversion module, 8—high voltage DC photocurrent signal receiving and computing equipment, 9—the first optical fiber transceiver, 10—the second optical fiber transceiver, 11—the third optical fiber transceiver, 12—the fourth Optical fiber transceiver, 13—fifth optical fiber transceiver, 14—sixth optical fiber transceiver, 15—seventh optical fiber transceiver, 16—eighth optical fiber transceiver

Detailed ways

Below in conjunction with accompanying drawing and specific embodiment the utility model is described in further detail:

Since the DC current has no alternating effect, electromagnetic induction cannot be formed, and the current cannot be directly measured. Therefore, a dual-resistor multi-channel high-voltage DC photocurrent measurement system designed by the utility model, as shown in Figure 1, includes the first modulus Conversion module 4, second analog-to-digital conversion module 5, third analog-to-digital conversion module 6, fourth analog-to-digital conversion module 7, high-voltage DC photocurrent signal receiving and computing equipment 8, first optical fiber transceiver 9, second optical fiber transceiver 10. The third optical fiber transceiver 11, the fourth optical fiber transceiver 12, the fifth optical fiber transceiver 13, the sixth optical fiber transceiver 14, the seventh optical fiber transceiver 15, the eighth optical fiber transceiver 16, and the The first resistor 1 and the second resistor 2 in the primary high-voltage circuit 3 (the ground voltage of the primary high-voltage circuit 3 of the high-voltage DC line is generally ±400kV, ±500kV, ±800kV, ±1100kV, the voltage at both ends of the first and second resistors 0-20mV), wherein, the voltage analog measurement terminals of the first analog-to-digital conversion module 4, the second analog-to-digital conversion module 5, the third analog-to-digital conversion module 6 and the fourth analog-to-digital conversion module 7 are respectively connected to the serially connected The first resistor 1 and the second resistor 2 are connected in parallel, the digital signal output end of the first analog-to-digital conversion module 4 is connected to the digital signal input end of the first optical fiber transceiver 9, and the optical signal output end of the first optical fiber transceiver 9 is connected through an optical fiber The optical signal input end of the second optical fiber transceiver 10, the digital signal output end of the second optical fiber transceiver 10 is connected to the first digital signal communication interface of the high voltage DC photocurrent signal receiving computing device 8;

The digital signal output end of the second analog-to-digital conversion module 5 is connected to the digital signal input end of the third optical fiber transceiver 11, and the optical signal output end of the third optical fiber transceiver 11 is connected to the optical signal input end of the fourth optical fiber transceiver 12 by an optical fiber , the digital signal output end of the fourth optical fiber transceiver 12 is connected to the second digital signal communication interface of the high-voltage DC photocurrent signal receiving computing device 8;

The digital signal output end of the third analog-to-digital conversion module 6 is connected to the digital signal input end of the fifth optical fiber transceiver 13, and the optical signal output end of the fifth optical fiber transceiver 13 is connected to the optical signal input end of the sixth optical fiber transceiver 14 by an optical fiber The digital signal output end of the sixth optical fiber transceiver 14 is connected to the third digital signal communication interface of the high voltage DC photocurrent signal receiving computing device 8;

The digital signal output end of the fourth analog-to-digital conversion module 7 is connected to the digital signal input end of the seventh optical fiber transceiver 15, and the optical signal output end of the seventh optical fiber transceiver 15 is connected to the optical signal input end of the eighth optical fiber transceiver 16 through an optical fiber , the digital signal output end of the eighth optical fiber transceiver 16 is connected to the fourth digital signal communication interface of the high voltage DC photocurrent signal receiving computing device 8 .

In the above technical solution, the high-voltage direct-current photocurrent signal receiving and calculating device 8 is used to calculate the corresponding high-voltage direct-current line according to the received digital signal of each channel and the resistance values of the first resistor 1 and the second resistor 2 respectively. The high-voltage loop current value, and when the calculated primary high-voltage loop current values of all high-voltage DC lines are equal, the primary high-voltage loop current value of the high-voltage DC line calculated by the high-voltage DC photocurrent signal receiving computing device 8 is a correct value.

In the above technical solution, the total resistance value of the first resistor 1 and the second resistor 2 is determined by the measurement range, so that the maximum current value multiplied by the total resistance value is equal to 20mV, for example, when the maximum current is 3000A, the first resistor 1 plus the second resistor 2 As long as the resistance value is equal to 6.66μΩ, 3000A multiplied by 6.66μΩ is equal to 20mV. The above 20mV value is not fixed and is selected according to the specific project.

In the above technical solution, the high-voltage direct current photocurrent signal receiving and computing device 8 can be SG101 or SG102 produced by ABB or PCS-221JA produced by NARI.

In the above calculation scheme, the dual-resistor mode in series is used at the same time, which can realize the advantages of dual-resistance series mutual compensation and improve measurement reliability; the total resistance value of the first and second resistors is relatively small, only 10 ^-6 ohm level, and the accuracy requirement is relatively high , Manufacturing is difficult. Due to the resistance manufacturing process, the difficulty of adding two resistors to achieve a required high-precision resistance is much less than that of a single resistor to achieve high-precision resistance.

In the above technical solution, one of the first analog-to-digital conversion module 4, the second analog-to-digital conversion module 5, the third analog-to-digital conversion module 6 and the fourth analog-to-digital conversion module 7 is a redundant analog-to-digital conversion module.

In the above technical solution, the digital signal output terminals of the first analog-to-digital conversion module 4, the second analog-to-digital conversion module 5, the third analog-to-digital conversion module 6 and the fourth analog-to-digital conversion module 7 output voltage signals.

A current measuring method of the above-mentioned system, it comprises the steps:

Step 1: The current of the primary high-voltage loop 3 of the high-voltage DC line is converted into a corresponding voltage through the first resistor 1 and the second resistor 2, and is respectively converted by the first analog-to-digital conversion module 4, the second analog-to-digital conversion module 5, and the second analog-to-digital conversion module. The voltage analog measurement terminals of the three analog-to-digital conversion modules 6 are collected;

Step 2: the first analog-to-digital conversion module 4, the second analog-to-digital conversion module 5, and the third analog-to-digital conversion module 6 respectively convert the collected voltage analog quantities into voltage digital quantities;

Step 3: The first optical fiber transceiver 9 converts the voltage digital quantity output by the first analog-to-digital conversion module 4 into a corresponding first voltage optical signal, and the first voltage optical signal is transmitted to the second optical fiber transceiver 10 by an optical fiber , the second optical fiber transceiver 10 converts the first voltage optical signal into a corresponding first voltage digital signal, and the second optical fiber transceiver 10 transmits the first voltage digital signal to the high voltage DC photocurrent signal receiving computing device 8 The first digital signal communication terminal;

The third optical fiber transceiver 11 converts the voltage digital quantity output by the second analog-to-digital conversion module 5 into a corresponding second voltage optical signal, and the second voltage optical signal is transmitted to the fourth optical fiber transceiver 12 by an optical fiber. The optical fiber transceiver 12 converts the second voltage optical signal into a corresponding second voltage digital signal, and the fourth optical fiber transceiver 12 transmits the second voltage digital signal to the second high voltage DC photocurrent signal receiving computing device 8 Digital signal communication terminal;

The fifth optical fiber transceiver 13 converts the voltage digital quantity output by the third analog-to-digital conversion module 6 into a corresponding third voltage optical signal, and the third voltage optical signal is transmitted to the sixth optical fiber transceiver 14 by an optical fiber. The optical fiber transceiver 14 converts the third voltage optical signal into a corresponding third voltage digital signal, and the sixth optical fiber transceiver 14 transmits the third voltage digital signal to the third high voltage DC photocurrent signal receiving computing device 8 Digital signal communication terminal;

Step 4: The high-voltage DC photocurrent signal receiving computing device 8 is based on the received first voltage digital signal, the second voltage digital signal and the third voltage digital signal, and combines the resistance of the first resistor 1 and the second resistor 2 Calculate the primary high-voltage loop current values of the corresponding three high-voltage direct current lines respectively, when the primary high-voltage loop current values of the three high-voltage direct current lines calculated are equal (this design makes the utility model have a self-check function, which improves the current measurement accuracy), the primary high-voltage loop current value of the high-voltage direct current line calculated by the high-voltage direct current photocurrent signal receiving computing device 8 is a correct value;

Step 5: When the calculated primary high-voltage circuit current values of the three high-voltage direct current lines are not equal, respectively conduct voltage acquisition branches corresponding to the first voltage digital signal, the second voltage digital signal, and the third voltage digital signal Fault inspection, when one of the faults is found, disconnect the faulty voltage acquisition branch, and connect the fourth analog-to-digital conversion module 7, the seventh optical fiber transceiver 15 and the eighth optical fiber transceiver 16 as redundant backup voltage acquisition branches into the system to replace the faulty voltage acquisition branch. When the primary high-voltage loop current values of the three high-voltage direct current lines calculated according to the three-way voltage digital signals at this time are equal, the high-voltage direct current signal receiving calculation device 8 calculates the high-voltage direct current The primary high-voltage loop current value of the line is the correct value.

The content not described in detail in this specification belongs to the prior art known to those skilled in the art.

Claims (4)

1. a kind of dual-resistance multi-channel type high-voltage direct-current photocurrent measuring system is characterized in that: it comprises the first analog-to-digital conversion module (4), the second analog-to-digital conversion module (5), the third analog-to-digital conversion module (6 ), a fourth analog-to-digital conversion module (7), a high-voltage direct current photocurrent signal receiving computing device (8), a first optical fiber transceiver (9), a second optical fiber transceiver (10), a third optical fiber transceiver (11) , the fourth optical fiber transceiver (12), the fifth optical fiber transceiver (13), the sixth optical fiber transceiver (14), the seventh optical fiber transceiver (15), the eighth optical fiber transceiver (16), connected in series at high voltage direct current The first resistor (1) and the second resistor (2) in the primary high-voltage circuit (3) of the line, wherein, the first analog-to-digital conversion module (4), the second analog-to-digital conversion module (5), the third analog-to-digital The voltage analog measurement terminals of the conversion module (6) and the fourth analog-to-digital conversion module (7) are respectively connected in parallel with the first resistor (1) and the second resistor (2) connected in series, and the first analog-to-digital conversion module (4) The digital signal output end of the first optical fiber transceiver (9) is connected to the digital signal input end of the first optical fiber transceiver (9), and the optical signal output end of the first optical fiber transceiver (9) is connected to the optical signal input end of the second optical fiber transceiver (10) by an optical fiber, The digital signal output end of the second optical fiber transceiver (10) is connected to the first digital signal communication interface of the high-voltage DC photocurrent signal receiving computing device (8); The digital signal output end of the second analog-to-digital conversion module (5) is connected to the digital signal input end of the third optical fiber transceiver (11), and the optical signal output end of the third optical fiber transceiver (11) is connected to the fourth optical fiber transceiver through an optical fiber The optical signal input end of (12), the digital signal output end of the fourth optical fiber transceiver (12) is connected to the second digital signal communication interface of the high voltage DC photocurrent signal receiving computing device (8); The digital signal output end of the third analog-to-digital conversion module (6) is connected to the digital signal input end of the fifth optical fiber transceiver (13), and the optical signal output end of the fifth optical fiber transceiver (13) is connected to the sixth optical fiber transceiver through an optical fiber The optical signal input end of (14), the digital signal output end of the sixth optical fiber transceiver (14) is connected to the third digital signal communication interface of the high voltage DC photocurrent signal receiving computing device (8); The digital signal output end of the fourth analog-to-digital conversion module (7) is connected to the digital signal input end of the seventh optical fiber transceiver (15), and the optical signal output end of the seventh optical fiber transceiver (15) is connected to the eighth optical fiber transceiver through an optical fiber The optical signal input end of (16), the digital signal output end of the eighth optical fiber transceiver (16) is connected to the fourth digital signal communication interface of the high-voltage DC photocurrent signal receiving computing device (8). 2. The dual-resistor multi-channel high-voltage direct-current photocurrent measurement system according to claim 1, characterized in that: the high-voltage direct-current photocurrent signal receiving computing device (8) is used to combine and combine The resistance values of the first resistor (1) and the second resistor (2) respectively calculate the primary high-voltage loop current values of the corresponding high-voltage DC lines, and when the calculated primary high-voltage loop current values of all high-voltage DC lines are equal, the high-voltage DC The primary high-voltage loop current value of the high-voltage direct current line calculated by the photocurrent signal receiving computing device (8) is a correct value. 3. the dual-resistance multi-channel type high-voltage direct-current photocurrent measurement system according to claim 1, is characterized in that: the first analog-to-digital conversion module (4), the second analog-to-digital conversion module (5), the third analog-to-digital conversion module One of the digital conversion module (6) and the fourth analog-to-digital conversion module (7) is a redundant analog-to-digital conversion module. 4. dual-resistor multi-channel type high-voltage direct-current photocurrent measuring system according to claim 1, is characterized in that: described first analog-to-digital conversion module (4), the second analog-to-digital conversion module (5), the third analog-to-digital conversion module (5), the third analog-to-digital conversion module Both the digital signal output terminals of the digital conversion module (6) and the fourth analog-to-digital conversion module (7) output voltage signals.