CN112731248A - Electronic distribution automation feeder terminal test conversion equipment - Google Patents
Electronic distribution automation feeder terminal test conversion equipment Download PDFInfo
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Abstract
The invention discloses an electronic distribution automation feeder terminal test conversion device, which comprises an acquisition module, a test module and a conversion module, wherein the acquisition module is used for acquiring a first analog quantity signal value T1 output by an automatic test platform of a distribution automation feeder terminal; a conversion module for converting the first analog signal value T1 into a second analog signal value T2; the acquisition module is used for acquiring a second analog quantity signal value T2 and feeding back the second analog quantity signal value T2 to the acquisition module; the obtaining module is further prestored with a fixed transformation ratio K, a first precision threshold D1 and a second precision threshold D2, and is used for adjusting the conversion module according to the fixed transformation ratio K, the second analog quantity signal value T2 and the first analog quantity signal value T1 until the second analog quantity signal is within the preset precision threshold range. The invention aims to provide an electronic distribution automation feeder terminal test conversion device which is used for completing platform automatic test of an electronic distribution automation feeder terminal.
Description
Technical Field
The invention relates to the technical field of distribution network automation terminal testing, in particular to an electronic distribution automation feeder terminal testing conversion device.
Background
Distribution automation Feeder Terminal (FTU) is the intelligent terminal equipment who installs on electricity distribution room or feeder, have the remote control, the telemetering measurement, the remote signaling, the remote regulation, the fault detection function, can communicate with the distribution substation in distant place, provide distribution system operation condition and various parameters and monitor the required information of control promptly, including on-off state, the electric energy parameter, the interphase fault, parameter when earth fault and trouble, adjust and control distribution equipment, realize functions such as fault location, fault isolation and regional quick recovery power supply of non-trouble, and the order of carrying out distribution main website and issuing, send distribution equipment's operating data to distribution substation, can also accept the control command of distribution substation, control and adjust distribution equipment. The device has the advantages of convenient installation and wiring, simple debugging, easy expanded networking, strong reliability, high measurement precision and the like. Thereby realizing the distribution network automation economically and practically.
The FTU can be made of a high-performance singlechip, and in order to adapt to severe environment, an industrial chip capable of working at 75 ℃ is selected and is made to be lightning-proof, rain-proof and moisture-proof through proper structural design.
The input nominal value adopts a small signal phase voltage alternating current of 3.25V, a zero sequence voltage adopts an alternating current of 6.5V as a rated input (mostly adopting the rated value without excluding other rated parameter conditions), the secondary value or the primary voltage value of the analog quantity test is displayed through transformation ratio calculation, the current input nominal value adopts an alternating voltage small signal of 1V, the zero sequence current adopts an alternating current of 0.2V as the rated input (mostly adopting the rated value without excluding other rated parameter conditions), and the secondary value or the primary current value of the analog quantity test is displayed through transformation ratio calculation corresponding to the rated current. The electronic distribution automation feeder terminal is convenient to install on site, free of mutual inductor and magnetic saturation and safer to use on site.
In the prior art, as shown in fig. 1, a conventional testing method is to test an automatic feeder terminal through a conventional relay protection tester or by using an automatic testing platform, the conventional testing method cannot effectively test an electronic distribution automation feeder terminal, the electronic distribution automation feeder terminal is converted through a small signal mode, and a special testing mode of the conventional testing method cannot effectively perform automatic testing at present.
Disclosure of Invention
The invention aims to provide an electronic distribution automation feeder terminal test conversion device which is used for completing platform automatic test of an electronic distribution automation feeder terminal.
The invention is realized by the following technical scheme:
an electronic distribution automation feeder terminal test conversion device comprises an acquisition module, a conversion module and an acquisition module;
the acquisition module is used for acquiring a first analog quantity signal value T1 output by the automatic test platform of the distribution automation feeder terminal;
the conversion module is internally provided with a conversion circuit and is used for converting the first analog quantity signal value T1 into a second analog quantity signal value T2;
the acquisition module is used for acquiring the second analog quantity signal value T2 and feeding back the second analog quantity signal value T2 to the acquisition module;
the obtaining module also stores a fixed transformation ratio K, a first precision threshold D1 and a second precision threshold D2 in advance, and adjusts the resistance value of the conversion circuit according to the fixed transformation ratio K, the second analog quantity signal value T2 and the first analog quantity signal value T1 until the second analog quantity signal value T2 is greater than or equal to the first precision threshold D1 and the second analog quantity signal value T2 is less than or equal to the second precision threshold D2.
Preferably, the acquisition module comprises a storage unit, an input unit, a calculation unit and an adjustment unit;
the storage unit is used for storing the fixed transformation ratio K, the first precision threshold D1 and the second precision threshold D2;
the input unit is used for acquiring the first analog quantity signal value T1;
the calculating unit is used for acquiring a third analog quantity signal value T3 according to the fixed transformation ratio K and the second analog quantity signal value T2; wherein the third analog signal value T3 is obtained by the following formula:
T3＝K*T2；
the adjusting unit is configured to determine whether the second analog signal value T2 satisfies: the second analog signal value T2 is greater than or equal to the first precision threshold D1, the second analog signal value T2 is less than or equal to the second precision threshold D2, and the adjusting unit adjusts the resistance value of the converting circuit if the second analog signal value T2 is not satisfied.
Preferably, the first analog signal value T1 includes a voltage analog signal value T1a and a current analog signal T1 b.
Preferably, the conversion module includes a current conversion unit, and the current conversion unit includes a UA small signal channel, a UB small signal channel, a UC small signal channel, and a UN small signal channel, which are all connected to the acquisition module and the acquisition module; and a low temperature drift adjustable resistor Ra is connected in series between the UA small signal channel and the UN small signal channel, a low temperature drift adjustable resistor Rb is connected in series between the UB small signal channel and the UN small signal channel, and a low temperature drift adjustable resistor Rc is connected in series between the UC small signal channel and the UN small signal channel.
Preferably, the conversion module comprises a voltage conversion unit, and the voltage conversion unit comprises a Ua small signal channel, a Ub small signal channel, a Uc small signal channel, a Un small signal channel, a low temperature drift adjustable resistor Ra1, a low temperature drift adjustable resistor Ra2, a low temperature drift adjustable resistor Rb1, a resistor Rb2, a resistor Rc1 and a resistor Rc 2;
the Un small signal channel is connected to the acquisition module and the acquisition module, and the low temperature drift adjustable resistor Ra1 and the resistor Ra2 are connected in series and then connected to the acquisition module and the Un small signal channel; the low-temperature-drift adjustable resistor Rb1 and the resistor Rb2 are connected in series and then are connected to the acquisition module and the Un small signal channel; the low-temperature-drift adjustable resistor Rc1 and the resistor Rc2 are connected in series and then are connected to the acquisition module and the Un small signal channel;
the Ua small signal channel is connected with the low temperature drift adjustable resistor Ra1 and the acquisition module; the Ub small signal channel is connected with the low temperature drift adjustable resistor Rb1 and the acquisition module; the Uc small signal channel is connected with the low temperature drift adjustable resistor Rc1 and the acquisition module
Preferably, the resistor Rb2, the resistor Rc1 and the resistor Rc2 are constant resistors or adjustable resistors.
Preferably, the device further comprises a constant temperature controller, wherein the constant temperature controller is used for keeping the resistance value of the conversion circuit stable.
Preferably, the thermostatic controller comprises a current heat preservation unit, and the current heat preservation unit comprises an a-phase current heat preservation branch, a B-phase current heat preservation branch, a C-phase current heat preservation branch, an a-phase connection switch, a B-phase connection switch, a C-phase connection switch, an adjustable resistor R1, an adjustable resistor R2, an adjustable resistor R3 and an adjustable resistor R4;
the circuit structures of the phase A current heat preservation branch, the phase B current heat preservation branch and the phase C current heat preservation branch are the same, and the phase A current heat preservation branch is connected to the UA small signal channel and the UN small signal channel; the B-phase current heat preservation branch is connected with the UB small signal channel and the UN small signal channel; the C-phase current heat preservation branch is connected with the UC small signal channel and the UN small signal channel;
the A-phase current heat-preservation branch circuit comprises a first current link and a second current link which have the same circuit structure;
the first current link comprises 2N constant-value resistors, wherein every N resistors are sequentially connected in series to form a first resistor string and a second resistor string, the first resistor string and the second resistor string are both connected to the UA small signal channel and the UN small signal channel, and the resistors on the first resistor string and the second resistor string are sequentially connected in parallel; wherein N is more than or equal to 4;
the A-phase connection switch is connected with the UA small signal channel and the UN small signal channel after being connected with the adjustable resistor R1 in series, the B-phase connection switch is connected with the UB small signal channel and the UN small signal channel after being connected with the adjustable resistor R2 in series, and the C-phase connection switch is connected with the UC small signal channel and the UN small signal channel after being connected with the adjustable resistor R3 in series;
the adjustable resistor R4 is arranged on the UN small signal channel.
Preferably, the constant temperature controller comprises a voltage heat preservation unit, wherein the voltage heat preservation unit comprises an A-phase voltage heat preservation branch, a B-phase voltage heat preservation branch and a C-phase voltage heat preservation branch;
the A-phase voltage heat-preservation branch circuit comprises 2M constant-value resistors and an adjustable resistor Ru1, wherein every M resistors are sequentially connected in series to form a third resistor string and a fourth resistor string, the third resistor string and the fourth resistor string are connected in parallel and then are arranged in the Ua small signal channel, and the resistors on the third resistor string and the fourth resistor string are sequentially connected in parallel; wherein M is more than or equal to 2;
the adjustable resistor Ru1 is connected to the Ua small signal channel and the Un small signal channel;
the B-phase voltage heat-preservation branch circuit comprises 2M constant-value resistors and an adjustable resistor Ru2, wherein every M resistors are sequentially connected in series to form a fifth resistor string and a sixth resistor string, the fifth resistor string and the sixth resistor string are connected in parallel and then are arranged in the Ub small signal channel, and the resistors on the fifth resistor string and the sixth resistor string are sequentially connected in parallel; wherein M is more than or equal to 2;
the adjustable resistor Ru2 is connected to the Ub small signal channel and the Un small signal channel;
the C-phase voltage heat-preservation branch circuit comprises 2M constant-value resistors and an adjustable resistor Ru3, wherein every M resistors are sequentially connected in series to form a seventh resistor string and an eighth resistor string, the seventh resistor string and the eighth resistor string are connected in parallel and then are arranged in the Uc small signal channel, and the resistors on the seventh resistor string and the eighth resistor string are sequentially connected in parallel; wherein M is more than or equal to 2;
the adjustable resistor Ru3 is connected to the Uc small signal channel and the Un small signal channel.
Preferably, the device further comprises a constant temperature box, and the acquisition module, the conversion module and the acquisition module are all arranged in the constant temperature box.
Compared with the prior art, the invention has the following advantages and beneficial effects:
1. the electronic distribution automation feeder terminal system test can be carried out through the traditional test, and the problem of the electronic distribution automation feeder terminal can be detected more efficiently and truly;
2. the development of an analog quantity and small signal back-stepping comparison analysis automatic adjusting system device is provided, the comparison with analog quantity input can be carried out after the current and voltage small signal back-stepping is carried out, and the accurate small signal value is adjusted through an accurate low-temperature drift adjustable resistor;
3. the circuit loop is reformed and the thermostatic system device is developed, the circuit loop can be carried out in a thermostat through a circuit, current is connected in parallel after being connected in series through a plurality of resistors, adjustable parameter setting is carried out, and voltage is connected in parallel after being connected in series through resistors and is divided by adjustable resistors to adjust an output value.
Drawings
The accompanying drawings, which are included to provide a further understanding of the embodiments of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principles of the invention. In the drawings:
FIG. 1 is a diagram of feeder terminal test wiring under a conventional test method;
fig. 2 is a wiring diagram after being modified by the test conversion device of the electronic distribution automation feeder terminal system;
FIG. 3 is a schematic diagram of the development of an analog quantity and small signal back-stepping comparison analysis automatic regulating system device;
fig. 4 is a development schematic diagram of a circuit loop modified constant temperature system device.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to examples and accompanying drawings, and the exemplary embodiments and descriptions thereof are only used for explaining the present invention and are not meant to limit the present invention.
Example 1
An electronic distribution automation feeder terminal test conversion device, as shown in fig. 2 and 3, includes an acquisition module, a conversion module, and an acquisition module;
the acquisition module is used for acquiring a first analog quantity signal value T1 output by the automatic test platform of the distribution automation feeder terminal;
the first analog quantity signal value T1 comprises a voltage analog quantity signal value T1a and a current analog quantity signal T1 b;
the conversion module is internally provided with a conversion circuit and is used for converting the first analog quantity signal value T1 into a second analog quantity signal value T2;
the acquisition module is used for acquiring a second analog quantity signal value T2 and feeding back the second analog quantity signal value T2 to the acquisition module;
the obtaining module is used for adjusting the resistance value of the conversion circuit according to the fixed transformation ratio K, the second analog quantity signal value T2 and the first analog quantity signal value T1 until the second analog quantity signal value T2 is greater than or equal to the first precision threshold value D1, and the second analog quantity signal value T2 is smaller than or equal to the second precision threshold value D2.
Wherein, the fixed transformation ratio K is as follows: under the standard condition, the ratio of the analog quantity signal value output by the automatic testing platform of the distribution automation feeder terminal acquired by the module to the analog quantity signal value acquired by the acquisition module and scaled by the small signal stepping-back communication circuit is obtained. The standard conditions were: the resistance value in the conversion module does not change with the change of the external condition.
In the testing process, the resistance value or the resistance value of the resistor changes along with the rise of the environment temperature or the rise of the temperature of the resistor, at the moment, the second analog quantity signal value T2 acquired by the acquisition module is inaccurate, so that the deviation of the final testing result and the actual result is large, therefore, in the scheme, the fixed transformation ratio K, the first precision threshold D1 and the second precision threshold D2 are arranged, when the acquisition module receives the analog quantity signal value T2, the analog quantity signal value T2 is not directly output for testing, but is fed back to the acquisition module for comparison, and if the deviation of the analog quantity signal value T2 and the analog quantity signal value T1 is not within the range of the first precision threshold D1 and the second precision threshold D2, the resistance value of the conversion module is adjusted, so that the accuracy of the testing result is ensured.
Specifically, in this embodiment, the obtaining module includes a storage unit, an input unit, a calculating unit, and an adjusting unit;
a storage unit for storing a fixed transformation ratio K, a first precision threshold D1 and a second precision threshold D2;
an input unit for acquiring a first analog quantity signal value T1;
a calculating unit, for obtaining a third analog quantity signal value T3 according to the fixed transformation ratio K and the second analog quantity signal value T2; wherein, the third analog signal value T3 is obtained by the following formula:
T3＝K*T2；
and the adjusting unit is used for judging whether the second analog quantity signal value T2 meets the following conditions: the second analog quantity signal value T2 is greater than or equal to the first precision threshold D1, the second analog quantity signal value T2 is less than or equal to the second precision threshold D2, and if the second analog quantity signal value T2 is not met, the adjusting unit adjusts the resistance value of the conversion module.
The conversion module comprises a current conversion unit and a voltage conversion unit, wherein the current conversion unit comprises a UA small signal channel, a UB small signal channel, a UC small signal channel and a UN small signal channel which are connected with the acquisition module and the acquisition module; a low-temperature drift adjustable resistor Ra is connected in series between the UA small signal channel and the UN small signal channel, a low-temperature drift adjustable resistor Rb is connected in series between the UB small signal channel and the UN small signal channel, and a low-temperature drift adjustable resistor Rc is connected in series between the UC small signal channel and the UN small signal channel;
the voltage conversion unit comprises a Ua small signal channel, a Ub small signal channel, a Uc small signal channel, a Un small signal channel, a low temperature drift adjustable resistor Ra1, a low temperature drift adjustable resistor Ra2, a low temperature drift adjustable resistor Rb1, a resistor Rb2, a resistor Rc1 and a resistor Rc 2;
the Un small signal channel is connected with the acquisition module and the acquisition module, and the low-temperature drift adjustable resistor Ra1 and the resistor Ra2 are connected in series and then connected with the acquisition module and the Un small signal channel; the low-temperature-drift adjustable resistor Rb1 and the resistor Rb2 are connected in series and then are connected to the acquisition module and the Un small signal channel; the low-temperature-drift adjustable resistor Rc1 and the resistor Rc2 are connected in series and then are connected to the acquisition module and the Un small signal channel;
the Ua small signal channel is connected with the low temperature drift adjustable resistor Ra1 and the acquisition module; the Ub small signal channel is connected with the low temperature drift adjustable resistor Rb1 and the acquisition module; the Uc small signal channel is connected with the low temperature drift adjustable resistor Rc1 and the acquisition module. The resistor Rb2, the resistor Rc1, and the resistor Rc2 may be constant resistors or adjustable resistors.
The following description will be made with respect to the testing of an electronic distribution automation feeder terminal when a distribution automation test platform has a passing current output rated value of 5A and a voltage output rated value of 100V, where table 1 is an electronic automation Feeder Terminal (FTU) transformation ratio.
Table 1 electronic distribution automation Feeder Terminal (FTU) test transformation ratio table
| Type (B) | Power distribution automatic test platform output value (rating) | Transformation ratio |
| Phase current | 5A | 600A/1V |
| Zero sequence current | 5A | 20A/0.2V |
| Phase voltage | 100V | 10kV/3.25V |
| Zero sequence voltage | 100V | 10kV/3.25V |
When the rated current of the distribution automatic test platform is 5A, the phase current input of the corresponding electronic distribution automatic Feeder Terminal (FTU) should be 1V, the zero sequence current input should be 0.2V, and the calculation is carried out according to the ohm theorem U-I R
And obtaining the phase current loop resistance R as 0.2 omega and the zero-sequence current loop resistance as 0.04 omega.
At this time, taking the phase current as an example, the resistance of the current conversion unit in the test loop is 0.2 Ω for specific analysis.
As shown in fig. 3, the power distribution automatic test platform passes through a phase current with a rated value of 5A, passes through a sampling standard table, the value of the sampling standard table is T1 after sampling, and then returns through an N-phase common terminal after passing through a high-precision low-temperature drift adjustable resistor with a resistance value of 0.2 Ω. The small signal sampling standard meter samples voltage small signals, is connected to two sides of the high-precision low-temperature drift adjustable resistor, measures the small signals, measures the value of the measured small signals to be T2, and steps back to the analog quantity sampling standard meter through a communication line, the voltage value of the small signals is calculated through test transformation ratio and is calculated back to analog quantity, the back calculation value is set to be T3, and the analog quantity value is compared with the analog quantity of the original input standard meter (namely the T1 is compared with the T3 value). If the back stepping value is larger, the resistance value of the low-temperature-drift adjustable resistor can be adjusted to be smaller through the automatic adjusting device; otherwise, the back stepping value is smaller, and the resistance value of the low-temperature drift adjustable resistor can be adjusted to be larger through the automatic adjusting device.
The power through the resistance calculates W ═ U × I, it is 5W to obtain resistance power, so resistance power needs more than 5W, can find out from the formula that electronic distribution automation feeder terminal input voltage is relevant with distribution automation test platform output current and the resistance that forms in the return circuit, distribution automation test platform output rated current is certain, output voltage just is relevant with the resistance, so the precision of resistance can influence the voltage value of electronic distribution automation feeder terminal input, consequently should adopt high-accuracy low temperature drift adjustable resistance when selecting for use resistance in order to improve the sampling precision, and adopt and step back the return circuit and carry out the automatically regulated, satisfy the small-signal test requirement.
The resistors of the current conversion unit are all set to be adjustable resistors, and can be adjusted according to different input rated currents of the electronic distribution automation feeder terminal. Therefore, the small signal that the electronic distribution automation feeder terminal adopts the current of 1V can be tested, and the resistance value can be flexibly adjusted according to the rated value change.
When the distribution automatic test platform passes through rated value voltage, an output voltage loop is connected in parallel with the analog quantity sampling standard meter, the input voltage of the sampling standard meter is also connected in parallel with the high-precision low-temperature-drift adjustable resistor, then a group of high-precision low-temperature-drift adjustable resistors are connected in series, the small-signal standard meter sampling small-signal wiring is connected between the two adjustable resistors, and voltage after voltage division is obtained. And the small signal standard meter N phase is connected with the analog quantity sampling standard meter N phase in parallel. This forms a voltage regulation loop.
The principle of a current-to-voltage circuit of the electronic distribution automation Feeder Terminal (FTU) system testing device is that the function is realized in a resistance voltage division circuit mode.
The passing rated value voltage according to the distribution automatic test platform is 100V, the input of the corresponding electronic distribution automatic Feeder Terminal (FTU) is 3.25V, and the A phase is divided according to the voltageThe voltage is calculated by the formula
The calculation formula of the B phase voltage is
The C phase voltage calculation formula is
Setting the total resistance to be 100k omega, and obtaining that the resistance value of Ra1 is 96.75k omega and Ra2 is 3.25k omega through calculation; the resistance value of Rb1 is 96.75 kOmega, and the resistance value of Rb2 is 3.25 kOmega; the resistance value of Rc1 is 96.75k omega, Rc2 is 3.25k omega, and the zero sequence voltage is selected similarly.
Power according to resistance of
The resistance power is 0.1W, so the resistance power needs more than 0.1W, the formula shows that the input A phase voltage of the electronic distribution automation feeder terminal and the output voltage of the distribution automatic test platform are Ra1, Ra2 resistance is related, the input B phase voltage of the electronic distribution automation feeder terminal and the output voltage of the distribution automatic test platform are Rb1, Rb2 resistance is related, the input C phase voltage of the electronic distribution automation feeder terminal and the output voltage of the distribution automatic test platform and Rc1, and Rc2 resistance is related, when the voltage is constant, the output voltage is only related to the resistance, so the precision of the resistance in a loop can affect the output voltage value, because the two resistance values in each phase are difficult to match, the resistance alignment can be very precise by analog quantity and small signal back stepping on the contrast analysis automatic adjusting system, and the precision of the output voltage is ensured.
Through the circuit arrangement of the conversion module, the electronic distribution automation feeder line terminal can be adjusted according to different input rated voltages. The adjusted loop can test the rated voltage of the electronic distribution automation feeder terminal, wherein the voltage acquisition is 3.25 omega, and can also test other parameter values.
Example 2
In the test process, the resistance heating often influences the output precision, especially a small signal output loop, and after the resistance changes, the precision is greatly influenced. Therefore, in the embodiment, a thermostatic controller is also arranged to solve the problem that the change of the loop resistance affects the precision output.
As shown in fig. 4, the thermostat controller includes a current keeping unit, a voltage keeping unit, and a thermostat. The acquisition module, the conversion module and the acquisition module are all arranged in the incubator, and the current heat preservation unit and the voltage heat preservation unit are respectively used for ensuring the stability of the resistance values of the current conversion unit and the voltage conversion unit.
Specifically, in this embodiment, the current thermal insulation unit includes an a-phase current thermal insulation branch, a B-phase current thermal insulation branch, a C-phase current thermal insulation branch, an a-phase connection switch, a B-phase connection switch, a C-phase connection switch, an adjustable resistor R1, an adjustable resistor R2, an adjustable resistor R3, and an adjustable resistor R4;
the circuit structures of the phase A current heat preservation branch, the phase B current heat preservation branch and the phase C current heat preservation branch are the same, and the phase A current heat preservation branch is connected to the UA small signal channel and the UN small signal channel; the B-phase current heat preservation branch is connected with the UB small signal channel and the UN small signal channel; the C-phase current heat preservation branch is connected with the UC small signal channel and the UN small signal channel;
the A-phase current heat-preservation branch circuit comprises a first current link and a second current link which have the same circuit structure;
the first current link comprises 2N constant-value resistors, wherein every N resistors are sequentially connected in series to form a first resistor string and a second resistor string, the first resistor string and the second resistor string are both connected to the UA small signal channel and the UN small signal channel, and the resistors on the first resistor string and the second resistor string are sequentially connected in parallel; wherein N is more than or equal to 4;
the A connection switch is connected with the UA small signal channel and the UN small signal channel after being connected with the adjustable resistor R1 in series, the B connection switch is connected with the UB small signal channel and the UN small signal channel after being connected with the adjustable resistor R2 in series, and the C connection switch is connected with the UC small signal channel and the UN small signal channel after being connected with the adjustable resistor R3 in series;
the adjustable resistor R4 is arranged on the UN small signal channel.
The voltage heat-preservation unit comprises an A-phase voltage heat-preservation branch, a B-phase voltage heat-preservation branch and a C-phase voltage heat-preservation branch;
the A-phase voltage heat-preservation branch circuit comprises 2M constant-value resistors and an adjustable resistor Ru1, wherein every M resistors are sequentially connected in series to form a third resistor string and a fourth resistor string, the third resistor string and the fourth resistor string are connected in parallel and then are arranged on a Ua small signal channel, and the resistors on the third resistor string and the fourth resistor string are sequentially connected in parallel; wherein M is more than or equal to 2;
the adjustable resistor Ru1 is connected to the Ua small signal channel and the Un small signal channel;
the B-phase voltage heat-preservation branch circuit comprises 2M constant-value resistors and an adjustable resistor Ru2, wherein every M resistors are sequentially connected in series to form a fifth resistor string and a sixth resistor string, the fifth resistor string and the sixth resistor string are connected in parallel and then are arranged in a Ub small signal channel, and the resistors on the fifth resistor string and the sixth resistor string are sequentially connected in parallel; wherein M is more than or equal to 2;
the adjustable resistor Ru2 is connected to the Ub small signal channel and the Un small signal channel;
the C-phase voltage heat-preservation branch circuit comprises 2M constant-value resistors and an adjustable resistor Ru3, wherein every M resistors are sequentially connected in series to form a seventh resistor string and an eighth resistor string, the seventh resistor string and the eighth resistor string are connected in parallel and then are arranged in a Uc small signal channel, and the resistors on the seventh resistor string and the eighth resistor string are sequentially connected in parallel; wherein M is more than or equal to 2;
the adjustable resistor Ru3 is connected to the Uc small signal channel and the Un small signal channel.
In this embodiment, an oven is first set, and circuit design is performed in the oven using the entire circuit. The current heat preservation unit is connected in series through a plurality of resistors, and then the series resistor loops are connected in parallel, so that the current passing through each resistor is reduced, and the constant resistance effect is achieved. High-precision low-temperature drift adjustable resistors are connected in parallel on each phase of output current side, and a connection switch is arranged, so that required rated parameters can be finely adjusted and output when necessary; and a high-precision low-temperature drift adjustable resistor is arranged on the N-phase side of the current to match with various high-precision low-temperature drift adjustable resistors connected in parallel.
The voltage heat preservation unit is connected in series after being connected in parallel through a voltage division mode, and a high-precision low-temperature-drift adjustable resistor is arranged at the voltage division position to finely adjust a required output value.
The following description is given of a specific embodiment, and this specific embodiment only shows that the electronic distribution automation feeder terminal is tested when the passing current output rated value of the distribution automation test platform is 1A and the voltage output rated value is 100V. Table 2 gives the electronic automated Feeder Terminal (FTU) transformation ratio.
Table 2 electronic distribution automation Feeder Terminal (FTU) test transformation ratio table
| Type (B) | Power distribution automatic test platform output value (rating) | Transformation ratio |
| Phase current | 1A | 600A/1V |
| Zero sequence current | 1A | 20A/0.2V |
| Phase voltage | 100V | 10kV/3.25V |
| Zero sequence voltage | 100V | 10kV/3.25V |
When the rated value current of the distribution automatic test platform is 1A, the phase current input of the corresponding electronic distribution automatic Feeder Terminal (FTU) should be 1V, the zero sequence current input should be 0.2V, and the phase current input is calculated according to the ohm theorem U-I R
And obtaining the phase current loop resistance R which is 1 omega and the zero sequence current loop resistance which is 0.04 omega.
At this time, taking the phase current as an example, the phase current resistance in the test loop should be 1 Ω for analyzing the test process of the circuit loop modified constant temperature system device.
The development of the circuit loop transformation constant temperature system device is that firstly a constant temperature box is arranged, and the whole circuit is arranged in the constant temperature box.
The current heat preservation unit is connected in series through a plurality of resistors (4 resistors are connected in series for example, not less than 4 resistors), after the resistors are connected in series, the resistors are 4 omega, and then the series resistor loops are connected in parallel, and the total 4 resistors are connected in parallel. At this time, the total resistance value becomes 1 Ω, and this arrangement has the advantage of reducing the passing current of each resistor, and after the current is shunted, the passing current of each resistor is reduced to one fourth of the passing current of the original resistor. The current of 1A is passed, and only 0.25A is passed. Therefore, the temperature of the resistor does not change greatly, and correspondingly, the resistance value does not change greatly. After each phase is set in such a way, 1 adjustable resistor is added in each parallel connection and a connection switch is arranged, and when an individual phase does not meet the requirement, the connection switch of the phase is conducted to adjust the resistor. An adjustable resistor is set at the N phase, and initially the resistance should be set to 0, and adjustment can be made if the requirements are not met.
When a small signal is required to output a larger value, the resistance should be reduced, and the test should close the corresponding phase switch to perform value adjustment. When the required small signal output value is smaller, the resistance should be increased, the adjustable resistance at the N-phase side can be adjusted, but when the adjustable resistance at the N-phase side corresponding to the individual phase does not meet the requirement, the resistance of the individual phase can be reduced, the switch can be closed, and the parallel adjustable resistance can be adjusted.
When the distribution automatic test platform passes through rated value voltage, the output voltage loop is that every phase connects two (taking two resistors as a string at this moment as an example, no less than two groups) resistors in series, then connects two resistors in parallel after connecting in series, finally connects a high-precision low-temperature-drift adjustable resistor in series every phase, and takes voltage after voltage division. And the small signal standard meter N phase is connected with the analog quantity sampling standard meter N phase in parallel. This forms a voltage regulation loop.
According to the fact that the passing rated value voltage of the distribution automatic test platform is 100V, the input of a corresponding electronic distribution automatic Feeder Terminal (FTU) is 3.25V, and according to the divided voltage A phase voltage, the calculation formula is
The calculation formula of the B phase voltage is
The C phase voltage calculation formula is
Setting the total resistance to be 100k omega, and obtaining the fixed series and parallel resistance value of each phase to be 96.75k omega and the initial resistance value of the adjustable resistor to be 3.25k omega through calculation through parallel voltage division; the zero sequence voltage is likewise selected.
The output voltage is only related to the resistor, so the precision of the resistor in the loop can influence the output voltage value, and because the two resistor values in each phase are difficult to match, the thermostat and the resistor distribution can reduce the temperature to the minimum to the change of the resistor, and the accurate requirement on the output value can be finished after the adjustable resistor is arranged.
Through setting up thermostatic control ware, reduced every way resistance and passed through the electric current, reached the invariable effect of resistance value to set up the thermostated container, get rid of the external temperature interference to the resistance value, output precision is higher like this.
The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are merely exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.
Claims (10)
1. An electronic distribution automation feeder terminal test conversion device is characterized by comprising an acquisition module, a conversion module and an acquisition module;
the acquisition module is used for acquiring a first analog quantity signal value T1 output by the automatic test platform of the distribution automation feeder terminal;
the conversion module is internally provided with a conversion circuit and is used for converting the first analog quantity signal value T1 into a second analog quantity signal value T2;
the acquisition module is used for acquiring the second analog quantity signal value T2 and feeding back the second analog quantity signal value T2 to the acquisition module;
the obtaining module also stores a fixed transformation ratio K, a first precision threshold D1 and a second precision threshold D2 in advance, and adjusts the resistance value of the conversion circuit according to the fixed transformation ratio K, the second analog quantity signal value T2 and the first analog quantity signal value T1 until the second analog quantity signal value T2 is greater than or equal to the first precision threshold D1 and the second analog quantity signal value T2 is less than or equal to the second precision threshold D2.
2. The electronic distribution automation feeder-terminal test conversion equipment of claim 1 wherein the acquisition module comprises a storage unit, an input unit, a calculation unit and an adjustment unit;
the storage unit is used for storing the fixed transformation ratio K, the first precision threshold D1 and the second precision threshold D2;
the input unit is used for acquiring the first analog quantity signal value T1;
the calculating unit is used for acquiring a third analog quantity signal value T3 according to the fixed transformation ratio K and the second analog quantity signal value T2; wherein the third analog signal value T3 is obtained by the following formula:
T3＝K*T2；
the adjusting unit is configured to determine whether the second analog signal value T2 satisfies: the second analog signal value T2 is greater than or equal to the first precision threshold D1, the second analog signal value T2 is less than or equal to the second precision threshold D2, and the adjusting unit adjusts the resistance value of the converting circuit if the second analog signal value T2 is not satisfied.
3. The electronic distribution automation feeder-terminal test conversion equipment of claim 1 wherein the first analog signal values T1 include voltage analog signal values T1a and current analog signal values T1 b.
4. The electronic distribution automation feeder terminal test conversion device of claim 3, wherein the conversion module comprises a current conversion unit, the current conversion unit comprises a UA small signal channel, a UB small signal channel, a UC small signal channel and a UN small signal channel which are connected to the acquisition module and the acquisition module respectively; and a low temperature drift adjustable resistor Ra is connected in series between the UA small signal channel and the UN small signal channel, a low temperature drift adjustable resistor Rb is connected in series between the UB small signal channel and the UN small signal channel, and a low temperature drift adjustable resistor Rc is connected in series between the UC small signal channel and the UN small signal channel.
5. The electronic distribution automation feeder terminal test conversion device of claim 4, wherein the conversion module comprises a voltage conversion unit, the voltage conversion unit comprises a Ua small signal channel, a Ub small signal channel, a Uc small signal channel, a Un small signal channel, a low temperature drift adjustable resistor Ra1, a low temperature drift adjustable resistor Ra2, a low temperature drift adjustable resistor Rb1, a resistor Rb2, a resistor Rc1 and a resistor Rc 2;
the Un small signal channel is connected to the acquisition module and the acquisition module, and the low temperature drift adjustable resistor Ra1 and the resistor Ra2 are connected in series and then connected to the acquisition module and the Un small signal channel; the low-temperature-drift adjustable resistor Rb1 and the resistor Rb2 are connected in series and then are connected to the acquisition module and the Un small signal channel; the low-temperature-drift adjustable resistor Rc1 and the resistor Rc2 are connected in series and then are connected to the acquisition module and the Un small signal channel;
the Ua small signal channel is connected with the low temperature drift adjustable resistor Ra1 and the acquisition module; the Ub small signal channel is connected with the low temperature drift adjustable resistor Rb1 and the acquisition module; the Uc small signal channel is connected to the low temperature drift adjustable resistor Rc1 and the acquisition module.
6. The electronic distribution automation feeder-terminal test conversion equipment of claim 5, wherein the resistor Rb2, the resistor Rc1 and the resistor Rc2 are constant value resistors or adjustable resistors.
7. An electronic distribution automation feeder terminal test switching device as claimed in claim 5 or 6 further including a thermostatic control for maintaining a resistance value of the switching circuit stable.
8. The electronic distribution automation feeder-terminal test conversion equipment of claim 7 wherein the thermostatic controller includes a current thermal insulating unit, the current thermal insulating unit includes a phase A current thermal insulating branch, a phase B current thermal insulating branch, a phase C current thermal insulating branch, a phase A connection switch, a phase B connection switch, a phase C connection switch, an adjustable resistor R1, an adjustable resistor R2, an adjustable resistor R3 and an adjustable resistor R4;
the circuit structures of the phase A current heat preservation branch, the phase B current heat preservation branch and the phase C current heat preservation branch are the same, and the phase A current heat preservation branch is connected to the UA small signal channel and the UN small signal channel; the B-phase current heat preservation branch is connected with the UB small signal channel and the UN small signal channel; the C-phase current heat preservation branch is connected with the UC small signal channel and the UN small signal channel;
the A-phase current heat-preservation branch circuit comprises a first current link and a second current link which have the same circuit structure;
the first current link comprises 2N constant-value resistors, wherein every N resistors are sequentially connected in series to form a first resistor string and a second resistor string, the first resistor string and the second resistor string are both connected to the UA small signal channel and the UN small signal channel, and the resistors on the first resistor string and the second resistor string are sequentially connected in parallel; wherein N is more than or equal to 4;
the A-phase connection switch is connected with the UA small signal channel and the UN small signal channel after being connected with the adjustable resistor R1 in series, the B-phase connection switch is connected with the UB small signal channel and the UN small signal channel after being connected with the adjustable resistor R2 in series, and the C-phase connection switch is connected with the UC small signal channel and the UN small signal channel after being connected with the adjustable resistor R3 in series;
the adjustable resistor R4 is arranged on the UN small signal channel.
9. The electronic distribution automation feeder terminal test conversion equipment as claimed in claim 7, wherein the thermostatic controller includes a voltage holding unit, the voltage holding unit includes an a-phase voltage holding branch, a B-phase voltage holding branch and a C-phase voltage holding branch;
the A-phase voltage heat-preservation branch circuit comprises 2M constant-value resistors and an adjustable resistor Ru1, wherein every M resistors are sequentially connected in series to form a third resistor string and a fourth resistor string, the third resistor string and the fourth resistor string are connected in parallel and then are arranged in the Ua small signal channel, and the resistors on the third resistor string and the fourth resistor string are sequentially connected in parallel; wherein M is more than or equal to 2;
the adjustable resistor Ru1 is connected to the Ua small signal channel and the Un small signal channel;
the B-phase voltage heat-preservation branch circuit comprises 2M constant-value resistors and an adjustable resistor Ru2, wherein every M resistors are sequentially connected in series to form a fifth resistor string and a sixth resistor string, the fifth resistor string and the sixth resistor string are connected in parallel and then are arranged in the Ub small signal channel, and the resistors on the fifth resistor string and the sixth resistor string are sequentially connected in parallel; wherein M is more than or equal to 2;
the adjustable resistor Ru2 is connected to the Ub small signal channel and the Un small signal channel;
the C-phase voltage heat-preservation branch circuit comprises 2M constant-value resistors and an adjustable resistor Ru3, wherein every M resistors are sequentially connected in series to form a seventh resistor string and an eighth resistor string, the seventh resistor string and the eighth resistor string are connected in parallel and then are arranged in the Uc small signal channel, and the resistors on the seventh resistor string and the eighth resistor string are sequentially connected in parallel; wherein M is more than or equal to 2;
the adjustable resistor Ru3 is connected to the Uc small signal channel and the Un small signal channel.
10. The electronic distribution automation feeder terminal test conversion equipment of claim 9 further comprising an incubator, wherein the acquisition module, the conversion module and the collection module are all disposed in the incubator.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113985169A (en) * | 2021-10-26 | 2022-01-28 | 广东电网有限责任公司 | Relay test protection instrument and FTU's termination |
Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3308847A1 (en) * | 1983-03-12 | 1984-09-13 | Timm-Elektronik GmbH, 2000 Hamburg | Arrangement for detecting faulty limit monitors |
| CN104237729A (en) * | 2014-09-15 | 2014-12-24 | 珠海许继电气有限公司 | Automatic joint debugging testing system for feeder line terminal |
| CN106646120A (en) * | 2016-11-25 | 2017-05-10 | 国网江苏省电力公司扬州供电公司 | Distribution network small resistance single phase grounding fault positioning method and power distribution terminal |
| CN108957187A (en) * | 2018-07-17 | 2018-12-07 | 国网辽宁省电力有限公司电力科学研究院 | A kind of test device of ac analog channel hardware |
| US20190137557A1 (en) * | 2015-09-09 | 2019-05-09 | Beijing Inhand Networks Technology Co., Ltd. | Method and system for detecting and locating single-phase ground fault on low current grounded power-distribution network |
| CN208955366U (en) * | 2018-09-06 | 2019-06-07 | 贵州电网有限责任公司 | A kind of pipeline system distribution feeder terminal detection platform and equipment under test switching device |
| CN110108978A (en) * | 2019-04-14 | 2019-08-09 | 广西电网有限责任公司南宁供电局 | A kind of FTU accuracy test system and its test point detecting method |
| CN110988527A (en) * | 2019-11-25 | 2020-04-10 | 国网宁夏电力有限公司电力科学研究院 | Feeder automation testing device and using method thereof |
| CN211043532U (en) * | 2019-08-14 | 2020-07-17 | 青岛云路特变智能科技有限公司 | Transformer test system |
| CN111564905A (en) * | 2020-06-10 | 2020-08-21 | 国网四川省电力公司电力科学研究院 | Automatic simultaneous joint debugging method and system for unattended multiple power distribution terminals of main station |
| CN111694288A (en) * | 2020-05-20 | 2020-09-22 | 国网河北省电力有限公司电力科学研究院 | On-site feeder automation function closed-loop automatic test platform |
| CN111711274A (en) * | 2020-07-02 | 2020-09-25 | 河南华盛隆源电气有限公司 | Test fixture at feeder terminal |
-
2020
- 2020-12-29 CN CN202011596390.5A patent/CN112731248B/en active Active
Patent Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3308847A1 (en) * | 1983-03-12 | 1984-09-13 | Timm-Elektronik GmbH, 2000 Hamburg | Arrangement for detecting faulty limit monitors |
| CN104237729A (en) * | 2014-09-15 | 2014-12-24 | 珠海许继电气有限公司 | Automatic joint debugging testing system for feeder line terminal |
| US20190137557A1 (en) * | 2015-09-09 | 2019-05-09 | Beijing Inhand Networks Technology Co., Ltd. | Method and system for detecting and locating single-phase ground fault on low current grounded power-distribution network |
| CN106646120A (en) * | 2016-11-25 | 2017-05-10 | 国网江苏省电力公司扬州供电公司 | Distribution network small resistance single phase grounding fault positioning method and power distribution terminal |
| CN108957187A (en) * | 2018-07-17 | 2018-12-07 | 国网辽宁省电力有限公司电力科学研究院 | A kind of test device of ac analog channel hardware |
| CN208955366U (en) * | 2018-09-06 | 2019-06-07 | 贵州电网有限责任公司 | A kind of pipeline system distribution feeder terminal detection platform and equipment under test switching device |
| CN110108978A (en) * | 2019-04-14 | 2019-08-09 | 广西电网有限责任公司南宁供电局 | A kind of FTU accuracy test system and its test point detecting method |
| CN211043532U (en) * | 2019-08-14 | 2020-07-17 | 青岛云路特变智能科技有限公司 | Transformer test system |
| CN110988527A (en) * | 2019-11-25 | 2020-04-10 | 国网宁夏电力有限公司电力科学研究院 | Feeder automation testing device and using method thereof |
| CN111694288A (en) * | 2020-05-20 | 2020-09-22 | 国网河北省电力有限公司电力科学研究院 | On-site feeder automation function closed-loop automatic test platform |
| CN111564905A (en) * | 2020-06-10 | 2020-08-21 | 国网四川省电力公司电力科学研究院 | Automatic simultaneous joint debugging method and system for unattended multiple power distribution terminals of main station |
| CN111711274A (en) * | 2020-07-02 | 2020-09-25 | 河南华盛隆源电气有限公司 | Test fixture at feeder terminal |
Non-Patent Citations (2)
| Title |
|---|
| PRACHI SHARMA 等: "Design and Implementation of a Stand-Alone Remote Terminal Unit", 《IOSR JOURNAL OF ELECTRICAL AND ELECTRONICS ENGINEERING》 * |
| 吴鹏 等: "基于大数据技术的就地型馈线自动化终端自动测试方法", 《电气应用》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113985169A (en) * | 2021-10-26 | 2022-01-28 | 广东电网有限责任公司 | Relay test protection instrument and FTU's termination |
| CN113985169B (en) * | 2021-10-26 | 2024-04-30 | 广东电网有限责任公司 | Wiring device of relay protection tester and FTU |
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|---|---|
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