CN111693797A - Test method and device for transformer protection equipment - Google Patents
Test method and device for transformer protection equipment Download PDFInfo
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Abstract
The invention discloses a test method and a test device for transformer protection equipment, wherein the current amplitude of each branch and a medium-voltage side are set under various working conditions of a transformer, the current amplitude is used as test data, the action of the corresponding transformer protection equipment is set according to the test data, the action of the transformer protection equipment is used as a preset test result, and if the test result shows that the action of the transformer protection equipment is consistent with the preset test result, the test result is determined to be passed; otherwise, determining that the test result is failed, and solving the problem that TA abnormal alarm is caused due to the defects of the existing test method of the transformer protection equipment.
Description
Technical Field
The application relates to the field of power system protection, in particular to a test method for transformer protection equipment, and also relates to a test device for the transformer protection equipment.
Background
With the continuous acceleration of the construction steps of power grids, the structures of the power grids are increasingly complex, and accidents such as alarming, misoperation and the like of current Transformers (TA) and the like of power lines and transformers occur at times, so that great pressure is applied to the safe and stable operation of equipment and facilities such as the power lines and the transformers. If TA disconnection fault is light, the wiring terminal or secondary equipment is burnt out, and if the TA disconnection fault is heavy, serious accidents of electric shock and casualties are caused. The equipment causing the 'TA disconnection' alarm comprises a TA body, a secondary loop, protection equipment and the like, and the main reasons for TA disconnection are 3: the secondary wiring terminal is in poor contact due to unfastening or corrosion; the secondary wiring of a current loop is manually removed or cut by mistake, and the event often occurs in the transformation of an old transformer substation with a complicated current loop; failure of a protection device sampling plug-in or a CPU plug-in, resulting in data sampling or data calculation errors, is typically due to device out-of-service or poor manufacturing process. Therefore, when a TA abnormal alarm signal occurs in the substation, the substation operation and maintenance personnel pay attention to the event and need to process the event in time. At present, two branches are selected from protection equipment to test precision, logic and the like. Three-phase positive sequence currents which are the same in size and opposite in direction are added into the two branches simultaneously, single-phase TA disconnection of one branch is simulated, and disconnection phase current is reduced to zero. The main protection can be locked reliably and does not act, and the TA disconnection action message of the branch circuit is reported. When a system of a transformer substation in Fujian works normally, TA abnormal alarms frequently occur on main transformer protection equipment. The protection equipment is detected by conventional precision, logic and the like, and the problem that the logic defect of the protection equipment cannot be found in the current detection project is exposed. The TA abnormal alarm is caused by unbalanced three-phase current distribution of each branch due to the impedance difference of each phase of the two branches of the primary system, and the three-phase current and the current of the two branches of the primary system are balanced actually, so that the system operates normally. Therefore, in combination with the field situation, the existing testing method of the transformer protection equipment has defects, which leads to TA abnormal alarm.
Disclosure of Invention
The application provides a testing method and a testing device for transformer protection equipment, which solve the problem that TA abnormal alarm is caused due to the defects of the existing testing method for the transformer protection equipment.
The application provides a test method for transformer protection equipment, which comprises the following steps:
testing the transformer protection equipment by using test data, wherein the test data are current amplitudes of each branch and a medium-voltage side obtained by setting under various working conditions of the transformer;
if the action of the transformer protection equipment is consistent with a preset test result, determining that the test result is a pass; otherwise, determining that the test result is failed; and the preset test result is the action of setting the corresponding transformer protection equipment according to the test data.
Preferably, under various working conditions of the transformer, setting the current amplitude of each branch and the medium-voltage side, including:
and under the operating condition, the disconnection condition and the fault condition of the transformer, setting the three-phase current amplitude values of the high 1 branch, the high 2 branch and the medium-voltage side respectively.
Preferably, set up 1 branch road of height, 2 branch roads of height and medium voltage side three-phase current amplitude respectively under the transformer is at operating condition, broken string operating mode to and the trouble operating mode, include:
setting the sum of the amplitudes of the currents of each phase in the three-phase current of the high 1 branch and the high 2 branch to be equal to the amplitude of each phase in the three-phase current of the medium-voltage side under the operation condition of the transformer;
in the transformer disconnection working condition, three-phase currents of a high 1 branch and a high 2 branch are set, wherein the sum of the amplitudes of one phase currents is not equal to the amplitude of the one phase current corresponding to the medium-voltage side, and the sum of the zero-sequence currents of the external three-phase currents of the high 1 branch and the high 2 branch is zero;
in the fault working condition of the transformer, three-phase currents of a high 1 branch and a high 2 branch are set, wherein the sum of one-phase current amplitudes is not equal to the one-phase current amplitude corresponding to the medium-voltage side, and the sum of zero-sequence currents of external three-phase currents of the high 1 branch and the high 2 branch is not zero.
Preferably, in a condition of a broken line of the transformer, setting a sum of phase current amplitudes of three phases of the high 1 branch and the high 2 branch, which is not equal to a phase current amplitude corresponding to the medium voltage side, including:
and under the condition of the disconnection of the transformer, the phase A of the high 1 branch is disconnected, the current of the high 1 branch is 0, and the amplitude of the phase A of the medium-voltage side current keeps the amplitude of the operation condition of the transformer.
Preferably, in a condition of a broken line of the transformer, setting a sum of phase current amplitudes of three phases of the high 1 branch and the high 2 branch, which is not equal to a phase current amplitude corresponding to the medium voltage side, including:
under the fault working condition of the transformer, the phase A of the high 1 branch is disconnected, the current of the high 1 branch is 0, and the phase amplitude of the current A of the medium-voltage side is 0.
Preferably, if the action of the transformer protection device is consistent with a preset test result, determining that the test result is a pass; otherwise, determining that the test result is not passed: the method comprises the following steps:
comparing the actual test result of the transformer protection equipment with a preset test result;
if the actual test result is consistent with the preset test result, determining that the test result is a pass; otherwise, determining that the test result is not passed.
Preferably, the setting of the corresponding action of the transformer protection device according to the test data includes:
setting the action of corresponding transformer protection equipment to protect the transformer from being started for test data under the operating condition of the transformer;
for test data under the condition of the line break of the transformer, when the phase A current of the high 1 branch is smaller than a no-current threshold and the zero-sequence current of the high 1 branch is larger than a zero-sequence current threshold, the action of corresponding transformer protection equipment is protection starting, and TA line break warning information is sent out; when the A-phase current of the high 1 branch is larger than the zero-sequence current threshold or the zero-sequence current of the high 1 branch is smaller than the zero-sequence current threshold, the corresponding action of the transformer protection equipment is protection and no starting;
for test data under the transformer fault working condition, when the differential value is larger than a preset high action fixed value, the action of the corresponding transformer protection equipment is protection starting and an action outlet; when the differential value is smaller than the preset high action fixed value, the action of the corresponding transformer protection equipment is protection starting and does not act at an outlet.
Preferably, the method further comprises the following steps:
under the operation condition of the transformer, the high 1 branch current and the high 2 branch current are connected in parallel and then reversely connected to the medium-voltage side;
under the condition of the disconnection of the transformer, the high 1 branch circuit and the high 2 branch circuit are connected in parallel and then reversely connected to the medium-voltage side;
in the fault condition of the transformer, B, C high-1 branch and high-2 branch are connected in parallel and then reversely connected to the medium-voltage side.
This application provides a testing arrangement for transformer protection equipment simultaneously, includes:
the test execution unit is used for testing the transformer protection equipment by using test data, wherein the test data are current amplitudes of each branch and a medium-voltage side obtained by setting under various working conditions of the transformer;
the test result determining unit is used for determining that the test result is passed if the action of the transformer protection equipment is consistent with the preset test result; otherwise, determining that the test result is failed; and the preset test result is the action of setting the corresponding transformer protection equipment according to the test data.
Preferably, the test execution unit includes:
the operation working condition action subunit sets the action of the corresponding transformer protection equipment to protect the transformer from being started for the test data under the operation working condition of the transformer;
the circuit breaking working condition action subunit is used for testing data under the circuit breaking working condition of the transformer, when the phase A current of the high 1 branch is smaller than a no-current threshold and the zero sequence current of the high 1 branch is larger than a zero sequence current threshold, the action corresponding to the transformer protection equipment is protection starting, and TA circuit breaking alarm information is sent out; when the A-phase current of the high 1 branch is larger than the zero-sequence current threshold or the zero-sequence current of the high 1 branch is smaller than the zero-sequence current threshold, the corresponding action of the transformer protection equipment is protection and no starting;
the fault working condition action subunit is used for judging whether the action of the corresponding transformer protection equipment is protection starting and action export when the differential value of the test data under the fault working condition of the transformer is larger than a preset high action fixed value; when the differential value is smaller than the preset high action fixed value, the action of the corresponding transformer protection equipment is protection starting and does not act at an outlet.
The application provides a test method and a test device for transformer protection equipment, wherein the current amplitude of each branch and a medium-voltage side are set under various working conditions of a transformer, the current amplitude is used as test data, corresponding actions of the transformer protection equipment are set according to the test data, the actions of the transformer protection equipment are used as preset test results, and if the test results show that the actions of the transformer protection equipment are consistent with the preset test results, the test results are determined to be passed; otherwise, determining that the test result is failed, and solving the problem that TA abnormal alarm is caused due to the defects of the existing test method of the transformer protection equipment.
Drawings
Fig. 1 is a schematic flowchart of a testing method for transformer protection equipment provided in the present application;
fig. 2 is a diagram of a substation structure and protection configuration to which the present application relates;
FIG. 3 is a schematic diagram of a test connection to which the present application relates;
fig. 4 is a schematic diagram of a testing apparatus for a transformer protection device provided in the present application.
Detailed Description
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. This application is capable of implementation in many different ways than those herein set forth and of similar import by those skilled in the art without departing from the spirit of this application and is therefore not limited to the specific implementations disclosed below.
Fig. 1 is a schematic flowchart illustrating a testing method for transformer protection equipment provided in the present application, and the method provided in the present application is described in detail below with reference to fig. 1.
And S101, testing the transformer protection equipment by using test data, wherein the test data are current amplitudes of each branch and a medium-voltage side, which are obtained by setting under various working conditions of the transformer.
The test number is that under the transformer operation condition, the disconnection condition and the fault condition, the high 1 branch, the high 2 branch and the medium-voltage side three-phase current amplitude are respectively set.
And setting the sum of the amplitude of each phase current in the three-phase current of the high 1 branch and the high 2 branch to be equal to the amplitude of each phase current in the three-phase current of the medium-voltage side under the operating condition of the transformer.
And under the condition of line break of the transformer, setting the sum of the phase current amplitudes of the high 1 branch and the high 2 branch in the three-phase currents, wherein the sum of the phase current amplitudes of one phase is not equal to the phase current amplitude corresponding to the medium-voltage side, and the sum of the zero sequence currents of the external three-phase currents of the high 1 branch and the high 2 branch is zero. Specifically, the phase a of the high-1 branch is set to be disconnected, the current of the high-1 branch is 0, and the amplitude of the phase a of the medium-voltage side current keeps the amplitude of the operating condition of the transformer.
In the fault working condition of the transformer, three-phase currents of a high 1 branch and a high 2 branch are set, wherein the sum of one-phase current amplitudes is not equal to the one-phase current amplitude corresponding to the medium-voltage side, and the sum of zero-sequence currents of external three-phase currents of the high 1 branch and the high 2 branch is not zero. Specifically, if the phase a of the high 1 branch is disconnected, the current of the high 1 branch is 0, and the amplitude of the phase a of the medium-voltage side current is 0.
In actual operation, the relay protection tester can be used for testing the transformer protection equipment. A relay protection tester and a transformer protection device need to be connected, and the connection mode is shown in fig. 3. Before testing, related parameters of transformer protection equipment need to be set, and corresponding test data is set in a relay protection tester, and the specific steps are as follows: (1) and setting related parameters of the transformer protection equipment to enable the rated current Ie of the high-voltage side to be 0.2A and the no-current judgment condition to be 0.05Ie, and connecting two loops of corresponding phase currents output by the relay protection tester to the high-voltage side of the protection equipment. (2) And setting test data by using a state sequence menu of the relay protection tester. The setting is carried out according to the following parameters:
state 1 (operating condition):
the amplitude of the three-phase current of the high 1 branch and the high 2 branch is 0.1Ie, and the currents of the high 1 side and the high 2 side are reversely connected to the medium voltage side after being connected in parallel.
State 2 (operating condition):
the amplitude of the three-phase current of the high 1 branch is 0.1Ie, the amplitude of the three-phase current of the high 2 branch is gradually increased from 0.1Ie to 1.5Ie, and the currents of the high 1 side and the high 2 side are reversely connected to the medium voltage side after being connected in parallel.
State 3 (operating condition):
the phase A currents of the high 1 branch and the high 2 branch are changed, the phase A current of the high 1 branch ranges from 0 to 1.5Ie, the phase A current of the high 2 branch ranges from 0 to 1.5Ie, but the relationship that I1A/I2A is not more than 1:15 is met, the three-phase currents of the high 1 branch and the high 2 branch are unbalanced and have zero sequence currents, the phase currents of the high voltage side are the same, and the currents of the high 1 branch and the high 2 branch are reversely connected to the medium voltage side after being connected in parallel.
The three states are operating conditions. From the test data of the three states, the sum of the amplitudes of the currents of the three phases of the high 1 branch and the high 2 branch is equal to the amplitude of the current of the middle voltage side three phase. Namely, the sum of the high 1 branch A phase amplitude and the high 2 branch A phase amplitude is equal to the medium-voltage side A phase amplitude, the sum of the high 1 branch B phase amplitude and the high 2 branch B phase amplitude is equal to the medium-voltage side B phase amplitude, and the sum of the high 1 branch C phase amplitude and the high 2 branch C phase amplitude is equal to the medium-voltage side C phase amplitude.
State 4 (wire break condition);
changing the phase A currents of the high 1 branch and the high 2 branch, wherein the phase A current of the high 1 branch is 0-1.5 Ie, the phase A current of the high 2 branch is 0-1.5 Ie, but the phase A current of the high 1 branch meets the relation that I1A/I2A is not more than 1:15, disconnecting the phase A current signal flowing into the high 1 branch, so that the phase A currents of the high 1 branch and the high 2 branch are changed, the three-phase currents of the high 1 branch and the high 2 branch are unbalanced, each branch has a zero-sequence current, but the zero-sequence current sum of the external three-phase currents of the high 1 branch and the high 2 branch is zero; the high 1 and high 2 branch circuits are connected in parallel and then connected to the medium voltage side.
From the test data of the wire-breaking working condition, it can be seen that, in the three-phase currents of the high 1 branch and the high 2 branch, the sum of the phase current amplitudes of one of the three phases is not equal to the phase current amplitude corresponding to the medium-voltage side, i.e., the sum of the phase amplitude of the high 1 branch and the phase amplitude of the high 2 branch. And in other two-phase currents, the sum of the high 1 branch B-phase amplitude and the high 2 branch B-phase amplitude is equal to the medium-voltage side B-phase amplitude, and the sum of the high 1 branch C-phase amplitude and the high 2 branch C-phase amplitude is equal to the medium-voltage side C-phase amplitude.
State 5 (fault condition):
changing the phase A currents of the high 1 branch and the high 2 branch, wherein the phase A current of the high 1 branch is 0-1.5 Ie, the phase A current of the high 2 branch is 0-1.5 Ie, but the phase A current of the high 1 branch is not more than 1:15 of I1A/I2A, disconnecting the phase A current signal flowing into the high 1 branch, so that the phase A currents of the high 1 branch and the high 2 branch are changed, the three-phase currents of the high 1 branch and the high 2 branch are unbalanced, each branch has a zero-sequence current, but the zero-sequence current sum of the external three-phase currents of the high 1 branch and the high 2 branch is not zero; the high 1, high 2 branch side A phase current is connected in parallel and is not connected to the middle voltage side A phase, and the high 1, high 2 branch side B, C phase current is connected in parallel and is reversely connected to the middle voltage side.
From the test data of the fault working condition, it can be seen that when the phase a of the high 1 branch is disconnected, the current of the high 1 branch is 0, and the amplitude of the phase a of the medium-voltage side current keeps the amplitude of the operating condition of the transformer, i.e., the sum of the amplitude of the phase a of the high 1 branch and the amplitude of the phase a of the high 2 branch.
And then, calling the state sequence from the state 1 to the state 6 by using a state sequence menu of the relay protection tester to carry out the test.
State 1: the three-phase current amplitude of the high 1 branch and the high 2 branch is 0.1Ie, and balance is kept without differential current;
state 2: the amplitude of the three-phase current of the high 1 branch is 0.1Ie, and the current is kept unchanged; the current amplitude of the three phases of the high 2 branch is gradually increased from 0.1Ie to 1.5Ie in a gradient mode, and each state holding state is larger than 10 s.
State 3: the phase A currents of the high 1 branch and the high 2 branch are changed, the phase A currents of the high 1 branch and the high 2 branch are not changed, the three-phase currents of the high 1 branch and the high 2 branch are unbalanced, zero sequence currents exist, and each state keeping state is larger than 10 s. And selecting a test value according to the tested object, the zero sequence current threshold and the no-current threshold, wherein the threshold needs to be covered.
And 4: the phase a current for the high 1 and high 2 legs is changed in increments of 0.05Ie, and the phase a current signal flowing into the high 1 leg is interrupted, each state holding state being greater than 10 s.
And state 5: the phase A current of the high 1 branch and the high 2 branch is changed by 0.05Ie as a gradual change increment, the signal of the phase A current flowing into the high 1 branch is disconnected, the phase A current of the high 1 branch and the high 2 branch is not connected to the phase A of the medium voltage side after being connected in parallel, and the phase A current of the high 1 branch and the high 2 branch is connected to the phase B, C of the medium voltage side after being connected in parallel, and each state holding state is more than 10 s.
Step S102, if the action of the transformer protection equipment is consistent with a preset test result, determining that the test result is a pass; otherwise, determining that the test result is failed; and the preset test result is the action of setting the corresponding transformer protection equipment according to the test data.
And presetting a test result as an action of setting corresponding transformer protection equipment according to the test data. The method comprises the following steps:
setting the action of corresponding transformer protection equipment to protect the transformer from being started for test data under the operating condition of the transformer;
for test data under the condition of the line break of the transformer, when the phase A current of the high 1 branch is smaller than a no-current threshold and the zero-sequence current of the high 1 branch is larger than a zero-sequence current threshold, the action of corresponding transformer protection equipment is protection starting, and TA line break warning information is sent out; when the A-phase current of the high 1 branch is larger than the zero-sequence current threshold or the zero-sequence current of the high 1 branch is smaller than the zero-sequence current threshold, the corresponding action of the transformer protection equipment is protection and no starting;
for test data under the transformer fault working condition, when the differential value is greater than the high action fixed value 1.2Ie, the action of the corresponding transformer protection equipment is protection starting and an action outlet; and when the differential value is smaller than the high action constant value 1.2Ie, the action of the corresponding transformer protection equipment is protection starting and does not act as an outlet.
And then, comparing the actual test result of the transformer protection equipment with a preset test result, and if the test result of the transformer protection equipment meets the protection non-starting condition in the states 1-3 and no TA abnormal alarm action information exists, judging that the action of the transformer protection equipment is correct.
If the test result of the transformer protection equipment meets the test in the state 1-4, in the state 4, when the A-phase current of the high 1 branch is smaller than the no-current threshold and the zero-sequence current of the high 1 branch is larger than the zero-sequence current threshold, the transformer protection equipment is started and sends out TA disconnection warning information, and then the action of the transformer protection equipment is judged to be correct. And when the A-phase current of the high 1 branch is larger than the zero-sequence current threshold or the zero-sequence current of the high 1 branch is smaller than the zero-sequence current threshold, the transformer protection equipment is not started, and the action of the transformer protection equipment is judged to be correct.
If the test result of the protection equipment meets the test in the state 1-5, in the state 5, when the differential value is greater than the preset high action fixed value 1.2Ie, the transformer protection equipment is started and acts at an outlet, and then the action of the transformer protection equipment is judged to be correct; when the differential value is smaller than the preset high action fixed value 1.2Ie, the transformer protection equipment is started and does not act at the outlet, and then the action of the transformer protection equipment is judged to be correct.
If the action of the transformer protection equipment is consistent with a preset test result, determining that the test result is a pass; otherwise, determining that the test result is not passed.
The present application is further described with reference to specific examples.
Example (b):
fig. 2 shows a configuration diagram suitable for a substation system structure and transformer protection equipment. The current flowing on the 500kV bus flows into the 220kV transformer through the breakers 5DL and 6DL, and the current flowing on the 500kV bus is sourced from other power supply points and is injected into the bus through a line. Therefore, when the current flows into the 220kV transformer after flowing through 5DL and 6DL, the current passes through different electrical circuits. The loop resistance is composed of the sum (Ra) of the intrinsic resistances of the conductors, the connection resistance (Rb) between the conductors and the contacts and between the conductors, and the contact resistance (Rc) between the moving contact and the static contact.
Under normal conditions, the paths of the two loops through which the current flows are similar, the impedances are the same, the resistance ratio of the two loops is 1:1, and the relationship of current distribution meets the relationship of 1: 1.
In an unfavorable situation, the current flows through two buses and two loops, namely a circuit breaker 4-1-2-3-6 loop and a circuit breaker 5 loop. And the resistance of the electrical circuit is composed of a bus resistance and a breaker resistance. The inherent resistance is the resistance of the conductive loop of the non-contact connecting part, and the resistance value of the inherent resistance is far smaller than that of the contact resistance; the connection resistance between the conductor and the contact and between the conductors is also much smaller than the contact resistance. The bus resistor is an inherent resistor, the value is small, the resistance value is not more than 6 mu omega, and the resistance value can be ignored; the circuit breaker loop resistance is composed of three parts of an inherent resistance, a connecting resistance and a contact resistance. The circuit breaker loop resistance is therefore dependent on the contact resistance in the loop circuit. Generally, each fracture of the contact resistance of the circuit breaker is 20 mu omega, the high-voltage circuit breaker generally has two fractures, and the total resistance is generally less than 60 mu omega considering the influences of the connection resistance, the inherent resistance and the like. The resistance of each circuit breaker typically varies between 60-200 μ Ω due to the inconsistent oxidation of the switch resistances in the two circuits, resulting in inconsistent circuit impedances for each phase of the circuit breaker. Assuming that the circuit breaker loop resistances all meet the standard requirements and do not exceed the standard, in the worst case, the resistance ratio of two different loops is 60:180 x 5, and the relationship of current distribution is inversely proportional to the resistance value and also satisfies the relationship of 15: 1.
If the paths of the two loops are similar, the current respectively flows through two loops of 1 bus and a circuit breaker 1-4-5 and 1 bus and a circuit breaker 2-3-6. Considering the extreme case, the resistance of one phase loop is small, 60 × 3 ═ 180 μ Ω, the resistance of one phase loop is large, and the resistance ratio of two different loops is 3:1, 180 × 3 ═ 540 μ Ω, and then the relationship of current distribution satisfies the relationship of 1: 3.
If the loop resistance of the circuit breaker exceeds the standard, the circuit breaker resistance is larger, and the circuit breaker resistance belongs to primary equipment abnormity, and the circuit breaker resistance is out of the discussion range.
Because the power system is a three-phase symmetrical system, the sum of three-phase currents is zero when the power system is in normal operation. The on-site TA abnormal alarm is caused by unbalanced three-phase current distribution of each branch due to the impedance difference of each phase of the two branches of the primary system, and the three-phase current and the current of the two branches of the primary system are balanced actually. Therefore, by combining the current distribution relation under the more extreme condition, a transformer protection test method suitable for 3/2 wiring TA abnormal alarm is provided, and if the tested protection can correctly act under the condition range, the transformer protection equipment is qualified; if the transformer protection equipment can not act correctly, the transformer protection equipment has hidden danger and is unqualified. Such a situation occurs again on site by the tested device, and the device will not alarm abnormally.
The method comprises the following specific steps:
(1) and setting equipment parameters of the transformer protection equipment to enable the rated current Ie of the high-voltage side to be 0.2A and the no-current judgment condition to be 0.05Ie, and connecting two loops of corresponding phase currents output by the relay protection tester to the high-voltage side of the transformer protection equipment.
(2) Using the tester state sequence menu, the states are set according to the following parameters:
state 1 (operating condition): the amplitude of the three-phase current of the high 1 branch and the high 2 branch is 0.1Ie, and the currents of the high 1 side and the high 2 side are reversely connected to the medium voltage side after being connected in parallel.
State 2 (operating condition):
the amplitude of the three-phase current of the high 1 branch is 0.1Ie, the amplitude of the three-phase current of the high 2 branch is gradually increased from 0.1Ie to 1.5Ie, and the currents of the high 1 side and the high 2 side are reversely connected to the medium voltage side after being connected in parallel.
State 3 (operating condition):
the phase A currents of the high 1 branch and the high 2 branch are changed, the phase A current of the high 1 branch ranges from 0 to 1.5Ie, the phase A current of the high 2 branch ranges from 0 to 1.5Ie, but the relationship that I1A/I2A is not more than 1:15 is met, the three-phase currents of the high 1 branch and the high 2 branch are unbalanced and have zero sequence currents, the phase currents of the high voltage side are the same, and the currents of the high 1 branch and the high 2 branch are reversely connected to the medium voltage side after being connected in parallel.
State 4 (line break condition):
changing the phase A currents of the high 1 branch and the high 2 branch, wherein the phase A current of the high 1 branch is 0-1.5 Ie, the phase A current of the high 2 branch is 0-1.5 Ie, but the phase A current of the high 1 branch meets the relation that I1A/I2A is not more than 1:15, disconnecting the phase A current signal flowing into the high 1 branch, so that the phase A currents of the high 1 branch and the high 2 branch are changed, the three-phase currents of the high 1 branch and the high 2 branch are unbalanced, each branch has a zero-sequence current, but the zero-sequence current sum of the external three-phase currents of the high 1 branch and the high 2 branch is zero; the high 1 and high 2 branch circuits are connected in parallel and then connected to the medium voltage side.
State 5 (fault condition):
changing the phase A currents of the high 1 branch and the high 2 branch, wherein the phase A current of the high 1 branch is 0-1.5 Ie, the phase A current of the high 2 branch is 0-1.5 Ie, but the phase A current of the high 1 branch is not more than 1:15 of I1A/I2A, disconnecting the phase A current signal flowing into the high 1 branch, so that the phase A currents of the high 1 branch and the high 2 branch are changed, the three-phase currents of the high 1 branch and the high 2 branch are unbalanced, each branch has a zero-sequence current, but the zero-sequence current sum of the external three-phase currents of the high 1 branch and the high 2 branch is not zero; the high 1, high 2 branch side A phase current is connected in parallel and is not connected to the middle voltage side A phase, and the high 1, high 2 branch side B, C phase current is connected in parallel and is reversely connected to the middle voltage side.
(3) And calling the state sequence by using a tester state sequence menu to carry out testing.
State 1: the three-phase current amplitude of the high 1 branch and the high 2 branch is 0.1Ie, and balance is kept without differential current;
state 2: the amplitude of the three-phase current of the high 1 branch is 0.1Ie, and the current is kept unchanged; the current amplitude of the three phases of the high 2 branch is gradually increased from 0.1Ie to 1.5Ie in a gradient mode, and each state holding state is larger than 10 s.
State 3: the phase A currents of the high 1 branch and the high 2 branch are changed, the phase A currents of the high 1 branch and the high 2 branch are not changed, the three-phase currents of the high 1 branch and the high 2 branch are unbalanced, zero sequence currents exist, and each state keeping state is larger than 10 s. And selecting a test value according to the tested object, the zero sequence current threshold and the no-current threshold, wherein the threshold needs to be covered.
And 4: the phase a current for the high 1 and high 2 legs is changed in increments of 0.05Ie, and the phase a current signal flowing into the high 1 leg is interrupted, each state holding state being greater than 10 s.
And state 5: the phase A current of the high 1 branch and the high 2 branch is changed by 0.05Ie as a gradual change increment, the signal of the phase A current flowing into the high 1 branch is disconnected, the phase A current of the high 1 branch and the high 2 branch is not connected to the phase A of the medium voltage side after being connected in parallel, and the phase A current of the high 1 branch and the high 2 branch is connected to the phase B, C of the medium voltage side after being connected in parallel, and each state holding state is more than 10 s.
(4) Test result of transformer protection equipment
And if the test result of the transformer protection equipment meets the conditions that the protection is not started in the states 1-3 and no TA abnormal alarm action information exists, judging that the action of the transformer protection equipment is correct.
If the test result of the transformer protection equipment meets the test in the state 1-4, in the state 4, when the A-phase current of the high 1 branch is smaller than the no-current threshold and the zero-sequence current of the high 1 branch is larger than the zero-sequence current threshold, the transformer protection equipment is started and sends out TA disconnection warning information, and then the action of the transformer protection equipment is judged to be correct. And when the A-phase current of the high 1 branch is larger than the zero-sequence current threshold or the zero-sequence current of the high 1 branch is smaller than the zero-sequence current threshold, the transformer protection equipment is not started, and the action of the transformer protection equipment is judged to be correct.
If the test result of the protection equipment meets the test in the state 1-5, in the state 5, when the differential value is greater than the preset high action fixed value 1.2Ie, the transformer protection equipment is started and acts at an outlet, and then the action of the transformer protection equipment is judged to be correct; when the differential value is smaller than the preset high action fixed value 1.2Ie, the transformer protection equipment is started and does not act at the outlet, and then the action of the transformer protection equipment is judged to be correct.
Based on the same inventive concept, the present application also provides a testing apparatus 400 for transformer protection equipment, as shown in fig. 4, including:
the test execution unit 410 is used for testing the transformer protection equipment by using test data, wherein the test data are current amplitudes of each branch and a medium-voltage side obtained by setting under various working conditions of the transformer;
a test result determining unit 420, configured to determine that the test result is a pass if the action of the transformer protection device is consistent with a preset test result; otherwise, determining that the test result is failed; otherwise, determining that the test result is failed; and presetting a test result as the movement of the corresponding transformer protection equipment according to the test data.
Preferably, the test execution unit includes:
the operation working condition action subunit sets the action of the corresponding transformer protection equipment to protect the transformer from being started for the test data under the operation working condition of the transformer;
the circuit breaking working condition action subunit is used for testing data under the circuit breaking working condition of the transformer, when the phase A current of the high 1 branch is smaller than a no-current threshold and the zero sequence current of the high 1 branch is larger than a zero sequence current threshold, the action corresponding to the transformer protection equipment is protection starting, and TA circuit breaking alarm information is sent out; when the A-phase current of the high 1 branch is larger than the zero-sequence current threshold or the zero-sequence current of the high 1 branch is smaller than the zero-sequence current threshold, the corresponding action of the transformer protection equipment is protection and no starting;
the fault working condition action subunit is used for judging whether the action of the corresponding transformer protection equipment is protection starting and action export when the differential value of the test data under the fault working condition of the transformer is larger than a preset high action fixed value; when the differential value is smaller than the preset high action fixed value, the action of the corresponding transformer protection equipment is protection starting and does not act at an outlet.
The alarm logic aiming at TA abnormity of the transformer protection equipment cannot meet the field operation requirement, and false alarm is given when a primary system and a secondary system both operate normally, but the current test scheme and method cannot detect the defects of the logic and avoid the condition that the three-phase current distribution of each branch is unbalanced due to the impedance difference of each phase of two branches of the primary system. The application provides a relay protection testing method suitable for 3/2 wiring TA abnormal alarm, which can cover various electric quantity working conditions when a primary system and a secondary system both normally operate, and ensure that the protection equipment tested by the detection method does not have error alarm when the system normally operates.
The method comprises the steps that under various working conditions of a transformer, current amplitudes of all branches and a medium-voltage side are set, the current amplitudes serve as test data, corresponding actions of transformer protection equipment are set according to the test data, the actions of the transformer protection equipment serve as preset test results, and if the test results show that the actions of the transformer protection equipment are consistent with the preset test results, the test results are determined to be passed; otherwise, determining that the test result is failed, and solving the problem that TA abnormal alarm is caused due to the defects of the existing test method of the transformer protection equipment.
As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
Finally, it should be noted that: although the present invention has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the spirit and scope of the invention.
Claims (10)
1. A test method for transformer protection equipment, comprising:
testing the transformer protection equipment by using test data, wherein the test data are current amplitudes of each branch and a medium-voltage side obtained by setting under various working conditions of the transformer;
if the action of the transformer protection equipment is consistent with a preset test result, determining that the test result is a pass; otherwise, determining that the test result is failed; and the preset test result is the action of setting the corresponding transformer protection equipment according to the test data.
2. The method of claim 1, wherein setting the magnitude of the current in each branch and the medium voltage side for each operating condition of the transformer comprises:
and under the operating condition, the disconnection condition and the fault condition of the transformer, setting the three-phase current amplitude values of the high 1 branch, the high 2 branch and the medium-voltage side respectively.
3. The method of claim 2, wherein the setting of the high 1 branch, the high 2 branch and the medium voltage side three-phase current amplitudes respectively under the operation condition, the disconnection condition and the fault condition of the transformer comprises:
setting the sum of the amplitudes of the currents of each phase in the three-phase current of the high 1 branch and the high 2 branch to be equal to the amplitude of each phase in the three-phase current of the medium-voltage side under the operation condition of the transformer;
in the transformer disconnection working condition, three-phase currents of a high 1 branch and a high 2 branch are set, wherein the sum of the amplitudes of one phase currents is not equal to the amplitude of the one phase current corresponding to the medium-voltage side, and the sum of the zero-sequence currents of the external three-phase currents of the high 1 branch and the high 2 branch is zero;
in the fault working condition of the transformer, three-phase currents of a high 1 branch and a high 2 branch are set, wherein the sum of one-phase current amplitudes is not equal to the one-phase current amplitude corresponding to the medium-voltage side, and the sum of zero-sequence currents of external three-phase currents of the high 1 branch and the high 2 branch is not zero.
4. The method of claim 3, wherein setting the sum of the phase current magnitudes of the three-phase currents of the high 1 branch and the high 2 branch in the transformer disconnection condition, which is not equal to the phase current magnitude corresponding to the medium voltage side, comprises:
and under the condition of the disconnection of the transformer, the phase A of the high 1 branch is disconnected, the current of the high 1 branch is 0, and the amplitude of the phase A of the medium-voltage side current keeps the amplitude of the operation condition of the transformer.
5. The method of claim 3, wherein setting the sum of the phase current magnitudes of the three-phase currents of the high 1 branch and the high 2 branch in the transformer disconnection condition, which is not equal to the phase current magnitude corresponding to the medium voltage side, comprises:
under the fault working condition of the transformer, the phase A of the high 1 branch is disconnected, the current of the high 1 branch is 0, and the phase amplitude of the current A of the medium-voltage side is 0.
6. The method according to claim 1, wherein if the action of the transformer protection device is consistent with a preset test result, the test result is determined to be passed; otherwise, determining that the test result is not passed: the method comprises the following steps:
comparing the actual test result of the transformer protection equipment with a preset test result;
if the actual test result is consistent with the preset test result, determining that the test result is a pass; otherwise, determining that the test result is not passed.
7. The method of claim 1, wherein the act of setting the corresponding transformer protection device according to the test data comprises:
setting the action of corresponding transformer protection equipment to protect the transformer from being started for test data under the operating condition of the transformer;
for test data under the condition of the line break of the transformer, when the phase A current of the high 1 branch is smaller than a no-current threshold and the zero-sequence current of the high 1 branch is larger than a zero-sequence current threshold, the action of corresponding transformer protection equipment is protection starting, and TA line break warning information is sent out; when the A-phase current of the high 1 branch is larger than the zero-sequence current threshold or the zero-sequence current of the high 1 branch is smaller than the zero-sequence current threshold, the corresponding action of the transformer protection equipment is protection and no starting;
for test data under the transformer fault working condition, when the differential value is larger than a preset high action fixed value, the action of the corresponding transformer protection equipment is protection starting and an action outlet; when the differential value is smaller than the preset high action fixed value, the action of the corresponding transformer protection equipment is protection starting and does not act at an outlet.
8. The method of claim 1, further comprising:
under the operation condition of the transformer, the high 1 branch current and the high 2 branch current are connected in parallel and then reversely connected to the medium-voltage side;
under the condition of the disconnection of the transformer, the high 1 branch circuit and the high 2 branch circuit are connected in parallel and then reversely connected to the medium-voltage side;
in the fault condition of the transformer, B, C high-1 branch and high-2 branch are connected in parallel and then reversely connected to the medium-voltage side.
9. A testing device for transformer protection equipment, comprising:
the test execution unit is used for testing the transformer protection equipment by using test data, wherein the test data are current amplitudes of each branch and a medium-voltage side obtained by setting under various working conditions of the transformer;
the test result determining unit is used for determining that the test result is passed if the action of the transformer protection equipment is consistent with the preset test result; otherwise, determining that the test result is failed; and the preset test result is the action of setting the corresponding transformer protection equipment according to the test data.
10. The apparatus of claim 9, wherein the test execution unit comprises:
the operation working condition action subunit sets the action of the corresponding transformer protection equipment to protect the transformer from being started for the test data under the operation working condition of the transformer;
the circuit breaking working condition action subunit is used for testing data under the circuit breaking working condition of the transformer, when the phase A current of the high 1 branch is smaller than a no-current threshold and the zero sequence current of the high 1 branch is larger than a zero sequence current threshold, the action corresponding to the transformer protection equipment is protection starting, and TA circuit breaking alarm information is sent out; when the A-phase current of the high 1 branch is larger than the zero-sequence current threshold or the zero-sequence current of the high 1 branch is smaller than the zero-sequence current threshold, the corresponding action of the transformer protection equipment is protection and no starting;
the fault working condition action subunit is used for judging whether the action of the corresponding transformer protection equipment is protection starting and action export when the differential value of the test data under the fault working condition of the transformer is larger than a preset high action fixed value; when the differential value is smaller than the preset high action fixed value, the action of the corresponding transformer protection equipment is protection starting and does not act at an outlet.
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