JP4154369B2 - Relay device for detecting mixed phases of AC feeding circuits - Google Patents

Description

  This invention converts three phases into two phases, takes out two sets of quadrature single-phase power supplies, and detects cross-phase contact in a feed transformer that supplies two sets of different-phase single-phase power supplies to an AC feeder circuit The present invention relates to a heterogeneous contact detection relay device for an AC feeding circuit.

  The AC feeding load is a single-phase load, and the AC feeding system uses two sets of quadrature power sources using a three-phase to two-phase conversion transformer to balance the single-phase load on the three-phase power source side. Composed. On the other hand, the AC feeder circuit is provided with a heterogeneous mixture detection relay device, and when an accident of intertwining between two sets of single-phase power supplies is detected, the power supply system is opened to protect the heterogeneous mixture.

  The feeding transformer converts three phases into two phases, takes out two sets of quadrature single-phase power supplies, and supplies two sets of single-phase power supplies of different phases to the AC feeding circuit. Then, the heterogeneous contact detection relay device of the AC feeding circuit takes out the secondary voltage vector obtained by dividing the middle point from each of the two sets of single-phase power supplies, calculates their voltage value, When the voltage value is equal to or less than the operation detection value K, it is determined that a heterogeneous mixture has occurred and the protection operation is performed.

  That is, of the two sets of single-phase power supplies, the voltage vector of the secondary voltage divided at the midpoint of one single-phase power supply is represented by va1, va2, and the secondary voltage divided by the midpoint of the other single-phase power supply is represented by vb1. , Vb2, voltage vectors v1 to v4 of two sets of single-phase power supply voltages are obtained by the following equation. These inter-phase power supply voltage vectors v1 to v4 are different-phase power supply voltage vectors obtained by combining the secondary voltage vectors va1, va2, vb1, and vb2, and are formed in a quadrilateral shape.

v1 = va1-vb1
v2 = vb1-va2
v3 = vb2-va2
v4 =-(va1 + vb2)
Then, the voltage values V1 to V4 of the interphase power supply voltage vectors v1 to v4 are compared with a predetermined operation detection value K, and any one or more of the interphase power supply voltage values V1 to V4 are detected. The operation output is executed when the value is equal to or less than the value K.

By the way, in order to detect contact between AC power supply circuits at different frequencies where the power supply frequency is 50 Hz and 60 Hz, it is determined that contact has occurred when an intermediate 55 Hz voltage or current is detected. (For example, refer to Patent Document 1).
JP-A-7-170608 (FIG. 2)

  However, Patent Document 1 is designed to detect the incompatibility of different frequencies and cannot be directly applied to a different-phase power source at the same frequency. In addition, in the case of comparing the voltage values V1 to V4 of the interphase power supply voltage vectors v1 to v4 with the predetermined operation detection value K, any one or a plurality of the interphase power supply voltage values V1 to V4 is obtained. Since the operation output is executed when the operation detection value K is less than or equal to the operation detection value K, a short circuit accident outside the protection section occurring in another customer branch system on the three-phase power supply side in the power company upstream of the feeding transformer Unnecessary operation may occur due to a ground fault.

  That is, when the power supply system voltage (three-phase power supply side voltage) in the power company outside the protection section of the heterogeneous cross detection relay is reduced, the single-phase voltage vector of the secondary and secondary sets of the feeder transformer becomes small In some cases, the heterogeneous mixture detection relay device may cause unnecessary operation. In order to prevent this unnecessary operation, time cooperation with the power protection device of the electric power company and the host system is required, and if the heterogeneous mixture detection relay device is time-coordinated, the high-speed protection is hindered.

  Further, even in the normal stop operation of the power source, the secondary single-phase voltage vector of the feeding transformer is lost, so that unnecessary operation is caused. In order to avoid this unnecessary operation, the circuit configuration becomes complicated because it must be suppressed by upper equipment conditions such as a switch on the three-phase power supply side and an undervoltage detection relay.

  On the other hand, there is a case where unnecessary operation may occur even in a short circuit accident or a ground fault that occurs outside the branch line downstream of the AC feeder circuit. In other words, the voltage drop and impedance sharing due to the fault current, the system impedance, and the fault point impedance may reduce the two sets of single-phase voltage vectors, leading to unnecessary operation. In order to prevent this unnecessary operation, time cooperation with the lower system is required. If time cooperation is taken, high speed is hindered.

  The object of the present invention is to provide an alternating current capable of detecting a mixed phase accident at high speed without causing unnecessary operation due to a voltage drop or loss of voltage such as a short circuit, ground fault, power supply release, etc. occurring outside the protection section on the upper power supply side or lower load side. It is an object of the present invention to provide a relay device for detecting a mixed phase in a feeding circuit.

According to a first aspect of the present invention, an AC feeding circuit different phase mixing detection relay device converts three phases into two phases, takes out two sets of quadrature single phase power supplies, and supplies the AC feeding circuit with two different phases. In the different phase mixing detection relay device of the AC feeding circuit that detects the mixing of different phases in the feeding transformer that supplies a single phase power supply of the set,
Amplitude value calculation means for taking out the secondary voltage vectors obtained by dividing the middle point from the two sets of single-phase power supplies and calculating their magnitudes, respectively.
Of the two sets of single-phase power supplies, the magnitude of the secondary voltage vector obtained by dividing the midpoint of one single-phase power supply is VA1, VA2, and the magnitude of the secondary voltage vector obtained by dividing the midpoint of the other single-phase power supply. VB1, VB2, the angle formed by the secondary voltages VA1, VB1 is φ1, the angle formed by the secondary voltages VB1, VA2 is φ2, the angle formed by the secondary voltages VA2, VB2 is φ3, and the secondary voltages VB2, VA1 form When the angle is φ4, four areas S1, S2, S3, S4 divided by two diagonal lines of a quadrilateral formed by the inter-phase power supply voltage vector obtained by combining the secondary voltage vectors are Inscribed area calculating means for obtaining the opposite side area difference ratios S% 1, S% 2 and the ratio difference ΔS% by the following expression,
S1 = | (VA1 × VB1 × sinφ1) | / 2
S2 = | (VA2 × VB1 × sinφ2) | / 2
S3 = | (VA2 × VB2 × sinφ3) | / 2
S4 = | (VA1 × VB2 × sinφ4) | / 2
S% 1 = | (S1−S3) | / (S1 + S3)
S% 2 = | (S2−S4) | / (S2 + S4)
ΔS% ＝ ｜ S% 1−S% 2 ｜
= | 2 × {(S1 × S4) − (S2 × S3)} / {(S1 + S3) × (S2 + S4)} |
A comparison determination unit that determines that a heterogeneous mixture has occurred when the ratio difference ΔS% obtained by the inscribed area calculation unit is equal to or greater than a predetermined value set in advance;
And an output processing means for performing protection interruption of the AC feeder circuit when it is determined by the comparison and determination means that a heterogeneous mixture has occurred.

According to a second aspect of the present invention, there is provided an AC feeding circuit different phase mixture detection relay device that converts three phases into two phases, takes out two sets of quadrature single phase power supplies, and supplies the AC feeding circuit with two different phases. In the different phase mixing detection relay device of the AC feeding circuit that detects the mixing of different phases in the feeding transformer that supplies a single phase power supply of the set,
Extract the secondary voltage vector divided by the middle point from each of the two sets of single-phase power supplies, calculate the vector sum of the adjacent secondary voltage vectors, and calculate the magnitude of the inter-phase power supply voltage vector forming the parallelogram An amplitude value calculating means for calculating;
When the magnitudes of the inter-phase power supply voltage vectors forming the parallelogram are V1, V2, V3, and V4, the differential voltage ratios v% 1 and v% 2 of the opposing different-phase power supply voltage vectors are expressed by the following equations: A difference voltage ratio calculation means to be obtained;
v% 1 = (V1-V3) / (V1 + V3)
v% 2 = (V2-V4) / (V2 + V4)
A comparison determination means for determining whether or not a heterogeneous mixture has occurred based on the difference voltage ratios v% 1 and v% 2 obtained by the difference voltage ratio calculation means;
And an output processing means for performing protection interruption of the AC feeder circuit when it is determined by the comparison and determination means that a heterogeneous mixture has occurred.

  According to the present invention, a mixed-phase accident that is an original detection target accident without an unnecessary operation for an operation or a non-detection accident such as a short circuit / ground fault of the three-phase power supply side or single homologous system outside the protection section Therefore, detection coordination and timed coordination with other equipment and devices are not necessary. As a result, high-speed protection can be achieved, and on-site adjustment tests and maintenance inspections can be simplified and workability can be improved.

  Hereinafter, a first embodiment of the present invention will be described. FIG. 1 is an AC feeding circuit protection system diagram in which the heterogeneous mixture detection relay device 11 according to the first embodiment of the present invention is applied to an AC feeding circuit. In the first embodiment, a quadrilateral formed by synthesizing a voltage vector of a secondary voltage divided at a midpoint from two sets of single-phase power supplies is divided into four areas by two diagonal lines, and When two sets of opposite side area difference ratios S% 1 and S% 2 are obtained from the area, and the ratio difference ΔS% between the two sets of opposite side area difference ratios S% 1 and S% 2 is equal to or larger than a predetermined value set in advance. It is determined that a mixed-phase accident has occurred.

  In FIG. 1, the power of an AC feeder circuit that is a consumer is received by a three-phase power source from a transmission facility 12 of a power company, and the received three-phase power source is a single-phase two-phase power that is orthogonally crossed by a consumer feeder transformer 13. It is converted into a set of A seat power source and B seat power source. Then, power is supplied from the A seat power source to the load, and the B seat power source is further boosted by the step-up transformer 14 and supplied to the load.

  Here, a different phase intrusion detection relay device 11 is provided for detecting contact between the A seat power supply and the B seat power supply, and a protection operation is performed when the contact between the A seat power supply and the B seat power supply is detected. That is, the voltages of the two sets of single-phase A-seat power supply and single-phase B-seat power supply are taken out as secondary voltages va1, va2, vb1, and vb2 that are divided through the transformers 15 and 16, respectively. , And input to the heterogeneous mixture detection relay device 11. The heterogeneous mixture detection relay device 11 determines the heterogeneous mixture based on these secondary voltages va1, va2, vb1, and vb2.

  FIG. 2 is an explanatory diagram of the voltage vector and the feeding voltage vector of the feeding transformer 13. The primary receiving three-phase vectors a, b, and c of the feeding transformer 13 are 120 ° phase balanced vectors, and are indicated by interphase voltages each having a magnitude of V. For the sake of simplicity, assuming that the transformation ratio of the feeding transformer 13 is 1: 1, the secondary A-side single-phase voltage va of the feeding transformer 13 is the three-phase power source bc. The voltage value V is in phase with the phase. Further, the B-side single-phase voltage on the other side of the secondary side of the feeding transformer 13 is in phase with the three-phase power source a-phase and has a voltage value V / √3. Therefore, the voltage is boosted by the step-up transformer 14 having a transformation ratio of 1: √3, and a feeder circuit voltage vb having a magnitude of V is obtained.

  The two sets of single-phase power supply voltages va and vb are taken out as secondary voltages va1, va2, vb1, and vb2 divided by the above-described instrument transformers 15 and 16 to the heterogeneous mixture detection relay device 11. Have been entered. The secondary voltages va1 and va2 and the secondary voltages vb1 and vb2 have the same value and are orthogonal to each other, φ1 to φ4 are 90 °, respectively, and the voltages V1 to v4 between the different-phase power sources in the steady state are A-position and B It is a regular quadrilateral outer periphery hypotenuse voltage with two sets of orthogonal single-phase power sources v as diagonal lines, and its value is V / √2. The quadrilateral formed by the inter-phase power supply voltage vectors v1 to v4 is represented by two diagonal lines {A-seat single-phase voltage va (va = va1 + va2), B-seat single-phase voltage vb (vb = vb1 + vb2)}. It is divided into four areas S1, S2, S3 and S4.

  FIG. 3 is a block configuration diagram of the heterogeneous mixture detection relay device 11 according to the first embodiment of the present invention. Two sets of single-phase power supply voltages va 1, va 2, vb 1, vb 2 input from the instrument transformers 15, 16 are input to the input conversion means 21 of the heterogeneous mixture detection relay device 11. The input conversion means 21 converts the single-phase power supply voltages va1, va2, vb1, vb2 at a predetermined ratio, passes the analog filter, and outputs it to the sampling hold means 22. The sampling and holding means 22 samples and holds the single-phase power supply voltages va1, va2, vb1, and vb2 every predetermined electrical angular velocity time of the system frequency, and the sampled and held values are converted into digital values by the A / D conversion means 23. The

  Each input voltage data converted into a digital value every predetermined electrical angular velocity time by the A / D conversion means 23 is stored in the data storage means 24. This stored data is updated and stored every predetermined electrical angular velocity time as time-series stored data for a predetermined number of sampling times.

  The amplitude value calculating means 25 calculates the magnitudes VA1, VA2, VB1, VB2, secondary voltages of the input voltages va1, va2, vb1, vb2 from the sampling data of the input voltages va1, va2, vb1, vb2 stored in the data storage means 24. An angle φ1 formed by the voltages VA1 and VB1, an angle φ2 formed by the secondary voltages VB1 and VA2, an angle φ3 formed by the secondary voltages VA2 and VB2, and an angle φ4 formed by the secondary voltages VB2 and VA1 are obtained.

  Then, the inscribed area calculating means 26 has an angle φ1, 2 formed by the voltage values VA1, VA2, VB1, VB2 and secondary voltages VA1, VB1 of the input voltages va1, va2, vb1, vb2 obtained by the amplitude value calculating means 25. The quadrilateral formed by the interphase power supply voltage vectors v1 to v4 from the angle φ2 formed by the secondary voltages VB1 and VA2, the angle φ3 formed by the secondary voltages VA2 and VB2, and the angle φ4 formed by the secondary voltages VB2 and VA1. Four areas S1, S2, S3, and S4 divided by two diagonal lines are obtained by the following formula, and two sets of opposite side area difference ratios S% 1, S% 2, and S4 are obtained from the respective areas S1, S2, S3, and S4. The ratio difference ΔS% is obtained by the following formula.

S1 = | (VA1 × VB1 × sinφ1) | / 2
S2 = | (VA2 × VB1 × sinφ2) | / 2
S3 = | (VA2 × VB2 × sinφ3) | / 2
S4 = | (VA1 × VB2 × sinφ4) | / 2
S% 1 = | (S1−S3) | / (S1 + S3)
S% 2 = | (S2−S4) | / (S2 + S4)
ΔS% ＝ ｜ S% 1−S% 2 ｜
= | 2 × {(S1 × S4) − (S2 × S3)} / {(S1 + S3) × (S2 + S4)} | (1)
The comparison determination unit 27 compares the ratio difference ΔS% of the opposite side area difference ratios S% 1 and S% 2 obtained by the inscribed area calculation unit 26 with a predetermined motion detection value Ks%, and the opposite side area difference ratio When the ratio difference ΔS% between S% 1 and S% 2 is equal to or greater than the motion detection value Ks%, it is determined that contact has occurred. In that case, the comparison / determination means 27 compares and determines the respective inter-phase power supply voltage values VA1, VA2, VB1, and VB2 obtained by the amplitude value calculation means 25 and a predetermined motion detection value K to determine the incompatibility phase. Sort out.

  Then, the comparison / determination unit 27 outputs the mixed phase to the output processing unit 28 together with the occurrence of the mixed contact. When it is determined by the comparison / determination means 27 that the out-of-phase contact has occurred, the output processing means 28 executes protection interruption of the AC feeder circuit for the in-phase.

  That is, in the heterogeneous mixture detection relay device 11 according to the first embodiment of the present invention, the heterogeneous mixture accident is determined based on the magnitude of the ratio difference ΔS% between the two opposite side area difference ratios S% 1 and S% 2. Therefore, it is possible to distinguish between an accident outside the protection section and a phase-intrusion accident.

  FIG. 4 is a voltage vector diagram when a two-phase short circuit (ab phase short circuit) occurs on the three-phase power supply side. As shown in FIG. 3, the constant-phase different-phase voltages v1 to v4 are regular quadrilateral outer peripheral hypotenuse voltages whose diagonals are two sets of orthogonal single-phase power sources v of A seat and B seat. However, if a two-phase short circuit (ab phase short circuit) occurs on the three-phase power supply side, the quadrilateral outer peripheral voltages v2 and v4 decrease according to the voltage drop on the three-phase side. The quadrilateral outer peripheral voltages v2 and v4 are 0V when the short circuit is complete and are rated V / √2 when there is no short circuit, and therefore are in the range of 0V to V / √2 depending on the magnitude of the short circuit impedance. .

  When a two-phase short circuit (ab phase short circuit) occurs on the three-phase power supply side, as shown in FIG. 4, the voltage values VA1, VA2 of the input voltages va1, va2, and the voltage value VB1 of the input voltages vb1, vb2 , VB2 are substantially equal, an angle φ1 formed by the secondary voltages VA1 and VB1 and an angle φ3 formed by the secondary voltages VA2 and VB2, an angle φ2 formed by the secondary voltages VB1 and VA2, and an angle φ4 formed by the secondary voltages VB2 and VA1. Are almost equal to each other. Accordingly, the areas S1 and S3 are substantially equal, and the areas S2 and S4 are substantially equal. That is, as can be seen from the equation (1), the ratio difference ΔS% between the two sets of opposite-side area difference ratios S% 1 and S% 2 is substantially zero, and the heterogeneous mixture detection relay device 11 of the first embodiment is provided. Is not determined to be incompatible.

  FIG. 5 is a voltage vector diagram when a short circuit accident occurs outside the branch line of the B-seat single-phase power supply of the AC feeder circuit. The short-circuit current of the B-seat single-phase circuit flows in the a-phase on the three-phase side, and half of the b-phase current flows in the opposite directions in the b and c phases on the three-phase side. Since the voltage drop that is combined with the voltage value and the phase displacement occurs due to the impedance of the electric transformer 13, the quadrilateral of the interphase voltages v1 to v4 in the steady state is reduced, and the voltage value of the quadrilateral outer peripheral voltages v1 to v4 is reduced. To do.

  When a short circuit accident occurs outside the branch line of the B-seat single-phase power supply of the AC feeding circuit, as shown in FIG. 5, the voltage values VA1, VA2 of the input voltages va1, va2, and the voltages of the input voltages vb1, vb2 The values VB1 and VB2 are substantially equal, the angle φ1 formed by the secondary voltages VA1 and VB1, the angle φ2 formed by the secondary voltages VB1 and VA2, the angle φ3 formed by the secondary voltages VA2 and VB2, and the secondary voltages VB2 and VA1. The angle φ4 is almost equal. Therefore, the areas S1 and S3 are substantially equal, and the areas S2 and S4 are substantially equal. As can be seen from the equation (1), the ratio difference ΔS% between the two sets of opposite side area difference ratios S% 1 and S% 2 is substantially zero. become. That is, the heterogeneous mixture detection relay device 11 according to the first embodiment does not determine that the occurrence of the mixture occurs.

  FIG. 6 is a voltage vector diagram when a ground fault occurs outside the branch line of the A-seat single-phase power supply of the AC feeder circuit. In this case, the angle φ1 formed by the secondary voltages VA1 and VB1 and the angle φ2 formed by the secondary voltages VB1 and VA2, the angle φ3 formed by the secondary voltages VA2 and VB2, and the angle φ4 formed by the secondary voltages VB2 and VA1 are almost the same. The voltage values VA1 and VA2 of the input voltages va1 and va2 are substantially equal. Accordingly, the areas S1 and S2 are substantially equal and the areas S3 and S4 are substantially equal, so that the two sets of opposite side area difference ratios S% 1 and S% 2 are substantially equal, and the ratio difference ΔS% is substantially zero. Therefore, the heterogeneous mixture detection relay device 11 of the first embodiment does not determine that the occurrence of the mixture occurs.

  On the other hand, FIG. 7 is a voltage vector diagram when the A-seat single-phase power supply and the B-seat single-phase power supply of the AC feeder circuit are mixed. In this case, the areas S2 and S4 are substantially equal, and the areas S1 and S3 have different values, so that the two sets of opposite-side area difference ratios S% 1 and S% 2 have different values, and the two sets of opposite-side area differences The ratio difference ΔS% between the ratios S% 1 and S% 2 increases. When this ratio difference ΔS% is equal to or greater than the operation detection value Ks%, the heterogeneous mixture detection relay device 11 of the first embodiment determines that the occurrence of the mixture occurs.

  As described above, in the heterogeneous mixture detection relay device 11 according to the first embodiment of the present invention, in the case of a short-circuit accident or a ground fault on the three-phase power supply side or downstream of the feeder circuit, the difference in opposite area between the two sets Since the value of the ratio difference ΔS% of the ratio is extremely small or almost zero, malfunction is suppressed. On the other hand, when a heterogeneous mixture occurs, the ratio difference ΔS% of the opposite side area difference ratio is obtained, so that it is possible to operate normally for the heterogeneous mixture.

  Next, a second embodiment of the present invention will be described. FIG. 8 is a block diagram of the heterogeneous mixture detection relay device 11 according to the second embodiment of the present invention. The second embodiment is different from the first embodiment in that a difference voltage ratio calculation means 29 is provided in place of the inscribed area calculation means 26 in FIG. From the magnitude of the quadrilateral different-phase power supply voltage vector formed by combining the point-divided secondary voltage vectors, the difference voltage ratios v% 1 and v% 2 between the opposite-phase power supply voltage vectors facing each other are obtained. In other words, it is determined whether or not the heterogeneous mixture has occurred based on the difference voltage ratios v% 1 and v% 2. In the following description, the description of the same part as the first embodiment is omitted.

  Two sets of single-phase power supply voltages va1, va2, vb1, and vb2 input from the instrument transformers 15 and 16 of FIG. 1 are input to the input conversion means 21 of the heterogeneous mixture detection relay device 11 shown in FIG. . The input conversion means 21 converts the single-phase power supply voltages va1, va2, vb1, vb2 at a predetermined ratio, passes the analog filter, and outputs it to the sampling hold means 22. The sampling and holding means 22 samples and holds the single-phase power supply voltages va1, va2, vb1, and vb2 every predetermined electrical angular velocity time of the system frequency, and the sampled and held values are converted into digital values by the A / D conversion means 23. The

  Each input voltage data converted into a digital value every predetermined electrical angular velocity time by the A / D conversion means 23 is stored in the data storage means 24. This stored data is updated and stored every predetermined electrical angular velocity time as time-series stored data for a predetermined number of sampling times.

  The amplitude value calculation means 25 calculates the magnitudes V1, V2, V3, and V4 of the interphase power supply voltage vectors from the difference in the simultaneous series sampling data of the input voltages va1, va2, vb1, and vb2 stored in the data storage means 24. Ask. That is, the secondary voltage vectors va1, va2, vb1, and vb2 that have been subjected to midpoint voltage division from the two sets of single-phase power supplies are extracted, and the vector sum of adjacent secondary voltage vectors is calculated to form a parallelogram. The magnitudes V1, V2, V3 and V4 of the inter-phase power supply voltage vectors v1 to v4 are calculated. Thus, the magnitudes V1, V2, V3, V4 of the amplitude values of the interphase power supply voltage vectors v1 to v4, which are quadrilateral outer peripheral voltages composed of two sets of single-phase power supply vectors shown in the voltage vector of FIG. Is obtained and output to the differential voltage ratio calculation means 29.

  In the differential voltage ratio calculation means 29, the magnitudes of the amplitude values V1, V2, V3, V4 of the different phase power supply voltage vectors v1 to v4 obtained by the amplitude value calculation means 25 are used to calculate the opposite different phase power supply voltage vector. The differential voltage ratios v% 1 and v% 2 are obtained by the following equation (2).

v% 1 = (V1-V3) / (V1 + V3)
v% 2 = (V2−V4) / (V2 + V4) (2)
The comparison determination unit 27 compares the absolute values of the difference voltage ratios v% 1 and v% 2 obtained by the difference voltage ratio calculation unit 29 with a predetermined operation detection value Kv% to determine whether color mixing has occurred. Determine whether or not. Further, the incompatible phase is determined based on whether the differential voltage ratios v% 1 and v% 2 are positive or negative.

  For example, when the absolute value of the differential voltage ratio v% 1 is the motion detection value Kv%, if the differential voltage ratio v% 1 is positive, it is determined that the quadrilateral outer peripheral voltage v1 is incompatible, and if it is negative, v3 is incompatible. Is determined. Then, the comparison / determination unit 27 outputs the mixed phase to the output processing unit 28 together with the occurrence of the mixed contact. When it is determined by the comparison / determination means 27 that the out-of-phase contact has occurred, the output processing means 28 executes protection interruption of the AC feeder circuit for the in-phase.

  As described above, in the second embodiment, the magnitudes of the difference voltage ratios v% 1 and v% 2 of the voltage vectors between the opposite-phase power supply of the quadrilateral facing each other formed by two sets of single-phase power supplies crossing each other. Therefore, the three-phase power supply side or single-phase voltage source side short-circuit / ground fault vector shown as an example in FIGS. 4, 5, and 6 shows a parallelogram, so The magnitudes of the difference voltage ratios v% 1 and v% 2 of the voltage vectors between the different-phase power sources to be generated become extremely small, and the detection operation is suppressed.

  On the other hand, in the heterogeneous color mixture vector shown as an example in FIG. 7, the balance of the quadrilateral is broken and a difference voltage ratio v% 1 is generated. The value of the difference voltage ratio v% 1 is generated according to the degree of unbalance of the quadrilateral. Then, the mixed phase is also determined by determining the polarity of the difference voltage ratio v% 1. According to the second embodiment, in addition to the effects of the first embodiment, the incompatible phase can also be determined.

The AC feeder circuit protection system figure which applied the heterophase mixture detection relay apparatus concerning the 1st Embodiment of this invention to the AC feeder circuit. Explanatory drawing of the voltage vector and feeding voltage vector of the feeding transformer in the 1st Embodiment of this invention. The block block diagram of the heterogeneous mixture detection relay apparatus concerning the 1st Embodiment of this invention. The voltage vector diagram when a two-phase short circuit (ab phase short circuit) occurs on the three-phase power supply side. The voltage vector diagram when a short circuit accident occurs outside the branch line of the B-seat single-phase power supply of the AC feeder circuit. FIG. 6 is a voltage vector diagram when a ground fault occurs outside a branch line of an A-seat single-phase power supply of an AC feeder circuit. The voltage vector figure at the time of the A seat single phase power supply and B seat single phase power supply of an AC feeder circuit being mixed. The block block diagram of the heterogeneous mixture detection relay apparatus concerning the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Cross-phase detection relay device, 12 ... Power transmission equipment, 13 ... Feed transformer, 14 ... Step-up transformer, 15, 16 ... Instrument transformer, 21 ... Input conversion means, 22 ... Sampling hold means, 23 ... A / D conversion means, 24 ... data storage means, 25 ... amplitude value calculation means, 26 ... inscribed area calculation means, 27 ... comparison determination means, 28 ... output processing means, 29 ... difference voltage ratio calculation means

Claims (2)

AC power feeding that detects out-of-phase interference in a feeding transformer that converts three phases into two phases, takes out two sets of quadrature single-phase power supplies, and supplies two sets of single-phase power supplies with different phases to the AC feeding circuit In the heterogeneous contact detection relay device of the circuit,
Amplitude value calculation means for taking out the secondary voltage vectors obtained by dividing the middle point from the two sets of single-phase power supplies and calculating their magnitudes, respectively.
Of the two sets of single-phase power supplies, the magnitude of the secondary voltage vector obtained by dividing the midpoint of one single-phase power supply is VA1, VA2, and the magnitude of the secondary voltage vector obtained by dividing the midpoint of the other single-phase power supply. VB1, VB2, the angle formed by the secondary voltages VA1, VB1 is φ1, the angle formed by the secondary voltages VB1, VA2 is φ2, the angle formed by the secondary voltages VA2, VB2 is φ3, and the secondary voltages VB2, VA1 form When the angle is φ4, four areas S1, S2, S3, S4 divided by two diagonal lines of a quadrilateral formed by the inter-phase power supply voltage vector obtained by combining the secondary voltage vectors are Inscribed area calculating means for obtaining the opposite side area difference ratios S% 1, S% 2 and the ratio difference ΔS% by the following expression,
S1 = | (VA1 × VB1 × sinφ1) | / 2
S2 = | (VA2 × VB1 × sinφ2) | / 2
S3 = | (VA2 × VB2 × sinφ3) | / 2
S4 = | (VA1 × VB2 × sinφ4) | / 2
S% 1 = | (S1−S3) | / (S1 + S3)
S% 2 = | (S2−S4) | / (S2 + S4)
ΔS% ＝ ｜ S% 1−S% 2 ｜
= | 2 × {(S1 × S4) − (S2 × S3)} / {(S1 + S3) × (S2 + S4)} |
A comparison determination unit that determines that a heterogeneous mixture has occurred when the ratio difference ΔS% obtained by the inscribed area calculation unit is equal to or greater than a predetermined value set in advance;
And an output processing means for performing protection interruption of the AC feeding circuit when it is judged by the comparison and judgment means that an out-of-phase contact has occurred. AC power feeding that detects out-of-phase interference in a feeding transformer that converts three phases into two phases, takes out two sets of quadrature single-phase power supplies, and supplies two sets of single-phase power supplies with different phases to the AC feeding circuit In the heterogeneous contact detection relay device of the circuit,
Extract the secondary voltage vector divided by the middle point from each of the two sets of single-phase power supplies, calculate the vector sum of the adjacent secondary voltage vectors, and calculate the magnitude of the inter-phase power supply voltage vector forming the parallelogram An amplitude value calculating means for calculating;
When the magnitudes of the inter-phase power supply voltage vectors forming the parallelogram are V1, V2, V3, and V4, the differential voltage ratios v% 1 and v% 2 of the opposing different-phase power supply voltage vectors are expressed by the following equations: A difference voltage ratio calculation means to be obtained;
v% 1 = (V1-V3) / (V1 + V3)
v% 2 = (V2-V4) / (V2 + V4)
A comparison determination means for determining whether or not a heterogeneous mixture has occurred based on the difference voltage ratios v% 1 and v% 2 obtained by the difference voltage ratio calculation means;
And an output processing means for performing protection interruption of the AC feeding circuit when it is judged by the comparison and judgment means that an out-of-phase contact has occurred.

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