RU2214667C2 - Method for power-up control of automatic load transfer center in ring mains - Google Patents

Abstract

FIELD: automatic control of power lines. SUBSTANCE: method intended to check automatic load transfer center in ring mains supplied with power from two-transformer substation buses for reliable closure due to receiving information about its faultless turn-on includes recording of two inrush currents and measuring time period between them from instant of occurrence of first inrush short- circuit current at transformer buses of main power supply equal to time delay before throwing automatic load transfer center on line; in the process second inrush current at transformer of stand-by power supply is checked at instant of final time reading and if it is higher than normal operating current but lower than short-circuit current, the fact of reliable change-over to automatic load transfer center is stated. EFFECT: enlarged functional capabilities. 1 cl, 2 dwg

Description

 The invention relates to the automation of electrical networks and is intended to control the successful inclusion of a point of automatic inclusion of a reserve (ABP) in a ring network powered by different buses of a two-transformer substation.

 A known method of controlling the failure of the automatic switch-on of the reserve for short circuit (short circuit) in the ring network, powered by two-transformer substation buses, which consists in fixing the surges of short-circuit currents and in measuring the time between them. Count the time from the moment of the appearance of the first inrush short-circuit current on the tires of the transformer of the main power source, equal to the time delay of the operation of the ABP network item, at the moment of the end of its countdown, the appearance of a second inrush current short circuit is controlled. on the tires of the backup power source and when it appears, the fact of the unsuccessful inclusion of the ABP point for a short circuit is established [1].

 The disadvantage of this method is the impossibility of using its control to successfully enable the item ABP in the ring network.

 The objective of the invention is to expand the functionality of the method by obtaining information about the successful inclusion of the ABP point in a ring network powered by different buses of a two-transformer substation.

 According to the proposed method, the appearance of an inrush caused by a short circuit in the line powered by this transformer is recorded on the tires of the transformer of the main power source. When the appearance of an inrush short-circuit current begins to count down the time equal to the time delay point ABP. At the end of this time, the appearance of an inrush of the operating current is monitored (the current increases to a value of a more normal operating current, but less than a short circuit current) on the tires of the transformer of the backup power source. The appearance of this inrush current indicates that the ABP item was successfully turned on.

The essence of the invention is illustrated using the drawings, where:
in FIG. 1 presents a structural diagram containing elements for implementing the method;
figure 2 - diagrams of the signals at the outputs of the elements shown in figure 1 with a short circuit at point 20 (see figure 1).

 The circuit (see Fig. 1) contains: point ABP 1, current transformer 2, short-circuit current sensor 3, element MEMORY 4, element DELAY 5, one-shot 6, element I 7, recording device (RU) 8, current transformer 9, short-circuit current sensor 10, one-shot 11, element HE 12, head switch of the main power supply line 13, section switch of the line 14, head switch of the backup power supply line 15, section switch of the line 16, main power supply transformer 17, backup power transformer I am 18, a sectional substation circuit breaker 19, a short circuit point 20, consumers 21 and 22.

 The signal diagrams at the outputs of the elements shown in figure 1 with a short circuit at point 20 (see figure 1) have the form (see figure 2): 23 - at the output of element 2; 24 - at the output of element 3; 25 - at the output of element 4; 26 - at the output of element 5; 27 - at the output of element 6; 28 - at the output of element 9; 29 - at the output of element 10; 30 - at the output of element 12; 31 - at the output of element 11; 32 - at the output of element 7; 33 - the availability of information in element 8.

 In normal mode, the ABP 1 item is turned off and consumers 21 and 22 are fed through the head switch 13 and the section switch 14 from the transformer 17 of the main power source. At the outputs of current transformers 2 and 9, there is a certain value of the output signals (Fig. 2, diagrams 23, 28), due to operating currents, but insufficient for the operation of short-circuit current sensors 3 and 10, and a single-shot element 11, so there are no signals at the inputs of the rest circuit elements and the circuit does not start.

 In case of a short circuit at point 20 (see FIG. 1), the output signal of current transformer 2 is sufficient to trigger a short circuit current sensor 3 (FIG. 2 diagram 23), at the output of which a signal appears (FIG. 2, diagram 24). This signal is remembered by the element MEMORY 4 (Fig. 2, diagram 25) and is input to the element DELAY 5, from the output of which the signal appears after a time equal to the delay time of switching on the ATS item (Fig. 2, diagram 26). The signal from element 5 will go to the input of one-shot 6, this element will give a single pulse (figure 2 diagram 27), which will "reset" the element MEMORY 4 and will go to one of the inputs of the element And 7. If at the same time the item ABP 1 is turned on, then at the output of current transformer 9 there will be a signal (Fig. 2 diagram 28), insufficient for operation of the short-circuit current sensor 10 (Fig. 2 diagram 29), but sufficient for operation of the element one-shot 11 (Fig. 2 diagram 31), which will arrive at the second input of the element And 7. In this case, the element one-shot 11 will work pr and the presence of a surge in operating current more than normal. At the output of the element NOT 12 there is also a signal that goes to the third input of the element And 7 (Fig. 2 diagram 30). The presence of signals at all inputs of the element And 7 will lead to the appearance of a signal at its output (figure 2 diagram 32). This signal includes a recording device 8, where information is stored or displayed in some form (Fig. 2, diagram 33) on the successful inclusion of an ABP point in a ring network.

 Upon successful inclusion of the ABP point in the ring network, information about this on the basis of the proposed method will go to the maintenance personnel.

 Thus, the proposed method allows to provide timely information about the successful inclusion of the point ABP in the ring network. This will undoubtedly lead to an increase in the reliability of power supply to consumers through the adoption of necessary decisions based on the information received by operational personnel.

Sources of information
1. RF patent 2169979 C1, cl. H 02 J 9/04, 06/27/2001 - prototype.

Claims (1)

 A way to control the successful inclusion of an automatic reserve switch-on point (ATS) in a ring network powered by different buses of a two-transformer substation, which consists in fixing two inrush currents and in counting the time between them, starting from the moment the first inrush of a short circuit occurs (short circuit) on the transformer tires of the main power source, equal to the time delay for switching on the ABP point, characterized in that at the time the timer ends, the appearance of a second inrush on the transformer tires is reserved power source and if it is more than the normal operating current, but less than the short-circuit current, then when it appears, the fact of the successful inclusion of the ABP item is established.

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