JP3082213B2 - Voltage adjustment relay device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a voltage regulating relay device for switching a transformation ratio of a transformer used in a substation.

(Prior art) The substation is, for example, 270,000 V
The high voltage is reduced to about 6,600V by a transformer and distributed to each customer. In this case, even if the secondary voltage of the transformer is fixed, the terminal voltage given to each customer fluctuates as the load current increases or decreases based on the line loss of the transmission line.

That is, when the load current increases, the terminal voltage decreases, and when the load current decreases, the terminal voltage increases. Therefore, when the load current increases, the secondary side voltage is increased, and when the load current decreases, the secondary side voltage is adjusted so that the transformer ratio is adjusted.

The adjusting operation of the transformer is performed by switching the tap changer of the transformer based on a command signal of the voltage adjusting relay.

The command signal of the relay compares the time integral value of the deviation between the detected voltage value on the secondary side of the transformer and the target voltage value based on the detected current value on the secondary side with the set value, and sets the time integrated value. It is output when the value is exceeded. FIG. 4 is a graph showing the correlation between the deviation e and the integration time t. The calculation of the time integral of the deviation is performed by setting a dead zone.

Switching of the tap changer of the transformer is performed in consideration of two points, that is, if the switching is not performed frequently, the response of the voltage control becomes poor, and if the switching is performed frequently, the tap changer is changed. Is consumed and the life is shortened.

(Problems to be Solved by the Invention) Therefore, the above-described setting of the dead zone is performed so that the responsiveness and the maintenance of the tap changer are compatible. At present, settings are made empirically, settings are not made in accordance with actual conditions, and responsiveness is poor, and tap changers are frequently damaged.

The present invention has been made in view of such a problem, and an object of the present invention is to make it possible to appropriately perform switching adjustment of a voltage ratio in a transformer in view of the actual situation.

(Means for Solving the Problems) In order to achieve such an object, a voltage adjustment relay device according to the present invention includes a voltage fluctuation detector for detecting a voltage fluctuation on a secondary side of a transformer, and a voltage ratio detector. A counter of the number of times of switching of the tap changer for switching, the amount of voltage fluctuation from the voltage fluctuation amount detector, and the number of times of switching from the counter as antecedent variables, and the deviation between the target voltage value and the current voltage value Fuzzy rules that use the dead zone setting value when calculating the time integral of the consequent variable, and the membership function of each antecedent variable and consequent variable assigned to each fuzzy label. A fuzzy controller for inferring the dead zone set value, a calculating unit for calculating a time integral value of the deviation based on the dead zone set value provided from the fuzzy controller, An output control unit that outputs a relay drive signal when the time integral value of the deviation provided by the calculation unit exceeds a set range; and an output control unit that is driven when a relay drive signal is supplied from the output control unit and transforms the transformer. And a relay for outputting a ratio switching signal.

(Operation) According to the above configuration, a dead zone set value is fuzzy inferred from the amount of secondary voltage fluctuation and the number of tap changers in the transformer, and the deviation between the target voltage value and the current voltage value is determined based on the dead zone set value. Is calculated, and when the time integrated value of the deviation exceeds the set range, the relay is driven and the relay outputs a transformation ratio switching signal to the transformer.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention.

In the figure, reference numeral 1 denotes a transformer, 2 denotes a voltage adjusting relay device, 3 denotes a voltage detector, 4 denotes a current detector, and the voltage adjusting relay device 2 supplies a voltage ratio switching command signal S1 to the transformer 1. The voltage detector 3 and the current detector 4 are provided on the secondary side of the transformer 1 so that the detected voltage signal V and the detected current signal I are supplied to the voltage adjusting relay device 2. Has become.

The voltage adjustment relay device 2 includes a relay 5 and a control unit 6, and an output control unit 10, a calculation unit 7, and a fuzzy controller 8 are provided in the control unit 6. Reference numeral 12 denotes a voltage fluctuation detector, and reference numeral 13 denotes a counter for the number of times the tap changer has been switched.

With the above configuration, the voltage signal V from the voltage detector 3 is supplied to the voltage fluctuation detector 12 to detect the voltage fluctuation, and the switching signal from the tap changer of the transformer 1 is counted by the counter 13. Then, the fuzzy controller 8 fuzzy infers a dead zone set value that is considered appropriate by the fuzzy controller 8 based on the voltage fluctuation amount and the number of times of switching. Then, based on the voltage signal V, the current signal I, and the dead zone set value obtained from the fuzzy controller 8, the arithmetic unit 7 calculates the time of the deviation between the detected voltage value and the target voltage value based on the secondary-side detected current value. The integrated value is calculated, and the time integrated value is sent to the output control unit 10. The output control unit 10 compares the value with the set value, and outputs a relay drive signal when the value exceeds the upper set value and when the value is lower than the lower set value.
Thereby, the relay 5 is driven to supply an up / down signal as a transformation ratio switching command signal S1 from the relay 5 to the tap changer of the transformer 1.

The fuzzy controller 8 uses a plurality of fuzzy rules shown in the rule matrix of FIG. The dead zone setting value y is fuzzy inferred in accordance with the membership functions of the antecedent variables x1, x2 and the consequent variable y assigned to each fuzzy label shown in each of FIGS. .

The rule matrix shown in FIG. 2 will be described. The fuji labels of the antecedent variable x1 are as follows: "NL" is "Small voltage fluctuation", "NS" is "Slightly small voltage fluctuation", "ZR" is "No voltage fluctuation", and "PS" is "Slightly large voltage fluctuation". "PL" is set to "large voltage fluctuation", and the fuji label of the antecedent variable x2 is "NL" for "slight switching", "NS" for "slightly switching", and "ZR" for "switching". 0 ",
"PS" is set to "slightly many times", "PL" is set to "many times", and fuzzy labels of consequent variable y are "NL" for "small set value" and "NS" for "fuzzy label". “Slightly small value”, “ZR” is set to “medium setting value”, “PS” is set to “slightly large setting value”, and “PL” is set to “large setting value”. For example, rule 1 is [if x1 = NL x2 = NL then y = ZR], and according to the linguistic expression, "when the voltage variation is small and the number of times of tap changer switching is small, the dead zone setting value is an intermediate value."

In the membership functions shown in FIGS. 3A and 3B, the horizontal axis in FIG. 3A is the voltage fluctuation amount x1, the horizontal axis in FIG. 3B is the number of tap changer switching times x2, and FIG. )
The horizontal axis indicates the dead zone set value y, and the vertical axis indicates the degree of matching.

Next, the inference operation of the fuzzy controller 8 will be described with reference to FIGS.

First, when the voltage variation x1 is α and the tap changer switching frequency x2 is β, the fitness A, B, C, D in the membership function corresponding to each fuzzy rule from FIGS. 3 (a) and 3 (b), respectively. Is required.

Then, for each fuzzy rule, the smallest value of the conformity of each of the antecedent parts x1 and x2 is selected as the antecedent part conformity (MIN operation). As shown in FIG. 3 (c), each membership function relating to y of each fuzzy rule is cut according to the antecedent degree obtained in each rule, and each membership function relating to y of all cut fuzzy rules is obtained. Are superimposed (MAX operation), and αβ is obtained as a dead zone set value y at a position corresponding to the position of the center of gravity G of the superimposed figure indicated by the oblique line.

In the above embodiment, the voltage fluctuation detector 12 and the counter 13
Are provided integrally with the voltage adjusting relay device, but they may be separately arranged.

(Effects of the Invention) As is apparent from the above description, according to the present invention, a dead zone set value which is actually adapted by the secondary-side voltage fluctuation amount and the number of tap changers of the transformer can be obtained by fuzzy inference. Thereby, the responsiveness of the voltage control is appropriately maintained, and the switching of the tap changer is minimized, so that the life of the tap changer can be extended.

[Brief description of the drawings]

FIG. 1 relates to an embodiment of the present invention. FIG. 1 is a block diagram showing a configuration of a voltage adjusting relay device according to an embodiment of the present invention.
The figure is a rule matrix diagram showing the fuzzy rules stored in the fuzzy control of FIG. 1, and FIGS. 3 (a), (b) and (c) show the antecedent variable and the consequent membership function, respectively. FIG. 4 is a graph showing the correlation between the deviation and the integration time. DESCRIPTION OF SYMBOLS 1 ... Transformer, 2 ... Voltage adjustment relay device, 5 ... Relay, 7 ... Operation part, 8 ... Fuzzy controller, 10 ... Output control part, 12 ... Voltage fluctuation amount detector, 13 ... counter.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-57-3113 (JP, A) JP-A-60-250415 (JP, A) JP-A-3-145930 (JP, A) JP-A-4- 251525 (JP, A) JP-A-61-156317 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H02J 3/00-3/18

Claims (1)

(57) [Claims] A voltage change amount detector for detecting a voltage change amount on a secondary side of the transformer; a counter for switching the number of tap changers for switching a voltage ratio; The voltage fluctuation amount from the voltage fluctuation amount detector (12) and the number of times of switching from the counter (13) are set as antecedent variables, and are used to calculate the time integral value of the deviation between the target voltage value and the current voltage value. A fuzzy rule for inferring the dead zone set value based on a plurality of fuzzy rules using the dead zone set value as a consequent variable and membership functions of each antecedent variable and consequent variable assigned to each fuzzy label. A controller (8); a calculation unit (7) for calculating a time integral of the deviation based on the dead zone setting value provided from the fuzzy controller (8); and a calculation unit for the deviation provided from the calculation unit (7). An output control unit (10) for outputting a relay drive signal when the inter-integral value exceeds a set range; and the transformer (1) driven when a relay drive signal is given from the output control unit (10). And a relay (5) for outputting a transformation ratio switching signal to the voltage adjusting relay device.