JPH081861B2 - Monitoring device for tap switching device under load - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Industrial field of application) The present invention relates to a load tap switching device for performing voltage adjustment by switching a tap of a transformer tap winding while a load is being applied to a transformer. The present invention relates to a monitoring device that monitors the switching operation status.

(Prior Art) A tap switching device at load is a tap switch at load composed of a switching switch that cuts off current and a tap selector that selects a tap of a transformer tap winding, as defined in JECI86. The entire device is composed of a switching device, an electric operating mechanism that mechanically drives the load tap switching device in a predetermined order, and the electric device.

The operation of an example of such a tap switching device under load is
This will be described with reference to FIGS. Fig. 6 shows Japanese Patent Publication 62-1
The switching circuit of the 2-resistor 4-valve system described in Japanese Patent No. 6004 and its switching order are shown in the order from to. The thick line in the figure shows the energizing path of the transformer load current. FIG. 5 (a)
6B is a sequence diagram showing the switching order in the switching circuit of FIG. 6, FIG. 6A is the switching sequence diagram, and FIG. 6B is an example of the current resistance flowing in the current limiting resistor. .

These figures will be described below. In FIGS. 5 and 6, indicates the operating state selected by the tap T ₁ . In this state, the tap switching operation is started by the switching operation of the electric operating mechanism (not shown). First, when the main valve HA opens, the main valve HA ignites, interrupts the load current, and transfers the load current IA to the limited resistance R (in the figure). Next, the resistance valve WB closes, and the bridge between taps is set.
A load current of IA and IB and a short-circuit current between the taps flow in one current limiting resistor R (in the figure). Next, when the resistance valve WA opens to cut off the load current and transfer it to the tap T ₂ (in the figure), only the load current IB flows through the current limiting resistance R. Finally, the main valve
HB is completely transferred to the tap T ₂ closed, become a driving state of the tap T ₂ to end the switching operation (in the drawing).

In FIGS. 5 and 6, the time required for one tap of the switching switch (the time from when the main valve HA is open to when the other main valve HB is closed) is defined as t ₂ . this
If t ₂ is not a constant value at all times, it will affect the load current interruption capability of the main valves HA, HB and the resistance valves WA, WB. Further, in FIGS. 5 and 6, the tap selector M ₁ ,
Although the operation of M ₂ is omitted, when switching from the state of FIG. 6 to tap T ₃ not shown, after the tap selector M ₁ completes the movement from tap T ₁ to T ₃ , the switching switch Will switch from state to state in the reverse order of the above operation.

The operation sequence of the entire load tap switching device is as described above as an example, and the relationship between the total switching time t and the switching time t ₂ of the switching switch in this device is as shown in FIG. . In FIG. 2, the switching time t is the tap switching operation time of the electric operating mechanism described above, that is, the electromagnetic contactor operates in response to the raising / lowering signal to rotate the electric motor to switch the tap switching unit under load in a predetermined order. The total time to be performed, t ₁ is the time from the operation of the electromagnetic contactor to the operation of the switching switch, and t ₂ is the switching time of each phase of the switching switch.

(Problems to be Solved by the Invention) By the way, the load tap changer and the electric operating mechanism are mechanically connected by a transmission shaft, whereby the operation is performed in accordance with the switching order as shown in FIG. In this case, the most important one of the load tap changers is the switching switch part that cuts off the load current, and the switching operation should stop due to congestion and the switching time t ₂ should be abnormal. If any trouble occurs such as lengthening or no switching at all, a serious accident such as short-circuiting between taps will immediately develop.

In order to prevent such accidents, at present, regular inspections are performed to inspect whether or not smooth operation is being performed. However, it is difficult to detect the precursory phenomenon of mechanical part failure, and it is virtually impossible to judge the timing.

Therefore, in order to conventionally monitor the operation of the switching switch itself, a mechanical contact is provided in the switching switch as described in JP-B-42-2891, or disclosed in JP-A-61-102012. Thus, an invention has been proposed in which the current flowing in the current limiting resistor is detected and monitored using a light emitting diode or the like. However, all of these prior arts are for the switching switch itself and do not monitor the operation of the entire apparatus, and have the drawback that abnormalities in other parts and the entire apparatus cannot be monitored.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems of the prior art and to provide a load tap switching device monitoring device capable of monitoring an abnormality of not only the switching switch but also the entire device. .

[Configuration of the Invention] (Means for Solving the Problems) A monitoring device for a load tap switching device of the present invention includes a tap selector that arbitrarily selects a tap of a transformer tap winding,
A switching switch which cuts off the load current flowing through the selected tap and switches the tap, and an electric operating mechanism which operates in response to an up / down signal from the control device and switches the tap switching and the switching switch in a predetermined switching order. In the load tap switching device configured by, a switch switching time detection unit that detects the switching time of the switching switch, a total switching time detection unit that detects the switching time of the electric operating mechanism, and at least both of these detections. It is characterized in that an arithmetic determination unit for comparing and detecting the time signal value of the unit and a preset setting value is provided.

(Operation) With the above configuration, according to the present invention, the switch switching time detecting unit and the time signal value detected by the total switching time detecting unit are compared and determined by the preset value and the calculation determining unit. If there is an abnormality as a result, an abnormality signal is output.

(Embodiment) An embodiment of the present invention will be specifically described below with reference to FIGS. 3 and 4.

In FIG. 3, the tap winding TW is provided with taps T ₁ and T ₂ . M ₁ and M ₂ are tap selectors, and the taps T ₁ and T _{2 are}
Is arbitrarily selected. Reference numeral 1 denotes a switching circuit of the switching switch, which operates in the switching sequence as shown in FIGS. 5 and 6. 2, 2 'in the switch switching time detecting unit for detecting a switching time t ₂ of the diverter switch, the switching circuit 1 and the switch switching between the detection unit 2, 2' as conventionally known, for example JitsuHiraku The one described in Sho 61-102012 is used. Three
Is a contact of an electromagnetic contactor provided in the electric operation mechanism, and is a detection unit that detects the total switching time t in the raising / lowering direction. A tap position detector 4 is also provided in the electric operation mechanism and mechanically detects the tap position for each switching operation. 5 is a gas temperature detector 5a and a gas pressure detector installed in the switching switch room
5b is a detection unit for correcting the switching time. Reference numeral 8 denotes an optical fiber for optically transmitting the optical signal output from the switch switching time detecting unit 2, 2'to the outside of the transformer tank 10 via the connector 9 and transmitting the signal to the receiver 6. Reference numeral 7 denotes a calculation determination unit, which processes each signal of the reception unit 6, the total switching time detection unit 3, the tap position detection unit 4, and the switching time correction detection unit 5, and stores the signal for each switching operation in a storage device. At the same time, an abnormal signal is output for the abnormal value.

FIG. 4 is a flow chart of the calculation determining section 7, and the operation of FIG. 3 will be described.

First, an electric operating mechanism (not shown) receives a switching signal for tapping up or down, and switching is started, and the electromagnetic contactor 88R / L is closed by this switching signal. Since the tap position is detected by the mechanical detector 4, the tap position is read by the calculation determination unit 7. In this state, the electric operating mechanism continues the switching operation, and when the switching time reaches t ₁ , the switching switch is disconnected. The switching time t ₁ is read by measuring the time difference between the up / down switching signal and the start signal of the switching switch. This measured time t ₁ is compared with a set value t ₁ ′ obtained by performing temperature and pressure correction on the set value set by the tap position in advance, and is judged in four steps. If it is within the set value, it is stored in the storage device as a normal operation. In the figure, cases of F1, F2, and F3 are cases in which it is determined that there is an abnormality, F1 is 0, that is, a state in which the switching operation is not performed,
Is a state that is shorter than the set value, and F3 is a state that is longer than the set value. In the states of F2 and F3, mechanical failure such as an increase in load torque or a shift in the connecting portion of the mechanical system has occurred.

Next, the switching time t ₂ of the switching switch itself is read and compared with the set value t ₂ ′ similar to the above to calculate 4
A stage determination is made. Further, the total switching time t is read, and the comparison operation is performed in the same manner to make four-stage determination, and the monitoring of the one-tap switching operation is completed.

As described above, according to the load tap switching device monitoring device of the present embodiment, the following operational effects are exhibited.

Since the relative motion of the entire device is constantly monitored by the switching switch operation start time t ₁ , the switching switch switching time t ₂ and the total switching time t from the start of switching, mechanical abnormal phenomena that occur suddenly can be prevented. Can immediately detect and give an abnormal signal.
As a result, it is possible to prevent the development of an abnormal phenomenon into a secondary serious accident.

Even during normal operation, it is possible to know the change in switching time due to deterioration over time such as wear of mechanical parts.
t ₂ In the contact life limit, and may determine the t _1, t the mechanical life.

Conventionally, periodic inspections have been performed, but since changes over time are monitored, it is only necessary to check the changes and inspect only when it is necessary, so the frequency of maintenance work can be reduced.

The present invention has the constitution and the action and effect as shown in the above-mentioned embodiment, but is not necessarily limited to this embodiment. For example, it is also possible to adopt a configuration as the circuit of the switching switch 1 and its switching time detecting units 2, 2 '. Further, when the influence of the temperature and the gas pressure on the switching time is small, it is possible to use a non-corrected set value that is input in advance to the calculation determination unit 7.

Further, it is sufficient to compare and judge only the switching time t ₂ of the switching switch and the total switching time t with the set value, and it is possible to perform monitoring far superior to the conventional monitoring of only the switching switch. Therefore, the time t ₁ from the start of switching to the start of the operation of the switching switch can be expected to have a sufficiently good effect without comparing with the set value.

[Advantages of the Invention] As described above, according to the present invention, only the conventional switching switch is monitored by the means of comparing and calculating the switching time of the switching switch and the total switching time of the entire device with the set value. For excellent load tap switching device that can detect abnormalities in the entire device more reliably than devices and can detect failures due to aged deterioration of mechanical parts that were difficult to predict A monitoring device can be provided.

[Brief description of drawings]

FIG. 1 is a block diagram showing a basic structure of a monitoring device for a load tap switching device of the present invention, FIG. 2 is an operation sequence diagram of the load tap switching device, and FIG. 3 is an embodiment of the present invention. FIG. 4 is a configuration diagram, FIG. 4 is a system flow chart of the operation determining unit of FIG. 3, FIG. 5 is a sequence diagram showing a switching operation of the switching switch, and FIG. 6 is a circuit diagram thereof. TW ... tap winding, T _1, T ₂ ... taps, M _1, M ₂ ... tap selector, 1 ... diverter switch, 2,2 '... switching time detecting unit, 3 ... total switching Time detection unit, 4 ... Tap position detector, 5 ... Gas temperature, gas pressure detector, 6 ... Reception unit, 7 ...
… Calculation judgment part, 8 …… Optical fiber, 9 …… Connector, 10 …… Transformer tank, 88R / L …… Electromagnetic contactor in the electric operation mechanism.

Claims (1)

[Claims] Claim: What is claimed is: 1. A tap selector for arbitrarily selecting a tap of a transformer tap winding, a switching switch for interrupting a load current flowing through the selected tap and switching the tap, and a rise / fall signal from a control device. And a switch switching time detecting unit for detecting a switching time of the switching switch, wherein the tap switching device and the switching switch are switched in a predetermined switching order. A total switching time detecting unit for detecting a switching time of the electric operating mechanism, and an operation determining unit for determining at least a time signal value of both the detecting units and a preset setting value. Monitoring device for tap switching device under load.