JP6928202B2 - OCR tester - Google Patents

Description

The present invention relates to an OCR tester used for periodic inspection work of power receiving and transforming equipment.

An overcurrent relay (OCR) connected to the main circuit of a power receiving and transforming facility is one year as one of the safety inspections stipulated by the business operator for private electric facilities based on the Electricity Business Act. It is required to carry out the operation characteristic test once every time. This test is generally performed together with a circuit breaker interlocking characteristic test (see, for example, Patent Document 1). These tests are performed using a tester that can carry out both the operating characteristic test of the overcurrent relay and the interlocking characteristic test of the circuit breaker. In the present specification, this tester is referred to as an "OCR tester".

Hereinafter, with reference to FIG. 8, a configuration of a conventionally known OCR tester and a test method of an overcurrent relay and a circuit breaker using the same will be described. FIG. 8 is a diagram showing a state in which a conventionally known OCR tester is connected to an overcurrent relay and a circuit breaker provided in a main circuit of a power receiving / transforming facility.

As shown in FIG. 8, the current transformer 101, the overcurrent relay 102 connected to the current transformer 101, the current transformer 101, and the overcurrent relay are included in the current transformer 100 that constitutes the main circuit of the current transformer equipment. A test terminal 103 provided in a circuit connecting the 102 is provided. Further, the distribution wire 100 is provided with a circuit breaker 104 and a circuit breaker detection unit 105 that detects the circuit breaker 104's circuit breaker operation and outputs a detection signal. A drive coil (hereinafter, this coil is referred to as a “trip coil”) 106 of an electromagnetic plunger (hereinafter, this coil) provided in the circuit breaker 104 is connected to the output terminal of the overcurrent relay 102.

The OCR tester 200 according to the conventional example is driven by an AC100V power supply, and is an autotransformer slidac 201, a current limiting resistor 202 for facilitating protection and adjustment of the output current, and a circuit breaker detection unit. It is configured to include a counter 203 that takes in the output signal of 105 and measures the operating time of the overcurrent relay 102 and the circuit breaker 104. In principle, safety inspections of power receiving and transforming equipment should be carried out during power outages in order to ensure work safety. Therefore, in order to carry out the operation characteristic test using the OCR tester 200 according to the conventional example, as shown in FIG. 8, a generator 300 that supplies AC100V power to the OCR tester 200 is required.

The OCR tester 200 according to the conventional example is a test specified by the safety regulations from an AC100V power supply by operating an adjustment knob (not shown) provided on the slidac 201 and a selection knob (not shown) provided on the current limiting resistor 202. Generates a current and outputs it from the current output terminal. The test current output from the current output terminal is applied to the input terminal of the overcurrent relay 102 via the test terminal 103 separated from the current transformer 101.

As a result, the overcurrent relay 102 operates at the time set in the overcurrent relay 102, the test current is instantaneously transferred to the trip coil 106, and the circuit breaker 104 operates. The circuit breaker detection unit 105 detects the circuit breaker 104's circuit breaker operation and outputs a detection signal to the OCR tester 200. The OCR tester 200 receives the detection signal of the cutoff detection unit 105 and cuts off the output of the test current to the overcurrent relay 102, and the elapsed time from the output of the test current to the cutoff, that is, the overcurrent relay 102 and The operating time of the circuit breaker 104 is measured by the counter 203. Then, when the operating current and operating time of the overcurrent relay 102 and the circuit breaker 104 are within the ranges specified by the overcurrent relay manufacturer and the circuit breaker manufacturer, the overcurrent relay 102 and the circuit breaker 104 are determined to be normal.

The circuit breaker 105 is provided in the circuit breaker 104 and mechanically detects the operation of the auxiliary contact that operates in conjunction with the main contact of the circuit breaker 104, or is attached in the vicinity of the circuit breaker 104. A sound sensor or the like that detects the operating sound when the circuit breaker 104 operates can be used.

Japanese Unexamined Patent Publication No. 11-118862

By the way, the current value of the test current applied to the overcurrent relay 102 needs to be at least 40 A in consideration of the instantaneous settling value and the timed settling value set in the overcurrent relay 102. Further, in order to operate the circuit breaker 104 reliably, it is usually required to pass a current of 3 A or more through the trip coil 106, but considering the winding impedance of the trip coil 106, it is at least 40 V or more. Since an AC voltage is required, the power supply of the OCR tester 200 needs to be at least 1600VA.

Therefore, in the OCR tester 200 according to the conventional example, the built-in slidac 201 and the current limiting resistor 202 are inevitably enlarged, and the whole becomes heavy. Further, in order to carry out the operation characteristic test of the overcurrent relay 102 and the interlocking characteristic test of the circuit breaker 104 using the OCR tester 200 according to the conventional example, as described above, a large-sized power capable of outputting 1600VA or more can be output. Since the generator 300 is required, the transportation of equipment for carrying out the test becomes even larger. Therefore, when the OCR tester 200 according to the conventional example is used, the physical burden on the worker who carries out the test is large, and it is difficult to improve the work efficiency.

As a solution to such problems, the applicant of the present application first invented a compact and lightweight OCR tester driven by a battery and applied for a patent (Japanese Patent Application No. 2018-146289). The OCR tester previously invented by the applicant of the present application is an operation characteristic test of an overcurrent relay connected to the main circuit of a power receiving / transforming facility and an interlocking characteristic test of a circuit breaker that operates in conjunction with the operation of the overcurrent relay. In an OCR tester that performs A current that instantly switches the current source supplied to the overcurrent relay from the test current source to the DC current source according to the operation detection circuit that detects the moment when the current relay operates and the output signal of the motion detection circuit. It is characterized by having a switching circuit.

As described above, the OCR tester invented earlier by the applicant of the present application detects the moment when the overcurrent relay operates by using the motion detection circuit, and uses the current switching circuit to supply the current source to the overcurrent relay as a test current source. Since the current is switched to the DC current source instantly, the operation detection circuit needs to be able to stably and surely detect the moment when the overcurrent relay operates regardless of the magnitude of the test current value. Further, in order to facilitate the use of the OCR tester, it is desirable that the operation detection conditions of the operation detection circuit according to the magnitude of the test current value are automatically set. The OCR tester previously invented by the applicant of the present application could be further improved in this respect.

Therefore, an object to be solved by the present invention is to provide a compact and lightweight OCR tester that is easy to use and has excellent operational stability.

In order to solve the above problems, one aspect of the present invention is a test of operating characteristics of an overcurrent relay connected to a main circuit of a power receiving / transforming facility and an interlocking characteristic of a breaker that operates in conjunction with the operation of the overcurrent relay. In the OCR tester that performs the test, the test current source that supplies the test current to the overcurrent relay, the DC current source that operates the breaker, and the test current supplied from the test current source are received. The motion detection circuit that detects the moment when the overcurrent relay operates and the current source supplied to the overcurrent relay are instantly switched from the test current source to the DC current source according to the output signal of the motion detection circuit. The operation detection circuit includes a current switching circuit, and the operation detection circuit is input to the comparator and a comparator that outputs a current switching signal when the magnitude relation of each input signal input to the plus terminal and the minus terminal is inverted. A bias adjusting circuit for applying a DC bias voltage corresponding to the current value of the test current output from the test current source is provided between the input signals, and the positive terminal of the comparator has the test. The pulsating voltage obtained by pulsating the AC voltage output from the current source was input, and the negative terminal of the comparator was detected by a current transformer that detects the output current to the overcurrent relay. It is characterized in that a pulsating voltage obtained by converting a current value into a voltage and pulsating it is input. The bias adjusting circuit may also allow the DC bias voltage to be automatically adjusted to a predetermined value in conjunction with the current value adjusting operation performed on the test current source.

According to the present invention, a DC bias voltage corresponding to the test current value is applied between each input signal input to the comparator, so that each input when the overcurrent relay operates regardless of the magnitude of the test current value. Malfunctions of the motion detection circuit due to signal phase shift or the like are avoided, and the operational stability of the OCR tester is improved. Issues, configurations and effects other than those described above will be clarified by the description of the embodiments described below.

It is a figure which shows the use state of the OCR tester which concerns on 1st Embodiment. It is a functional block diagram of the digital audio amplifier provided in the OCR tester of this invention. It is a functional block diagram of the motion detection circuit which concerns on embodiment. It is a graph which shows the adjustment method of the DC bias voltage according to the test current value. It is a figure which shows the change of the pulsating current applied to the minus terminal and the plus terminal of a comparator at the time of operation of an overcurrent relay. It is a functional block diagram of the overcurrent relay of the current trip type known conventionally. It is a figure which shows the use state of the OCR tester which concerns on 2nd Embodiment. It is a figure which shows the use state of the OCR tester which concerns on a conventional example.

Hereinafter, the configuration of the OCR tester according to the present invention will be described with reference to each embodiment.

[First Embodiment]
As shown in FIG. 1, the OCR tester 1A according to the first embodiment includes a battery 2 as a power source, and unlike the conventional technique shown in FIG. 8, has a configuration that does not require a generator. As the battery 2, a lithium polymer battery, a lithium ferrite battery, or the like is preferably used because it is required to be small, lightweight, and have a large capacity, but the battery 2 is not limited thereto. Further, the battery 2 can be used alone, or a battery pack in which a plurality of batteries are connected in series or in parallel can be used. Theoretically, the battery capacity may be about 30V3000mAh, but practically, it is desirable that the battery capacity is 30V6000mAh or more. Further, the battery 2 can be built in the housing of the OCR tester 1A or can be externally attached to the OCR tester 1A.

In FIG. 1, 3 is a test current source that generates a test current of an overcurrent relay 102, 4 is a DC current source that generates an operating current of a breaker 104, and 5 is an operation detection that detects the moment when the overcurrent relay 102 operates. The circuit, 6 is a relay that is turned on or off by an operator, 7 is a current transformer that detects the output current to the overcurrent relay 102, and 8 is the overcurrent relay 102 according to the detection signal of the operation detection circuit 5. A semiconductor relay that instantly switches the current supplied to the current from the test current source 3 to the DC current source 4, 9 is an arithmetic circuit that calculates the current signal output from the current transformer 7 and displays it on the current meter 10. A control circuit that controls the start and stop of the overcurrent relay 102 and measures the operating time of the overcurrent relay 102 and the breaker 104, and 12 shows a counter circuit that displays the operating time of the overcurrent relay 102 and the breaker 104. ing. In the present specification, "instantaneous" means a time of about 1 to several μS (microseconds).

As shown in FIG. 1, the test current source 3 protects the output of the oscillation circuit 21, the digital audio amplifier 23 connected to the oscillation circuit 21 via the variable resistor 22, and the output of the digital audio amplifier 23, and also digitally. It is composed of a current limiting resistor 24 for improving the controllability of the output current of the audio amplifier 23.

The oscillation circuit 21 is for matching the AC frequency output from the OCR tester 1A to the electrical specifications of the power receiving and transforming equipment protected by the overcurrent relay 102, and outputs a 50 Hz sine wave north of the Kanto area. In the west of the Kansai area, the one that outputs a 60 Hz sine wave is used. The oscillation circuit 21 may be configured so that the output frequency can be switched so that the same OCR tester 1A can be used all over Japan. The oscillation circuit 21 is a reference oscillation circuit that generates a sinusoidal voltage, and the circuit method is not particularly limited.

The variable resistor 22 sets the output current of the OCR tester 1A, adjusts the voltage of the output of the oscillation circuit 21 and supplies it to the digital audio amplifier 23. The variable resistor 22 is operated by an operator.

As shown in FIG. 2, the digital audio amplifier 23 includes an A / D conversion circuit 31, a driver circuit 32, a power amplifier circuit (FET PA circuit) 33 including a field effect transistor (FET), and a waveform shaping device. It is composed of an LC filter circuit 34 and. Since the FET PA circuit 33 outputs an alternating current of at least 40 A, the FET PA circuit 33 includes an FET having a high-speed switching characteristic and a drain current capacity of 60 A or more as an output element. As described above, since the digital audio amplifier 23 includes the FET as an output element, the capacity of the battery 2 can be effectively utilized. That is, the digital audio amplifier 23 is used only for operating the overcurrent relay 102, and its output voltage depends almost entirely on the current limiting resistor 24 in view of the circuit impedance including the overcurrent relay 102. .. Therefore, the output voltage of the digital audio amplifier 23 may be about 15V, although it depends on the selection of the resistance value of the current limiting resistor 24, and the capacity of the battery 2 can be effectively utilized.

Since the combined impedance of the circuit to which the overcurrent relay 102 is connected of the current limiting resistor 24 is close to a short circuit state of 0.1Ω to 0.2Ω, the output protection of the digital audio amplifier 23 and the controllability of the output current can be improved. In order to improve it, it is inserted for the purpose of limiting the current for each settling current range. Generally, in order to switch the test current value in four stages of 0 to 5A, 0 to 10A, 0 to 25A, and 0 to 50A, the four resistors are switched by a rotary switch or the like.

As shown in FIG. 1, the DC current source 4 is for exciting the trip coil 106 built in the breaker 104, and uses the DC / DC converter 41 and the DC voltage generated by the DC / DC converter 41. It is composed of a capacitor 42 for storing electricity and a relay circuit 43 for disconnecting the DC / DC converter 41 for a period of time for discharging the capacitor 402. The capacitor 42 stores a DC voltage of 40 V or more necessary for operating the circuit breaker 104. The relay circuit 43 is switched from the conduction state to the cutoff state by the output signal of the operation detection circuit 5 at the timing when the overcurrent relay 102 is operated.

The operation detection circuit 5 detects an increase in the AC voltage output from the test current source 3 and a decrease in the test current value detected by the current transformer 7 when the overcurrent relay 102 operates. As shown, the current value detected by the current transformer 7 is voltage-converted, amplified to a predetermined voltage by the amplification circuit 51, and then pulsated by the first rectifying circuit 52. Further, a positive DC bias voltage adjusted by the bias adjusting circuit 58 is applied to the pulsating voltage pulsed by the first rectifier circuit 52, and is input to the negative (−) terminal of the comparator 53. On the other hand, the AC voltage output from the test current source 3 is pulsated by the second rectifier circuit 54 and input to the positive (+) terminal of the comparator 53 via the photocoupler 55. By providing the photocoupler 55, the input / output circuit is insulated, so that the pulsating current pulsated by the first rectifier circuit 52 and the pulsating current pulsated by the second rectifier circuit 54 are mixed. Can be avoided.

The comparator 53 outputs a current switching signal when the magnitude relationship between the pulsating voltage input to the negative terminal and the pulsating voltage input to the positive terminal is reversed. as shown in FIGS. 4 (a) and 4 (b), and the peak value V _B of the pulsating voltage B which is input to the peak value V _a and the positive terminal of the pulsating voltage a inputted to the negative terminal It is adjusted to be about the same. _{Further, a DC bias voltage V bias} adjusted by the bias adjusting circuit 58 is applied to the pulsating voltage A input to the negative terminal. DC bias voltage V _bias, as is clear from the comparison shown in FIG. 4 (b) 4 and (a), as the peak value V _A of the pulsating voltage A inputted to the minus terminal is high, i.e., the test current source It is adjusted so that the higher the output current value of 3, the larger the value. Note that in FIGS. 4 (a) and 4 (b), for ease of understanding, the peak value _{V A} of the pulsating voltage A, the relationship of the peak value _{V B} and the DC bias voltage _{V bias} of the pulsating voltage B Is displayed more extreme than it actually is.

As shown in FIG. 3, the bias adjusting circuit 58 includes a variable resistor 58a for adjusting the DC bias voltage and one fixed resistor 58b for removing the influence on the output impedance of the rectifying circuit 52. The variable resistor 58a is adapted so that the resistance value is adjusted in conjunction with the operation of the variable resistor 22 provided in the test current source 3. That is, the variable resistor 58a and the variable resistor 22 are arranged coaxially on one operation shaft (not shown), and increase the current value (test current value) of the test current output from the test current source 3. When the variable resistor 22 is operated in the direction, the variable resistor 58a is automatically operated in the direction in which the positive DC bias voltage applied to the pulsating current in the first rectifier circuit 52 increases. It is configured in. _{As a result, a DC bias voltage V bias} having a magnitude corresponding to the test current value is applied to the pulsating voltage A input to the negative terminal. The DC bias voltage V _bias does not cause a malfunction in the motion detection circuit 5 in consideration of the phase shift of the pulsating voltages A and B, the noise superimposed on the pulsating voltages A and B, the sensitivity of the motion detection circuit 5, and the like. , And is set to an appropriate value that can maintain good sensitivity. The specific value of the DC bias voltage V _bias can be obtained by experiments or simulations.

The bias adjustment circuit 58 does not necessarily have to be linked to the operation of the variable resistor 22 provided in the test current source 3, and the operator may manually adjust the DC bias voltage.

Hereinafter, the operation of the operation detection circuit 5 according to the embodiment will be described.

In Before the overcurrent relay 102 operates, as shown in FIGS. 4 (a) and 4 (b), compared with the peak value V _A of the pulsating voltage A inputted to the negative terminal of the comparator 53 53 _{The peak value V B} of the pulsating voltage B input to the positive terminal of is adjusted to be approximately the same. _{Further, a DC bias voltage V bias} adjusted by the bias adjusting circuit 58 is applied to the pulsating voltage A input to the negative terminal of the comparator 53. Before the overcurrent relay 102 operates, the phase of the pulsating voltage A input to the negative terminal of the comparator 53 and the phase of the pulsating voltage B input to the positive terminal of the comparator 53 are in phase. _{Moreover, since} the DC bias voltage V vias adjusted by the bias adjusting circuit 58 is applied to the pulsating voltage A input to the negative terminal of the comparator 53, the pulsating flow input to the negative terminal of the comparator 53 The voltage A is always higher than the pulsating voltage B input to the positive terminal of the comparator 53. Therefore, no current switching signal is output to the output terminal of the comparator 53.

On the other hand, at the moment when the overcurrent relay 102 operates (OCR operating point), the test current instantly pulsates from the overcurrent relay 102 to the trip coil 106. Therefore, as shown in FIG. 5, the comparator 53 The pulsating voltage A input to the negative terminal of is lowered to a level corresponding to the current value flowing through the trip coil 106. On the other hand, the pulsating voltage B input to the positive terminal of the comparator 53 increases because the test current is transferred from the overcurrent relay 102 to the trip coil 106 and the voltage drop due to the current limiting resistor 24 is reduced. That is, since the impedance of the trip coil 106 is larger than the impedance of the overcurrent relay 102, the test current is reduced and the output voltage of the test current source 3 is increased at the moment when the overcurrent relay 102 is operated. It will be. Then, when the pulsating voltage B input to the positive terminal of the comparator 53 exceeds the pulsating voltage A input to the negative terminal of the comparator 53 (comparator output point), a current switching signal is output from the comparator 53. Then, the semiconductor relay 8 operates and the current source supplied to the comparator 102 is switched from the test current source 3 to the DC current source 4.

In FIG. 5, for easy understanding, the pulsating voltages A and B are also shown after the comparator output point, but the current switching signal is output from the comparator 53 and the semiconductor relay 8 operates. After that, the current source supplied to the overcurrent relay 102 is switched from the test current source 3 to the DC current source 4, so that the current source disappears.

In the operation detection circuit 5A of this example, in order to maintain the current switching signal stably for a short time, the current switching signal output from the comparator 53 is input to the signal temporary holding circuit 57 and output as a control signal of the semiconductor relay 8. doing. As the first rectifier circuit 52, since the output voltage of the amplifier circuit 51 is low, an absolute value circuit using an IC arithmetic element or the like is used. On the other hand, as the second rectifier circuit 54, one made of a diode bridge can be used. Further, as the signal temporary holding circuit 57, a monostable multivibrator can be used.

Returning to FIG. 1, the relay 6 is a normally open type relay, and is switched to a conductive state by an operator operating a measurement start switch 11a attached to the control circuit 11. As a result, the output of the test current from the current output terminal 1a of the OCR tester 1A to the overcurrent relay 102 is started. The relay 6 is omitted, and when the measurement start switch 11a is operated by the operator, the semiconductor relay 8 is controlled by the control circuit 11 to test the OCR tester 1A from the current output terminal 1a to the overcurrent relay 102. It can also be configured to start the output of current.

The semiconductor relay 8 is a current switching circuit that instantly switches the current supplied to the overcurrent relay 102 from the test current source 3 to the DC current source 4 at the moment when the overcurrent relay 102 operates, and is an IC relay using an FET. It is composed of. The semiconductor relay 8 may be a circuit shown in FIG. 1 as long as the current supplied to the overcurrent relay 102 can be instantaneously switched from the test current source 3 to the DC current source 4 at the moment when the overcurrent relay 102 operates. It is not limited to the configuration.

The arithmetic circuit 9 amplifies and calculates the output voltage of the current transformer 7, measures the current value of the current output to the overcurrent relay 102, and displays the measured value on the ammeter 10.

The control circuit 11 includes a measurement start switch 11a, and has a function of controlling output on / off control, measurement of output time (time from the operation of the measurement start switch 11a to the operation of the circuit breaker 104), and the like. There is. The counter circuit 12 counts the output time and displays it on the display unit. As a result, the operating time of the overcurrent relay 102 and the circuit breaker 104 is detected.

As described above, in the motion detection circuit 5A of this example, the pulsating voltage A that decreases at the OCR operating point is input to the negative terminal of the comparator 53, and the pulsating voltage B that increases at the OCR operating point is input to the comparator 53. Since the input is made to the positive terminal, a large DC bias voltage V _vias corresponding to an increase in the pulsating voltage B at the OCR operating point can be applied to the pulsating voltage A. Therefore, the motion detection circuit 5A of this example is superimposed on the larger phase shift and pulsating voltage A and B generated between the pulsating voltage A and B as compared with the OCR tester previously applied by the applicant of the present application. It can tolerate larger noise and has excellent operational stability.

Hereinafter, a test method for an operation characteristic test using the OCR tester 1A according to the first embodiment will be described. In the following, a case where the receiving / distributing electric wire 100 of the power receiving / transforming facility is provided with the overcurrent relay 102 of the current trip type will be described as an example.

As shown in FIG. 6, the current trip type overcurrent relay 102 has a main circuit 112 having a built-in off contact 111 for flowing a load current flowing from a current transformer 101 or the like, and a current transformer that detects the current of the main circuit 112. When the output current value of the current transformer 113 is compared with the set current value of the built-in operation setting circuit and it is determined that the output current value of the current transformer 113 exceeds the set current value of the operation setting circuit, a predetermined value is determined. It is composed of a control circuit 114 that outputs a control signal and a control circuit 114. Then, when the control circuit 114 determines that the output current value of the current transformer 113 exceeds the set current value of the operation setting circuit, the off contact built in the main circuit 112 has a time limit determined by the set current value. The 111 is operated, and the current flowing into the overcurrent relay 102 is flowed into the trip coil 106 built in the circuit breaker 104. This causes the circuit breaker 104 to shut off.

When carrying out the operation characteristic test, as shown in FIG. 1, the current output terminal 1a of the OCR tester 1A is connected to the test terminal 103, and the output terminal of the cutoff detection unit 105 is connected to the control circuit 11.

Next, the worker operates the measurement start switch 11a provided in the control circuit 11 to adjust the variable resistor 22, and the overcurrent relay 102 from the current output terminal 1a of the OCR tester 1A via the test terminal 103. At the input terminal, a current value required for driving the overcurrent relay 102, for example, 40 A, which is twice the instantaneous settling current value (minimum 20 A) in the case of an instantaneous characteristic test, is set and output. As a result, the overcurrent relay 102 operates at the time set in the overcurrent relay 102.

The operation detection circuit 5 detects the moment when the overcurrent relay 102 operates from the output signal of the current transformer 7 and the output voltage of the test current source 3, generates a current switching signal, and sends a current switching signal to the semiconductor relay 8. Send. As a result, the current source supplied from the current output terminal 1a to the overcurrent relay 102 is instantaneously switched from the test current source 3 to the DC current source 4 (about 1 to several μS), and the DC current stored in the condenser 42 is stored. Flows into the trip coil 106, and the circuit breaker 104 switches to the circuit breaker side. The operation of the circuit breaker 104 at this time is detected by the circuit breaker detection unit 105, and the circuit breaker detection unit 105 outputs the detection signal to the control circuit 11.

The counter circuit 12 measures the elapsed time from the output of the test current to the time of interruption, that is, the operating time of the overcurrent relay 102 and the circuit breaker 104. Then, when the operating current and operating time of the overcurrent relay 102 are within the ranges specified by the overcurrent relay maker and the circuit breaker maker, the control circuit 11 determines that the overcurrent relay 102 and the circuit breaker 104 are normal.

Since the OCR tester 1A according to the first embodiment uses the battery 2 as a power source, the entire body can be manufactured in a small size and light weight. Further, since the OCR tester 1A according to the first embodiment includes the oscillation circuit 21 and the digital audio amplifier 23 in the test current source 3, the AC of at least 40 A required for the operation of the overcurrent relay 102 from the output current of the battery 2 Test current can be generated efficiently. Further, the OCR tester 1A according to the first embodiment outputs the DC voltage stored in the condenser 42 to the trip coil 106 after the operation of the overcurrent relay 102, so that the breaker 104 can be operated. Since it is only necessary to continue for the momentary time when the trip coil 106 is activated, the DC power supply capacity is small, and the electric charge stored in the condenser 42 can be used.

Explaining this point in more detail, the voltage of the test current source 3 that operates the overcurrent relay 102 has a very small load impedance of 0.1Ω to 0.2Ω, so even if the current limiting resistor 24 is added. It should be 15V or more. Therefore, theoretically, the power capacity should be 600 W or more at 40 A × 15 V. On the other hand, the operating voltage of the circuit breaker 104 is required to be an AC voltage of 40 V or more because the inflow current to the trip coil 106 is often regulated to be 3 A or more. Therefore, in the test current source 3 that operates the overcurrent relay 102, even if the current is transferred to the circuit breaker 104 as it is, the circuit breaker 104 cannot operate or the operation becomes unstable.

The OCR tester 1A of the first embodiment generates an operating current of the overcurrent relay 102 and an operating current of the breaker 104 from the output of the battery 2, respectively, and the overcurrent is overcurrented by the semiconductor relay 8 at the moment when the overcurrent relay 102 is operated. Since the current source supplied to the relay 102 is instantaneously switched from the test current source 3 to the DC current source 4, the breaker 104 can be operated stably.

[Second Embodiment]
Hereinafter, the configuration of the OCR tester 1B according to the second embodiment will be described with reference to FIG. 7. As shown in FIG. 7, the OCR tester 1B according to the second embodiment sets the test mode of the overcurrent relay 102 and the circuit breaker 104 to the OCR tester 1A according to the first embodiment, and tests the operating characteristics of the overcurrent relay 102. Mode selector switches 8a and 8b that switch to the first mode or the second mode in which only the operation characteristic test of the overcurrent relay 102 is performed for both the interlocking characteristic test of the circuit breaker 104 and the interlocking characteristic test of the circuit breaker 104. Is characterized by the addition of.

The mode changeover switch 8a is manually switched by the user of the OCR tester 1B. When the user switches the mode changeover switch 8a to the closed state, the current stored in the DC current source 4 is supplied to the circuit breaker 104 at the moment when the overcurrent relay 102 operates, so that the test is performed in the first mode. It can be performed. On the other hand, when the user switches the mode changeover switch 8a to the open state, the current stored in the DC current source 4 is not supplied to the circuit breaker 104 even after the overcurrent relay 102 operates. The test can be performed in two modes. In this case, by switching the mode changeover switch 8b to the operation detection circuit 5 side, the operation signal is directly input from the operation detection circuit 5 to the control circuit, so that the operation time of the overcurrent relay 102 can be measured. Since the other parts are the same as those of the OCR tester 1A according to the first embodiment, the corresponding parts are designated by the same reference numerals and the description thereof will be omitted.

Since the OCR tester 1B according to the second embodiment is configured in this way, it is possible to separately carry out the operation characteristic test of the overcurrent relay 102 and the interlocking characteristic test of the circuit breaker 104, and in the power receiving state. It is possible to carry out an operating characteristic test of the overcurrent relay 102. Further, since the operation characteristic test of the overcurrent relay 102 can be performed independently, the noise problem associated with the operation of the circuit breaker 104 can be solved.

The scope of the present invention is not limited to the above-described embodiment, and various changes, additions, or deletions can be made without departing from the gist of the present invention.

For example, in the above embodiment, the battery 2 is used as a power source, but a generator can be used as a power source instead of the battery. In this case, the test current source 3 is provided with a slidac. As described above, in the OCR testers 1A and 1B of the embodiment, since the test current source 3 and the DC current source 4 are configured separately, it is sufficient to provide a slidac smaller than that of the prior art, and a small generator. Can be used to carry out an operating characteristic test of the overcurrent relay 102 and an interlocking characteristic test of the circuit breaker 104. Therefore, the operating characteristic test of the overcurrent relay 102 and the interlocking characteristic test of the circuit breaker 104 can be easily performed.

In addition, by adding a switching tap for the current limiting resistor 24, the output current value can be made small (in mA units), and a small-capacity voltage source that can change the phase with this current and the output voltage is added. It can also be used as a tester for entanglement direction relays (DGR).

1A, 1B ... OCR tester, 1a ... current output terminal, 2 ... battery, 3 ... test current source, 4 ... DC current source, 5, 5A, 5B, 5C, 5D ... motion detection circuit, 6 ... relay, 7 ... variable Flow device, 8 ... semiconductor relay (current switching circuit), 8a, 8b ... mode selector switch, 9 ... arithmetic circuit, 10 ... current meter, 11 ... control circuit, 11a ... measurement start switch, 12 ... counter circuit, 21 ... oscillation Circuit, 22 ... Variable resistor, 23 ... Digital audio amplifier, 24 ... Current limiting resistor, 31 ... A / D conversion circuit, 32 ... Driver circuit, 33 ... FET PA circuit, 34 ... LC filter circuit, 41 ... DC / DC converter, 42 ... condenser, 43 ... relay circuit, 51 ... amplification circuit, 52 ... rectifying circuit, 53 ... comparator, 54 ... rectifying circuit, 55 ... photocoupler, 56 ... phase compensation circuit, 57 ... signal temporary holding circuit, 58 ... Bias adjustment circuit, 58a ... Variable resistor, 58b ... Fixed resistor, 100 ... Distribution wire, 101 ... Current current generator, 102 ... Overcurrent relay, 103 ... Test terminal, 104 ... Breaker, 105 ... Breakage detector , 106 ... trip coil, 111 ... off contact, 112 ... main circuit, 113 ... current source, 114 ... control circuit.

Claims (2)

In an OCR tester that performs an operation characteristic test of an overcurrent relay connected to the main circuit of a power receiving / transforming facility and an interlocking characteristic test of a circuit breaker that operates in conjunction with the operation of the overcurrent relay.
Detects the moment when the overcurrent relay operates by receiving the test current source that supplies the test current to the overcurrent relay, the DC current source that operates the breaker, and the test current supplied from the test current source. A current switching circuit that instantaneously switches the current source supplied to the overcurrent relay from the test current source to the DC current source according to the output signal of the motion detection circuit is provided.
The motion detection circuit is said to be between a comparator that outputs a current switching signal when the magnitude relation of each input signal input to the plus terminal and the minus terminal is inverted, and each input signal input to the comparator. It has a bias adjustment circuit that applies a DC bias voltage according to the current value of the test current output from the test current source.
A pulsating voltage obtained by pulsating the AC voltage output from the test current source is input to the positive terminal of the comparator, and the negative terminal of the comparator is connected to the overcurrent relay. An OCR tester characterized in that a pulsating voltage obtained by voltage conversion and pulsating a current value detected by a current transformer that detects an output current is input. The bias adjustment circuit, in conjunction with the adjustment operation of the current to be made to the test current source, to claim 1, wherein the DC bias voltage is adjusted automatically to a predetermined value The described OCR tester.

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