JPH0128477B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a series lighting circuit in which a constant current type AC power supply device such as a constant current regulator is used to light a plurality of lamps via an insulating transformer. The present invention relates to a core break detection device for a series lighting circuit that detects the number of core-broken lamps from the voltage-time area of the output voltage due to magnetic saturation of a transformer.

In general, a wide variety of indicator lights are used on airport runways, such as runway lights, touchdown lights, terminal lights, approach lights, and approach angle indicator lights. At airports, keeping these marker lights on at all times and maintaining a constant brightness are essential conditions from the standpoint of the safety of aircraft arriving at and departing from the airport. For this reason, power supplies for marker lights at airports have strict constant current characteristics, and groups of marker lights of the same type are connected in series so that the same type of marker lights are lit at a constant brightness.

For example, as shown in FIG. 1, a conventional airport beacon light device includes a thyristor-type constant current regulator (hereinafter referred to as thyristor-type CCR) 2 connected to an AC power source 1 and a series lighting circuit for runway lighting. It consists of 3.

The thyristor type CCR 2 is connected to an AC power supply 1 through a thyristor circuit 5 in which a smoothing reactor 4 and thyristors 5a and 5b are connected in anti-parallel.
an output transformer 6 to which the next side is connected; a current detector 7 that detects the output current of the output transformer 6; a voltage detector 8 that detects the primary voltage of the output transformer 6;
A breakage detection device 9 receives the detected voltage v of the voltage detector 8 and the detected current i of the current detector 7 and detects breakage of the series lighting circuit 3, and an alarm output from the breakage detection device 9. An alarm device 10 that issues an alarm when signal A is input, and a differential amplifier 12 that will be described later.
A current setting device 11 outputs a setting signal C _S for setting the reference value of the current setting device 11, and the setting signal C _S output from this current setting device 11 and the detection current i of the current detector 7 are inputted and compared, and an amplified signal is obtained. A differential amplifier 12 that outputs G ₀ is input to the amplified signal G ₀ of this differential amplifier 12, and the thyristors 5a and 5 of the thyristor circuit 5
Pulse phase shifter 1 that provides gate signals G ₁ and G ₂ to b
It is composed of 3.

The core breakage detection device 9 is constructed as shown in FIG. In FIG. 2, D1 and D2 are rectifiers, R is a resistor, C is a capacitor, and Tr is a transistor.

Moreover, the series lighting circuit 3 of FIG.
4B-1, 14B-2,..., 14B-n and a plurality of lamps 15A-1, 15A-2,..., 15A
-n, 15B-1, 15B-2,..., 15B-n
The above isolation transformers 14A-1 to 14A-14
The primary sides of A-n and 14B-1 to 14B-n are connected in series to the secondary side of the output transformer 6, and the lamps 15A-1 to 15A-n and 15B-1 to each secondary side are connected in series to the secondary side of the output transformer 6. 15B-n are connected to each other.

In such a configuration, when supplying a constant current to the series lighting circuit 3, the output current of the output transformer 6 shown in FIG. is compared with the reference value selected by the setting signal C _S in the differential amplifier 12 and amplified to generate the signal G ₀ , which is applied to the pulse phase shifter 13 to generate the gate signals G ₁ , _G2 and controls the thyristor output voltage to keep the output current of CCR2 constant and the brightness of the lamp in the series lighting circuit 3 constant.

In this case, as shown in FIG. 2, the core breakage detection device 9 inputs the voltage signal v from the voltage detector 8 and the current signal i from the current detector 7, rectifies it with rectifiers D ₁ and D ₂ , and then Take out the difference e in the waveform area and set the resistance R
and the voltage value smoothed by capacitor C, the transistor
Operate the Tr and output alarm signal A. The alarm device 10 uses the alarm signal A to display an alarm using a buzzer or a lamp.

For example, if there is no core break lamp, the voltage signal v and current signal i given to the core break detection device 9 have waveforms v ₁ and i ₁ shown in FIG. The waveform _e1 shown in Figure c is obtained. This waveform
e ₁ is small as shown in FIG. 3c, and the voltage value obtained by smoothing this waveform e ₁ is not a sufficient value to operate the transistor Tr, so the alarm signal A is not output.

On the other hand, when a certain number of lamps are broken, the voltage signal v and current signal i will have the waveforms shown in Figure 3 d and e.
v ₂ , i ₂ . The rising edge of this waveform v ₂ is large, and the rising edge of waveform i ₂ is small. Therefore, the waveform of the difference e becomes _e2 shown in FIG. 3f, and the voltage value obtained by smoothing this waveform operates the transistor Tr, and the alarm signal A is output.

Although the lamp is inspected for core breakage in this manner, the waveforms of the voltage signal v and current signal i may be significantly deformed due to disturbances such as noise specific to analog signals. Therefore, even though the lamp is not actually broken, the voltage value obtained by smoothing the waveform area difference e becomes a value that allows the transistor Tr to operate, and the alarm signal A may be output. In order to avoid such erroneous detection, it is necessary to set a large voltage value for operating the transistor Tr, which makes highly sensitive detection impossible.
The detection sensitivity is limited to about 10% of the rated load, and detection of 5% is not possible. This may lead to danger due to inadequate runway lighting, and furthermore, the isolation transformer whose secondary side is open due to a broken lamp may be left unused for a long period of time, which may lead to damage due to high voltage pulses and burnout due to temperature rise. There is. Additionally, in order to display the number of actually broken lamps in addition to the alarm function, it is necessary to add a new circuit.

Further, even if a broken core of the lamp is detected, the lamp cannot be replaced while the lamp of the series lighting circuit 3 is lit, since it is dangerous for airport runway lighting. However, core breakage can only be detected when the lamp of the series lighting circuit 3 is turned on, and the lamp must be turned on during maintenance and inspection. In addition, in order to make this type of core break detection highly sensitive (for example, detecting a single light core break), an advanced circuit must be installed for each CCR2 (per runway).
There are about 50 CCRs).

This invention has been made based on the above circumstances, and provides a safe and reliable detection of a broken lamp in a series lighting circuit, which can detect a broken lamp even when the lamp in the series lighting circuit is not lit. The purpose is to provide equipment.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 4 is a circuit diagram showing the configuration of this embodiment. In FIG. 4, 16 is an AC power supply that supplies power to the thyristor type CCR 17. This thyristor type CCR 17 supplies a constant current to the series lighting circuit 18. This series lighting circuit 18
is a plurality of isolation transformers 19-1, 19-2,...,
19-n (when any one is shown, it is expressed as the isolation transformer 19) and a plurality of lamps 20-1,
20-2, .
17, and the lamps 20-1 to 20-n are connected to each secondary side. The above CCR17 has a magnetic contactor contact 21
A and a series circuit of the reactor 22 are connected in parallel. The contact 21a is a contact that is closed only when the control of the CCR 17 is stopped.

PT1 is a transformer, whose primary side is connected to the output terminal of the AC power supply 16, and whose secondary side is connected to the voltage zero cross detector 2.
Connected to 3. This voltage zero cross detector 2
3 is the pulse signal S at the point where the power supply voltage signal V applied through the transformer PT1 crosses the zero level.
This outputs the following. PT2 is a transformer, the primary side of which is connected to the output end of the CCR 17, and the secondary side connected to the voltage detector 21. This voltage detector 24 outputs a voltage signal v having an appropriate amplitude. 25 inputs the voltage signal v,
It is an analog-to-digital converter that obtains a digital signal proportional to the magnitude of that signal. Hereinafter, this will be abbreviated as A/D converter 25.

26 is an electronic computer which receives and processes the pulse signal S output from the voltage zero cross detector 23 and the digital signal output from the A/D converter 25. This electronic computer 26 includes an input circuit 27, a central processing unit (hereinafter referred to as CPU) 28, and a random access memory (hereinafter referred to as CPU).
It is abbreviated as RAM. ) 29, read-on memory (hereinafter abbreviated as ROM) 30, output circuit 31
The CPU 28 executes calculations according to the program stored in the ROM 30, inputs data via the input circuit 27 as necessary,
The calculation results can be stored in the RAM 29 or output circuit 3.
1 to output an alarm signal B. Reference numeral 32 denotes an alarm device, which operates an alarm buzzer and an alarm display to issue an alarm in response to the alarm signal B output from the computer 26.

The operation of the above configuration will be explained with reference to the waveform diagram in FIG.

When detecting the presence or absence of a broken lamp in the series lighting circuit 18, when the lamps 20-1 to 20-n of the series lighting circuit 18 are not lit, such as during the day, the contact 21a is closed and the AC power supply 16 is disconnected. A minute power supply that does not light up the lamps 20-1 to 20-n is applied to the series lighting circuit 18 through the relay contact 21a and the reactor 22. Note that the reactor 2
2 (reactance X) is a current limiting circuit for flowing a minute current. Further, at night, the contact 21a is opened, and a constant current of the thyristor type CCR 17 is passed through the series lighting circuit 18 to light the lamps 20-1 to 20-n.

In a state in which each lamp 20 is flowing a minute current that does not cause it to light up, if there is no core-broken lamp, a voltage signal v and a current signal are applied to the series lighting circuit 18 with respect to the power supply voltage signal V. i
has a waveform as shown in FIG. 5a. Now, when the lamp 20 is broken, the secondary side of the insulating transformer 19 to which the broken lamp 20 is connected is opened, so a magnetic saturation phenomenon occurs, and the series lighting circuit 18
load inductance increases. Therefore, the circuit voltage v generates a voltage proportional to the inductance until the isolation transformer 19 is magnetically saturated, and as shown in FIG. 5b, a waveform v' suddenly rises at the zero cross of the voltage. The degree to which the voltage suddenly rises when the voltage crosses zero at this time increases as the number of broken lamps increases.

Next, the operation at the rise of the voltage waveform v' will be explained using an equivalent circuit. That is, each isolation transformer 19
If the primary and secondary impedances of the transformer are ignored, the equivalent circuit of is shown in Figure 6a.
As shown in , a circuit is formed in which the excitation impedance Z ₀ and the lamp resistance R _L of the lamp 20 converted to the primary side of the transformer are connected in parallel. And generally Z ₀
>>R _L , so the impedance Z of this equivalent circuit becomes Z≈R _L when the lamp 20 is not disconnected. However, when the lamp 20 is broken, R _L becomes very large, so that the excitation impedance Z ₀ cannot be ignored.

Therefore, in Fig. 4, the thyristor type
When the CCR 17 is inactive and there is no breakage in all n lamps 20, the equivalent circuit of this breakage detection device can be shown in FIG. 6b. That is, the impedance component of the series lighting circuit 18 is ignored, and only the resistance component nR _L remains.

On the other hand, among the n lamps 20, m lamps 2
0 is broken, the value of the excitation impedance Z ₀ cannot be ignored as described above, and the equivalent circuit shown in FIG. 6c including the inductance mZ ₀ with magnetic flux saturation due to the iron core is obtained. Note that the resistance in this case is (n-m)R _L.

Therefore, in order to obtain the voltage and current waveforms shown in FIG. 6c when there is a core break in the lamp 20, it is possible to further replace FIG. 6c with the equivalent circuit shown in FIG. 6d. That is, FIG. 6d shows an equivalent circuit when the secondary side of the isolation transformer 19 is opened to create no load, and represents a no-load excitation circuit in which the core inductance L and the winding resistance R are connected via a switch. and is connected to an AC power source with voltage e. however,
e is the power supply voltage and is expressed by the following equation.

e=√2Vsinωt The circuit equation of the equivalent circuit in Figure 6d is Ri+N(dφ/dt)=e...(1) where the number of turns of the coil is N. In the minute time from t=0 to t until the iron core is saturated with magnetic flux, the current i value is minute, so the Ri term can be ignored compared to the N(dφ/dt) term. Therefore, the magnetic flux change amount Δφ in the minute time from t=0 to t is as follows: Δφ=(1/N)∫ ^t ₀ edt = (1/N) ∫ ^t ₀ √2Vsinωtdt ……(2), When the power supply voltage e exceeds the saturation voltage, the resistance R
A current i begins to flow. The saturation time at this time is
When t ₀ and the saturation magnetic flux are φ _S , the magnetic flux change amount Δφ is −
It changes from φ _S to +φ _S.

Figure 8 is a diagram showing the relationship between the saturated/unsaturated state of magnetic flux φ and the voltage waveform. At t=-t ₀ , magnetic flux φ is -
It is saturated at φ _S and remains saturated during the period from t=-t ₀ to 0, and current i flows (voltage v' decreases). Then, at t=0, the power supply voltage e (V) is reversed, and the magnetic flux φ changes to the + side. Therefore, the magnetic flux φ becomes unsaturated and the impedance increases, making it difficult for the current i to flow (voltage v' increases). And t=t ₀
When this happens, the magnetic flux φ saturates to +φ _S. Then, current i flows again (voltage v' decreases).

Therefore, the magnetic flux change amount Δφ is becomes.

Now, if equation (3) is rearranged using constants specific to a coil having an iron core and set to S ₀ , then S ₀ =√2V∫ ^t0 ₀ sinωtdt=2φ _S N ...(4).

That is, equation (4) is a value obtained by integrating the voltage between t=0 and _t0 , and represents the voltage time area. This voltage time area corresponds to the magnetic flux saturation value of the core of the coil. Therefore, if the number m of isolation transformers 19 having broken lamps 20 increases, the voltage time area increases in proportion to the number m and becomes saturated. For example, as shown in FIG. 9, the voltage time area indicated by diagonal lines changes depending on the number m of core breaks.

Therefore, the relational expression between the number m of insulating transformers 19 having broken lamps 20 and the voltage time area S required for magnetic flux saturation is S=2φ _S Nm (5).

As the voltage time area S changes in proportion to the number of broken lamps, the voltage time area of a half cycle also changes from S ₁ in Figure 5a to S ₂ in Figure 5B,
The area integral of S′ increases. Therefore, by comparing the voltage-time area S ₂ including the increase in voltage-time area S' in the state with a broken lamp with the reference voltage-time area S ₁ in the state without a broken lamp, Lamp breakage can be detected.

Now, when the voltage zero cross detector 23 generates the pulse S shown in FIG. 5 at the point where the power supply voltage signal V crosses the zero level, this pulse S is inputted to the input circuit 27 of the calculator 26 as an interrupt signal. . CPU2
8 reads the digital input signal from the A/D converter 25 at predetermined time intervals (for example, 500 microsecond intervals) from the time when the interrupt signal is input, according to the program stored in the ROM 30;
Store in RAM29. That is, the voltage signal v or
The voltage waveform of v′ is converted to a digital value,
The digitized voltage values for half a cycle are stored in RAM 29 in sequence (for example, in the case of 500 microsecond intervals, 19 digital values are stored at 50 Hz power supply, excluding the values at zero cross at both ends). ). These digital values are stored in RAM2, for example.
It is constantly updated and stored in addresses 100 to 118 of 9 every cycle. On the other hand, data serving as a reference for comparison is previously stored, for example, starting from address 200 and thereafter. This standard data includes, for example, the voltage waveform value with no broken lamp in addresses 200 to 218, the voltage waveform value with one broken lamp in addresses 219 to 237, and the voltage waveform value with one broken lamp in addresses 219 to 237. The voltage waveform value corresponding to the number of objects is stored in advance after address 238. In addition, when storing each voltage waveform in the RAM 29 in the actual circuit shown in Figure 4, the voltage waveform v is sampled and read every 500 μsec as described above with all lamps 20 attached to each isolation transformer 19. . Next, the lamp 20 is
By sequentially removing them one by one, voltage waveforms v' shown in FIG. 9 corresponding to the number m of core breaks are obtained, and these voltage waveforms v' are read into the designated areas in the RAM 29, respectively.

Therefore, every cycle of reading, data from addresses 100 to 118 is compared with data from address 218 if it is 200 (100 and 200, 101 and
Compare addresses 201, 102 and 202, ...118 and 218, respectively), and if they are the same, it is determined that there is no broken lamp, and if they are not the same, then
Compare the values from addresses 219 to 237 in the same way (comparing addresses 100 and 219, ..., addresses 118 and 237), and then compare until they match. If they match with a preset tolerance, it becomes possible to obtain the number m of broken lamps assigned to the matched address. In this manner, by comparing the voltage waveforms in digital values, the occurrence of core breakage in the lamp 20 and the number m of lamps in which core breakage has occurred can be detected. When the occurrence of core breakage in the lamp 20 and the number m of broken lamps are detected, an alarm signal B is output through the output circuit 31, and a digital output (for example, a binary code decimal output) of the number of core breaks is output,
The alarm device 32 sounds an alarm buzzer and displays an alarm such as the number of broken cores.

FIG. 7 is an example of a flowchart of the above-mentioned arithmetic processing.

As described above, according to this embodiment, there is a time delay in the rise of the current applied through the reactor 22 so as to bypass the CCR 17 until the isolation transformer of each lamp in the series lighting circuit 18 is magnetically saturated due to the breakage of the lamp. During this period, the voltage increases and the voltage waveform changes as the number of broken lamps increases.By comparing the voltage waveforms, we can issue alarms for excessive core breakage and determine the number of broken lamps. Since the display is now displayed, the voltage waveform itself can be identified with high precision for detecting disconnection of the core, and for detecting disconnections in the secondary side wiring of the isolation transformer, poor contact in the lamp socket, or if the lamp unit is damaged by an aircraft or car. It becomes possible to detect when the device is destroyed.

Also, when the control of CCR17 is stopped,
Since only a small current flows through the series lighting circuit 18 through the contact 21a and the reactor 22, the lamps 20-1 to 20-1 are turned on when the lamps do not need to be lit during the day.
The presence or absence of a break in the lamp can be detected without the lamp 20-n being turned on, and a break check for nighttime use can be performed in advance. moreover,
Since the number of broken lamps in the series lighting circuit 18 can be easily displayed without lighting them, replacement work for broken lamps can be planned in advance based on the lamp's broken state, making it easier to use at airports. Maintenance work can be performed efficiently, and safety and reliability can be improved.

Note that this invention is not limited to the above embodiments. For example, in the embodiment, one thyristor type CCR 17 and the series lighting circuit 18
For example, one computer 26 is used to detect a broken lamp. However, for multiple series lighting circuits, one computer can be used to detect broken lamps in each of the plurality of circuits. You may do so. That is, the voltage detector 24 and the voltage zero-cross detector 23 are each provided in a plurality of circuits, and the voltage signals v ₁ , v ₂ , v _o (not shown) are switched by a multiplexer (not shown) to output the A/ The voltage zero cross signals S ₁ , S _{2 .} By switching and sequentially comparing the voltage waveforms of a plurality of series lighting circuits with respective reference values, a single computer may detect broken lamps in a plurality of circuits.

Furthermore, instead of A/D converting the voltage waveform v every cycle and immediately comparing it with the reference value, the average value of several cycles is taken and then compared with the reference value to prevent malfunctions due to noise etc. It may also be possible to prevent this. Further, the present invention is applicable not only to airport equipment but also to all series lighting circuits using isolation transformers. It goes without saying that various other modifications can be made without departing from the gist of the invention.

As explained above, according to the present invention, when the lamps in the series lighting circuit are not lit, a voltage is applied that causes a minute current that does not cause the lamps to light up, and the magnetic saturation of the isolation transformer is used to control the amount of lamp breakage. Therefore, it is possible to provide a safe and highly reliable serial lighting circuit breakage detection device that can detect a broken lamp even when the lamp in the series lighting circuit is not lit.

[Brief explanation of drawings]

Figure 1 is a circuit diagram of a conventional airport beacon device;
3 is a waveform diagram showing the operation of FIG. 2, FIG. 4 is a circuit diagram showing an embodiment of the present invention, and FIG. 5 is a circuit diagram of a conventional core breakage detection device. FIG. 6 is an equivalent circuit diagram of the series lighting circuit of FIG. 1, FIG. 7 is a flowchart of an embodiment of the present invention, and FIGS. 8 and 9 are for explaining the operation. FIG. 17... Thyristor type constant current regulator, 18...
...Series lighting circuit, 19-1 to 19-n...Isolation transformer, 20-1 to 20-n...Lamp, 21a...
... Contact, 22 ... Reactor, 23 ... Voltage zero cross detector, 24 ... Voltage detector, 25 ... A/
D converter, 26...electronic computer, 32...alarm device.

Claims (1)

[Claims] 1. In a series lighting circuit in which lamps individually connected to the secondary sides of a plurality of isolation transformers whose primary sides are connected in series are lit by a constant current type AC power supply device, the lamps of the series lighting circuit are lit. A circuit that supplies the series lighting circuit with a minute alternating current that does not cause the lamp to light up when the lamp is not lit, and a voltage signal that is applied to the series lighting circuit by this circuit or the AC power supply device to a digital signal every predetermined time. an analog-to-digital converter for converting the voltage signal to a zero cross, a voltage zero cross detector for detecting a zero cross of the voltage signal, and storing the digital signal at predetermined time intervals from the time when the voltage zero cross of the voltage zero cross detector is detected; Compare the above digital signal with a pre-stored reference voltage digital signal,
A device for determining whether or not the lamp is broken based on the comparison result, and detecting the number of broken lamps based on the comparison result if there is a break. Core detection device.