Single lamp monitoring system

Abstract

The invention discloses a single lamp monitoring system. Wherein N series loops are included, power line carrier communication is carried out in each series loop, the time slice lengths of carrier signals are equal, and the ratio of the maintenance duration of the carrier signals to the period of power frequency signals is smaller than or equal to 1 / 2N; wherein the time slices of the carrier signals in different series loops are not overlapped. The system can avoid interference between different series loops, and the implementation mode is simple, safe and reliable.

Description

Technical Field

[0001] The invention relates to a single lamp monitoring system. Background Art

[0002] Chinese invention patent CN116915285B discloses a lamp monitoring system. Multiple lamps are connected in series in a cable through a transformer, and the two ends of the cable are connected to the two output ends of a dimmer. The dimmer can be considered as an AC constant current source. Ideally, it is a sine wave AC constant current source. In addition, a communication host is also connected in series in the cable through a transformer. Power line carrier communication is performed between the lamp and the communication host. Summary of the invention

[0003] The invention provides a single lamp monitoring system.

[0004] The technical solution of the present invention is as follows: a single lamp monitoring system, comprising N series circuits, N is 2 or 3, each series circuit comprises a dimmer, a communication host and a plurality of monitors connected in series, wherein the communication host and the plurality of monitors are respectively connected to the corresponding series circuit through a transformer, the monitor is used to monitor the lamp, two spatially adjacent lamps are monitored by monitors located in different series circuits, the dimmer receives single-phase AC power from a three-phase AC power supply, and the phases of the single-phase AC power received by different dimmers are different; the communication host and / or the monitor as a carrier signal sender applies a carrier signal to the industrial frequency signal in the following manner:

[0005] Detect the zero-crossing moment of a fixed item of the rising edge or falling edge of the power frequency signal;

[0006] Starting timing from the zero-crossing point, applying a carrier signal to the power frequency signal after a set time, stopping applying the carrier signal to the power frequency signal after a set time, applying the carrier signal to the power frequency signal after a set time, and stopping applying the carrier signal to the power frequency signal after a set time;

[0007] Among them, two segments of carrier signals are sent in one cycle of the power frequency signal, and the time slice of the carrier signal includes the extreme value moment of the power frequency signal;

[0008] The time slice lengths of the carrier signals are equal, and the ratio of the maintenance time of the carrier signal to the period of the power frequency signal is less than or equal to 1 / 2N;

[0009] There is no overlap in the time slices of the carrier signals in different series loops.

[0010] By limiting the duration and time position of the carrier signal, interference between different series loops can be avoided.

[0011] Optionally, the carrier signal senders in the same series circuit all choose to start timing at the rising edge of the industrial frequency signal or the falling edge of the industrial frequency signal, and the carrier signal senders in the same series circuit have the same set time length at the same time position relative to the zero-crossing moment.

[0012] This can simplify the design difficulty.

[0013] Optionally, the time slice of the carrier signal is selected to be centered at the extreme value moment of the power frequency signal, and the ratio of the maintenance duration of the carrier signal to the period of the power frequency signal is less than or equal to 1 / 6.

[0014] In this way, the design difficulty can be further simplified.

[0015] Optionally, the lamp and the corresponding monitor are separate structures or integrated into one.

[0016] Optionally, the lamp is a navigation light.

[0017] The system can avoid interference between different series circuits, and the implementation method is simple, safe and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the distribution of cables in a loop where multiple dimmers are located in the related art.

[0019] Figure 2 It is a schematic diagram of the time position of a carrier time slice when a single lamp monitoring system according to an embodiment of the present invention performs power line carrier communication.

[0020] Figure 3 It is a schematic diagram of the time position of a carrier time slice when a single lamp monitoring system according to another embodiment of the present invention performs power line carrier communication.

[0021] Figure 4 It is a schematic circuit diagram of a series loop in a single lamp monitoring system.

[0022] The reference numerals are as follows: 1, 1a, 1b, dimmer; 2, communication host; 3, monitor; 4, transformer; 5, navigation light; L, L1, L2, cable. DETAILED DESCRIPTION

[0023] The present invention is further described below in conjunction with specific embodiments, but the protection scope of the present invention is not limited thereto.

[0024] The inventors have found in actual work that in an airport navigation light single-light monitoring system, hundreds of navigation lights are usually connected in series through a transformer. Figure 1Two series circuits are shown. Dimmer 1a drives hundreds of navigation lights (not shown) through cable L1; dimmer 1b drives hundreds of navigation lights (not shown) through cable L2. In order to improve the safety of airport light guidance, two spatially adjacent navigation lights must be located in different series circuits. In this way, even if one series circuit fails and the other series circuits work normally, the single light monitoring system can still provide light guidance for the aircraft. The distance between cables is very close (bundled together) and there is a certain amount of parasitic capacitance.

[0025] Figure 4 The circuit diagram of a single series circuit is shown. Any series circuit includes a dimmer 1, a communication host 2 and multiple monitors 3 connected in series, wherein the communication host 2 and the multiple monitors 3 are respectively connected to the corresponding series circuit through a transformer 4, and the monitor 3 is used to monitor the lamps 5. Two spatially adjacent lamps 5 are monitored by the monitors 3 located in different series circuits.

[0026] The lamp 5 and the monitor 3 are designed to be separate or integrated.

[0027] A dimmer is usually a step-up transformer, and the phase of its output voltage is usually the same as the input voltage. A lamp can basically be considered as a resistive load, and the phase of the voltage in the loop is basically the same as the phase of the current.

[0028] Figure 1 Both the dimmer 1a and the dimmer 1b receive 220V or 380V single-phase AC power, which makes the current of the series circuit where the dimmer 1a is located and the current of the series circuit where the dimmer 1b is located basically in the same phase.

[0029] The carrier signal is usually applied near the peak or trough of the current. Conventional dimmers output 50Hz AC current signals, and one current cycle is 20ms. The carrier signal on the series circuit where dimmer 1a is located and the carrier signal on the series circuit where dimmer 1b is located are usually highly overlapped in time, which will cause the carrier signals between different series circuits to interfere with each other.

[0030] The present invention proposes to stagger the phases of the output currents (ie, power frequency currents) of the dimmers, and further design the starting time and duration of the carrier signal, thereby ensuring that the carrier signals of the series circuits do not overlap in time. The specific scheme is as follows.

[0031] The dimmer receives single-phase AC power from a three-phase AC power supply, and the phases of the single-phase AC power received by different dimmers are different; the communication host and / or the monitor, as the sender of the carrier signal, applies the carrier signal to the industrial frequency signal in the following manner: detect the zero-crossing moment of a fixed item in the rising edge or falling edge of the industrial frequency signal; start timing from the zero-crossing moment, apply the carrier signal to the industrial frequency signal after a set time, stop applying the carrier signal to the industrial frequency signal after a set time, apply the carrier signal to the industrial frequency signal after a set time, and stop applying the carrier signal to the industrial frequency signal after a set time; wherein, two segments of carrier signals are sent within one cycle of the industrial frequency signal, and the time slice of the carrier signal includes the extreme value moment of the industrial frequency signal; wherein, the time slice lengths of each carrier signal are equal, and the ratio of the maintenance time of the carrier signal to the cycle of the industrial frequency signal is less than or equal to 1 / 2N; wherein, the time slices of the carrier signals in different series circuits do not overlap.

[0032] In the first embodiment of the present invention, N=2. The two dimmers respectively select the AB phase and the BC phase of the three-phase power supply as the input voltage of the constant current dimmer. The dimmer in the I series circuit (referred to as I circuit) receives the single-phase power supply of the AB phase, and the dimmer in the II series circuit (referred to as II circuit) receives the single-phase power supply of the BC phase. The operating frequency is 50Hz, and the period of the power frequency signal is 20ms.

[0033] refer to Figure 2 , the starting point of one cycle of the power frequency signal of the I circuit is at the time of 0ms. The first carrier signal is maintained from 3.33ms to 8.33ms, the duration is 5ms, and it is located near the peak time (5ms). In this cycle, the second carrier signal of the I circuit is maintained from 13.33ms to 18.33ms, the duration is 5ms, and it is located near the trough time (15ms).

[0034] The starting point of one cycle of the power frequency signal of II is at 6.67ms. The first carrier signal is maintained from 8.33ms to 13.33ms, with a duration of 5ms, and is located near the peak moment (11.67ms). In this cycle, the second carrier signal of II is maintained from 18.33ms to 23.33ms, with a duration of 5ms, and is located near the trough moment (21.67ms).

[0035] The period of the power frequency signal is 20ms, the phase difference between the two signals is 6.67ms, the duration of a continuous carrier signal is 5ms, and the phases of the two carrier signals in this loop relative to the power frequency signal of this loop are the same.

[0036] In order to avoid mutual interference between carrier signals I and II, the maximum duration of a continuous carrier signal is 5ms. The shorter the duration of a carrier signal, the more difficult it is to detect and decode the transmitted information.

[0037] It should be noted that the starting time of one cycle of the output current of each dimmer in Embodiment 1 is the zero-crossing time of the rising edge. For any dimmer, the starting time of one cycle of its output current can also be the zero-crossing time of the falling edge, which is fixed after selection.

[0038] In the second embodiment of the present invention, the three dimmers respectively select the AB phase, BC phase and CA phase of the three-phase power supply as the input voltage of the constant current dimmer. The dimmer in the I circuit receives the single-phase power supply of the AB phase, the dimmer in the II circuit receives the single-phase power supply of the BC phase, and the III series circuit (referred to as III circuit) receives the single-phase power supply of the CA phase. The operating frequency is 50Hz, and the period of the power frequency signal is 20ms.

[0039] refer to Figure 3 , the starting point of one cycle of the power frequency signal of the I circuit is at the time of 0ms. The first carrier signal is maintained from 3.33ms to 6.67ms, the duration is 3.34ms, and it is located near the peak time (5ms). In this cycle, the second carrier signal of the I circuit is maintained from 13.33ms to 16.67ms, the duration is 3.34ms, and it is located near the trough time (15ms).

[0040] The starting point of one cycle of the power frequency signal of II is at 6.67ms. The first carrier signal is maintained from 10ms to 13.33ms for 3.33ms and is located near the peak moment (11.67ms). In this cycle, the second carrier signal of II is maintained from 20.00ms to 23.33ms for 3.34ms and is located near the trough moment (21.67ms).

[0041] The end of one cycle of the power frequency signal of channel III is at 13.33ms, and the maintenance period of a carrier signal before the end moment is from 6.67ms to 10ms, and is located at the trough moment (8.33ms). In the next cycle, the maintenance period of the first carrier signal of channel III is from 16.67ms to 20ms, and is located near the peak moment (18.33ms).

[0042] The period of the power frequency signal is 20ms, the phase difference of the three signals is 6.67ms, and the duration of a continuous carrier signal is 3.33ms. The phase of the three carrier signals in this loop relative to the power frequency signal of this loop is the same. The error in the percentile is caused by rounding.

[0043] In order to avoid mutual interference between carrier signals I, II and III, the maximum duration of a continuous carrier signal is 3.33ms. The shorter the duration of a carrier signal, the more difficult it is to detect and decode the transmitted information.

[0044] It should be noted that the starting time of one cycle of the output current of each dimmer in Embodiment 2 is the zero-crossing time of the rising edge. For any dimmer, the starting time of one cycle of its output current can also be the zero-crossing time of the falling edge, which is fixed after selection.

[0045] By designing the duration and starting position of the carrier signal, interference between carrier signals on different cables can be avoided.

[0046] Based on Example 2, if the time slice of the carrier signal is set to be centered on the extreme moment of the power frequency signal, and the ratio of the maintenance duration of the carrier signal to the period of the power frequency signal is less than or equal to 1 / 6. There is no need to pay attention to whether a specific circuit is connected to a single-phase power supply of AB phase, BC phase or CA phase, nor to the polarity of the two output ends of the constant current source, nor to whether the single-lamp monitoring system includes 2 series circuits or 3 series circuits, nor to whether the timing starting point is fixed to the zero-crossing moment of the rising edge or the zero-crossing moment of the falling edge. This greatly reduces the design difficulty.

[0047] The monitor and the communication host are provided with a current sensor for detecting the zero-crossing moment of the power frequency signal. The monitor and the communication host are also provided with a timer for starting timing from the zero-crossing moment of the power frequency signal, thereby determining the starting moment of a cycle of the carrier signal. The maintenance duration of the carrier signal can be set in advance, so that the above method can be implemented in a single lamp monitoring system.

[0048] The various embodiments of the present invention are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments.

[0049] The protection scope of the present invention is not limited to the above-mentioned embodiments. Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the scope and spirit of the present invention. If these changes and modifications fall within the scope of the claims of the present invention and their equivalents, the present invention is intended to include these changes and modifications.

Claims

1. A single lamp monitoring system, characterized in that: The single lamp monitoring system comprises N series circuits, N is 2 or 3, each series circuit comprises a dimmer, a communication host and a plurality of monitors connected in series, wherein the communication host and the plurality of monitors are respectively connected to the corresponding series circuit through a transformer, the monitor is used to monitor the lamps, two lamps adjacent in space are monitored by monitors located in different series circuits, the dimmer receives single-phase AC power from a three-phase AC power supply, and the phases of the single-phase AC power received by different dimmers are different; The communication host and / or the monitor as a carrier signal sender applies a carrier signal to the power frequency signal in the following manner: Detect the zero-crossing moment of a fixed item of the rising edge or falling edge of the power frequency signal; Starting timing from the zero-crossing point, applying a carrier signal to the power frequency signal after a set time, stopping applying the carrier signal to the power frequency signal after a set time, applying the carrier signal to the power frequency signal after a set time, and stopping applying the carrier signal to the power frequency signal after a set time; Among them, two segments of carrier signals are sent in one cycle of the power frequency signal, and the time slice of the carrier signal includes the extreme value moment of the power frequency signal; The time slice lengths of the carrier signals are equal, and the ratio of the maintenance time of the carrier signal to the period of the power frequency signal is less than or equal to 1 / 2N; There is no overlap in the time slices of the carrier signals in different series loops.

2. The single lamp monitoring system according to claim 1, characterized in that: in, The carrier signal senders in the same series circuit all choose to start timing at the rising edge of the power frequency signal or the falling edge of the power frequency signal, and the carrier signal senders in the same series circuit have the same set time length relative to the zero-crossing moment.

3. The single lamp monitoring system according to claim 1, characterized in that: The time slice of the carrier signal is selected to be centered at the extreme value moment of the power frequency signal, and the ratio of the maintenance duration of the carrier signal to the period of the power frequency signal is less than or equal to 1 / 6.

4. The single lamp monitoring system according to claim 1, characterized in that: The lamp and the corresponding monitor are of separate structures or integrated into one.

5. The single lamp monitoring system according to claim 1, characterized in that: The lamp is a navigation light.

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