A device and method for predicting the state of a harmonic filter unit of a shortwave transmitter

Abstract

The present invention discloses a state prediction device and method for a harmonic filter unit of a shortwave transmitter, comprising a detection circuit arranged in the harmonic filter unit of the shortwave transmitter, and a state prediction program unit arranged in a control module of the shortwave transmitter; the detection circuit is arranged at the radio frequency input end of the harmonic filter unit, and the radio frequency signal output by the harmonic filter unit is synthesized by a power synthesizer and then output; the state prediction program unit comprises a relay action counting module and a fault judgment module; the relay action counting module counts the number of relay actions in the harmonic filter unit of the shortwave transmitter; the fault judgment module receives the voltage sampling signal output by the detection circuit, and judges and determines the state of the harmonic filter unit. The present invention can perform online detection of harmonic filter unit faults, predict the remaining life of the relay; give a fault indication when the harmonic filter unit fails; give a warning and maintenance suggestion when the relay is close to the mechanical life, and realize condition-based maintenance.

Description

Technical Field

[0001] The invention belongs to the technical field of shortwave transmitters, and in particular to a device and method for predicting the state of a harmonic filter unit of a shortwave transmitter. Background Art

[0002] The harmonic filter unit of the shortwave transmitter mainly filters the input RF power signal and suppresses the second and third harmonics within the index range. The harmonic filter unit is generally divided into several bands. According to the operating frequency of the shortwave transmitter (2MHz~30MHz), the band is switched through relays (usually 6 bands and 12 relays) to achieve harmonic filtering of the input RF signal.

[0003] According to historical maintenance data, the main failure modes of harmonic filter units include open-band, short-band, and inability to disconnect the band. If the fault cannot be effectively detected, the harmonic filter unit or the shortwave transmitter core unit will be burned, which is highly harmful.

[0004] There are some methods for detecting harmonic filter unit faults in shortwave transmitter designs at home and abroad, such as judging the state of the RF path by the standing wave ratio on the output side of the harmonic filter unit; realizing the detection of the state of each channel by switching the band during the power-on self-test, etc. Harmonic filter unit failures generally occur during use. The existing detection methods can only detect fault information during the transmitter transmission process or when the transmitter is turned on. If the band is open or short-circuited during the operation of the equipment, or the band cannot be disconnected due to the adhesion or non-attraction of the relay contacts, it is difficult to detect the fault before the transmitter is transmitted, and there is a risk of burning the equipment when the shortwave transmitter is transmitting; the relay reaches the mechanical life and the contact breaks and fails, which cannot be predicted in advance, resulting in the inability to work of the shortwave transmitter or the burning of the harmonic filter unit, affecting the availability of the equipment. Summary of the invention

[0005] The purpose of the present invention is to provide a shortwave transmitter harmonic filter unit state prediction device and method, which can perform online detection of harmonic filter unit faults and predict the remaining life of a relay; provide a fault indication when the harmonic filter unit fails; and provide an early warning and maintenance suggestion when the relay is close to the mechanical life, thereby realizing condition-based maintenance.

[0006] The technical solution for achieving the purpose of the present invention is: a state prediction device for a harmonic filter unit of a shortwave transmitter, comprising a detection circuit arranged in the harmonic filter unit of the shortwave transmitter, and a state prediction program unit arranged in a shortwave transmitter control module; the detection circuit is arranged at the radio frequency input end of the harmonic filter unit, and the radio frequency signal output by the harmonic filter unit is synthesized by a power synthesizer and then output;

[0007] The state prediction program unit includes a relay action counting module and a fault judgment module; the relay action counting module counts the number of relay actions in the shortwave transmitter harmonic filter unit; the fault judgment module receives the voltage sampling signal output by the detection circuit, judges and determines the state of the harmonic filter unit.

[0008] A method for predicting the state of a harmonic filter unit of a shortwave transmitter, using the shortwave transmitter harmonic filter unit state prediction device, the prediction method is as follows:

[0009] The relay action counting module counts the number of relay actions. Relay action refers to switching from one contact to another. When the proportion of the number of relay actions relative to the total number of mechanical life of the relay reaches a set threshold, a maintenance suggestion to replace the relay is given.

[0010] The detection circuit is arranged at the RF input end of the harmonic filter unit, the inductor L0 is connected to the RF input end of the harmonic filter unit, the inductor L0 and the resistor R0 are connected in series and then connected to VCC, and the common end of the inductor L0 and the resistor R0 is the voltage sampling point X; during the channel switching process, the fault judgment module detects the voltage value of the voltage sampling point X under different actions, and judges the state of the harmonic filter unit according to the voltage value.

[0011] Compared with the prior art, the present invention has the following significant advantages: (1) it can perform online detection of harmonic filter unit faults, predict the remaining life of the relay, and provide a status indication of the harmonic filter unit before the shortwave transmitter is transmitted, thereby preventing damage to the shortwave transmitter; (2) the status of the harmonic filter unit is predicted during the operation of the shortwave transmitter, and the detection circuit and status prediction program are simple and the status prediction result is accurate; (3) when the relay is close to the mechanical life, an early warning and maintenance suggestions are given, thereby realizing the condition-based maintenance of the harmonic filter unit of the shortwave transmitter and improving the fault detection rate of the equipment built-in test (BIT), which has important practical significance for solving the problem of harmonic filter unit status prediction. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a principle block diagram of the state prediction method of the harmonic filter unit of the shortwave transmitter of the present invention.

[0013] Figure 2 It is a schematic diagram of a harmonic filter unit with a detection circuit. DETAILED DESCRIPTION

[0014] The present invention discloses a state prediction device for a harmonic filter unit of a shortwave transmitter, comprising a detection circuit arranged in the harmonic filter unit of the shortwave transmitter, and a state prediction program unit arranged in a control module of the shortwave transmitter; the detection circuit is arranged at the radio frequency input end of the harmonic filter unit, and the radio frequency signal output by the harmonic filter unit is synthesized by a power synthesizer and sent to an antenna for transmission;

[0015] The state prediction program unit includes a relay action counting module and a fault judgment module; the relay action counting module counts the number of relay actions in the shortwave transmitter harmonic filter unit; the fault judgment module receives the voltage sampling signal output by the detection circuit, judges and determines the state of the harmonic filter unit.

[0016] Furthermore, the detection circuit is arranged at the RF input end of the harmonic filter unit, and the detection circuit includes an inductor L0 and a resistor R0. The inductor L0 is connected to the RF input end of the harmonic filter unit. The inductor L0 and the resistor R0 are connected in series and then connected to VCC. The common end of the inductor L0 and the resistor R0 is the voltage sampling point X.

[0017] Further, the shortwave operating frequency range of the shortwave transmitter is 2MHz to 29.9999MHz, which is divided into 6 bands from the first to the sixth according to the requirements of the operating frequency and harmonic filtering: 2.0000 to 3.1408MHz, 3.1409 to 4.1325MHz, 4.1326 to 7.7459MHz, 7.7460 to 12.1642MHz, 12.1643 to 19.1027MHz, and 19.1028 to 29.9999MHz;

[0018] The harmonic filtering unit is used to filter out the harmonics of the working frequency, including the first to sixth channels corresponding to the first to sixth bands, and each channel includes an input end relay and an output end relay; when the working frequency falls in the first band, the shortwave transmitter control module controls the relay to connect the first channel to the radio frequency path, and the remaining channels are disconnected from the radio frequency path; when the working frequency changes and the frequency falls in another band, the transmitter control module controls the relay to disconnect the first channel from the radio frequency path, and connect another channel to the radio frequency path to achieve the harmonic filtering function.

[0019] Furthermore, the first wave channel includes an input-end relay K2 and an output-end relay K1, wherein the contact 3 of the input-end relay K2 is connected to the radio frequency path, and the contact 4 is grounded through the resistor R2; the contact 1 of the output-end relay K1 is connected to the radio frequency path, and the contact 2 is grounded through the resistor R1;

[0020] The sixth channel includes an input-end relay K12 and an output-end relay K11. The contact 5 of the input-end relay K12 is connected to the radio frequency path, and the contact 6 is grounded through the resistor R12. The contact 7 of the output-end relay K11 is connected to the radio frequency path, and the contact 8 is grounded through the resistor R11.

[0021] The circuit structures of the second to fifth channels are the same as those of the first and sixth channels.

[0022] Furthermore, when the rated current of the relay is ≥5A, VCC is 12V and the resistance R0 is 100Ω; when the rated current of the relay is <5A, VCC is 3.3V and the resistance R0 is 10Ω; the grounding resistance corresponding to each relay grounding contact is 10Ω.

[0023] The present invention provides a method for predicting the state of a harmonic filter unit of a shortwave transmitter, using the device for predicting the state of a harmonic filter unit of a shortwave transmitter, and the prediction method is as follows:

[0024] The relay action counting module counts the number of relay actions. Relay action refers to switching from one contact to another. When the proportion of the number of relay actions relative to the total number of mechanical life of the relay reaches a set threshold, a maintenance suggestion to replace the relay is given.

[0025] The detection circuit is arranged at the RF input end of the harmonic filter unit, the inductor L0 is connected to the RF input end of the harmonic filter unit, the inductor L0 and the resistor R0 are connected in series and then connected to VCC, and the common end of the inductor L0 and the resistor R0 is the voltage sampling point X; during the channel switching process, the fault judgment module detects the voltage value of the voltage sampling point X under different actions, and judges the state of the harmonic filter unit according to the voltage value.

[0026] Furthermore, the state of the harmonic filter unit is determined according to the voltage value, as follows:

[0027] For switching from the first channel to the sixth channel, the first channel includes a relay K2 at the input end and a relay K1 at the output end, contact 3 of the relay K2 is connected to the radio frequency path, and contact 4 is grounded through a resistor R2; contact 1 of the relay K1 is connected to the radio frequency path, and contact 2 is grounded through a resistor R1; the sixth channel includes a relay K12 at the input end and a relay K11 at the output end, contact 5 of the relay K12 is connected to the radio frequency path, and contact 6 is grounded through a resistor R12; contact 7 of the relay K11 is connected to the radio frequency path, and contact 8 is grounded through a resistor R11;

[0028] Before the transmitter switches channels, the fault judgment module detects the voltage V1 at the voltage sampling point X; then the relay K1 is controlled to operate, switching from contact 1 to contact 2, and the voltage V2 at the voltage sampling point X is detected after the relay is stable; after sampling, the relay K2 is driven to switch from contact 3 to contact 4, and the relay K12 is driven to operate from contact 6 to contact 5, and the voltage V3 at the voltage sampling point X is detected after the relay is stable; after sampling, the relay K11 is driven to switch from contact 8 to contact 7, and the voltage V4 at the voltage sampling point X is detected after the relay is stable;

[0029] According to the voltage V1~V4, determine the state of the harmonic filter unit:

[0030] When V1 = VCC, the first channel is open;

[0031] When V1=0, V2=0, the first wave channel is short-circuited to ground or the contacts of relay K1 are bonded;

[0032] When V1=0, When , the contacts of relay K2 are bonded;

[0033] When V1=0, When V3=0, the sixth channel is short-circuited to ground;

[0034] When V1=0, When V3 = VCC, the contact of relay K12 does not close or the sixth wave channel is open;

[0035] When V1=0, When , the contact of relay K11 does not close;

[0036] When V1=0, When V4=0, the harmonic filter unit works normally;

[0037] Wherein, Ra = R1·R11 / (R1+R11);

[0038] When switching between other channels, the state determination process of the harmonic filter unit is the same.

[0039] When the operating frequency of the shortwave transmitter is still the current operating band, the fault judgment module determines the state of the harmonic filter unit according to the voltage V1 of the detection voltage sampling point X.

[0040] When V1 = VCC, the current band is open;

[0041] When V1=0, the harmonic filter unit works normally;

[0042] Furthermore, when the proportion of the number of relay actions to the total number of times of the mechanical life of the relay reaches a set threshold, a maintenance suggestion to replace the relay is given, wherein the set threshold is 80%.

[0043] The present invention predicts the state of the harmonic filter unit during the operation of the shortwave transmitter by designing a detection circuit and a state prediction program. The invention has the characteristics of simple detection circuit and state prediction program and relatively accurate state prediction result, and has guiding significance for condition-based maintenance.

[0044] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0045] Example

[0046] The present invention is a shortwave transmitter harmonic filter unit state prediction device, the principle block diagram is as follows Figure 1 As shown, the shortwave transmitter control module and harmonic filter unit are the inherent hardware of the shortwave transmitter.

[0047] The detection circuit designed by the present invention is as follows Figure 2 As shown, the shortwave operating frequency range is 2MHz to 29.9999MHz. The harmonic filter unit is mainly used to filter out the harmonics of the operating frequency. The shortwave transmitter harmonic filter unit is generally divided into 6 bands according to Table 1 based on the technical requirements of the operating frequency and harmonic filtering.

[0048] Table 1 Band-frequency relationship table

[0049] Band number Frequency (MHz) 1 2.0000～3.1408 2 3.1409～4.1325 3 4.1326～7.7459 4 7.7460～12.1642 5 12.1643～19.1027 6 19.1028～29.9999

[0050] When the operating frequency falls on band 1 (the initial state of the shortwave transmitter is generally band 1), the shortwave transmitter controller controls the relay to connect band 1 to the RF path, and the remaining bands are disconnected from the RF path. When the operating frequency changes and the frequency falls on another band (such as band 6), the transmitter controller controls the relay to disconnect band 1 from the RF path and connect band 6 to the RF path to achieve the harmonic filtering function.

[0051] The parameters of "+VCC" and resistors "R0~R12" are detailed in Table 2 (the parameters are adaptively adjusted according to actual needs).

[0052] Table 2 Recommended parameters of detection circuit components

[0053]

[0054] The state prediction program designed in this embodiment consists of a relay action counting program block and a fault judgment program block. The relay action counting program block counts the number of relay actions (switching from one contact to another contact). When the number of relay actions reaches 80% of the mechanical life of the relay (which can be adjusted according to the derating requirements), a maintenance suggestion for replacing the relay is given; the fault judgment program block detects the voltage value of the voltage sampling point X under different actions during the channel switching process. Taking the switching of channel 1 to channel 6 as an example, before the transmitter switches the channel, the fault judgment program block detects the voltage V1 of the voltage sampling point X, and then controls the relay K1 to act (switching from contact 1 to contact 2), and detects the voltage V2 of the voltage sampling point X after the relay stabilizes. After sampling, the relays K2 and K12 are driven to act (switching from contact 3 to contact 4 and contact 6 to contact 5, respectively), and the voltage V3 of the voltage sampling point X is detected after the relay stabilizes. After sampling, the relay K11 is driven to operate (from contact 8 to contact 7), and after the relay is stable, the voltage V4 at the voltage sampling point X is detected. The state of the harmonic filter unit can be determined according to Table 3.

[0055] Table 3 Harmonic filter unit status judgment table

[0056]

[0057] Assuming that the detection circuit adopts the device parameters shown in Table 1, the state of the harmonic filtering unit can be determined according to Table 4.

[0058] Table 4 Sampling voltage and relay status judgment table

[0059]

[0060] The method for predicting the state of the harmonic filter unit of the shortwave transmitter of the present invention can perform online detection of the harmonic filter unit fault and predict the remaining life of the relay after use. When the harmonic filter unit fails, a fault indication is given before the shortwave transmitter is transmitted; when the relay is close to the mechanical life, an early warning and maintenance suggestions are given to achieve condition-based maintenance. The method solves the problems that the shortwave transmitter is burned out due to the failure of the harmonic filter unit during operation, and the relay is damaged when it reaches the end of its service life, affecting the availability of the shortwave transmitter.

[0061] The present invention solves the problems that after the harmonic filter unit of a shortwave transmitter fails, the harmonic filter unit is not detected in time, resulting in the burning of equipment during shortwave transmitter transmission, and the damage of relays at the end of their service life affecting the availability of the shortwave transmitter. The invention realizes the condition-based maintenance of the harmonic filter unit of the shortwave transmitter and improves the fault detection rate of the equipment built-in test (BIT), which has important practical significance for solving the problem of harmonic filter unit status prediction.

Claims

1. A shortwave transmitter harmonic filter unit state prediction device, characterized in that: It includes a detection circuit arranged in a harmonic filter unit of a shortwave transmitter, and a state prediction program unit arranged in a control module of the shortwave transmitter; the detection circuit is arranged at the radio frequency input end of the harmonic filter unit, and the radio frequency signal output by the harmonic filter unit is synthesized by a power synthesizer and then output; The state prediction program unit includes a relay action counting module and a fault judgment module; the relay action counting module counts the number of relay actions in the harmonic filter unit of the shortwave transmitter; the fault judgment module receives the voltage sampling signal output by the detection circuit, judges and determines the state of the harmonic filter unit; The detection circuit includes an inductor L0 and a resistor R0, wherein the inductor L0 is connected to the RF input terminal of the harmonic filter unit, the inductor L0 and the resistor R0 are connected in series and then connected to VCC, and the common terminal of the inductor L0 and the resistor R0 is a voltage sampling point X; The shortwave operating frequency range of the shortwave transmitter is 2MHz to 29.9999MHz, and is divided into the first to sixth bands according to the requirements of the operating frequency and harmonic filtering: 2.0000 to 3.1408MHz, 3.1409 to 4.1325MHz, 4.1326 to 7.7459MHz, 7.7460 to 12.1642MHz, 12.1643 to 19.1027MHz, and 19.1028 to 29.9999MHz; The harmonic filtering unit is used to filter out the harmonics of the working frequency, including the first to sixth channels corresponding to the first to sixth bands, and each channel includes an input end relay and an output end relay; when the working frequency falls within the first band, the shortwave transmitter control module controls the relay to connect the first channel to the radio frequency path, and the remaining channels are disconnected from the radio frequency path; when the working frequency changes and the frequency falls within another band, the shortwave transmitter control module controls the relay to disconnect the first channel from the radio frequency path, and connect another channel to the radio frequency path, so as to realize the harmonic filtering function; The first wave channel includes an input-end relay K2 and an output-end relay K1. Contact 3 of the input-end relay K2 is connected to the radio frequency path, and contact 4 is grounded through a resistor R2. Contact 1 of the output-end relay K1 is connected to the radio frequency path, and contact 2 is grounded through a resistor R1. The sixth channel includes an input-end relay K12 and an output-end relay K11. The contact 5 of the input-end relay K12 is connected to the radio frequency path, and the contact 6 is grounded through the resistor R12. The contact 7 of the output-end relay K11 is connected to the radio frequency path, and the contact 8 is grounded through the resistor R11. The circuit structures of the second to fifth channels are the same as those of the first and sixth channels; The shortwave transmitter harmonic filter unit state prediction device, the prediction method is as follows: The relay action counting module counts the number of relay actions. Relay action refers to switching from one contact to another. When the proportion of the number of relay actions relative to the total number of mechanical life of the relay reaches a set threshold, a maintenance suggestion to replace the relay is given. During the channel switching process, the fault judgment module detects the voltage value of the voltage sampling point X under different actions and determines the state of the harmonic filter unit according to the voltage value, as follows: Before the transmitter switches channels, the fault judgment module detects the voltage V1 at the voltage sampling point X; then the relay K1 is controlled to operate, switching from contact 1 to contact 2, and the voltage V2 at the voltage sampling point X is detected after the relay is stable; after sampling, the relay K2 is driven to switch from contact 3 to contact 4, and the relay K12 is driven to operate from contact 6 to contact 5, and the voltage V3 at the voltage sampling point X is detected after the relay is stable; after sampling, the relay K11 is driven to switch from contact 8 to contact 7, and the voltage V4 at the voltage sampling point X is detected after the relay is stable; According to the voltage V1~V4, determine the state of the harmonic filter unit: When V1 = VCC, the first channel is open; When V1=0, V2=0, the first wave channel is short-circuited to ground or the contacts of relay K1 are bonded; When V1=0, When , the contacts of relay K2 are bonded; When V1=0, When V3=0, the sixth channel is short-circuited to ground; When V1=0, When V3 = VCC, the contact of relay K12 does not close or the sixth wave channel is open; When V1=0, When , the contact of relay K11 does not close; When V1=0, When V4=0, the harmonic filter unit works normally; Wherein, Ra = R1·R11(R1+R11); When switching between other channels, the state determination process of the harmonic filter unit is the same; When the operating frequency of the shortwave transmitter is still the current operating band, the fault judgment module determines the state of the harmonic filter unit according to the voltage V1 of the detection voltage sampling point X; When V1 = VCC, the current band is open; When V1=0, the harmonic filtering unit works normally.

2. The shortwave transmitter harmonic filter unit state prediction device according to claim 1, characterized in that: When the rated current of the relay is ≥5A, VCC is 12V and the resistance R0 is 100Ω; when the rated current of the relay is <5A, VCC is 3.3V and the resistance R0 is 10Ω; the grounding resistance corresponding to each relay grounding contact is 10Ω.

3. The shortwave transmitter harmonic filter unit state prediction device according to claim 1, characterized in that: When the proportion of the number of relay actions to the total number of relay mechanical life reaches a set threshold, a maintenance suggestion to replace the relay is given, wherein the set threshold is 80%.

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