Zero-second off-broadcasting switching control system of transmitter

Abstract

The invention discloses a zero-second off-broadcasting switching control system for a transmitter. The system comprises a power phase controller, an in-phase power combiner, a radio frequency switching coaxial switch, a power meter, an absorption load and an intelligent controller. In a system normal state, two power amplifiers are used for synthesizing output, and the third power amplifier is used for hot backup. When any one of the main power amplifiers fails, the power of the system drops to 25% (not lower than 25% of a shutdown threshold), the controller immediately controls the normal power amplifier to quickly increase the power to 100% of the rated power of the system, so that the output power of the system is increased to 50% of the rated power of the system, the radio frequency switch network isolates the failed power amplifier and switches into the hot backup power amplifier, and then the power of the two power amplifiers is adjusted to 50% of the power of the system. And the total power is recovered to 100% of the rated system, and zero-second switching is realized. According to the invention, through the power redundancy architecture and the intelligent switching logic, the problems that the traditional switching mode is long in interruption time and easy to stop broadcasting are solved, and the broadcasting safety is greatly improved.

Description

Technical Field

[0001] This invention relates to the field of broadcast television transmission technology, specifically to an automatic switching control system for improving the reliability of terrestrial wireless broadcast transmission systems, and more particularly to a transmitter zero-second stop-broadcast switching control system. Background Technology

[0002] Terrestrial radio broadcasting systems are the final link in the transmission of broadcast television signals, and their stability directly affects broadcast security. The final stage power amplifier (power amplifier) ​​of the transmitter, operating at high power, is one of the most vulnerable modules in the system. According to the industry standard "GY / T 179-2001 Operation and Maintenance Procedures for Radio and Television Transmitters," broadcasting is considered to be suspended when the carrier power falls below 25% of the rated power.

[0003] Currently, most launch sites employ a traditional primary / backup switchover mechanism. When the primary unit fails, the system switches to the backup unit. However, this switchover method has significant drawbacks:

[0004] There is an interruption time during the switching process: from fault detection and logic judgment to the execution of standby machine power-on and power increase, the whole process takes tens of seconds or even longer. During this period, the output power may have dropped below the broadcast stop threshold, resulting in a broadcast stop event.

[0005] Significant switching shock: Cold start of the standby unit will produce large phase and power transients, which will affect the antenna feeder system and reception quality.

[0006] Lack of real-time power redundancy: In a simple primary-backup configuration, the system is actually in a vulnerable state of being a single machine without backup during the switchover period, and cannot cope with power drops during the switchover period.

[0007] Therefore, there is an urgent need in this field for an intelligent switching system that can achieve seamless, smooth, and power-limit-free switching, so as to fundamentally eliminate broadcast interruption accidents caused by power amplifier failure. Summary of the Invention

[0008] The purpose of this invention is to overcome the shortcomings of the prior art and provide a transmitter zero-second broadcast interruption switching control system. This system introduces a third hot backup power amplifier on the basis of dual-machine synthesized output to build a system with real-time power redundancy. In the event of a failure of any power amplifier, the switching can be completed before the power drop reaches the broadcast interruption threshold, achieving true "zero-second" broadcast interruption switching and ensuring the absolute continuity and stability of broadcasting.

[0009] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0010] In a first aspect, the present invention provides a transmitter zero-second pause switching control system.

[0011] The core concept of this system is as follows: Under normal conditions, the system outputs power from two power amplifiers combined at 100%. When either amplifier fails, the system's instantaneous power drops to 25% (assuming the amplifiers have the same rated power), but this power is not lower than the 25% shutdown threshold. Within one second, the system output power is rapidly increased to 50%, not lower than the poor performance threshold, providing a safe switching window. During this period, the control system automatically and quickly isolates the faulty amplifier from the system and switches on a third power amplifier in hot backup mode, recombining it with the normal amplifier to form a dual-amplifier combination, rapidly restoring the system's total power to 100%.

[0012] The system specifically includes:

[0013] Signal scheduling and preprocessing module: includes two exciters that serve as backups for each other and a power phase controller. The power phase controller is used to receive signals from the two exciters, has an automatic switching function, and can independently and precisely adjust the amplitude and phase of the RF signal output to the subsequent three power amplifiers through its internally integrated digitally controlled attenuator and phase shifter.

[0014] Power Amplification Module: Includes three terrestrial broadcast transmitter power amplifiers (Power Amplifier 1, Power Amplifier 2, and Power Amplifier 3). The three power amplifiers are of equal status. Through the configuration of the control system, two of them can be designated as "primary power amplifiers" to participate in the synthesized output, while the third one serves as a "hot backup power amplifier" in a state of being powered on, synchronized, but with its output blocked.

[0015] Radio frequency switching and combining networks: This is the key physical foundation for achieving flexible configuration and zero-second handover. It includes:

[0016] A 2-channel in-phase power combiner: It has two input ports, one main output port, and one unbalanced (isolated) port. When the two input signals are in phase and of equal amplitude, the energy is superimposed and output in phase at the main output port, and there is no output at the unbalanced port.

[0017] Three RF switching coaxial switches (SW1, SW2, SW3): SW1 and SW2 are used to flexibly connect or disconnect the three power amplifiers from the synthesizer. SW3 is used to select whether the system output comes from the synthesizer (dual-amplifier mode) or directly from a single power amplifier (single-amplifier mode).

[0018] An absorption load: permanently connected to the unbalanced port of the two-way in-phase power combiner, used to absorb residual power generated when the system is unbalanced.

[0019] Status monitoring module: includes four power meters. They are used to monitor: the power at input synthesizer port 1 (power meter 1); the power at input synthesizer port 2 (power meter 2); the total output power of the system (power meter 3); and the power at the unbalanced port of the synthesizer (power meter 4 is used to determine the phase and amplitude consistency of the two signals).

[0020] Intelligent control module:

[0021] Zero-second switching controller: As the system's brain, it is an intelligent controller based on an embedded industrial control computer. It collects the status of all power amplifiers and exciters, as well as the readings of four power meters, in real time through a network interface; runs the core control algorithm, identifies faults, and makes switching logic decisions; and issues control commands through the network and I / O interfaces.

[0022] Acquisition Controller: As an I / O extension of the zero-second switching controller, it acquires the contact position status of three RF switching coaxial switches through the digital input (DI) interface and drives the motor action of the switching switches through the relay output (DO) interface.

[0023] Secondly, the present invention provides a zero-second switching method based on the above system.

[0024] The method includes the following steps:

[0025] System initialization and synchronization: The system starts in dual-machine mode, with power amplifier 1 and power amplifier 2 designated as the main power amplifiers for combined output. Power amplifier 3 is powered on as a hot backup unit, and its output is directed to the absorption load by the RF switch network, but its input signal is provided by the power phase controller and kept synchronized.

[0026] Real-time monitoring and dynamic matching: The zero-second switching controller continuously monitors the status of each power amplifier, its output power (power meters 1 and 2), and the total system output power (power meter 3). At the same time, by monitoring the unbalanced power (power meter 4), it provides feedback control to the power phase controller, dynamically adjusting the phase and amplitude of the signal output to the main power amplifier to ensure that the two input signals are always in the optimal synthesis state of being in phase and having equal amplitude.

[0027] Fault Detection and Decision-Making: When a fault is detected in any primary power amplifier (e.g., power amplifier 1), the controller immediately confirms that the total system power has dropped to approximately 25%. Since the power drop is not less than 25%, the system does not enter a shutdown state. The controller then generates a switching command to quickly increase the output power of another primary power amplifier (e.g., power amplifier 2) to 100%, while simultaneously switching the faulty power amplifier 1 out of the system and switching to the hot backup power amplifier 3. The output power of power amplifiers 3 and 2 is adjusted to 50% of their respective output power, and the combined output is the rated power.

[0028] Zero-second switchover execution:

[0029] a. The controller, through the acquisition controller, drives SW1 to switch from the position connected to power amplifier 1 to the position connected to power amplifier 3. This operation isolates power amplifier 1 and connects power amplifier 3 to the synthesizer.

[0030] b. Almost simultaneously, the power of amplifier 2 is rapidly increased to the rated power, and the total power output is 50% of the rated power.

[0031] b. Almost simultaneously, the power phase controller rapidly fine-tunes the phase and amplitude of power amplifier channel 3 to quickly match the signal of another normal power amplifier 2.

[0032] c. After the switch is completed, the system outputs from power amplifiers 2 and 3, and the total power is restored to 100%.

[0033] Status Updates and Alarms: The system records fault and switchover events, issues alarms to notify maintenance personnel, and enters a new stable operating state.

[0034] Compared with the prior art, the significant advantages of the present invention are:

[0035] True zero-second switching: Through the architecture of "dual-machine synthesis + hot backup", power redundancy is created to ensure that the power does not exceed the limit during the moment of failure. The switching action is completed within a safe power window, achieving zero-second switching in terms of power indicators and user experience.

[0036] High reliability and smooth operation: The 3-out-of-2 redundancy design greatly improves system availability. The hot backup power amplifier is always in a synchronized state, with no cold start process during switching, precise phase and power adjustments, and no impact on broadcast quality or the antenna system.

[0037] Flexibility and Intelligence: The system supports multiple working modes, including single-machine and dual-machine modes, and can be flexibly configured according to operational needs. It integrates real-time monitoring, automatic diagnosis, intelligent decision-making, and remote monitoring functions, greatly reducing manual intervention and improving operational efficiency. Attached Figure Description

[0038] Figure 1 This is a block diagram of the overall structure of the transmitter zero-second broadcast stop switching control system of the present invention.

[0039] Figure 2 This diagram shows the interface connection between the data acquisition controller, the radio frequency switching coaxial switch, and the zero-second switching controller.

[0040] Figure 3 This is the equivalent circuit diagram of the system when SW1 is in position B and SW2 is in position A in stand-alone operation mode.

[0041] Figure 4 This is the equivalent circuit diagram of the system when SW1 and SW2 are in position B in stand-alone operation mode.

[0042] Figure 5 This is the equivalent circuit diagram of the system when SW1 is in position A and SW2 is in position A in stand-alone operation mode.

[0043] Figure 6 This is the equivalent circuit diagram of the system when SW1 is at position A and SW2 is at position B in stand-alone operation mode.

[0044] Figure 7 This is the equivalent circuit diagram of the system when SW1 is in position A and SW2 is in position A in dual-machine operation mode.

[0045] Figure 8 This is the equivalent circuit diagram of the system when SW1 is in position A and SW2 is in position B in the dual-machine working mode.

[0046] Figure 9 This is the equivalent circuit diagram of the system when SW1 is in position B and SW2 is in position A in dual-machine operation mode.

[0047] Figure 10 This is the equivalent circuit diagram of the system when SW1 and SW2 are in position B in dual-machine operation mode. Detailed Implementation

[0048] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0049] See Figure 1 The physical connections of this system are as follows: Exciter 1 and Exciter 2 outputs are connected to a power phase controller, which is then connected to power amplifiers 1, 2, and 3. SW1, SW2, and SW3 are RF switching coaxial switches. Power amplifiers 1, 2, and 3 are power amplifiers. All power meters are through-type power meters.

[0050] The output of power amplifier 1 is connected to SW1. One output of SW1 is connected to power meter 1. Power meter 1 is connected to one input of the two-channel in-phase power combiner. The other output of SW1 is connected to one input of SW3.

[0051] The output of power amplifier 2 is connected to SW2. One output of SW2 is connected to power meter 2. Power meter 2 is connected to the other input of the two-channel in-phase power combiner. The other output of SW2 is connected to the other input of SW1.

[0052] The output of power amplifier 3 is connected to the other input of SW2. One output of SW3 is connected to the absorber, and the other output of SW3 is connected to power meter 3. The output of power meter 3 is connected to the antenna.

[0053] The output of the 2-channel in-phase power combiner is connected to the other input of SW3. The unbalanced power output port of the 2-channel in-phase power combiner is connected to power meter 4, and power meter 4 is connected to the absorption load.

[0054] Power meters 1, 2, 3, and 4 are connected to the data acquisition controller. The data acquisition controller is also connected to SW1, SW2, and SW3. Its main purpose is to acquire the positions of these three RF switching coaxial switches and control the positions of SW1, SW2, and SW3 based on the control signals received from the zero-second switching controller.

[0055] The zero-second switching controller is connected to the power phase controller, acquisition controller, power amplifier, and exciter via a switch, and is also connected to three RF switching coaxial switches via the acquisition controller.

[0056] The transmitter zero-second pause switching control system of the present invention allows the exciter 1, exciter 2, and power amplifiers 1, 2, and 3 to directly use the existing modules without additional configuration.

[0057] The transmitter zero-second broadcast stop switching control system of the present invention has two main working states: single-machine working mode and dual-machine working mode.

[0058] Standalone working mode

[0059] In standalone mode, SW3 is in position B. The amplifier to be played in standalone mode is selected by switching the positions of SW1 and SW2. Details are as follows:

[0060] SW3 has two signal sources: the first is the signal from SW1, and the second is the signal from the two-channel co-directional power combiner. SW1's signal sources are power amplifier 1 and SW2. SW2's signal sources are power amplifier 2 and power amplifier 3.

[0061] When SW3 selects a signal from SW1, the signal source is selected by a combination of SW1 and SW2: when the selected signal source is the output of power amplifier 1, regardless of the state of SW2, the output is solely provided by power amplifier 1; when the selected signal source for SW1 is a signal from SW2, whether the output is provided by power amplifier 2 or power amplifier 3 depends on the state of SW2: when the selected signal source for SW2 is power amplifier 2, the system outputs independently by power amplifier 2; when the selected signal source is power amplifier 3, the system outputs independently by power amplifier 3.

[0062] In stand-alone operation, a primary / backup configuration can be adopted. One of the three power amplifiers can be selected as the primary amplifier, and the other as the backup amplifier, which is in a hot standby state. The control logic is as follows: When power meter 3 detects that the output power is low to a certain level (above 25% of the normal output power, to ensure the output power does not fall below 25% during switching), the zero-second switching controller, through combined control of SW1 and SW2, switches on the backup amplifier and switches off the faulty amplifier, thus completing the switching control; simultaneously, the other redundant amplifier is put into hot standby mode.

[0063] The wiring method of SW1, SW2, and SW3 is as follows: Figure 1 When SW3 is in position B, the output power amplifier selected by the combination of SW1 and SW2 is shown in Table 1.

[0064] Table 1

[0065] SW1 SW2 Power measured by power meter 3 Power measured by power meter 1 Power measured by power meter 2 B A Amplifier 1 Amplifier 3 Amplifier 2 B B Amplifier 1 Amplifier 2 Amplifier 3 A A Amplifier 3 Amplifier 1 Amplifier 2 A B Amplifier 2 Amplifier 1 Amplifier 3

[0066] When SW1 is in position B, regardless of whether SW2 is in position A or B, power amplifier 1 will work independently. Figure 3 , Figure 4 The equivalent circuit diagrams are shown for SW2 at positions A and B, respectively.

[0067] When SW1 is at position A and SW2 is at position A, the equivalent circuit is as follows: Figure 5 As shown, at this time, power amplifier 3 works independently.

[0068] When SW1 is at position A and SW2 is at position B, its equivalent circuit is as follows: Figure 6 As shown, at this time, power amplifier 2 works independently.

[0069] Dual-machine working mode

[0070] In dual-machine operation mode, SW3 is in position A, and its selected signal source is a two-channel in-phase power combiner. Switching the positions of SW1 and SW2 selects which two power amplifiers are used for combined output in dual-machine mode. Details are as follows:

[0071] When both SW1 and SW2 are at position A, power amplifier 1 and power amplifier 2 operate simultaneously, and the combined power is output. The equivalent circuit diagram is shown below. Figure 7 As shown.

[0072] When SW1 is at position A and SW2 is at position B, power amplifiers 1 and 3 operate simultaneously, and the combined power is output. The equivalent circuit diagram is shown below. Figure 8 As shown.

[0073] When SW1 is at position B, and SW2 is at position A or B, power amplifiers 2 and 3 operate simultaneously, and the power is combined and output. The equivalent circuit diagram is as follows. Figure 9 , Figure 10 As shown.

[0074] When SW3 is in position A, the combination selection and output of SW1 and SW2 are shown in Table 2.

[0075] Table 2

[0076] SW1 SW2 Power measured by power meter 3 Power measured by power meter 1 Power measured by power meter 2 A A Amplifier 1 + Amplifier 2 Amplifier 1 Amplifier 2 A B Amplifier 1 + Amplifier 3 Amplifier 1 Amplifier 3 B A Amplifier 2 + Amplifier 3 Amplifier 3 Amplifier 2 B B Amplifier 2 + Amplifier 3 Amplifier 2 Amplifier 3

[0077] The switching process for a faulty power amplifier 1 in dual-machine mode:

[0078] Initial state: The system is running in the "Amplifier 1 + Amplifier 2" combined mode.

[0079] Set SW1 to position A (connect power amplifier 1), set SW2 to position A (connect power amplifier 2), and set SW3 to position A (connect synthesizer output).

[0080] Amplifier 3 is powered on, but its output is directed to the absorption load by SW1 and SW2 (hot backup state).

[0081] The power phase controller is continuously fine-tuned to minimize the reading of power meter 4, and the total system output (power meter 3) is 100%, and the power phase controller parameters are saved.

[0082] Fault occurrence and detection: Power amplifier 1 suddenly malfunctioned, and the output power dropped sharply.

[0083] The reading of power meter 1 dropped sharply, and the reading of power meter 3 fell to about 25%.

[0084] The zero-second switching controller detects this change within hundreds of milliseconds and determines that power amplifier 1 is faulty. Since the output is not lower than 25%, the controller confirms that the system is in a safe switching window.

[0085] Switch execution:

[0086] Quickly boost the power of amplifier 2 to its rated power, with the total power output being approximately 50% of the rated power.

[0087] The controller sends a control signal to SW1 to switch from "position A" to "position B" by acquiring the data.

[0088] When SW1 is activated, the faulty power amplifier 1 is disconnected from the synthesizer input, while the hot-backup power amplifier 3 is connected to the 2-channel in-phase power synthesizer.

[0089] The power phase controller is activated synchronously with the preset phase and amplitude parameters of power amplifier 3, and performs rapid closed-loop adjustment based on the feedback of power meter 4, so that the signal of power amplifier 3 and the signal of power amplifier 2 can quickly reach the same phase synthesis state.

[0090] Restoration to stability: The switching action is completed in an extremely short time (approximately 1 second). The total system output power smoothly recovers from 50% to 100%. Throughout the process, the output power remains above the shutdown threshold, achieving a zero-second shutdown switching.

[0091] After that, the system enters a new stable state of combined output of "Power Amplifier 2 + Power Amplifier 3" until the next maintenance or fault occurs.

[0092] The system and method described in this invention provide an effective solution for high-reliability broadcast transmission through ingenious architectural design and intelligent control logic. Those skilled in the art can make various modifications and improvements based on the principles of this invention, and all such modifications should fall within the protection scope of this invention.

Claims

1. A zero-second pause switching control system for a terrestrial wireless broadcast transmitter, characterized in that, include: The system includes a power phase controller, a 2-channel in-phase power combiner, three RF switching coaxial switches, four power meters, an absorption load, an acquisition controller, and a zero-second switching controller. The power phase controller is used to receive and select signals from two exciters, and can independently adjust the phase and amplitude of the RF signals output to the three power amplifiers through its internal phase shifter and attenuator. The three RF switching coaxial switches are used to flexibly configure the connection between the three power amplifiers and the two input ports of the two in-phase power combiners, as well as the antenna feeder system. The four power meters are used to monitor the power of the two input ports of the synthesizer, the total power of the main output port of the synthesizer, and the power of the unbalanced port of the synthesizer, respectively. The zero-second switching controller is connected to the power phase controller, the power amplifier, the power meter, and the acquisition controller. It is used to monitor the system status and various power parameters in real time. When a power amplifier failure is detected, the power phase controller is controlled to adjust the signal, and the acquisition controller controls the three RF switching coaxial switches to perform a switching operation to switch in the hot backup power amplifier to replace the faulty power amplifier.

2. The system according to claim 1, characterized in that, The system operates by combining the output of two power amplifiers under normal conditions, with a third power amplifier serving as a hot backup. This ensures that in the event of a failure of any power amplifier, the instantaneous output power of the system is not less than 25% of the rated power, and can quickly increase the system output power to 50% within 1 second, thereby providing a safe time window for switching operations that is higher than the shutdown threshold.

3. The system according to claim 1 or 2, characterized in that, The zero-second switching controller monitors the power of the unbalanced port of the synthesizer to determine the matching status of the two input signals, and feeds back to control the power phase controller to dynamically adjust the phase and amplitude of the output signal in order to maintain the optimal operating state of the synthesizer.

4. The system according to claim 1 or 2, characterized in that, The acquisition controller acquires the contact position status of the RF switching coaxial switch through the digital input (DI) interface, and drives the RF switching coaxial switch to switch states through the relay output (DO) interface.

5. The system according to claim 1 or 2, characterized in that, The unbalanced output port of the two-way in-phase power combiner is connected to the absorption load via a power meter.

6. The system according to claim 1 or 2, characterized in that, The zero-second switching controller is an embedded industrial computer that communicates with the power phase controller, the transmitter power amplifier, the exciter, and the acquisition controller via a network interface, and is connected to the RF switching coaxial switch via the acquisition controller.

7. A zero-second pause switching method based on the system described in any one of claims 1-6, characterized in that, The method includes the following steps: System initialization and synchronization steps: The system starts in dual-machine mode, designating two power amplifiers as the main power amplifiers to combine the output, and the third power amplifier as a hot backup to be powered on and maintain signal synchronization; Real-time monitoring and dynamic matching steps: The zero-second switching controller continuously monitors the status, output power and total output power of each power amplifier, and monitors unbalanced power to provide feedback to the power phase controller, dynamically adjusting the phase and amplitude of the signal output to the main power amplifier; Fault detection and decision-making steps: When any main power amplifier fault is detected, the controller confirms that the total system power has dropped above the safety threshold and generates a switching command; Zero-second switching execution steps: The controller drives the RF switching coaxial switch through the acquisition controller to isolate the faulty power amplifier and switch to the hot backup power amplifier. At the same time, the power phase controller quickly matches the phase and amplitude of the hot backup power amplifier channel. System recovery steps: After the switch is completed, the system output is combined from another normal power amplifier and the hot backup power amplifier, and the total power is restored to the rated value.

8. A terrestrial wireless broadcasting transmitter, characterized in that, The zero-second pause switching control system of the terrestrial wireless broadcast transmitter described in claim 1 is adopted.

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