Single-live-wire low-voltage chopping power taking system based on flyback power supply topology and intelligent switch panel

Abstract

The invention relates to a flyback power supply topology-based single-live-wire low-voltage chopping power taking system and an intelligent switch panel, and the system comprises a low-voltage conduction device which is connected with a corresponding load in parallel, and a switch control module controls a first controllable switch Q1 to be switched on according to the voltage fed back by a sampling feedback module when the voltage at the two ends of the load is smaller than a preset voltage V1; the single-live-wire chopping controller comprises a second controllable switch M1, a gating device K1, an adjustable transformer, a flyback switch controller, a power supply main control module, a load voltage sampling module and a rectification and voltage stabilization module, and the maximum voltage U1 of the chopping voltage interval is greater than the preset voltage V1. And the power supply main control module switches the number of incoming coils of the adjustable transformer through the gating device K1 according to the state of the second controllable switch M1, and switches a feedback resistor of the flyback switch controller according to the state of the second controllable switch M1.

Description

Technical Field

[0001] The present invention relates to the field of single - wire low - voltage chopping power extraction, and specifically refers to a single - wire low - voltage chopping power extraction system and an intelligent switch panel based on a flyback power topology. Background Art

[0002] In the existing single - wire power extraction solutions, the prior art generally connects a response capacitor in parallel across the load, allowing a small amount of current to pass through the capacitor and supply power to the single - wire chopping power extraction module. At the switch panel end, by controlling the on - time and off - time of the MOS transistor, single - wire chopping power extraction with a specific voltage is achieved. Combining with the flyback power supply scheme, power is supplied to the circuit of the intelligent switch panel. When the current demand at the back end of the switch panel increases due to increased functions, the specific power is generally insufficient to meet the requirements of the back end. The prior art generally optimizes the power supply efficiency or increases the on - time of the MOS transistor.

[0003] Meanwhile, the existing solutions of connecting a response capacitor in parallel across the load and implementing single - wire power extraction through corresponding devices have the following defects:

[0004] Defect 1: Since the current passing through the response capacitor is small, the on - time of the switch set in the existing single - wire power extraction solutions on the market is long, and the chopping amplitude is relatively high, generally about 180V - 280V, and the impact voltage is also very high, which affects the normal operation of the load and shortens the service life of the load. The power extraction ability of the device itself is limited by the power supply scheme. It is possible that the MOS transistor has been turned off before sufficient power is obtained, resulting in voltage drop and causing the device to restart or crash.

[0005] Defect 2: Higher impact voltages require more protective devices to be added for limitation, and the cost also increases accordingly. The overall price of the deployed equipment is high, which affects popularization.

[0006] Defect 3: For different types of loads, such as inductive loads like coils and motors, the periodic switching noise will interfere with the load device, and at the same time, this noise will be transmitted on the power grid, affecting other electrical appliances or devices, posing a safety hazard.

[0007] Defect 4: The single - wire chopping power extraction scheme does not consider the working current waveform of the connected device load. Taking the voltage and current waveforms of a general LED load on the market during operation as an example, as Figure 1As shown, in the general case, the mains frequency is 50Hz and the AC effective value is 220V. Then, the period T = 1 / 50s = 0.02s can be obtained, U2 ≈ 311V. The load draws current from the mains during the period from t1 to t3. The specific power-taking duration is related to the maximum power-taking current I1 and the power topology and power of the device. If the chopping power-taking moment t > t1 for a single-phase device, that is, the chopping power-taking amplitude > U1, it will cause abnormal load current, and adding the load current to the working current of the intelligent switch panel is likely to cause heating.

[0008] Disadvantage 5: Using the method of increasing the chopping duration to increase the load-carrying capacity of the power supply, this solution has low efficiency and cannot achieve a high output power, restricting the functional diversity of the device, such as having a screen, CPU computing power, the number of relays, etc.

[0009] Aiming at the problems existing in the above-mentioned prior art, designing a single-phase low-voltage chopping power-taking system based on a flyback power topology and an intelligent switch panel is the purpose of the research of the present invention. Summary of the Invention

[0010] Aiming at the problems existing in the above-mentioned prior art, the present invention provides a single-phase low-voltage chopping power-taking system and an intelligent switch panel based on a flyback power topology, which can effectively solve at least one of the problems existing in the above-mentioned prior art.

[0011] The technical solution of the present invention is as follows:

[0012] A single-phase low-voltage chopping power-taking system based on a flyback power topology, characterized by comprising:

[0013] A low-voltage conductor, connected in parallel with the corresponding load. The low-voltage conductor includes a sampling feedback module, a switch control module, and a first controllable switch Q1. The sampling feedback module collects the voltage across the low-voltage conductor and feeds it back to the switch control module. The switch control module controls the first controllable switch Q1 to conduct when the voltage across the load is less than the preset voltage V1. The first controllable switch Q1 is connected in parallel with the load;

[0014] A single-fire chopper controller is connected between the live wire and the neutral wire of the mains after being connected in series with the load. The single-fire chopper controller includes a second controllable switch M1, a selector K1, an adjustable transformer, a flyback switch controller, a power main control module, a load voltage sampling module, and a rectification and voltage stabilization module. The second controllable switch is connected in series between the first controllable switch Q1 and the flyback switch controller. The load voltage sampling module collects the load voltage and feeds it back to the power main control module. The power main control module controls the second controllable switch M1 to turn off within the chopping voltage range according to the voltage fed back by the load voltage sampling module. The maximum voltage U1 of the chopping voltage range is greater than the preset voltage V1. The power main control module switches the number of incoming coils of the adjustable transformer according to the state of the second controllable switch M1 through the selector K1 to make the output voltage of the adjustable transformer smooth. The power main control module switches the feedback resistance of the flyback switch controller according to the state of the second controllable switch M1 to improve the output efficiency of the flyback switch controller. The rectification and voltage stabilization module is connected to the output end of the adjustable transformer.

[0015] Further, the low-voltage conduction device includes a power supply voltage stabilization module, which is connected in parallel with the first controllable switch Q1. When the switch control module and the sampling feedback module do not reach the operating voltage, the power supply voltage stabilization module supplies power to the switch control module and the sampling feedback module.

[0016] Further, the power supply voltage stabilization module includes a diode D1, a resistor R5, capacitors C2, C3, and a voltage regulator diode D3. The capacitors C2, C3, and the voltage regulator diode D3 are connected in parallel. The diode D1, the resistor R5, and the capacitors C2, C3, and the voltage regulator diode D3 connected in parallel are connected in series in sequence and then connected in parallel to the first controllable switch Q1. After the load is turned off, the mains charges the capacitors C2, C3 through the diode D1 and the resistor R5 and generates a power supply voltage at the positive terminal of the voltage regulator diode D3.

[0017] Further, the switch control module includes a totem pole drive circuit, a resistor R3, and a triode Q2. The output end after the resistor R3 and the triode Q2 are connected in series is connected to the base common terminal of the totem pole drive circuit. One end of the resistor R3 is connected to the positive terminal of the voltage regulator diode D3. The emitter of the triode Q2 is connected to the neutral wire of the mains. The output end of the totem pole drive circuit is connected to the control end of the first controllable switch Q1;

[0018] The sampling feedback module includes resistors R1, R2, and R4. The resistors R2 and R4 are connected in parallel and then connected in series with the resistor R1. The connection end of the resistor R1 and the parallel connection of the resistors R2 and R4 is connected to the control end of the triode Q2.

[0019] Further, the power supply main control module switches the number of incoming coils of the adjustable transformer through the selector K1 according to the state of the second controllable switch, including:

[0020] The selector K1 is a changeover switch. The selector K1 switches the first primary coil or the second primary coil of the adjustable transformer to be connected to the second controllable switch M1, and the number of turns of the second primary coil is less than that of the first primary coil;

[0021] An energy storage module is connected to the input end of the selector K1. The energy storage module stores energy when the first controllable switch Q1 is closed and releases energy when the first controllable switch Q1 is opened. The flyback switch controller takes power from the adjustable transformer and controls the power supplied to the rectification and voltage regulation module;

[0022] When the corresponding load is in the off state, the power supply main control module switches the first primary coil of the adjustable transformer to be connected to the second controllable switch M1 through the selector K1;

[0023] When the corresponding load is in the on state, the power supply main control module switches the second primary coil of the adjustable transformer to be connected to the second controllable switch M1 through the selector K1.

[0024] Further, the flyback switch controller includes a third controllable switch K2, resistors R10, R11, and R12. The resistors R10 and R11 are connected in series. After the third controllable switch K2 is closed, the resistor R12 is connected in parallel with the resistor R10. The power supply main control module controls the third controllable switch K2 to be closed or opened. The resistors R10 and R11 are connected in series and then connected to the secondary side terminal of the adjustable transformer and the feedback voltage input terminal of the power control module.

[0025] Further, it includes a load current sampling module. The load current sampling module samples the load current and feeds it back to the power supply main control module. The power supply main control module adjusts the chopping duration of the single-phase fire chopper controller according to the current fed back by the load current sampling module.

[0026] Further, the power supply main control module judges the type of the load according to the current fed back by the load current sampling module. The power supply main control module matches the preset value T0 of the chopping duration, the minimum value Ta of the chopping moment, and the chopping duration T of the single-phase fire chopper controller according to the type of the load. The power supply main control module periodically compares the current fed back by the load current sampling module and adaptively adjusts the chopping duration T of the single-phase fire chopper controller.

[0027] Further, adaptively adjusting the chopping duration T of the single-phase fire chopper controller includes:

[0028] Obtain the current startup rising time T1.

[0029] When T1 > T0, set the chopping duration T = T0.

[0030] When T1 < T0, if T1 > Ta, it is determined that the device is in the low - performance mode and the chopping power - taking current of the current load only meets the requirements of the device in the low - performance mode, and the user is prompted to unlock higher - performance functions and it is recommended to replace the load; if T1 < Ta, it is determined that the load is in the low - performance mode and the chopping power - taking current of the load will interact with the load current of the device, and the user is prompted to replace the load or the zero - fire device.

[0031] Furthermore, an intelligent switch panel is provided, which includes the single - live - wire low - voltage chopping power - taking system based on the flyback power topology described above.

[0032] Therefore, the present invention provides the following effects and / or advantages:

[0033] A single - live - wire low - voltage chopping power - taking method and system based on the flyback power topology involved in the present application mainly solve the problems existing in the existing single - live - wire chopping power - taking scheme, such as long chopping time, high amplitude, high impact voltage, and the failure to consider the device current waveform and interference situation, resulting in insufficient device load - carrying capacity, abnormal operation of the load, and shortened service life.

[0034] In the present application, by using the device low - voltage conductor and the single - fire chopping controller to work together, when the lamp is off, the low - voltage conductor closes, short - circuits both ends of the lamp, so that the single - fire chopping controller obtains the mains waveform at both ends; when the lamp is on, within the range from 0V to the low - voltage chopping amplitude, the low - voltage conductor still closes and short - circuits both ends of the lamp. After exceeding the chopping amplitude, the second controllable switch M1 inside the single - fire chopping controller closes, and the selector switches to the low - voltage startup state, so that the current waveform rises to the maximum value as soon as possible, obtains sufficient power, the low - voltage conductor disconnects synchronously, the voltage at both ends of the lamp rapidly increases to the chopping amplitude, and then continues to increase, and the lamp lights up normally until the next voltage zero - crossing arrives. Then the second controllable switch M1 disconnects again, so that the low - voltage conductor closes, the mains voltage is concentrated at both ends of the device, and there is only partial residual voltage in the low - voltage conductor to maintain the conducting state. The single - fire chopping controller continues to obtain voltage and current to complete the periodic switching operation.

[0035] A core idea of this application is to switch the turns ratio of the transformer coil through a controllable gating converter, and configure the device state in different states through software timing to adapt to different mains voltages. At the same time, this low-voltage chopping power supply scheme changes the starting power-taking moment and corresponding voltage of the equivalent capacitor at the front end of the power supply, which is earlier than the power-taking moment when the light is turned off and the voltage is lower, so as to enable the equivalent capacitor to obtain more energy as much as possible. Because except during the chopping time, due to the closing of the second controllable switch M1, the equivalent capacitor cannot obtain energy from the mains. In the case of continuous energy consumption by the rear-end load, if the power obtained at the front end is insufficient, it will lead to a voltage drop at the rear end, causing the device to malfunction or even power off and restart.

[0036] Compared with the devices on the market that usually increase the chopping duration to obtain higher power, such a power supply scheme not only reduces the power supply efficiency due to the need to adapt to different voltages, but also the higher the chopping amplitude, the higher the impact voltage generated. And if the individual current charging time t4 of the load < t3, it indicates that the operating voltage and current when the device turns on the light will definitely affect the normal lighting of the load. Moreover, there is a certain dead time for the switching of the low-voltage conductor and the single-fire chopper, which may cause interference in their operating currents and lead to heating phenomena, resulting in device failure. The present invention can judge the type of the load and the degree of influence by the chopping power-taking scheme through the voltage and current sampling modules through the preset internal software, configure a reasonable chopping power-taking duration, and be compatible with most lamps on the market, with good compatibility.

[0037] Other features and advantages of the present invention will be described in the following specification, and part of them will become obvious from the specification or be understood by implementing the present invention. The objectives and other advantages of the present invention are achieved and obtained by the structure specifically pointed out in the specification and the drawings.

[0038] It should be understood that the above summary and the following detailed description of the present invention are exemplary and explanatory, and are intended to provide further explanation of the present invention as claimed. Description of the Drawings

[0039] Figure 1 It is a waveform diagram of single-fire power-taking for the prior art.

[0040] Figure 2 It is a schematic diagram of module connection for an embodiment of the present invention.

[0041] Figure 3 It is a schematic circuit diagram of the low-voltage conductor.

[0042] Figure 4 It is a current schematic diagram of the initial power-on cycle of the low-voltage conductor.

[0043] Figure 5Schematic diagram of the current when the low-voltage conductor is conducting at low voltage.

[0044] Figure 6 Schematic diagram of the current when the low-voltage conductor is conducting at high voltage.

[0045] Figure 7 Schematic diagram of a partial circuit of the single-phase chopper controller.

[0046] Figure 8 Schematic diagram of another part of the circuit of the single-phase chopper controller.

[0047] Figure 9 Schematic diagram of the self-checking process of the power supply main control module.

[0048] Figure 10 Process for adaptively adjusting the chopping duration T of the single-phase chopper controller.

[0049] Figure 11 Waveform diagram of the voltage and current at both ends of the single-phase low-voltage chopping power supply system.

[0050] Figure 12 Waveform diagram of the voltage and current at both ends of the load. Detailed implementation manners

[0051] For the convenience of those skilled in the art to understand, the embodiments will be further described in detail in conjunction with the accompanying drawings for the structure of the present invention:

[0052] Reference Figure 2 , a single-phase low-voltage chopping power supply system based on a flyback power supply topology, includes:

[0053] A low-voltage conductor, connected in parallel with the corresponding load, the low-voltage conductor includes a sampling feedback module, a switch control module, and a first controllable switch Q1. The sampling feedback module collects the voltage across the low-voltage conductor and feeds it back to the switch control module. The switch control module controls the first controllable switch Q1 to conduct when the voltage across the load is less than a preset voltage V1. The first controllable switch Q1 is connected in parallel with the load;

[0054] The single - fire chopper controller is connected between the live wire and the neutral wire of the mains after being connected in series with the load. The single - fire chopper controller includes a second controllable switch M1, a selector K1, an adjustable transformer, a flyback switch controller, a power main control module, a load voltage sampling module, and a rectification and voltage - stabilization module. The second controllable switch M1 is connected in series between the first controllable switch Q1 and the flyback switch controller. The load voltage sampling module collects the load voltage and feeds it back to the power main control module. The power main control module controls the second controllable switch M1 to disconnect within the chopping voltage range according to the voltage fed back by the load voltage sampling module. The maximum voltage U1 of the chopping voltage range is greater than the preset voltage V1. The power main control module switches the number of incoming - line coils of the adjustable transformer through the selector K1 according to the state of the second controllable switch M1 to make the output voltage of the adjustable transformer smooth. The power main control module switches the feedback resistance of the flyback switch controller according to the state of the second controllable switch M1 to improve the output efficiency of the flyback switch controller. The rectification and voltage - stabilization module is connected to the output end of the adjustable transformer.

[0055] The specific composition and function description of each module in this embodiment are as follows:

[0056] The switch control module is mainly composed of a circuit for driving the first controllable switch Q1, and is responsible for closing the first controllable switch Q1 under the low - voltage state at both ends of the circuit and disconnecting the first controllable switch Q1 when a switch signal is detected. Its trigger signal is introduced by the sampling feedback module. The first controllable switch Q1 can be an IGBT, which has a low on - state voltage drop, a high current - carrying capacity, and low switching losses, and is suitable for use under high - voltage and large - current conditions of the mains. It can operate reliably as a switch at a very low voltage, such as about 5 - 6V, while ensuring a low temperature - rise level.

[0057] The sampling feedback module samples the voltage at both ends of the low - voltage conductor and feeds it back to the switch control module, and converts and outputs it into high - and low - level signals to guide the first controllable switch Q1 to switch.

[0058] The second controllable switch M1 is mainly composed of a drive circuit and a MOS - tube switch, and is controlled by the power main control module to close and disconnect the second controllable switch M1 to achieve voltage change.

[0059] The load voltage sampling module is mainly used to collect the voltage waveform at the end of the load far from the live wire of the mains to obtain the moment of the voltage zero - crossing point.

[0060] The power main control module is composed of a core control chip and peripheral devices, and is responsible for processing the switching load device, while processing the voltage information fed back by the load voltage sampling module, controlling the working states of the selector K1 and the flyback switch controller, and switching the power working mode, etc.

[0061] The flyback switch controller is mainly composed of a switch chip with a built-in MOS transistor and peripheral devices. It is controlled by the power supply main control module, obtains power from the adjustable transformer and inputs it to the selector K1;

[0062] The selector K1 is used to switch the number of incoming line coils of the adjustable transformer when turning the light on or off, so that the adjustable transformer adapts to high and low voltages when turning the light on (high voltage) and turning the light off (low voltage), thereby changing the phase and amplitude of the device current and the output efficiency of the adjustable transformer;

[0063] The rectification and voltage stabilization module is connected to the output end of the adjustable transformer, converts the output voltage of the adjustable transformer into direct current and supplies it to the intelligent switch panel, so that the intelligent switch panel maintains sufficient power to work.

[0064] By making the maximum voltage U1 in the chopping voltage range greater than the preset voltage V1, a period of the delay continuous chopping duration T gives the single-fire chopping controller a longer conduction time and obtains more electric energy.

[0065] Further, the low-voltage conductor includes a power supply voltage stabilization module, which is connected in parallel to the first controllable switch Q1. When the switch control module and the sampling feedback module do not reach the operating voltage, the power supply voltage stabilization module supplies power to the switch control module and the sampling feedback module.

[0066] Further, referring to Figure 3 , the power supply voltage stabilization module includes a diode D1, a resistor R5, capacitors C2, C3, and a voltage stabilizing diode D3. The capacitors C2, C3, and the voltage stabilizing diode D3 are connected in parallel. The diode D1, the resistor R5, and the capacitors C2, C3, and the voltage stabilizing diode D3 connected in parallel are connected in series in sequence and then connected in parallel to the first controllable switch Q1. After the load is turned off, the commercial power charges the capacitors C2, C3 through the diode D1 and the resistor R5 and generates a power supply voltage at the positive terminal of the voltage stabilizing diode D3.

[0067] Further, the switch control module includes a totem pole drive circuit, a resistor R3, and a triode Q2. The output end after the resistor R3 and the triode Q2 are connected in series is connected to the base common terminal of the totem pole drive circuit. One end of the resistor R3 is connected to the positive terminal of the voltage stabilizing diode D3. The emitter of the triode Q2 is connected to the commercial power zero line. The output end of the totem pole drive circuit is connected to the control end of the first controllable switch Q1;

[0068] The sampling feedback module includes resistors R1, R2, and R4. The resistors R2 and R4 are connected in parallel and then connected in series with the resistor R1. The connection end of the resistor R1 and the parallel connection of the resistors R2 and R4 is connected to the control end of the triode Q2.

[0069] The working principle of the low-voltage conductor is as follows: Its main function is to be connected in parallel across the load and provide the mains circuit and voltage for the single-phase chopper controller when the load is off. It approximately shorts the load terminals to prevent the load from working. When the load is powered on, the internal switch is disconnected, and the parallel circuit across the load is disconnected, allowing the load to obtain sufficient voltage and current to make the load light up normally.

[0070] Specifically as follows: When the load is off, the current path is as shown by the bold lines in Figure 4 . In the initial few mains cycles, since the voltage has not reached the normal control voltage and is not sufficient to turn on the first controllable switch Q1, the current passes through D1 and R5 to charge the backend C3 and C2 until it reaches the zener voltage of the zener diode D3 and a voltage is generated at the positive terminal of the zener diode D3, i.e., the VCC voltage. When the VCC voltage is stable, since the voltage between L1 and N is low, the divided voltage value of R1 and R2 in parallel with R4 is less than the preset voltage V1 and does not reach the turn-on voltage of Q2. The V2 voltage is pulled up to a high level through the R3 resistor. The Q3 and Q4 transistors act as a totem-pole driver to accelerate the charging and discharging operations of the load, thereby reducing the delay of signal transmission. At this time, the upper transistor Q3 is turned on, V3 is at a high level, then the IGBT transistor is in the on state, and L1 is connected to N through the first controllable switch Q1. The current path is as shown by the bold lines in Figure 5 , and the low-voltage conductor remains in the low-voltage state;

[0071] When the load is turned on, it is divided into the following two cases: Around the zero-crossing point of the AC mains, the current path is also as shown by the bold lines in Figure 5 ;

[0072] When the mains voltage changes to the preset voltage V1 and reaches the threshold voltage VT, the current path is as shown by the bold lines in Figure 6 . Q2 is turned on, the V2 level flips to a low level, then Q3 is turned off, while Q4 continues to be turned on, V3 quickly becomes a low level, then the first controllable switch Q1 is in the off state, ensuring a high level across the load terminals and preventing a large current from flowing through the interior of the low-voltage conductor, making the load light up and obtaining a high-level state periodically.

[0073] Through the action of the low-voltage conductor, when the load is off, the low-voltage conductor closes, shorting the load terminals, so that the mains waveform is obtained at both ends of the single-phase chopper controller; when the load is on, within the range from 0V to the low-voltage chopping amplitude, the low-voltage conductor remains closed and shorts the load terminals, thereby providing a path for the power-taking current of the single-phase chopper controller.

[0074] Furthermore, the power supply main control module switches the number of incoming line coils of the adjustable transformer according to the state of the second controllable switch through the selector K1, including:

[0075] The selector K1 is a change-over switch. The selector K1 switches the first primary coil or the second primary coil of the adjustable transformer to be connected to the second controllable switch M1, and the number of turns of the second primary coil is less than that of the first primary coil;

[0076] An energy storage module is connected to the input end of the selector K1. The energy storage module stores energy when the first controllable switch Q1 is closed and releases energy when the first controllable switch Q1 is opened. The flyback switch controller takes power from the adjustable transformer and controls the power supplied to the rectification and voltage regulation module;

[0077] When the corresponding load is in the off state, the power supply main control module switches the first primary coil of the adjustable transformer to be connected to the second controllable switch M1 through the selector K1;

[0078] When the corresponding load is in the on state, the power supply main control module switches the second primary coil of the adjustable transformer to be connected to the second controllable switch M1 through the selector K1.

[0079] Reference Figure 7-8 , the energy storage module is composed of L2, C1, and C2, the load voltage sampling module is composed of U1 and its peripheral circuits, the power supply main control module is composed of U3 and its peripheral circuits, the flyback switch controller is composed of U4 and its peripheral circuits, the adjustable transformer is T1, and the rectification and voltage regulation module is composed of U5 and its peripheral circuits.

[0080] One end of the energy storage module is connected to the adjustable transformer to provide input voltage and current for the adjustable transformer. When the load lamp is off, the main control U3 changes the M_control output signal from a square wave of high and low levels to a low level, then the gate G of the first controllable switch M1 quickly becomes low level. R6 provides a path for the M_control voltage to quickly discharge to the ground. R5 is a small resistor to adjust the on and off time of the first controllable switch M1. Then the source S and drain D of the first controllable switch M1 quickly disconnect, and L and L1 are not conducting. Synchronously, the main control flips the level of the K_control signal. Originally, the selector K1 connects C to B, and now it is changed to connect C to A. Since the number of turns of the first primary coil is greater than that of the second primary coil, at this time, the number of turns of the input coil of the adjustable transformer is reduced, thereby increasing the ratio of the output coil to the input coil, and switching the adjustable transformer from the low-voltage power-taking mode to the high-voltage power-taking mode. When the load lamp is on, the first controllable switch M1 is short-circuited, so the power supply to the input end of the selector K1 is lost. At this time, the residual electrical energy of the adjustable transformer is stored in the energy storage module, and the voltage at this time is relatively high. The main control flips the level of the K_control signal, and the selector K1 connects from C to B, thereby reducing the ratio of the output coil to the input coil, and switching the adjustable transformer from the high-voltage power-taking mode to the low-voltage power-taking mode.

[0081] Further, the flyback switch controller includes a third controllable switch K2, resistors R10, R11, and R12. The resistors R10 and R11 are connected in series. After the third controllable switch K2 is closed, the resistor R12 is connected in parallel with the resistor R10. The power supply main control module controls the third controllable switch K2 to be closed or opened. The resistors R10 and R11 are connected in series and then connected to the secondary side terminal of the adjustable transformer and the feedback voltage input terminal of the power supply control module.

[0082] In order to adapt to the deviation of the FB voltage from the normal level caused by different turns ratios, the power supply main control module adds a Switch signal to control the third controllable switch K2. When the third controllable switch K2 is closed, R12 is connected in parallel to R10 to switch the ratio of the feedback resistors. When the selector K1 is connected to B with C, the feedback resistors are R10 and R11 at this time; when the selector K1 is connected to A with C, the corresponding third controllable switch K2 is closed. At this time, the feedback resistors are the resistance value after R10 and R12 are connected in parallel and R11 for voltage division. The resistance composed of R10, R11, and R12 is smaller than the resistance composed of R10 and R11. When the load is turned on, first, the main control chip reads the signal ZERO output by the zero-crossing circuit. If it is a high level, it is the effective value, then controls M_control to be a low level, so that the second controllable switch M1 is turned off, and delays for a period of time of the continuous chopping duration T. Synchronously, the levels of K_control and Switch signals are inverted to switch to the low-voltage chopping power-taking scheme. At this time, the current path changes from CA to CB, and the feedback resistors change from R10 and R11 to R10 / / R12 and R11. This can change the phase of the current, enable the front-end energy storage capacitor to be charged earlier in the time domain, improve the obtained power, and avoid interfering with the current waveform of the load.

[0083] Further, it includes a load current sampling module. The load current sampling module samples the load current and feeds it back to the power supply main control module. The power supply main control module adjusts the chopping duration of the single-phase chopper controller according to the current fed back by the load current sampling module.

[0084] Further, the power supply main control module judges the type of the load according to the current fed back by the load current sampling module. The power supply main control module matches the preset value T0 of the chopping duration, the minimum value Ta of the chopping moment, and the chopping duration T of the single-phase chopper controller according to the type of the load. The power supply main control module periodically compares the current fed back by the load current sampling module and adaptively adjusts the chopping duration T of the single-phase chopper controller.

[0085] Further, adaptively adjusting the chopping duration T of the single-phase chopper controller includes:

[0086] Obtaining the current start rising moment T1

[0087] When T1 > T0, set the chopping duration T = T0;

[0088] When T1 < T0, if T1 > Ta, it is determined that the device is in the low - performance mode and the chopping power - taking current of the current load only meets the requirements of the device in the low - performance mode, and the user is prompted to unlock higher - performance functions and it is recommended to replace the load; if T1 < Ta, it is determined that the load is in the low - performance mode and the chopping power - taking current of the load will interact with the load current of the device, and the user is prompted to replace the load or the zero - fire device.

[0089] Reference Figure 7-8 , the load current sampling module is composed of U2 and its peripheral circuits.

[0090] First, refer to Figure 9 , at the moment of power - on start, the first controllable switch Q1 in the low - voltage conductor and the second controllable switch M1 in the single - fire low - voltage chopper are both in the off state. However, about 100 ms after power - on, the first controllable switch Q1 of the low - voltage conductor is affected by voltage fluctuations to the normal power supply. Due to its low - voltage conduction characteristics, the first controllable switch Q1 closes, and the normal mains waveform is loaded across the single - fire low - voltage chopper. At this time, the power supply main control module has not started, and the gating controller K1 defaults to the high - voltage conduction state, so the flyback switch controller starts to work, and the subsequent rectification and voltage - regulation module starts to output DC voltage.

[0091] Then, the power supply main control module starts and enters the self - test mode according to the running program, reads the system - inherent chopping duration preset value T0 and the minimum chopping moment Ta corresponding to it from the register. This self - test mode is mainly to enable the power supply main control module to obtain and judge the type of the connected load and the corresponding current start - up time, so as to adjust the chopping duration and chopping amplitude of the system. The chopping duration preset value T0 is the value measured in the laboratory environment, which corresponds to the current start - up time T1 of various different typical loads (such as various different loads, electrical appliances such as fans) during test analysis. T0 meets more than 95% of the products on the market, and T0 < T1. And Ta is the chopping amplitude that the device satisfies when meeting the minimum system functions of each module, that is, when part of the power consumption is reduced, such as the maximum volume of the speaker is reduced, the system backlight is reduced, and part of the system is in the sleep state. Therefore, Ta < T0.

[0092] After the self-check program, the device will output the self-check result. If it can meet the load operation requirements, it will report the chopping duration. If not, it will prompt the user about the relevant situation and handling measures, etc. At the same time, during the process of turning on the load, the software will periodically compare the data fed back by the load current sampling module with the previous judgment result to check if they are consistent. If they are, it indicates that the load is operating normally without obvious open circuit. If not, it means that the load may have been damaged by an open circuit or the user has replaced the load, and the self-check program needs to be repeated to reset the required chopping duration to meet the power consumption requirements of the device.

[0093] After entering the self-check program, the main control module first obtains the zero-crossing signal based on the mains from the L1 voltage sampling module, and then the main control module controls the MOS transistor switch to close. The mains cycle is 50Hz, and closing for 40ms is exactly 2 complete AC mains cycles. During this cycle, the L1 current sampling module works synchronously to obtain the current signal of the load with high-precision resolution and thereby judge the type of the load.

[0094] Reference Figure 10 , since the load is just powered on and its state is not stable in the first cycle, the current waveform is different from the actual normal waveform. Therefore, the load current waveform of the second cycle is taken for analysis. If the current value is constantly 0, it means that there is no current in the load operation, that is, it is in an open circuit state, which may occur when the load is damaged or not properly connected. Then the device will feedback to the user that the load is open circuit or there is an abnormal state, and please check and replace it. When it is not constantly equal to 0, it is defaulted that the load is operating. Then the current waveform is collected and Fourier transform is performed on it at the software algorithm level to convert it into spectrum analysis to judge whether it meets the same frequency band and the same phase as the mains. If the judgment conditions are met, the load is judged to be a resistive load, and the chopping scheme has little impact on its product, and the chopping duration T = T0. If the judgment conditions are not met, the load is judged to be other types of loads. At this time, the current start rising moment T1 is obtained. When T1 > T0, it means that before the load current starts, the chopping has been completed, indicating that the load has no influence on the single-phase chopping controller current, and the chopping duration T = T0 can be set. When T1 < T0, then judge the size of T1 and Ta. If T1 > Ta, it means that the user is prompted that the device is currently in a low-performance mode, and only then can the chopping current be separated from the device current without mutual influence. If you need to unlock higher-performance functions, it is recommended to replace the load. If T1 < Ta, it means that even in the low-performance mode, the chopping power-taking current of the load will still interact with the load current of the device, resulting in phenomena such as power failure and restart of the device. The user is strongly reminded that the single-phase panel and the connected load are not compatible, and please replace the load or the zero-phase device as soon as possible.

[0095] Such as Figure 11-12As shown, it is assumed that the load is turned on at time T, that is, the load is off from 0 to T, and the load is in the lit state after time T. Analyzing from 0 to T, since the low-voltage conductor is in the closed state, the load is short-circuited, and almost all the voltage on the mains is concentrated on both sides of the low-voltage chopper device. At time t1, the front-end capacitors C1 and C2 start to charge and generate current. At this time, the corresponding mains voltage is U1, which is approximately around the mains peak value of 311V. At T / 4, the charging current of capacitors C1 and C2 reaches the peak value I1 and then rapidly decreases. Since there is no high mains voltage across the load, it cannot be started, so the voltage and current are approximately 0.

[0096] After the load is turned on, the system quickly switches to the low-voltage chopping power supply scheme. Therefore, at time t2, that is, when the mains voltage is U2, the front-end equivalent capacitor has started to charge and generate current. Then t2 - T < t1 and U2 < U1. The chopping duration is t3 - T, and the amplitude corresponds to U3. The front-end equivalent capacitor obtains the maximum charging current I2 at this moment. Since the switch control module controls the first controllable switch Q1 to close at this moment, the device voltage drops to 0, and capacitors C1 and C2 no longer obtain current from the mains. The corresponding low-voltage conductor disconnects the internal second controllable switch M1 due to the instantaneous high voltage detected at both ends, and the normal high voltage is restored across the load. At time t4, t3 < t4, the equivalent capacitor inside the load starts to charge and gradually increases to the maximum value I3. The negative half-cycle of the mains is the same by analogy.

[0097] Furthermore, an intelligent switch panel is provided, which includes the single-wire low-voltage chopping power supply system based on the flyback power topology described above.

[0098] It should be noted that in the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" does not exclude the presence of elements or steps not listed in the claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The present invention can be implemented by means of hardware including several different elements and by means of a suitably programmed computer. In the unit claims listing several means, several of these means can be embodied by the same item of hardware. The use of the words first, second, and third, etc. does not denote any order. These words can be interpreted as names.

[0099] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications once they learn the basic creative concept. Therefore, the appended claims are intended to be construed to include the preferred embodiments as well as all changes and modifications falling within the scope of the present invention.

[0100] In the present invention, unless otherwise clearly specified or limited, the terms "mounted", "connected", "coupled", "fixed", etc. shall be construed broadly. For example, it may be a fixed connection, a detachable connection, or an integral body; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention may be understood according to specific circumstances.

[0101] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms should not be understood as necessarily referring to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, without conflict, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

Claims

1. A single live wire low voltage chopping power supply system based on flyback power supply topology, characterized in that: include: A low-voltage conductor is connected in parallel with a corresponding load, the low-voltage conductor comprises a sampling feedback module, a switch control module, and a first controllable switch Q1, the sampling feedback module collects the voltage at both ends of the low-voltage conductor and feeds it back to the switch control module, the switch control module controls the first controllable switch Q1 to be turned on when the voltage at both ends of the load is less than a preset voltage V1 according to the voltage fed back by the sampling feedback module, and the first controllable switch Q1 is connected in parallel with the load; A single-fire chopper controller is connected in series with the load and connected between the mains live line and the mains neutral line. The single-fire chopper controller includes a second controllable switch M1, a selector K1, an adjustable transformer, a flyback switch controller, a power main control module, a load voltage sampling module, and a rectifier and voltage regulator module. The second controllable switch M1 is connected in series between the first controllable switch Q1 and the flyback switch controller. The load voltage sampling module collects the load voltage and feeds it back to the power main control module. The power main control module controls the second controllable switch M1 to be disconnected within the chopping voltage interval according to the voltage fed back by the load voltage sampling module. The maximum voltage U1 of the chopping voltage interval is greater than the preset voltage V1. The power main control module switches the number of incoming coils of the adjustable transformer according to the state of the second controllable switch M1 through the selector K1 to smooth the output voltage of the adjustable transformer. The power main control module switches the feedback resistor of the flyback switch controller according to the state of the second controllable switch M1. The rectifier and voltage regulator module is connected to the output end of the adjustable transformer.

2. According to claim 1, a single live wire low voltage chopping power supply system based on flyback power supply topology is characterized in that: The low-voltage conductor includes a power supply stabilizing module connected in parallel to the first controllable switch Q1. When the switch control module and the sampling feedback module do not reach the working voltage, the power supply stabilizing module supplies power to the switch control module and the sampling feedback module.

3. The single-live-line low-voltage chopping power supply system based on the flyback power supply topology according to claim 2 is characterized in that: The power supply and voltage stabilization module includes a diode D1, a resistor R5, capacitors C2, C3, and a voltage regulator D3. The capacitors C2, C3, and the voltage regulator D3 are connected in parallel. The diode D1, the resistor R5, the capacitors C2, C3, and the voltage regulator D3 connected in parallel are connected in series in sequence and then connected in parallel to the first controllable switch Q1. After the load is turned off, the mains charges the capacitors C2 and C3 through the diode D1 and the resistor R5 and generates a power supply voltage at the positive terminal of the voltage regulator D3.

4. The single-live-wire low-voltage chopping power supply system based on the flyback power supply topology according to claim 3 is characterized in that: The switch control module includes a totem pole drive circuit, a resistor R3, and a transistor Q2. The output end of the resistor R3 and the transistor Q2 connected in series is connected to the base common end of the totem pole drive circuit. One end of the resistor R3 is connected to the positive end of the voltage regulator D3. The emitter of the transistor Q2 is connected to the mains neutral line. The output end of the totem pole drive circuit is connected to the control end of the first controllable switch Q1. The sampling feedback module includes resistors R1, R2, and R4. The resistor R2 and the resistor R4 are connected in parallel and connected in series with the resistor R1. The connecting end of the resistor R1, the resistor R2, and the resistor R4 are connected in parallel and connected to the control end of the transistor Q2.

5. The single-live-wire low-voltage chopping power supply system based on the flyback power supply topology according to claim 1, characterized in that: The power supply main control module switches the number of incoming coils of the adjustable transformer according to the state of the second controllable switch M1 through the selector K1, including: The gate K1 is a conversion switch, and the gate K1 switches the first primary coil or the second primary coil of the adjustable transformer to be connected to the second controllable switch M1, and the number of turns of the second primary coil is less than the number of turns of the first primary coil; The input end of the gate K1 is connected to an energy storage module, which stores energy when the first controllable switch Q1 is closed and releases energy when the first controllable switch Q1 is disconnected. The flyback switch controller draws power from the adjustable transformer and controls the power supplied to the rectifier and voltage regulator module; When the corresponding load is in the off state, the power main control module switches the first primary coil of the adjustable transformer to be connected to the second controllable switch M1 through the gate K1; When the corresponding load is in the on state, the power main control module switches the second primary coil of the adjustable transformer to be connected to the second controllable switch M1 through the selector K1.

6. The single-live-wire low-voltage chopping power supply system based on the flyback power supply topology according to claim 5, characterized in that: The flyback switch controller includes a third controllable switch K2, resistors R10, R11, and R12. The resistors R10 and R11 are connected in series. After the third controllable switch K2 is closed, the resistor R12 is connected in parallel with the resistor R10. The power main control module controls the third controllable switch K2 to be closed or opened. The resistors R10 and R11 are connected in series to the secondary side of the adjustable transformer and the feedback voltage input end of the power control module.

7. The single-live-wire low-voltage chopping power supply system based on the flyback power supply topology according to claim 1, characterized in that: It includes a load current sampling module, which collects load current and feeds it back to the power main control module. The power main control module adjusts the chopping time of the single-fire chopper controller according to the current fed back by the load current sampling module.

8. The single-live-wire low-voltage chopping power supply system based on the flyback power supply topology according to claim 7, characterized in that: The power supply main control module determines the type of the load according to the current fed back by the load current sampling module. The power supply main control module matches the preset chopping time value T0, the minimum chopping time value Ta, and the chopping time T of the single-fire chopping controller according to the type of the load. The power supply main control module periodically compares the current fed back by the load current sampling module and adaptively adjusts the chopping time T of the single-fire chopping controller.

9. The single-live-wire low-voltage chopping power supply system based on the flyback power supply topology according to claim 8, characterized in that: Adaptively adjusting the chopping time T of the single-fire chopping controller includes: Get the current start rising time T1, When T1>T0, set the chopping time T=T0; When T1<T0, if T1>Ta, it is determined that the device is in low-performance mode and the chopping power current of the current load only satisfies the device in low-performance mode, prompting the user to unlock higher-performance functions and suggesting to replace the load; if T1<Ta, it is determined that the load is in low-performance mode and the chopping power current of the load will affect the load current of the device, prompting the user to replace the load or zero-fire device.

10. An intelligent switch panel, characterized in that: A single-live-wire low-voltage chopping power supply system based on a flyback power supply topology comprising the method described in any one of claims 1 to 9.

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