Intelligent multiphase power factor correction control method, control circuit and LED driving power supply

Abstract

The invention relates to an intelligent multi-phase power factor correction control method, a control circuit and an LED driving power supply. The intelligent multi-phase power factor correction control method comprises the following steps that a driving signal detection circuit collects a driving signal output by a PFC control module and outputs a driving detection signal; the MCU intelligent control module receives the driving detection signal and analyzes the driving detection signal to obtain a multi-phase control signal; the MCU intelligent control module sequentially sends the multi-phase control signals to the second PFC power conversion circuit to the Nth PFC power conversion circuit by adopting a preset method; wherein N is an integer greater than or equal to 2. The MCU intelligent control module and the PFC control module are used in cooperation, intelligent adjustment of the output voltage of the power factor correction circuit is achieved in a multi-phase interleaving control mode, and the problem that the efficiency is low when the output voltage is low is effectively solved.

Description

Technical Field

[0001] The present invention relates to the technical field of LED driving power supplies, and more specifically, to an intelligent multi-phase power factor correction control method, a control circuit and an LED driving power supply. Background Art

[0002] LED driver power supplies all need power factor correction. The power factor correction chip used in the current power factor correction circuit is not suitable for LED driver power supplies with a power of more than 300W, or there are similar ones but they have not been verified on a large scale for a long time, and their reliability is unstable. At the same time, the output voltage of the existing power factor correction circuit is a fixed value and cannot be adjusted intelligently, resulting in low efficiency of the power factor correction circuit at low output voltages. Therefore, a larger heat dissipation area is required, which inevitably leads to a larger volume and heavier weight of the glue-filled LED driver power supply, which cannot meet the requirements of energy conservation, emission reduction and carbon emissions. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide an intelligent multi-phase power factor correction control method, a control circuit and an LED driving power supply in view of the problems existing in the prior art.

[0004] The technical solution adopted by the present invention to solve the technical problem is: constructing an intelligent multi-phase power factor correction control method, comprising the following steps:

[0005] The driving signal detection circuit collects the driving signal output by the PFC control module and outputs a driving detection signal;

[0006] The MCU intelligent control module receives the drive detection signal and analyzes the drive detection signal to obtain a multi-phase control signal;

[0007] The MCU intelligent control module uses a preset method to send the multi-phase control signal to the second PFC power conversion circuit to the Nth PFC power conversion circuit in sequence; wherein N is an integer greater than or equal to 2.

[0008] In the intelligent multi-phase power factor correction control method of the present invention, the MCU intelligent control module receives the drive detection signal and analyzes the drive detection signal to obtain the multi-phase control signal, which includes:

[0009] The MCU intelligent control module receives the drive detection signal;

[0010] The MCU intelligent control module analyzes the drive detection signal to obtain the time length and pulse width of the drive detection signal;

[0011] The MCU intelligent control module stores and copies the pulse width of the time length of the drive detection signal to obtain the multi-phase control signal; the multi-phase control signal is a pulse width signal with the same length as the drive detection signal.

[0012] In the intelligent multi-phase power factor correction control method of the present invention, the MCU intelligent control module uses a preset method to send the multi-phase control signal to the second PFC power conversion circuit to the Nth PFC power conversion circuit in sequence, including:

[0013] The MCU intelligent control module uses a delay method to send the multi-phase control signal to the second PFC power conversion circuit to the Nth PFC power conversion circuit in sequence;

[0014] Alternatively, the MCU intelligent control module uses a pulse width falling edge detection method to send the multi-phase control signal to the second PFC power conversion circuit to the Nth PFC power conversion circuit in sequence.

[0015] In the intelligent multi-phase power factor correction control method of the present invention, the method further includes:

[0016] The MCU intelligent control module obtains an input sampling signal, an output sampling signal and a PFC sampling signal;

[0017] The MCU intelligent control module determines whether the input voltage drops to a set value according to the input sampling signal;

[0018] If not, no adjustment is performed;

[0019] If yes, then determine the topology type; the topology type includes: LLC resonant conversion topology and non-isolated BUCK conversion topology;

[0020] If the topology type is an LLC resonant conversion topology, adjusting based on a first adjustment method;

[0021] If the topology type is a non-isolated BUCK conversion topology, adjustment is performed based on the second adjustment method.

[0022] In the intelligent multi-phase power factor correction control method of the present invention, if the topology type is an LLC resonant conversion topology, the adjustment based on the first adjustment method includes:

[0023] The MCU intelligent control module outputs a PFC voltage control signal based on the output sampling signal and the PFC sampling signal, and adjusts the PFC voltage output by the first PFC power conversion circuit through the PFC voltage control signal;

[0024] While the MCU intelligent control module adjusts the PFC voltage output by the first PFC power conversion circuit, the PFC control module controls the PFC voltage output by the first PFC power conversion circuit according to its input signal.

[0025] In the intelligent multi-phase power factor correction control method of the present invention, if the topology type is a non-isolated BUCK conversion topology, the adjustment based on the second adjustment method includes:

[0026] The MCU intelligent control module outputs a PFC voltage control signal based on the output sampling signal and the PFC sampling signal, and adjusts the PFC voltage output by the first PFC power conversion circuit through the PFC voltage control signal;

[0027] While the MCU intelligent control module adjusts the PFC voltage output by the first PFC power conversion circuit, the PFC control module controls the PFC voltage output by the first PFC power conversion circuit to follow the non-isolated output according to its input signal.

[0028] In the intelligent multi-phase power factor correction control method of the present invention, the method further includes:

[0029] The MCU intelligent control module obtains an output sampling signal or a dimming signal;

[0030] The MCU intelligent control module determines whether it is in a half-load or light-load condition according to the output sampling signal;

[0031] If so, any one or multiple circuits from the second PFC power conversion circuit to the first NPFC power conversion circuit are controlled to be closed based on half load or light load.

[0032] The present invention also provides an intelligent multi-phase power factor correction control circuit, which is applied to the intelligent multi-phase power factor correction control method described above, comprising: a PFC control module, an MCU intelligent control module, a drive signal detection circuit, a first PFC power conversion circuit to an Nth PFC power conversion circuit, and an output power conversion module;

[0033] The driving signal detection circuit is used to collect the driving signal output by the PFC control module and output a driving detection signal;

[0034] The MCU intelligent control module is respectively connected to the drive signal detection circuit, the PFC control module, the second PFC power conversion circuit to the Nth PFC power conversion circuit and the output power conversion module, and is used to receive the drive detection signal and analyze the drive detection signal to obtain a multi-phase control signal; the MCU intelligent control module is also used to sequentially send the multi-phase control signal to the second PFC power conversion circuit to the Nth PFC power conversion circuit using a preset method; wherein N is an integer greater than or equal to 2;

[0035] The PFC control module is used to control the PFC voltage output by the first PFC power conversion circuit according to the input signal of the MCU intelligent control module, or to control the PFC voltage output by the first PFC power conversion circuit to follow the non-isolated output according to the input signal of the MCU intelligent control module.

[0036] The intelligent multi-phase power factor correction control circuit of the present invention further includes: an input sampling circuit, an output sampling circuit, and a PFC sampling circuit;

[0037] The input sampling circuit is used to sample the input signal and output the input sampling signal;

[0038] The output sampling circuit is used to sample the output signal and output the output sampling signal;

[0039] The PFC sampling circuit is used to sample the PFC voltage and output a PFC sampling signal.

[0040] The present invention also provides an LED driving power supply, comprising the above-mentioned intelligent multi-phase power factor correction control circuit.

[0041] The intelligent multi-phase power factor correction control method, control circuit and LED driving power supply of the present invention have the following beneficial effects: comprising the following steps: the driving signal detection circuit collects the driving signal output by the PFC control module and outputs the driving detection signal; the MCU intelligent control module receives the driving detection signal and analyzes the driving detection signal to obtain a multi-phase control signal; the MCU intelligent control module uses a preset method to send the multi-phase control signal to the second PFC power conversion circuit to the Nth PFC power conversion circuit in sequence; wherein N is an integer greater than or equal to 2. The present invention uses the MCU intelligent control module in conjunction with the PFC control module to realize intelligent adjustment of the output voltage of the power factor correction circuit through a multi-phase interleaved control method, effectively solving the problem of low efficiency at low output voltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0043] Figure 1 It is a functional block diagram of the intelligent multi-phase power factor correction control circuit provided by the present invention;

[0044] Figure 2 It is a circuit diagram of an intelligent multi-phase power factor correction control circuit provided by the present invention;

[0045] Figure 3 It is a flow chart of the intelligent multi-phase power factor correction control method provided by the present invention. DETAILED DESCRIPTION

[0046] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] refer to Figure 1 , Figure 1 This is a functional block diagram of a preferred embodiment of an intelligent multi-phase power factor correction control circuit provided by the present invention. The intelligent multi-phase power factor correction control circuit can be used to implement the intelligent multi-phase power factor correction control method disclosed in the embodiment of the present invention.

[0048] Specifically, Figure 1 As shown, the intelligent multi-phase power factor correction control circuit includes: a PFC control module 10, an MCU intelligent control module 20, a drive signal detection circuit, a first PFC power conversion circuit to an Nth PFC power conversion circuit (i.e. Figure 1 PFC power conversion 1, PFC power conversion 2, ..., PFC power conversion N) and output power conversion module 30.

[0049] In the embodiment of the present invention, the PFC control module 10 includes a PFC control chip U1, wherein the PFC control chip U1 can be a control chip commonly used in an LED driving power supply, for example, an L6562 control chip can be used, etc., which is mainly used to control the first PFC power conversion circuit, thereby realizing the control of power factor correction. The working principle of the PFC control chip U1 can refer to the PFC control chip U1 of the LED driving power supply, which will not be repeated here.

[0050] In the embodiment of the present invention, the first PFC power conversion circuit to the Nth PFC power conversion circuit, that is, the first PFC power conversion circuit, the second PFC power conversion circuit, ..., the Nth PFC power conversion circuit can all adopt the existing conventional structure, and its typical circuit composition is as follows: Figure 2As shown, the functions and working principles of the first PFC power conversion circuit to the Nth PFC power conversion circuit can refer to the existing solutions, and the present invention is not limited to this. Among them, the first PFC power conversion circuit is controlled by the PFC control module 10, and the second PFC power conversion circuit, the third PFC power conversion circuit, ..., the Nth PFC power conversion circuit are controlled by the MCU intelligent control module 20.

[0051] In the embodiment of the present invention, the output power conversion module 30 can be isolated control or non-isolated control. For example, when isolated control is adopted, an LLC resonant conversion topology is used, and when non-isolated control is adopted, a non-isolated BUCK conversion topology is used. The specific functions and working principles of the output power conversion module 30 can adopt existing solutions, and the present invention will not be repeated here.

[0052] In the embodiment of the present invention, the driving signal detection circuit is used to collect the driving signal output by the PFC control module 10 and output the driving detection signal. Optionally, in the embodiment of the present invention, the driving signal output by the PFC control module 10 is a PWM signal, and the driving detection signal is obtained by collecting the PWM signal. The collected signal includes but is not limited to the time, duty cycle, period, frequency, etc. of the PWM signal.

[0053] Furthermore, if Figure 1 As shown, the intelligent multi-phase power factor correction control circuit further includes: an input sampling circuit 40 , an output sampling circuit 50 , and a PFC sampling circuit 60 .

[0054] The input sampling circuit 40 is used to sample the input signal and output the input sampling signal. Specifically, the input signal collected by the input sampling circuit 40 includes input current, input voltage, etc. The output sampling circuit 50 is used to sample the output signal and output the output sampling signal. The output sampling circuit 50 can use output current, output voltage, etc. The PFC sampling circuit 60 is used to sample the PFC voltage and output the PFC sampling signal. The PFC sampling circuit 60 can use the current, voltage, etc. of the PFC conversion circuit.

[0055] In the embodiment of the present invention, the MCU intelligent control module 20 is respectively connected to the drive signal detection circuit, the PFC control module 10, the second PFC power conversion circuit to the Nth PFC power conversion circuit and the output power conversion module 30, and is used to receive the drive detection signal and analyze the drive detection signal to obtain a multi-phase control signal; the MCU intelligent control module 20 is also used to use a preset method to send the multi-phase control signal to the second PFC power conversion circuit to the Nth PFC power conversion circuit in sequence; wherein N is an integer greater than or equal to 2. The PFC control module 10 is used to control the PFC voltage output by the first PFC power conversion circuit according to its input signal or control the PFC voltage output by the first PFC power conversion circuit to follow the non-isolated output according to its input signal.

[0056] Specifically, the MCU intelligent control module 20 detects the driving detection signal collected by the driving signal detection circuit, thereby copying the driving signal for driving the first PFC power conversion circuit, and then sends the copied multi-phase control signal to the second PFC power conversion circuit, the third PFC power conversion circuit, ..., the Nth PFC power conversion circuit in sequence according to a preset method, thereby realizing multi-phase interleaving control and achieving the purpose of high power output.

[0057] Furthermore, LED driver power supplies are least efficient at rated low input voltages.

[0058] In the isolated LLC resonant conversion topology, the efficiency is highest when the operating frequency is approximately equal to the resonant frequency; in particular, the greater the difference between the output voltage of the PFC power conversion circuit and the rated low input voltage, the lower the efficiency. Therefore, in order to improve the efficiency of the LED driver power supply, the present invention reduces the output value of the PFC at the rated low input voltage and controls the PFC output voltage value to allow the LLC resonant conversion topology to operate near the resonance point. By using the two methods at the same time, the efficiency of the LED driver power supply is improved.

[0059] In the non-isolated BUCK conversion topology, the efficiency is highest when the difference between its output voltage and the output voltage of PFC is small; the efficiency is lower at the rated low input voltage, especially the greater the difference between the output voltage of PFC and the rated low input voltage, the lower the efficiency. Therefore, in order to improve the efficiency of the LED driver power supply, the present invention reduces the output value of PFC at the rated low input voltage to achieve the purpose of improving the efficiency of the PFC conversion circuit, and at the same time controls the PFC output voltage value to follow the non-isolated output, and the two always maintain a certain difference. By using the two methods at the same time, the efficiency of the LED driver power supply is improved.

[0060] refer to Figure 2 , Figure 2A circuit schematic diagram of a typical application example of the intelligent multi-phase power factor correction control circuit provided by the present invention.

[0061] Specifically, Figure 2 As shown, in this embodiment, the input sampling circuit 40 includes: a first resistor R1 and a second resistor R2. The output sampling circuit 50 includes: a fifth resistor R5 and a sixth resistor R6. The PFC sampling circuit 60 includes: a third resistor R3 and a fourth resistor R4. The MCU intelligent control module 20 includes: an MCU intelligent control chip U6. The drive signal detection circuit includes: an eleventh resistor R11 and a thirteenth resistor R13. The PFC regulation circuit is used to adjust the output voltage of the first PFC power conversion circuit according to the PFC voltage control signal output by the MCU intelligent control module 20. Among them, the PFC regulation circuit can be implemented by a digital resistor, or it can also be implemented by a resistor and an access switch, by connecting a PFC regulation circuit composed of a digital resistor or a PFC regulation circuit composed of a resistor and an access switch in parallel with the eighth resistor R8 to change the resistance value of the input detection circuit composed of the seventh resistor R7 and the eighth resistor R8 in series, thereby achieving the change of the PFC sampling signal of the PFC control chip U1 (that is, the output voltage of the first PFC power conversion circuit).

[0062] like Figure 2 As shown, the MCU intelligent control chip U6 samples the input voltage (VAC) through the first resistor R1 and the second resistor R2, samples the output voltage (i.e., the PFC voltage (VPFC)) of the power conversion circuit (i.e., the first PFC power conversion circuit, the second PFC power conversion circuit, ..., the Nth PFC power conversion circuit) through the third resistor R3 and the fourth resistor R4, samples the output voltage (i.e., VOUT+) through the fifth resistor R5 and the sixth resistor R6, and samples the pulse width signal of the PFC control chip U1 through the eleventh resistor R11 and the thirteenth resistor R13.

[0063] refer to Figure 3 , Figure 3 The present invention provides a flow chart of an intelligent multi-phase power factor correction control method. The intelligent multi-phase power factor correction control method can be implemented by an intelligent multi-phase power factor correction control circuit disclosed in an embodiment of the present invention.

[0064] Specifically, Figure 3 As shown, the intelligent multi-phase power factor correction control method includes the following steps:

[0065] Step S301. The driving signal detection circuit collects the driving signal output by the PFC control module 10 and outputs a driving detection signal;

[0066] Step S302: The MCU intelligent control module 20 receives the drive detection signal and analyzes the drive detection signal to obtain a multi-phase control signal.

[0067] In the embodiment of the present invention, the MCU intelligent control module 20 receives the drive detection signal and analyzes the drive detection signal to obtain the multi-phase control signal, including: the MCU intelligent control module 20 receives the drive detection signal; the MCU intelligent control module 20 analyzes the drive detection signal to obtain the time length and pulse width of the drive detection signal; the MCU intelligent control module 20 stores and copies the pulse width of the time length of the drive detection signal to obtain the multi-phase control signal; the multi-phase control signal is the same pulse width signal as the drive detection signal. Among them, the multi-phase control signal is a PWM signal, that is, a PWM signal that is the same as the drive signal output by the PFC control chip U1.

[0068] Step S303. The MCU intelligent control module 20 uses a preset method to send the multi-phase control signal to the second PFC power conversion circuit to the Nth PFC power conversion circuit in sequence; wherein N is an integer greater than or equal to 2.

[0069] In an embodiment of the present invention, the MCU intelligent control module 20 uses a preset method to send the multi-phase control signal to the second PFC power conversion circuit to the Nth PFC power conversion circuit in sequence, including: the MCU intelligent control module 20 uses a delay method to send the multi-phase control signal to the second PFC power conversion circuit to the Nth PFC power conversion circuit in sequence; or, the MCU intelligent control module 20 uses a pulse width falling edge detection method to send the multi-phase control signal to the second PFC power conversion circuit to the Nth PFC power conversion circuit in sequence.

[0070] Specifically, Figure 2As shown, the MCU intelligent control chip U6 collects the pulse width signal (i.e., the driving signal) output by the PFC control chip U1 through the eleventh resistor R11 and the thirteenth resistor R13, and copies and stores the time length, duty cycle, period, frequency, etc. of the pulse width signal currently output by the PFC control chip U1, that is, all the information of the pulse width signal output by the PFC control chip U1 is copied and saved, and then through methods such as delay or pulse width falling edge detection (wherein the delay time is set based on the time length of the pulse width signal currently output by the PFC control chip U1, and the pulse width falling edge is set based on the falling edge of the pulse width signal currently output by the PFC control chip U1), the currently copied pulse width signal is sent as a multi-phase control signal to the second PFC power conversion circuit, and so on, the copied pulse width signal is sent to the third PFC power conversion circuit to the Nth PFC power conversion circuit in sequence, thereby achieving the purpose of high-efficiency multi-phase interleaving control. It should be noted that, in the embodiment of the present invention, the MCU intelligent control chip U6 only collects and copies the pulse width signal currently output by the PFC control chip U1, and executes the signal, discards the pulse width signal that was previously saved and output, or only stores it without copying it to the PFC power conversion circuit 2 and the PFC power conversion circuit N. The present invention does not need to use expensive DSP processors and complex algorithms, but only uses the industry's mature control chip (i.e., the MCU intelligent control chip U6) to cooperate with the PFC control chip U1. By adopting a multi-phase interleaved control method, the demand for high-power LED drive power can be met, while also simplifying the circuit structure design, reducing costs, and achieving high-efficiency multi-phase control. Furthermore, the present invention can also achieve the natural superposition of output power by adopting a multi-phase interleaved control method, thereby increasing the output power and achieving the purpose of improving efficiency. At the same time, it can also reduce ripple and reduce the size of the power supply.

[0071] Furthermore, in an embodiment of the present invention, the intelligent multi-phase power factor correction control method also includes: the MCU intelligent control module 20 obtains an input sampling signal, an output sampling signal and a PFC sampling signal; the MCU intelligent control module 20 determines whether the input voltage drops to a set value based on the input sampling signal; if not, no adjustment is performed; if so, the topology type is determined; the topology types include: LLC resonant conversion topology and non-isolated BUCK conversion topology; if the topology type is LLC resonant conversion topology, adjustment is performed based on the first adjustment method; if the topology type is a non-isolated BUCK conversion topology, adjustment is performed based on the second adjustment method.

[0072] In an embodiment of the present invention, if the topology type is an LLC resonant conversion topology, the adjustment based on the first adjustment method includes: the MCU intelligent control module 20 outputs a PFC voltage control signal based on the output sampling signal and the PFC sampling signal, and adjusts the PFC voltage output by the first PFC power conversion circuit through the PFC voltage control signal; while the MCU intelligent control module 20 adjusts the PFC voltage output by the first PFC power conversion circuit, the PFC control module 10 controls the PFC voltage output by the first PFC power conversion circuit according to its input signal.

[0073] Specifically, Figure 2 As shown, specifically, in the embodiment of the present invention, for the LLC resonant conversion topology structure, the MCU intelligent control chip U6 samples the input voltage through the first resistor R1 and the second resistor R2, and determines whether the rated low input voltage is reached according to the input voltage. If the rated low input voltage is reached, the PFC voltage control signal is output to the PFC regulation circuit to change the resistance value of the input detection circuit, thereby changing the output voltage value (i.e., PFC voltage) of the first PFC power conversion circuit. At the same time, the PFC control chip U1 outputs a corresponding PFC drive signal according to the detected input sampling voltage (i.e., the input signal, that is, the voltage obtained by connecting the eighth resistor R8 and the PFC regulation circuit in parallel and then connecting the seventh resistor R7 in series to obtain a voltage division) to control the PFC voltage output by the first PFC power conversion circuit, so that the LLC resonant conversion topology operates near the resonance point, thereby achieving the purpose of improving the efficiency of the LED driving power supply.

[0074] For example, the input voltage range of a certain LED driver power supply is: 100VAC ~ 277VAC, in the conventional design, the output voltage of PFC power conversion 1 is fixed at 450VDC. Assuming that the output voltage of PFC power conversion 1 is 400V, it is the resonance point of LLC (although the PFC voltage of 450V is not the best efficiency working point, due to the 277V input, the efficiency of PFC is high, the front-end input rectification loss is low, and the efficiency of the whole machine is also high), then when the MCU intelligent control chip U6 detects that the input voltage is 120VAC, it will send a PFC voltage control signal, adjust the resistance value of the PFC adjustment circuit connected in parallel with the eighth resistor R8 or other, and then adjust the output voltage of PFC power conversion 1 to: 400VDC through the PFC control chip U1. That is, the method to improve efficiency here is: 1. Improve the efficiency of LLC: When the power supply works at the resonance point, the efficiency of LLC topology is the highest; 2. When the output voltage of PFC power conversion 1 is smaller than the input voltage, the efficiency is higher.

[0075] In an embodiment of the present invention, if the topology type is a non-isolated BUCK conversion topology, the adjustment based on the second adjustment method includes: the MCU intelligent control module 20 outputs a PFC voltage control signal based on the output sampling signal and the PFC sampling signal, and adjusts the PFC voltage output by the first PFC power conversion circuit through the PFC voltage control signal; while the MCU intelligent control module 20 adjusts the PFC voltage output by the first PFC power conversion circuit, the PFC control module 10 controls the PFC voltage output by the first PFC power conversion circuit to follow the non-isolated output according to its input signal.

[0076] Specifically, Figure 2 As shown, for the non-isolated BUCK conversion topology, the MCU intelligent control chip U6 samples the input voltage through the first resistor R1 and the second resistor R2, and determines whether the rated low input voltage is reached according to the input voltage. If the rated low input voltage is reached, the PFC voltage control signal is output to the PFC regulation circuit to change the resistance of the input detection circuit, thereby changing the output voltage value (i.e., PFC voltage) of the first PFC power conversion circuit. At the same time, the PFC control chip U1 outputs a corresponding PFC drive signal according to the detected input sampling voltage (i.e., input signal, that is, the voltage obtained by connecting the eighth resistor R8 and the PFC regulation circuit in parallel and then connecting the seventh resistor R7 in series to obtain a voltage division) to control the PFC voltage output by the first PFC power conversion circuit to follow the non-isolated output, so that the two voltages always maintain a certain difference, thereby achieving the purpose of improving the efficiency of the LED driving power supply.

[0077] For example, the input voltage range of a certain LED driver power supply is: 100-277VAC, conventional design: PFC power conversion 1 output voltage is fixed at 450VDC. Assuming that the difference of 100V between the BUCK voltage (BUCK output voltage 300V) and the output voltage of PFC power conversion 1 is the best working point of the non-isolated BUCK (although the 450V PFC voltage is not the best efficiency working point, due to the 277V input, the PFC efficiency is high, the front-end input rectification loss is low, and the efficiency of the whole machine is also high), then when the MCU intelligent control chip U6 detects that the input voltage is 120VAC, it will send a PFC voltage control signal, adjust the resistance value of the PFC regulation circuit in parallel with R8 or other, and adjust the output voltage of PFC power conversion 1 to: 400VDC through the PFC control chip U1. That is, the method to improve efficiency here is: 1. Improve the efficiency of the non-isolated BUCK: the best working point of the non-isolated BUCK, the highest efficiency; 2. The smaller the difference between the output voltage of the PFC and the input voltage, the higher the efficiency;

[0078] Furthermore, the intelligent multi-phase power factor correction control method also includes: the MCU intelligent control module 20 obtains an output sampling signal or a dimming signal; the MCU intelligent control module 20 determines whether it is in a half-load or light-load condition based on the output sampling signal; if so, any one or multiple circuits of the second PFC power conversion circuit to the Nth PFC power conversion circuit are controlled to be closed based on half-load or light-load.

[0079] Specifically, Figure 2 As shown, for the LLC resonant conversion topology and the non-isolated BUCK conversion topology, during operation, the intelligent control chip also determines the current operating condition of the LED driving power supply through the output current sampled by the output sampling circuit 50 or through the received dimming signal (the dimming signal is a PWM signal or a DC voltage signal). For example, the current output current is obtained by outputting a sampling signal, and the current output current is compared with the rated maximum output current to obtain the ratio percentage of the current output current to the rated maximum output current. The current operating condition of the LED driver power supply is determined according to the ratio percentage. If the ratio percentage is 50% (i.e., current output current / rated maximum output current=50%), the current operating condition of the LED driver power supply is determined to be half-load operation, and at this time, the MCU intelligent control chip U6 controls the second PFC power conversion circuit to one PWM output in the Nth PFC power conversion circuit; if the ratio percentage is 25% (i.e., current output current / rated maximum output current=25%), the current operating condition of the LED driver power supply is determined to be light-load operation, and the MCU intelligent control chip U6 controls the second PFC power conversion circuit to two PWM outputs in the Nth PFC power conversion circuit; and so on. This method can effectively improve the efficiency of the LED driver power supply at half load or light load. Similarly, it can also be controlled according to the dimming signal. Specifically, the MCU intelligent control chip U6 determines the current operating condition of the LED driving power supply according to the received dimming signal. If the dimming is reduced to 50% (such as the dimming signal is initially 10V, when it is reduced to 5V, it is determined to be reduced to 50%), the current operating condition of the LED driving power supply is determined to be half-load operation. At this time, the MCU intelligent control chip U6 controls the second PFC power conversion circuit to one PWM output in the Nth PFC power conversion circuit; if the percentage is 25% (that is, the dimming voltage drops to 2.5V), the current operating condition of the LED driving power supply is determined to be light-load operation, and the MCU intelligent control chip U6 controls the second PFC power conversion circuit to two PWM outputs in the Nth PFC power conversion circuit; and so on. This method can effectively improve the efficiency of the LED driving power supply at half load or light load.

[0080] The present invention samples input signals, output signals and PFC signals through the MCU intelligent control chip U6, and makes the PFC output voltage follow the input voltage and the output voltage through intelligent control, thereby effectively improving the efficiency of the LED driving power supply at the rated low input voltage and achieving the purpose of energy saving and efficiency improvement.

[0081] The present invention also provides an LED driving power supply, comprising the intelligent multi-phase power factor correction control circuit disclosed in the embodiment of the present invention.

[0082] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0083] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0084] The steps of the method or algorithm described in conjunction with the embodiments disclosed herein may be implemented directly using hardware, a software module executed by a processor, or a combination of the two. The software module may be placed in a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0085] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot limit the scope of protection of the present invention. All equivalent changes and modifications made to the scope of the claims of the present invention should fall within the scope of the claims of the present invention.

Claims

1. An intelligent multi-phase power factor correction control method, characterized in that: The following steps are involved: The driving signal detection circuit collects the driving signal output by the PFC control module and outputs a driving detection signal; The MCU intelligent control module receives the drive detection signal and analyzes the drive detection signal to obtain a multi-phase control signal; The MCU intelligent control module uses a preset method to send the multi-phase control signal to the second PFC power conversion circuit to the Nth PFC power conversion circuit in sequence; wherein N is an integer greater than or equal to 2.

2. The intelligent multi-phase power factor correction control method according to claim 1, characterized in that: The MCU intelligent control module receives the drive detection signal and analyzes the drive detection signal to obtain a multi-phase control signal, which includes: The MCU intelligent control module receives the drive detection signal; The MCU intelligent control module analyzes the drive detection signal to obtain the time length and pulse width of the drive detection signal; The MCU intelligent control module stores and copies the pulse width of the time length of the drive detection signal to obtain the multi-phase control signal; the multi-phase control signal is a pulse width signal with the same length as the drive detection signal.

3. The intelligent multi-phase power factor correction control method according to claim 1, characterized in that: The MCU intelligent control module uses a preset method to send the multi-phase control signal to the second PFC power conversion circuit to the Nth PFC power conversion circuit in sequence, including: The MCU intelligent control module uses a delay method to send the multi-phase control signal to the second PFC power conversion circuit to the Nth PFC power conversion circuit in sequence; Alternatively, the MCU intelligent control module uses a pulse width falling edge detection method to send the multi-phase control signal to the second PFC power conversion circuit to the Nth PFC power conversion circuit in sequence.

4. The intelligent multi-phase power factor correction control method according to claim 1, characterized in that: The method further comprises: The MCU intelligent control module obtains an input sampling signal, an output sampling signal and a PFC sampling signal; The MCU intelligent control module determines whether the input voltage drops to a set value according to the input sampling signal; If not, no adjustment is performed; If yes, then determine the topology type; the topology type includes: LLC resonant conversion topology and non-isolated BUCK conversion topology; If the topology type is an LLC resonant conversion topology, adjusting based on a first adjustment method; If the topology type is a non-isolated BUCK conversion topology, adjustment is performed based on the second adjustment method.

5. The intelligent multi-phase power factor correction control method according to claim 4, characterized in that: If the topology type is an LLC resonant conversion topology, adjusting based on the first adjustment method includes: The MCU intelligent control module outputs a PFC voltage control signal based on the output sampling signal and the PFC sampling signal, and adjusts the PFC voltage output by the first PFC power conversion circuit through the PFC voltage control signal; While the MCU intelligent control module adjusts the PFC voltage output by the first PFC power conversion circuit, the PFC control module controls the PFC voltage output by the first PFC power conversion circuit according to its input signal.

6. The intelligent multi-phase power factor correction control method according to claim 4, characterized in that: If the topology type is a non-isolated BUCK conversion topology, adjusting based on the second adjustment method includes: The MCU intelligent control module outputs a PFC voltage control signal based on the output sampling signal and the PFC sampling signal, and adjusts the PFC voltage output by the first PFC power conversion circuit through the PFC voltage control signal; While the MCU intelligent control module adjusts the PFC voltage output by the first PFC power conversion circuit, the PFC control module controls the PFC voltage output by the first PFC power conversion circuit to follow the non-isolated output according to its input signal.

7. The intelligent multi-phase power factor correction control method according to claim 1, characterized in that: The method further comprises: The MCU intelligent control module obtains an output sampling signal or a dimming signal; The MCU intelligent control module determines whether it is in a half-load or light-load condition according to the output sampling signal; If so, any one or multiple circuits from the second PFC power conversion circuit to the first NPFC power conversion circuit are controlled to be closed based on half load or light load.

8. An intelligent multi-phase power factor correction control circuit, applied to the intelligent multi-phase power factor correction control method according to any one of claims 1 to 7, characterized in that: include: A PFC control module, an MCU intelligent control module, a drive signal detection circuit, a first PFC power conversion circuit to an Nth PFC power conversion circuit, and an output power conversion module; The driving signal detection circuit is used to collect the driving signal output by the PFC control module and output a driving detection signal; The MCU intelligent control module is respectively connected to the drive signal detection circuit, the PFC control module, the second PFC power conversion circuit to the Nth PFC power conversion circuit and the output power conversion module, and is used to receive the drive detection signal and analyze the drive detection signal to obtain a multi-phase control signal; the MCU intelligent control module is also used to sequentially send the multi-phase control signal to the second PFC power conversion circuit to the Nth PFC power conversion circuit using a preset method; wherein N is an integer greater than or equal to 2; The PFC control module is used to control the PFC voltage output by the first PFC power conversion circuit according to the input signal of the MCU intelligent control module, or to control the PFC voltage output by the first PFC power conversion circuit to follow the non-isolated output according to the input signal of the MCU intelligent control module.

9. The intelligent multi-phase power factor correction control circuit according to claim 8, characterized in that: Also includes: Input sampling circuit, output sampling circuit, PFC sampling circuit; The input sampling circuit is used to sample the input signal and output the input sampling signal; The output sampling circuit is used to sample the output signal and output the output sampling signal; The PFC sampling circuit is used to sample the PFC voltage and output a PFC sampling signal.

10. An LED driving power supply, characterized in that: It comprises the intelligent multi-phase power factor correction control circuit as described in claim 8 or 9.

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