Resonance control system and method for high-power LED driving power supply

Abstract

The invention discloses a high-power LED driving power supply resonance control system and method, and the system comprises a control system, the control system comprises an LED driving power supply, a PFC controller, and an LLC resonant converter, the PFC controller and the LLC resonant converter are connected with the LED driving power supply, and the LED driving power supply is internally provided with an FSFR2100 integrated control chip; the PFC controller adjusts the frequency change value of the resonance part of the LED driving power supply, and Boost inductance demagnetization is detected before the switching period of the high-power LED driving power supply, the two modes of PFC and LLC half-bridge are combined, autonomous regulation and control of the resonance frequency of the high-power LED driving power supply and zero-voltage switching of a power supply switching tube are realized, the switching loss is reduced, and the switching efficiency is improved. The working performance of the LED driving power supply is improved, the overshoot phenomenon does not exist during startup and shutdown under the full-load condition, the working efficiency is over 89%, the power supply loss is low, the national switch performance index standard is completely met, and the energy-saving and environment-friendly effects are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of LED drive power supplies, and in particular to a high-power LED drive power supply resonance control system and method. Background Art

[0002] Lighting has become an indispensable part of human daily life. LED lighting has gradually replaced traditional incandescent lighting due to its advantages such as long service life, energy saving, environmental protection and fast response speed. It is not only used in people's daily life, but also in landscape lighting, automotive lighting, industrial production instrument indicator lights, and even military lighting. It has been widely used. LED lighting has replaced traditional incandescent lamps and become the main lighting tool in our life and production. In recent years, people have been dissatisfied with the response speed and switching loss of hard switches such as standard switches or double switches in previous LED lighting. The use of LLC resonant converter for LED switch control was born in this environment. The LLC resonant converter is based on traditional series and parallel resonant converters, combining the advantages of high efficiency of series resonant converters and low working conditions of parallel resonant converters, to achieve zero voltage and zero current switching control of LED drive power supply under full voltage and full load conditions.

[0003] However, the traditional LED drive power resonant control has the following disadvantages:

[0004] The traditional LED drive power supply resonant control method circuit control harmonic abnormality leads to output current overshoot, poor voltage stability control effect and high delay, which cannot meet people's usage needs. Summary of the invention

[0005] The purpose of the present invention is to provide a high-power LED drive power supply resonant control system and method to solve the problem that the traditional LED drive power supply resonant control method proposed in the above background technology has abnormal circuit control harmonics, resulting in output current overshoot, poor voltage stability control effect and high delay, which cannot meet people's usage needs.

[0006] To achieve the above object, the present invention provides the following technical solutions: a high-power LED driving power supply resonant control system, comprising a control system, the control system comprising an LED driving power supply, a PFC controller, and an LLC resonant converter, the PFC controller and the LLC resonant converter are both connected to the LED driving power supply, and the LED driving power supply is provided with a FSFR2100 integrated control chip;

[0007] The PFC controller adjusts the frequency change value of the resonant part of the LED driver power supply, detects the demagnetization of the Boost inductor before the switching cycle of the high-power LED driver power supply, and turns on the switch tube of the high-power LED driver power supply under zero current conditions. The LLC resonant converter is designed using the switching constant current source method to adjust the voltage gain to ensure that the switch tube achieves zero voltage switching. The FSFR2100 integrated control chip uses the feedback terminal RT through the high-voltage MOS-FET contained in the chip to adjust the output voltage of the resonant network by adjusting the switching frequency using a mirror current source.

[0008] As a preferred technical solution of the present invention, the LLC resonant converter includes a power supply U in , insulated gate field effect transistor Q2, insulated gate field effect transistor Q1, diode D s2 、Diode D s1 , capacitor C2, capacitor C1, capacitor C r 、Inductance L r 、Inductance L m , diode U2, diode U1, capacitors C0 and R0, the power supply U in The positive electrode is connected to one end of the insulated gate field effect transistor Q1, and the power supply U in The cathode of the insulated gate field effect transistor Q1 is connected to one end of the insulated gate field effect transistor Q2, the other end of the insulated gate field effect transistor Q1 is connected to the other end of the insulated gate field effect transistor Q2, and the outer side of the insulated gate field effect transistor Q1 is connected to the diode D s1 In parallel, the diode D s1 The outer side of the insulated gate field effect transistor Q2 is connected in parallel with the capacitor C1, and the outer side of the insulated gate field effect transistor Q2 is connected to the diode D s2 In parallel, the diode D s2 The outer side of the insulated gate field effect transistor Q1 is connected in parallel with the capacitor C2, and the connection point between the insulated gate field effect transistor Q1 and the insulated gate field effect transistor Q2 is connected to the capacitor C r One end of the capacitor C r The other end of the inductor L r One end of the inductor L is connected r The other end of the capacitor C2 and one end of the inductor L m The two ends of the inductor L m The outer sides of the diodes are connected in parallel with the diodes U1 and U2, respectively. The outer sides of the diodes U1 and R o In parallel, the diode U1 and R o The connection point and capacitor C o in parallel.

[0009] The present invention provides a method for using a high-power LED driving power supply resonance control system, comprising the following steps:

[0010] Step 1: Voltage input: The voltage is input into the LED driver power circuit and then into the filter and rectifier part;

[0011] Step 2, PFC control: Use the Boost topology method to calculate the critical, continuous mode LED driver power, inductance and capacitance parameters to calibrate the PFC circuit. The calibrated PFC circuit harmonizes the input current waveform to synchronize it with the input voltage waveform to achieve zero voltage switching;

[0012] Step 3: DC / DC conversion: DC / DC conversion based on LLC harmonic half-bridge;

[0013] Step 4: Output filtering: After DC / DC conversion, the output is filtered through feedback control.

[0014] As a preferred technical solution of the present invention, in the step 2, a control chip and a PFC controller magnetic core are provided in the PFC controller, the model of the control chip is L6562 chip, and the model of the PFC controller magnetic core is chip PC40E130.

[0015] As a preferred technical solution of the present invention, in the critical continuous mode in step 2, the inductance in the high-power LED driving power supply circuit is:

[0016]

[0017] Where: P omax is the maximum output power; power supply U in is the input voltage; U o is the total value of voltage input and output; f swmin is the circuit frequency; η is the efficiency, the calculated inductance value is L = 230μH, and the input filter capacitance calculation formula is:

[0018]

[0019] Where r is the input voltage ripple coefficient, which is 0.2. The output filter capacitor calculation formula is:

[0020]

[0021] Where: I o is the output current; U out is the output voltage.

[0022] As a preferred technical solution of the present invention, the DC / DC conversion in step 3 is specifically as follows: the square wave input voltage corresponding to the positive and negative half cycles is the power supply U in , the equivalent resistance R from the secondary side to the primary side e Indicated by, the input impedance of the LLC resonant converter is:

[0023]

[0024] Where P is power, P = 2πf, then the voltage gain of the LLC resonant converter is:

[0025]

[0026] Where: fm = f / f r ;λ is the resonant circuit,λ=L r / L m ; Insulated gate field effect transistor Q is the quality factor of the switch tube, The equivalent load impedance of the LLC resonant converter converted to the primary side is:

[0027]

[0028] In the formula, R o and n are the output resistance and transformer turns ratio respectively.

[0029] As a preferred technical solution of the present invention, the output filter in step 4 is specifically a resonant inductor L r and magnetizing inductance L m , resonant inductor L r The calculation formula is as follows:

[0030]

[0031] Magnetizing inductance L m The calculation formula is as follows:

[0032]

[0033] Compared with the prior art, the beneficial effects of the present invention are: a combination of PFC and LLC half-bridge is selected to realize autonomous regulation of the resonant frequency of a high-power LED driving power supply, zero voltage switching of the power switch tube, and reduced switching losses, thereby improving the working performance of the LED driving power supply. There is no overshoot phenomenon when starting and shutting down the power supply under full load, the working efficiency is above 89%, and the power loss is low, which fully meets the national switch performance index standards and has the effect of energy saving and environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of the architecture of the control system of the present invention;

[0035] Figure 2 is a circuit diagram of an LLC resonant converter of the present invention;

[0036] Figure 3 is a flow chart of the present invention;

[0037] Figure 4 is an equivalent circuit diagram of the LLC resonant converter of the present invention;

[0038] Figure 5 This is the output current waveform diagram of the present invention when it is turned on and fully loaded;

[0039] Figure 6 This is the output current waveform diagram of the present invention when the power is turned off and fully loaded;

[0040] Figure 7 The output voltage and output current waveform diagram of the present invention when the input voltage is 110V;

[0041] Figure 8 The output voltage and output current waveform diagram of the present invention when the input voltage is 220V;

[0042] Fig. 9 This is a diagram of power loss of high-power LED drivers under different control methods of the present invention. DETAILED DESCRIPTION

[0043] The following will be combined with 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 making creative work are within the scope of protection of the present invention.

[0044] See also Figure 1-9 The present invention provides a high-power LED driving power supply resonance control system, including a control system, the control system includes an LED driving power supply, a PFC controller, and an LLC resonant converter, the PFC controller and the LLC resonant converter are both connected to the LED driving power supply, and the LED driving power supply is provided with a FSFR2100 integrated control chip;

[0045] The PFC controller adjusts the frequency change value of the resonant part of the LED driver power supply, detects the demagnetization of the Boost inductor before the switching cycle of the high-power LED driver power supply, and turns on the switch tube of the high-power LED driver power supply under zero current conditions. The LLC resonant converter is designed using the switching constant current source method to adjust the voltage gain to ensure that the switch tube achieves zero voltage switching. The FSFR2100 integrated control chip uses the feedback terminal RT through the high-voltage MOS-FET contained in the chip to adjust the output voltage of the resonant network by adjusting the switching frequency using a mirror current source.

[0046] The LLC resonant converter includes a power supply U in , insulated gate field effect transistor Q2, insulated gate field effect transistor Q1, diode D s2 、Diode D s1, capacitor C2, capacitor C1, capacitor C r 、Inductance L r 、Inductance L m , diode U2, diode U1, capacitors C0 and R0, power supply U in The positive electrode is connected to one end of the insulated gate field effect transistor Q1, and the power supply U in The cathode of is connected to one end of the insulated gate field effect transistor Q2, the other end of the insulated gate field effect transistor Q1 is connected to the other end of the insulated gate field effect transistor Q2, and the outer side of the insulated gate field effect transistor Q1 is connected to the diode D s1 Parallel connection, diode D s1 The outer side of the insulated gate field effect transistor Q2 is connected in parallel with the capacitor C1, and the outer side of the insulated gate field effect transistor Q2 is connected with the diode D s2 Parallel connection, diode D s2 The outer side of the insulated gate field effect transistor Q1 is connected in parallel with the capacitor C2, and the connection point between the insulated gate field effect transistor Q1 and the insulated gate field effect transistor Q2 is connected to the capacitor C r One end of the capacitor C r The other end of the inductor L r One end of the inductor L r The other end of the capacitor C2 and one end of the inductor L m The two ends of the inductor L m The outer sides of the diodes are connected in parallel with diodes U1 and U2 respectively, and the outer sides of diode U1 are connected with R o In parallel, diode U1 and R o The connection point and capacitor C o in parallel.

[0047] The present invention provides a method for using a high-power LED driving power supply resonance control system, comprising the following steps:

[0048] Step 1: Voltage input: The voltage is input into the LED driver power circuit and then into the filter and rectifier part;

[0049] Step 2, PFC control: Use the Boost topology method to calculate the critical, continuous mode LED driver power, inductance and capacitance parameters to calibrate the PFC circuit. The calibrated PFC circuit harmonizes the input current waveform to synchronize it with the input voltage waveform to achieve zero voltage switching;

[0050] Step 3: DC / DC conversion: DC / DC conversion based on LLC harmonic half-bridge;

[0051] Step 4: Output filtering: After DC / DC conversion, the output is filtered through feedback control.

[0052] In step 2, a control chip and a PFC controller core are provided in the PFC controller. The model of the control chip is L6562 chip, and the model of the PFC controller core is chip PC40E130.

[0053] In the critical continuous mode in step 2, the inductance in the high-power LED driver power circuit is:

[0054]

[0055] Where: P omax is the maximum output power; power supply U in is the input voltage; U o is the total value of voltage input and output; f swmin is the circuit frequency; η is the efficiency, the calculated inductance value is L = 230μH, and the input filter capacitance calculation formula is:

[0056]

[0057] Where r is the input voltage ripple coefficient, which is 0.2. The output filter capacitor calculation formula is:

[0058]

[0059] Where: I o is the output current; U out is the output voltage.

[0060] The DC / DC conversion in step 3 is as follows: the square wave input voltage corresponding to the positive and negative half cycles is the power supply U in , the equivalent resistance R from the secondary side to the primary side e Indicated by, the input impedance of the LLC resonant converter is:

[0061]

[0062] Where P is power, P = 2πf, then the voltage gain of the LLC resonant converter is:

[0063]

[0064] Where: fm = f / f r ;λ is the resonant circuit,λ=L r / L m ; Insulated gate field effect transistor Q is the quality factor of the switch tube, The equivalent load impedance of the LLC resonant converter converted to the primary side is:

[0065]

[0066] In the formula, R oand n are the output resistance and transformer turns ratio respectively.

[0067] The output filter in step 4 is specifically the resonant inductor L r and magnetizing inductance L m , resonant inductor L r The calculation formula is as follows:

[0068]

[0069] Magnetizing inductance L m The calculation formula is as follows:

[0070]

[0071] In the present invention, in conjunction with the specification Figure 2 In the LLC resonant converter, when the secondary rectifier diode is connected, the transformer secondary voltage will m Clamp, L only r With C r There is resonance, and the resonant frequency in the circuit is f r ; When the secondary rectifier diode is not connected, the transformer stops working, L m , L r With C r There is resonance, combined with the instructions attached Figure 4 , the voltage gain is adjusted through the resonant network part in the LLC resonant converter to ensure that the switch tube achieves zero voltage switching;

[0072] In order to verify the control performance of the resonant control method of high-power LED driver power supply in critical continuous mode, a 48V / 1.2A bipolar driver power supply was selected for experiment. The clamp current probe HIOKI3275 was used for testing. The RIGOLDS5000E digital oscilloscope output the experimental results. The performance index parameters of the LED driver power supply used in the experiment are shown in Table 1. Table 1 LED driver power supply performance index

[0073] parameter Numeric Input voltage / V 85～265 Power frequency / Hz 50 Output current / A 1.2 Output voltage / V 46.6 Minimum switching frequency / kHz 71 Overall efficiency ＞88％ PF ＞0.97 Output voltage ripple / V ＜0.5

[0074] In conjunction with the instruction manual Figure 5-6 In the critical continuous mode, the current of the high-power LED driver power supply does not overshoot when the power is turned on and off, which meets the national power switch requirements. This shows that the control method has a good effect on controlling the high-power LED driver power supply in the critical continuous mode, avoiding the overshoot phenomenon when the high-power LED driver power supply is turned on and off;

[0075] In conjunction with the instruction manual Figure 7-8 , when the input voltage is 110V and 220V, the input voltage and output current waveforms are the same, which meets the control performance index requirements of high-power LED driver power supply in critical continuous mode;

[0076] In conjunction with the instruction manual Fig. 9 Under different input voltage conditions, the controlled high-power LED driver power loss is the lowest, both between 1-2W, while the LED driver power loss controlled by the CLL method and the voltage segmentation method is higher, especially the voltage segmentation method has a loss of up to 8.9W when the input voltage is 120V, which verifies the effect of reducing the switching loss of the high-power LED driver power supply in the critical continuous mode.

[0077] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A high-power LED drive power supply resonant control system, comprising a control system, characterized in that: The control system includes an LED driving power supply, a PFC controller, and an LLC resonant converter. The PFC controller and the LLC resonant converter are both connected to the LED driving power supply. The LED driving power supply is provided with an FSFR2100 integrated control chip. The PFC controller adjusts the frequency change value of the resonant part of the LED driver power supply, detects the demagnetization of the Boost inductor before the switching cycle of the high-power LED driver power supply, and turns on the switch tube of the high-power LED driver power supply under zero current conditions. The LLC resonant converter is designed using the switching constant current source method to adjust the voltage gain to ensure that the switch tube achieves zero voltage switching. The FSFR2100 integrated control chip uses the feedback terminal RT through the high-voltage MOS-FET contained in the chip to adjust the output voltage of the resonant network by adjusting the switching frequency using a mirror current source.

2. A high-power LED drive power supply resonance control system according to claim 1, characterized in that: The LLC resonant converter includes a power supply U in , insulated gate field effect transistor Q2, insulated gate field effect transistor Q1, diode D s2 、Diode D s1 , capacitor C2, capacitor C1, capacitor C r 、Inductance L r 、Inductance L m , diode U2, diode U1, capacitor C0 and resistor R0, the power supply U in The positive electrode is connected to one end of the insulated gate field effect transistor Q1, and the power supply U in The cathode of the insulated gate field effect transistor Q1 is connected to one end of the insulated gate field effect transistor Q2, the other end of the insulated gate field effect transistor Q1 is connected to the other end of the insulated gate field effect transistor Q2, and the outer side of the insulated gate field effect transistor Q1 is connected to the diode D s1 In parallel, the diode D s1 The outer side of the insulated gate field effect transistor Q2 is connected in parallel with the capacitor C1, and the outer side of the insulated gate field effect transistor Q2 is connected with the diode D s2 In parallel, the diode D s2 The outer side of the insulated gate field effect transistor Q1 is connected in parallel with the capacitor C2, and the connection point between the insulated gate field effect transistor Q1 and the insulated gate field effect transistor Q2 is connected to the capacitor C r One end of the capacitor C r The other end of the inductor L r One end of the inductor L is connected r The other end of the capacitor C2 and one end of the inductor L m The two ends of the inductor L m The outer sides of the diodes U1 and U2 are connected in parallel, and the outer side of the diode U1 is connected to the resistor R o In parallel, the diode U1 and the resistor R o The connection point and capacitor C o in parallel.

3. The method for using a high-power LED drive power supply resonance control system according to claim 1-2, characterized in that: The following steps are involved: Step 1: Voltage input: The voltage is input into the LED driver power circuit and then into the filter and rectifier part; Step 2, PFC control: Use the Boost topology method to calculate the critical, continuous mode LED driver power, inductance and capacitance parameters to calibrate the PFC circuit. The calibrated PFC circuit harmonizes the input current waveform to synchronize it with the input voltage waveform to achieve zero voltage switching; Step 3: DC / DC conversion: DC / DC conversion based on LLC harmonic half-bridge; Step 4: Output filtering: After DC / DC conversion, the output is filtered through feedback control.

4. The method for using a high-power LED driving power supply resonance control system according to claim 3, characterized in that: In the step 2, a control chip and a PFC controller magnetic core are provided in the PFC controller, the control chip is a L6562 chip, and the PFC controller magnetic core is a PC40E130 chip.

5. The method for using a high-power LED driving power supply resonance control system according to claim 3, characterized in that: In the critical continuous mode in step 2, the inductance in the high-power LED driving power supply circuit is: Where: P omax is the maximum output power; power supply U in is the input voltage; U o is the total value of voltage input and output; f swmin is the circuit frequency; η is the efficiency, the calculated inductance value is L = 230μH, and the input filter capacitance calculation formula is: Where r is the input voltage ripple coefficient, which is 0.

2. The output filter capacitor calculation formula is: Where: I o is the output current; U out is the output voltage.

6. The method for using a high-power LED driving power supply resonance control system according to claim 3, characterized in that: The DC / DC conversion in step 3 is specifically as follows: the square wave input voltage corresponding to the positive and negative half cycles is the power supply U in , the equivalent resistance R from the secondary side to the primary side e Indicated by, the input impedance of the LLC resonant converter is: Where P is power, P = 2πf, then the voltage gain of the LLC resonant converter is: Where: fm = f / f r ;λ is the resonant circuit,λ=L r / L m ; Insulated gate field effect transistor Q is the quality factor of the switch tube, The equivalent load impedance of the LLC resonant converter converted to the primary side is: In the formula, R o and n are the output resistance and transformer turns ratio respectively.

7. The method for using a high-power LED driving power supply resonance control system according to claim 3, characterized in that: The output filter in step 4 is specifically a resonant inductor L r and magnetizing inductance L m , resonant inductor L r The calculation formula is as follows: Magnetizing inductance L m The calculation formula is as follows:

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