CN214901370U

CN214901370U - Wide-voltage non-isolated AC-DC constant current driver and LED lighting equipment

Info

Publication number: CN214901370U
Application number: CN202120239700.1U
Authority: CN
Inventors: 胡炎申
Original assignee: Moso Power Supply Technology Co ltd
Current assignee: Moso Power Supply Technology Co ltd
Priority date: 2021-01-27
Filing date: 2021-01-27
Publication date: 2021-11-26
Anticipated expiration: 2031-01-27

Abstract

The application discloses a wide-voltage non-isolated AC-DC constant current driver and LED lighting equipment, wherein the wide-voltage non-isolated AC-DC constant current driver comprises a non-isolated PFC main converter, a PFC controller, a DC-DC auxiliary converter and a DC-DC controller; the non-isolated PFC main converter comprises a main conversion module and a main output port, wherein the main conversion module comprises a main output module and an auxiliary output module; the DC-DC auxiliary converter comprises an auxiliary input port and an auxiliary output port; the PFC controller comprises a main feedback port; the DC-DC controller comprises an auxiliary feedback port; the main output port and the auxiliary output port are connected in series to form a total output port. The auxiliary voltage of the auxiliary output module is controlled to be a fixed value in a closed-loop mode, the total current of the total output port is controlled to be a fixed value in a closed-loop mode, and the PFC controller can adjust the main voltage to enable the total voltage range to be wider when the total current is kept constant.

Description

Wide-voltage non-isolated AC-DC constant current driver and LED lighting equipment

Technical Field

The present disclosure relates to the field of circuit technologies, and in particular, to a wide voltage non-isolated AC-DC (alternating current-direct current) constant current driver and a Light Emitting Diode (LED) lighting device.

Background

The LED is applied to lighting devices, and has the advantages of wide color gamut, high brightness, large viewing angle, low power consumption, long service life, and the like, so that the LED lighting devices are widely applied to various lighting display fields. Such as the common stock exchange and financial information display, airport flight dynamic information display, port and station passenger guidance information display, stadium information display, road traffic information display, electric power scheduling, vehicle dynamic tracking and other scheduling command center information display, market shopping center and other service fields business propaganda information display, advertising media products and the like.

Generally, the LED lighting device needs a driving power supply for driving when working normally, and the driving power supply is generally a constant current driver. The current constant current driver comprises a single stage and a plurality of stages. Although the single-stage constant current driver has a simple structure and low cost, the output voltage of the single-stage constant current driver is narrow. Therefore, a multi-stage constant current driver is generally selected in the industry, wherein two stages are common, and although the output voltage of the two-stage constant current driver is wider, the number of components of the two-stage constant current driver is too large, the heating phenomenon is more serious, the cost is too high, and the resource saving is not facilitated.

SUMMERY OF THE UTILITY MODEL

The application aims to provide a wide-voltage non-isolated AC-DC constant current driver and an LED lighting device, which have a wider output voltage range, fewer components, lower cost and benefit for saving resources, and the heating phenomenon is relieved.

The application provides in a first aspect a wide voltage non-isolated AC-DC constant current driver, including: the system comprises a non-isolated PFC main converter, a PFC controller, a DC-DC auxiliary converter and a DC-DC controller; the non-isolated PFC main converter comprises a main conversion module and a main output port, wherein the main conversion module comprises a main output module and an auxiliary output module; the DC-DC auxiliary converter comprises an auxiliary input port and an auxiliary output port; the PFC controller comprises a main feedback port and a main control port; the DC-DC controller comprises an auxiliary feedback port and an auxiliary control port; the main output port and the auxiliary output port are connected in series to form a total output port; the main output module is connected with the main output port, the auxiliary output module is connected with the auxiliary input port, the main feedback port is connected with the auxiliary output port, and the auxiliary feedback port is connected with the main output port; the main control port is connected with the non-isolated PFC main converter, and the auxiliary control port is connected with the DC-DC auxiliary converter; the main voltage output by the main output module is transmitted to the main output port and the total output port; the auxiliary voltage output by the auxiliary output module is transmitted to the auxiliary input port and the main output port; after receiving the auxiliary voltage from the auxiliary input port, the DC-DC controller transmits the auxiliary voltage to the main feedback port through the auxiliary output port after processing the auxiliary voltage; after receiving the auxiliary voltage from the main feedback port, the PFC controller controls a non-isolated PFC main converter by using the auxiliary voltage; the main output port outputs a main current after receiving the main voltage and the auxiliary voltage; the total current is transmitted to the auxiliary feedback port; and after receiving the total current from the auxiliary feedback port, the DC-DC controller controls the DC-DC auxiliary converter by using the total current.

In one embodiment, the primary conversion module includes: the voltage converter comprises a main winding and an auxiliary winding; the PFC power conversion unit and the main winding form a main output module, and the PFC power conversion unit and the auxiliary winding form an auxiliary output module; the output end of the PFC power conversion unit is connected with one end of the main winding; the other end of the main winding is connected with the main output port; the auxiliary winding is connected with the auxiliary input port; after receiving the alternating current, the PFC power conversion unit converts the alternating current so that the main output port outputs main voltage and the auxiliary output port outputs auxiliary voltage.

In one embodiment, the non-isolated PFC main converter further comprises: a main power switch tube; the main power switch tube is connected between the output end of the PFC power conversion unit and one end of the main winding; or the main power switch tube is connected with the other end of the main winding; the PFC controller also comprises a first main acquisition port, a main reference voltage port and a main reference sawtooth wave signal port; the first main acquisition port is connected with the auxiliary winding, and the main control port is connected with the control end of the main power switch tube; the PFC controller also receives a voltage from the auxiliary winding of the first main acquisition port, a main reference voltage from the main reference voltage port, and a main reference sawtooth signal from the main reference sawtooth signal port; the non-isolated PFC main converter controlled by using the auxiliary voltage comprises: comparing the auxiliary voltage with the main reference voltage to form a voltage error signal; comparing the voltage error signal with the main reference sawtooth wave signal to form a stop pulse signal; forming a start pulse signal based on the voltage of the auxiliary winding; and controlling the on and off of the main power switch tube by using the stop pulse signal and the start pulse signal.

In one embodiment, the PFC controller further comprises a second primary acquisition port; the second main acquisition port is connected with the main power switch tube; the PFC controller also receives the voltage of a main power switch tube from the second main acquisition port; comparing the voltage error signal with the main reference sawtooth wave signal to form a stop pulse signal includes: and comparing the voltage error signal with the voltage of the main power switch tube to form a comparison result, and comparing the main reference sawtooth wave signal with the comparison result to form a stop pulse signal.

In one embodiment, a PFC controller includes a main reference voltage source, a main reference sawtooth signal source, a first main comparator, a second main comparator, a third main comparator, and a flip-flop; the trigger is provided with an S port, a Q port and an R port; the negative input end of the first main comparator is connected with the main feedback port, the positive input end of the first main comparator is connected with a main reference voltage source through a main reference voltage port, and the output end of the first main comparator is connected with the positive input end of the second main comparator; the negative input end of the second main comparator is connected with the second main acquisition port, and the output end of the second main comparator is connected with the positive input end of the third main comparator; the negative input end of the third main comparator is connected with the main reference sawtooth wave signal source through a main reference sawtooth wave signal port, and the output end of the third main comparator is connected with the R port; the Q port is connected with the main control port, and the S port is connected with the first main acquisition port; the first master comparator is to: comparing the auxiliary voltage with the main reference voltage to form a voltage error signal; the second master comparator is to: comparing the voltage error signal with the voltage of the main power switch tube to form a comparison result; the third master comparator is to: comparing the main reference sawtooth wave signal with the comparison result to form a stop pulse signal; the trigger is used for: forming a start pulse signal based on the voltage of the auxiliary winding; and controlling the on and off of the main power switch tube by using the stop pulse signal and the start pulse signal.

In one embodiment, the DC-DC auxiliary converter further comprises: an auxiliary power switch tube; the DC-DC controller also comprises an auxiliary reference current port and an auxiliary reference sawtooth wave signal port; the auxiliary control port is connected with the control end of the auxiliary power switch tube; the DC-DC controller also receives an auxiliary reference current from an auxiliary reference current port and an auxiliary reference sawtooth wave signal from an auxiliary reference sawtooth wave signal port; controlling the DC-DC auxiliary converter with the total current includes: comparing the total current with the auxiliary reference current to form a voltage error signal; and comparing the voltage error signal with the auxiliary reference sawtooth wave signal to form a control signal, and transmitting the control signal to the control end of the auxiliary power switch tube.

In one embodiment, a DC-DC controller includes: the auxiliary reference current source comprises a first auxiliary comparator, a second auxiliary comparator, an auxiliary reference current source and an auxiliary reference sawtooth wave signal source; the negative input end of the first auxiliary comparator is connected with the auxiliary feedback port, the positive input end of the first auxiliary comparator is connected with the auxiliary reference current source through the auxiliary reference current port, and the output end of the first auxiliary comparator is connected with the positive input end of the second auxiliary comparator; the negative input end of the second auxiliary comparator is connected with an auxiliary reference sawtooth wave signal source through an auxiliary reference sawtooth wave signal port, and the output end of the second auxiliary comparator is connected with an auxiliary control port; the first auxiliary comparator is for: comparing the total current with the auxiliary reference current to form a voltage error signal; the second auxiliary comparator is for: and comparing the voltage error signal with the auxiliary reference sawtooth wave signal to form a control signal, and outputting the control signal to a control end of the auxiliary power switch tube.

In one embodiment, the non-isolated PFC main converter comprises one of a buck converter, a boost converter, a buck-boost converter, a single-ended primary inductive converter, and a zero-voltage switching converter.

In one embodiment, the DC-DC auxiliary converter includes one of a buck converter, a boost converter, a buck-boost converter, a flyback converter, a forward converter, a buck-boost converter, a buck converter.

A second aspect of the application provides an LED lighting device comprising the wide voltage non-isolated AC-DC constant current driver of any one of the first aspects of the application.

According to the wide-voltage non-isolated AC-DC constant-current driver, the auxiliary voltage output by the auxiliary output module is fed back to the PFC controller, and the PFC controller controls the non-isolated PFC main converter based on the fed-back auxiliary voltage, so that closed-loop control of the auxiliary voltage is achieved. Wherein the total current of the port of the total output is fed back to the DC-DC controller, which controls the DC-DC converter based on the fed back total current, thereby achieving a closed loop control of the total current. In summary, the auxiliary voltage is controlled to be a fixed value through the PFC controller in a closed-loop manner, and the total current is also controlled to be a fixed value through the DC-DC controller in a constant-current manner, so that the PFC controller can indirectly adjust the magnitude of the main voltage under the condition of maintaining the total current to be constant, thereby widening the range of the total voltage. And because the main voltage is single-stage conversion, only the auxiliary voltage needs to be subjected to double-stage conversion, so that the number of required components is reduced, the heating degree is reduced, the cost is reduced, and the resources are saved.

Drawings

In order to more clearly illustrate the technical solution of the present application, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative efforts.

Fig. 1 is a schematic diagram of a wide voltage non-isolated AC-DC constant current driver provided in one embodiment of the present application;

fig. 2 is a schematic diagram of a wide voltage non-isolated AC-DC constant current driver provided in another embodiment of the present application;

fig. 3 is a schematic diagram of a wide voltage non-isolated AC-DC constant current driver provided in another embodiment of the present application;

fig. 4 is a schematic diagram of a wide voltage non-isolated AC-DC constant current driver provided in another embodiment of the present application;

fig. 5 is a schematic diagram of a non-isolated PFC main converter provided in an alternative embodiment of the present application;

fig. 6 is a schematic diagram of a non-isolated PFC main converter provided in an alternative embodiment of the present application;

FIG. 7 is a schematic diagram of a DC-DC auxiliary converter provided in an alternative embodiment of the present application;

FIG. 8 is a schematic diagram of a DC-DC auxiliary converter provided in an alternative embodiment of the present application;

FIG. 9 is a schematic diagram of a DC-DC auxiliary converter provided in an alternative embodiment of the present application;

fig. 10 is a schematic diagram of a DC-DC auxiliary converter provided in an alternative embodiment of the present application.

Description of reference numerals:

the main PFC converter comprises a non-isolated PFC main converter 10, a main conversion module 110, a main output module 111, an auxiliary output module 112, a PFC power conversion unit 11, a voltage converter 12, a main winding 121, an auxiliary winding 122, a DC-DC auxiliary converter 20, a PFC controller 30, a DC-DC controller 40, an alternating current power supply 50, a load 60,

main input ports

1 and 2,

main output ports

3 and 4,

auxiliary input ports

5 and 6 and

auxiliary output ports

7 and 8.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application.

Referring to fig. 1 to 10, a wide-voltage non-isolated AC-DC constant current driver according to an embodiment of the present disclosure includes a non-isolated PFC main converter 10, a PFC controller 30, a direct current to direct current (DC-DC) auxiliary converter 20, and a DC-DC controller 40.

The non-isolated PFC main converter 10 includes a main conversion module 110 and a main output port, and the main conversion module 110 includes a main output module 111 and an auxiliary output module 112; the DC-DC auxiliary converter 20 includes an auxiliary input port and an auxiliary output port; PFC controller 30 includes a primary feedback port a1 and a primary control port a 3; the DC-DC controller 40 includes an auxiliary feedback port b1 and an auxiliary control port b 2; the main output port and the auxiliary output port are connected in series to form a total output port.

Specifically, the main output module 111 is connected to the main output port, the auxiliary output module 112 is connected to the auxiliary input port, the main feedback port a1 is connected to the auxiliary output port, and the auxiliary feedback port b1 is connected to the total output port. The main control port a3 is connected to the non-isolated PFC main converter 10 and the auxiliary control port b2 is connected to the DC-DC auxiliary converter 20.

The main voltage Vo1 output by the main output module 111 is transmitted to the main output port and the main output port; the auxiliary voltage Vo2 output by the auxiliary output module 112 is transmitted to the auxiliary input port and the main output port; after receiving the auxiliary voltage Vo2 from the auxiliary input port, the DC-DC controller 40 processes the auxiliary voltage Vo2 and transmits the processed auxiliary voltage Vo to the main feedback port a1 through the auxiliary output port; the PFC controller 30 receives the auxiliary voltage Vo2 from the main feedback port a1, and then controls the non-isolated PFC main converter 10 using the auxiliary voltage Vo 2.

The total output port outputs total current Ios after receiving the main voltage Vo1 and the auxiliary voltage Vo 2; the total current Ios is transmitted to the secondary feedback port b 1; the DC-DC controller 40 receives the total current io from the auxiliary feedback port b1, and then controls the DC-DC auxiliary converter 20 by using the total current io.

In the wide-voltage non-isolated AC-DC constant current driver, the auxiliary voltage Vo2 output by the auxiliary output module 112 is fed back to the PFC controller 30, and the PFC controller 30 controls the non-isolated PFC main converter 10 based on the fed-back auxiliary voltage Vo2, thereby realizing closed-loop control of the auxiliary voltage Vo 2. Wherein the total current io of the total output port is fed back to the DC-DC controller 40, and the DC-DC controller 40 controls the DC-DC converter based on the fed-back total current io, thereby realizing closed-loop control of the total current io.

In summary, the auxiliary voltage Vo2 is closed-loop controlled to be a constant value by the PFC controller 30, and the total current io is constant-current controlled to be a constant value by the DC-DC controller 40, so that the PFC controller 30 can indirectly adjust the magnitude of the main voltage Vo1 under the condition of maintaining the total current io constant, thereby widening the range of the total voltage. And because the main voltage Vo1 is single-stage conversion, only the auxiliary voltage Vo2 needs to be subjected to double-stage conversion, the number of required components is reduced, the heating degree is reduced, the cost is reduced, and the resources are saved.

In addition, the PFC power conversion unit 11 only performs a single-stage conversion on part of the output power to the load 60. The DC-DC auxiliary converter 20 provides part of the power to the load 60, and although the power provided by the DC-DC auxiliary converter 20 is converted by two stages, only part of the power is converted by two stages as a whole, so that the power consumption can be reduced by performing two conversions on part of the power compared with a method in which all the output power is converted by two.

It will be appreciated by those skilled in the art that the non-isolated PFC main converter 10 also has a main input port. When the wide-voltage non-isolated AC-DC constant current driver provided by the above embodiment is applied, the main input port is connected to the AC power supply 50, and the total output port formed by connecting the main output port and the auxiliary output port in series is connected to the load 60. Of course, the load 60 may be any device that needs to be powered, and in the embodiment of the present application, a string of LEDs is used as the load 60 for illustration. The main output port provides the main voltage Vo1 to the load 60 and the auxiliary output port provides the auxiliary voltage Vo2 to the load 60, so that the total voltage of the load 60 is the sum of the main voltage Vo1 and the auxiliary voltage Vo 2. The main output port forms a direct current bus.

Referring to fig. 2, in one embodiment, the main conversion module 110 includes a PFC power conversion unit 11 and a voltage converter 12, and the voltage converter 12 includes a main winding 121 and an auxiliary winding 122; the PFC power conversion unit 11 and the main winding 121 form a main output module 111, and the PFC power conversion unit 11 and the auxiliary winding 122 form an auxiliary output module 112. Wherein, the output end of the PFC power conversion unit 11 is connected with one end of the main winding 121; the other end of the main winding 121 is connected with the main output port; the auxiliary winding 122 is connected to the auxiliary input port.

The voltage converter 12 may be a transformer or inductor L1 of the dual winding type having a primary winding 121 and a secondary winding 122.

The resistance of the main winding 121 is smaller than that of the auxiliary winding 122, so that under the condition of the same current, the voltage of the main winding 121 is larger than that of the auxiliary winding 122, that is, the main output voltage is larger than the auxiliary output voltage, and the output power of the main output port is larger than that of the auxiliary output port. Therefore, the conversion efficiency can be improved better.

Specifically, after the alternating current power supply 50 and the LED light string are connected, wherein the current provided by the alternating current power supply 50 passes through the PFC power conversion unit 11 and the main winding 121, and is directly output to the LED light string from the main output port in the form of the main voltage Vo 1; the current provided by the ac power source 50 is converted into a voltage by the PFC power conversion unit 11 and the auxiliary winding 122, and then output to the DC-DC auxiliary converter 20 in the form of an auxiliary voltage Vo2 from the auxiliary output port, and the DC-DC auxiliary converter 20 adjusts the voltage and then outputs the voltage to the LED string.

It can be seen that the PFC power conversion unit 11 provides most of the output power to the LED string and is only a single stage power conversion. The DC-DC auxiliary converter 20 provides a small portion of the output power to the string, and although the power provided by the DC-DC auxiliary converter 20 is converted in two stages, it only processes a small portion of the output power, i.e., only a small portion of the output power is converted in two stages.

Specifically, assume that the conversion efficiency of the non-isolated PFC main converter 10 is η_PFCConversion efficiency of the DC-DC auxiliary converter 20 is eta_DC-DC，P_PFC、P_DC-DC、P_outThe output power of the non-isolated PFC main converter 10, the output power of the DC-DC auxiliary converter 20, and the overall output power, respectively, the overall efficiency is:

let P_DC-DC＝10％xP_outAnd then:

is additionally provided with eta _DC-DC90%, the overall conversion efficiency η_total＝98.9％xη_PFC。

From the above, if the output power of the DC-DC auxiliary converter 20 is 10%Even if the conversion efficiency of the DC-DC auxiliary converter 20 is as low as 90%, the overall efficiency η_totalClose to 99%, very close to the conversion efficiency of a pure single stage converter directly provided to the LED string. Therefore, the wide-voltage non-isolated AC-DC constant-current driver provided by the embodiment of the application has lower power loss and can improve the overall efficiency.

In the embodiment of the application, most of the electric energy provided by the ac power supply 50 is transmitted to the LED light string through single conversion, and a small part of the electric energy is transmitted to the LED light string through primary and secondary conversion. Therefore, the power consumption is reduced, and the overall conversion efficiency is improved. In addition, because the DC-DC auxiliary converter 20 only converts a small part of electric energy, the voltage and current stress of the internal devices is also small, and the cost of the components can be reduced.

In one embodiment, referring to fig. 3 and 4, the non-isolated PFC main converter 10 further includes a main power switch Q1; the main power switching tube Q1 is connected between the output end of the PFC power conversion unit 11 and one end of the main winding 121; alternatively, the main power switch Q1 is connected to the other end of the main winding 121.

The PFC controller 30 includes a first main acquisition port a2, a main reference voltage port a4, and a main reference sawtooth signal port a 5; the first main acquisition port a2 is connected to the auxiliary winding 122, and the main control port a3 is connected to the control terminal of the main power switch Q1.

The PFC controller 30 also receives the voltage from the secondary winding 122 of the first primary acquisition port a2, a primary reference voltage from the primary reference voltage port a4, and a primary reference sawtooth signal from the primary reference sawtooth signal port a 5.

The control of the non-isolated PFC main converter 10 with the auxiliary voltage Vo2 may specifically be; the non-isolated PFC main converter 10 is controlled by the auxiliary voltage Vo2, the voltage of the auxiliary winding 122, the main reference voltage and the main reference sawtooth signal. The detailed process is as follows:

comparing the auxiliary voltage Vo2 with the main reference voltage to form a voltage error signal; comparing the voltage error signal with the main reference sawtooth wave signal to form a stop pulse signal; forming a start pulse signal based on the voltage of the auxiliary winding 122; the stop pulse signal and the start pulse signal are used to control the on and off of the main power switch tube Q1.

The stop pulse signal and the start pulse signal may form a Pulse Width Modulation (PWM) signal, which is used to control the main power switch Q1.

That is, the auxiliary voltage Vo2 of the auxiliary output port is fed back to the PFC controller 30 through the main feedback port a1, the main reference voltage is supplied to the PFC controller 30 through the main reference voltage port a4, and the PFC controller 30 compares the auxiliary voltage Vo2 with the main reference voltage and then forms a voltage error signal. Then, the PFC controller 30 compares the voltage error signal with the main reference sawtooth signal to generate a stop pulse signal; the PFC controller 30 may then control the turn off of the main power switch Q1 using the stop pulse signal.

The voltage of the auxiliary winding 122 is fed back to the PFC controller 30 through the first main collecting port a2, and the PFC controller 30 generates a start pulse signal by using the voltage of the auxiliary winding 122; the PFC controller 30 then uses the start pulse signal to control the turn-on of the main power switch Q1. The stop pulse signal and the start pulse signal form a Pulse Width Modulation (PWM) control signal, and the on/off of the main power switching tube Q1 can be controlled by the PWM control signal.

The control mode can control the auxiliary voltage Vo2 in a closed loop mode, and can also realize that the input current and the output voltage are sine waves with the same frequency and phase so as to achieve power factor correction and better power factor and realize zero pollution to a power grid.

In one embodiment, the PFC controller 30 further includes a second primary acquisition port a 6; the second primary collection port a6 is connected to the primary power switch Q1. The PFC controller 30 also receives the voltage from the main power switch Q1 of the second main acquisition port a 6. Comparing the voltage error signal with the main reference sawtooth wave signal to form a stop pulse signal includes: and comparing the voltage error signal with the voltage of the main power switch tube Q1 to form a comparison result, and comparing the main reference sawtooth wave signal with the comparison result to form a stop pulse signal.

That is, the PFC controller 30 compares the voltage error signal with the voltage of the main power switch Q1 before comparing the main reference sawtooth signal with the voltage error signal, and then compares the comparison result with the main reference sawtooth signal. The peak current of the main power switch Q1 can thus be controlled.

In an alternative embodiment, referring to fig. 4, the non-isolated PFC main converter 10 further includes a first main collecting element and a second main collecting element; the first primary pick-up is connected between the second primary pick-up port a6 and the main power switch Q1, and the second primary pick-up is connected between the first primary pick-up port a2 and the auxiliary winding 122. The second main collecting port a6 collects the voltage of the main power switch tube Q1 through the first main collecting piece, and the first main collecting port a2 collects the voltage of the auxiliary winding 122 through the second main collecting piece. Optionally, the first main collecting element and the second main collecting element may be a resistor Ri and a resistor Rdem, respectively.

The first main collecting part and the second main collecting part are arranged, so that the PFC can control and accurately collect required signals, and the precision of the PFC in controlling the main power switch tube Q1 is improved.

In one embodiment, the PFC controller 30 includes a main reference voltage source, a main reference sawtooth signal source, a first main comparator U1, a second main comparator U2, a third main comparator U3, and a flip-flop U4; flip-flop U4 has an S port, a Q port, and an R port.

Specifically, the negative input terminal of the first main comparator U1 is connected to the main feedback port a1, the positive input terminal of the first main comparator U1 is connected to a main reference voltage source through the main reference voltage port a4, and the output terminal of the first main comparator U1 is connected to the positive input terminal of the second main comparator U2; the negative input end of the second main comparator U2 is connected with the second main acquisition port a6, and the output end of the second main comparator U2 is connected with the positive input end of the third main comparator U3; the negative input end of the third main comparator U3 is connected with a main reference sawtooth wave signal source through a main reference sawtooth wave signal port a5, and the output end of the third main comparator U3 is connected with an R port; the Q port is connected to the primary control port a3 and the S port is connected to the first primary acquisition port a 2.

The first master comparator U1 is configured to: comparing the auxiliary voltage Vo2 with the main reference voltage to form a voltage error signal; the second master comparator U2 is configured to: comparing the voltage error signal with the voltage of the main power switch tube Q1 to form a comparison result; the third master comparator U3 is configured to: comparing the main reference sawtooth wave signal with the comparison result to form a stop pulse signal; the flip-flop U4 is used to: forming a start pulse signal based on the voltage of the auxiliary winding 122; the stop pulse signal and the start pulse signal are used to control the on and off of the main power switch tube Q1.

In detail, the first comparator receives the auxiliary voltage Vo2 from the main feedback port a1 and the main reference voltage from the main reference voltage port a4, compares the auxiliary voltage Vo2 with the main reference voltage, and then outputs a voltage error signal to the second comparator. The second comparator receives the voltage error signal and the voltage of the main power switch tube Q1, controls the peak current of the main power switch tube Q1, compares the voltage error signal with the voltage of the main power switch tube Q1, and outputs the comparison result to the third comparator. After receiving the comparison result and the main reference sawtooth wave signal, the third comparator compares the comparison result with the main reference sawtooth wave signal and outputs a signal to the R end of the contactor; the contactor generates a stop pulse signal according to the one signal, and the stop pulse signal is output to the control end of the main power switch tube Q1 through the Q end of the contactor so as to control the turn-off of the main power switch tube Q1. After receiving the voltage of the auxiliary winding 122 through the S terminal, the contactor generates a start pulse signal by using the voltage of the auxiliary winding 122; then, the start pulse signal is output to the control terminal of the main power switch Q1 through the Q terminal to control the main power switch Q1 to be turned on.

By using the PFC controller 30 with the above structure, the non-isolated PFC main converter 10 can be precisely controlled, and the PFC controller is simple to manufacture, low in cost and high in control precision.

In one embodiment, the DC-DC auxiliary converter 20 further includes an auxiliary power switch Q2; the DC-DC controller 40 further includes a secondary reference current port b3 and a secondary reference sawtooth signal port b 4; the auxiliary control port b2 is connected to the control terminal of the auxiliary power switch Q2. The DC-DC controller 40 also receives a secondary reference current from a secondary reference current port b3 and a secondary reference sawtooth signal from a secondary reference sawtooth signal port b 4.

Controlling the DC-DC auxiliary converter 20 with the total current Ios includes: comparing the total current Ios with the auxiliary reference current to form a voltage error signal; and comparing the voltage error signal with the auxiliary reference sawtooth wave signal to form a control signal, and transmitting the control signal to the control end of the auxiliary power switch tube Q2.

On one hand, the control strategy can realize closed-loop control of the current of the LED lamp string. In addition, the control strategy of the PFC controller 30 and the control strategy of the DC-DC controller 40 are combined, so that the reverse superposition of ripples of the main voltage Vo1 of the main output port and the auxiliary voltage Vo2 of the auxiliary output port can be realized to cancel each other, the ripple of the total output voltage Vo is reduced, and the ripple of the current of the LED string is reduced.

In detail, the main voltage Vo1 and the auxiliary voltage Vo2 have the purpose of reverse superposition of ripples to reduce or cancel power frequency ripples. The main voltage Vo1 of the main output port has a power frequency ripple, but is connected in series with the auxiliary voltage Vo2 of the auxiliary output port, and the reference signal in the current feedback loop of the DC-DC controller 40 of the DC-DC auxiliary converter 20 is an auxiliary reference current Iref, which is a direct current reference signal.

In addition, the switching frequency of the DC-DC auxiliary converter 20 is much higher than that of the non-isolated PFC main converter 10, so the dynamic response speed of the DC-DC auxiliary converter 20 is very fast, and theoretically, the total current io of the total output port formed by connecting the auxiliary output port and the main output port in series can be equal to Iref in real time, so the total current io is also infinitely close to a direct current value. Meanwhile, the main output port and the auxiliary output port are in series connection, so that the total current of the total output port formed by the series connection of the auxiliary output port and the main output port is equal to the current of the auxiliary output port, and the current of the auxiliary output port is a direct current value, so that the total current is also a direct current value, which is equivalent to the cancellation of power frequency ripples output by the main output port.

As can be seen from the above, the DC-DC auxiliary converter 20 is controlled in the fast loop, and the non-isolated PFC main converter 10 is controlled in the slow loop. In the application, in order to eliminate the power frequency ripple of the main output port, the main output port and the auxiliary output port are connected in series, so that the current of the main output port, the current of the auxiliary output port and the total current are equal.

The DC-DC controller 40 controls only the output current Ios, and the main voltage Vo1 or the total voltage Vo is controlled by the PFC controller 30. The reason for this is that if the amplitude of the total voltage output is smaller than the amplitude of the voltage for maintaining the normal operation of the load LED, the output DC current required by the load cannot be maintained by controlling the DC-DC controller 40 alone, so that on the one hand, the output voltage required by the load is high enough; on the other hand, when the total output voltage amplitude meets the load requirement, the DC-DC controller 40 maintains an output DC current required by the load, and the fast feedback loop of the DC-DC controller 40 makes the output current infinitely approach the DC value without the power frequency ripple. Therefore, the requirements of load working voltage and current can be met, and power frequency ripples can be eliminated.

In one embodiment, referring to fig. 4, the DC-DC auxiliary converter 20 further includes an auxiliary collecting element, and the auxiliary output port collects the current of the total output port through the auxiliary collecting element. Optionally, the auxiliary collecting element may be a resistor R3. The secondary pick-up may provide the current of the LED string to the secondary feedback port b 1.

In one embodiment, the DC-DC controller 40 includes: the circuit comprises a first auxiliary comparator U5, a second auxiliary comparator U6, an auxiliary reference current source and an auxiliary reference sawtooth wave signal source.

Specifically, the negative input end of the first auxiliary comparator U5 is connected to the auxiliary feedback port b1, the positive input end of the first auxiliary comparator U5 is connected to the auxiliary reference current source through the auxiliary reference current port b3, and the output end of the first auxiliary comparator U5 is connected to the positive input end of the second auxiliary comparator U6; the negative input end of the second auxiliary comparator U6 is connected with an auxiliary reference sawtooth wave signal source through an auxiliary reference sawtooth wave signal port b4, and the output end of the second auxiliary comparator U6 is connected with an auxiliary control port b 2.

The first auxiliary comparator U5 is configured to: and comparing the total current Ios with the auxiliary reference current to form a voltage error signal. The second auxiliary comparator U6 is used to: and comparing the voltage error signal with the auxiliary reference sawtooth wave signal to form a control signal, and outputting the control signal to a control end of the auxiliary power switch tube.

Specifically, the first auxiliary comparator U5 receives the auxiliary reference current from the auxiliary reference current port b3, and receives the total current Ios from the auxiliary feedback port b1, and then compares the total current Ios with the auxiliary reference current to form a voltage error signal, and outputs the voltage error signal to the second auxiliary comparator U6; after receiving the voltage error signal and the auxiliary reference sawtooth wave signal, the second auxiliary comparator U6 compares the voltage error signal with the auxiliary reference sawtooth wave signal to generate a control signal of the auxiliary power switch Q2, and then outputs the control signal to the control terminal of the auxiliary power switch Q2 to control the on and off of the auxiliary power switch Q2. The DC-DC controller 40 with the structure has the advantages of simple structure, higher control precision and lower cost. It will be appreciated that the control signal is a PWM control signal.

In an alternative embodiment, the non-isolated PFC main converter 10 comprises one of a buck converter, a boost converter, a buck-boost converter, a single-ended primary inductive converter, and a zero-voltage switching converter. The DC-DC auxiliary converter 20 includes one of a buck converter, a boost converter, a buck-boost converter, a flyback converter, a forward converter, a buck converter, a single-ended primary inductive converter, and a zero-voltage switching converter.

The non-isolated PFC main converter 10 comprises a PFC power conversion unit 11, a rectifier diode D5, a rectifier diode Db, a voltage converter 12 and a main power switch tube Q1. The several units may constitute a non-isolated PFC main converter 10 of the type buck converter, boost converter and buck-boost converter. The main power switch tube Q1 also has a body diode D_Q1. The main input ports include main input port 1 and main input port 2. The main output port includes a main output port 3 and a main output port 4.

Specifically, referring to fig. 4, the PFC power conversion unit 11 may include an LC filter circuit, a diode full-bridge rectifier circuit, and a filter capacitor Cin. The LC filter circuit comprises a capacitor Cf and an inductor Lf, and two half-bridge circuits of a diode full-bridge rectifying circuit, wherein one half-bridge circuit is formed by connecting diodes D1 and D3 in series, the other half-bridge circuit is formed by connecting diodes D2 and D4 in series, D1 and D2 are located on the upper portion, and D3 and D4 are located on the lower portion. There is a first node between D1 and D3 and a second node between D2 and D4. One end of the inductor Lf is connected with one pole of the alternating current power supply 50 through the main input port 1, and the other end is connected with the first node; one end of the capacitor Cf is connected to the other end of the inductor Lf, and the other end of the capacitor Cf and the second node are both connected to the other pole of the ac power supply 50 through the main input port 2. The filter capacitors Cin and D2 are connected in parallel with the half bridge formed by D4. In addition, the two half bridges and the filter capacitor Cin are connected in parallel and then grounded.

Referring to fig. 4, the following details the structure of the non-isolated PFC main converter 10 of the buck converter type:

the drain of the main power switch tube Q1 is connected with one end of the filter capacitor Cin, the source of the main power switch tube Q1 is connected with the main winding 121, and the grid of the main power switch tube Q1 is connected with the Q end of the trigger U4. One end of the rectifier diode D5 is connected with the source electrode of the power switch tube, and the other end is grounded. The rectifier diode Db is connected between one end of the auxiliary winding 122 and the auxiliary input port 5, and the other end of the auxiliary winding 122 is grounded.

Referring to fig. 5, the following details the structure of the boost converter type non-isolated PFC main converter 10:

one end of the main winding 121 is connected to the filter capacitor Cin, and the other end is connected to one end of the rectifier diode D5; the other end of the rectifying diode D5 is connected with the main output port 3; one end of the auxiliary winding 122 is connected to the auxiliary input port 5 through a rectifier diode Db, and the other end of the auxiliary winding 122 is directly connected to the auxiliary input port 6. The source of the main power switch Q1 is connected to the main output port 4, the drain is connected between the main winding 121 and the rectifier diode D5, and the gate is connected to the Q terminal of the flip-flop U4.

Referring to fig. 6, the following details the structure of the buck-boost converter type non-isolated PFC main converter 10:

the source electrode of the main power switch tube Q1 is connected with the main output port 4, the drain electrode is connected with the filter capacitor Cin, and the grid electrode is connected with the Q end of the trigger U4; one end of the main winding 121 is connected between the source of the main power switch tube Q1 and the main output port 4, the other end is connected between the filter capacitor Cin and one end of the rectifier diode D5, and the other end of the rectifier diode D5 is connected with the main output port 3; the rectifier diode Db is connected between one end of the auxiliary winding 122 and the auxiliary input port 5, and the other end of the auxiliary winding 122 is connected to the auxiliary input port 6.

The DC-DC auxiliary converter 20 includes an auxiliary power switch Q2, an inductor L2 (or transformer T2), and a rectifier diode D7. Wherein the auxiliary input ports comprise an auxiliary input port 5 and an auxiliary input port 6. The auxiliary output ports include an auxiliary output port 7 and an auxiliary output port 8. The auxiliary power switch tube Q2 also has a body diode D_Q2。

Referring to fig. 4, the construction of the buck converter type DC-DC auxiliary converter 20 is described in detail below:

the source of the auxiliary power switch Q2 is connected to one end of the inductor L2, the drain is connected to the auxiliary input port 5, and the gate is connected to the output of the second auxiliary comparator U6. The other end of the inductor L2 is connected to the auxiliary output port 7, one end of the rectifier diode D7 is connected between the source of the auxiliary power switch Q2 and one end of the inductor L2, and the other end of the rectifier diode D7 is connected between the auxiliary input port 6 and the auxiliary output port 8.

Referring to fig. 7, the constitution of the boost converter type DC-DC auxiliary converter 20 is described in detail below:

one end of the inductor L2 is connected to the auxiliary input port 5, and the other end is connected to one end of the rectifier diode D7. The other end of the rectifying diode D7 is connected to the auxiliary output port 7. The source of the auxiliary power switch Q2 is connected between the auxiliary input port 6 and the auxiliary output port 8, the drain is connected between the inductor L2 and the rectifier diode D7, and the gate is connected to the output of the second auxiliary comparator U6.

Referring to fig. 8, the following details the structure of the buck-boost converter type DC-DC auxiliary converter 20:

the source of the auxiliary power switch Q2 is connected to the auxiliary output port 8, the drain is connected to the auxiliary input port 5, and the gate is connected to the output of the second auxiliary comparator U6. The rectifier diode D7 is connected between the auxiliary input port 6 and the auxiliary output port 7. One end of the inductor L2 is connected between the source of the auxiliary power switch Q2 and the auxiliary output port 8, and the other end of the inductor L2 is connected between the auxiliary input port 6 and the rectifier diode D7.

Referring to fig. 9, the construction of the negative buck converter type DC-DC auxiliary converter 20 is described in detail below:

the source of the auxiliary power switch Q2 is connected to one end of the inductor L2, the drain is connected to the auxiliary input port 5, and the gate is connected to the output of the second auxiliary comparator U6. The other end of the inductor L2 is connected to the auxiliary output port 7. One end of the rectifier diode is connected between the auxiliary input port 6 and the auxiliary output port 8, and the other end is connected between the source of the auxiliary power switch tube Q2 and one end of the inductor L2.

Referring to fig. 10, the following details the configuration of the flyback converter type DC-DC auxiliary converter 20:

the transformer T2 comprises a first winding and a second winding, wherein one end of the first winding is connected with the auxiliary input port 5, and the other end of the first winding is connected with the drain electrode of the auxiliary power switch tube Q2; the source electrode of the auxiliary power switch tube Q2 is connected with the auxiliary input port 6, and the grid electrode of the auxiliary power switch tube Q2 is connected with the output end of the second auxiliary comparator U6; one end of the second winding of the transformer T2 is connected to the rectifier diode D7, the other end of the rectifier diode D7 is connected to the auxiliary output port 7, and the other end of the second winding is connected to the auxiliary output port 8.

In addition, the circuit is also provided with filter capacitors Co1, Cb and Co2, wherein the filter capacitor Co1 is connected between the

main input ports

3 and 4 for filtering the output voltage of the main input ports. The filter capacitor Cb is connected between the

auxiliary input ports

5 and 6, and filters the input voltage at the auxiliary input ports. The filter capacitor Co2 is connected between the

auxiliary output ports

7 and 8 to filter the output voltage at the auxiliary output ports.

Embodiments of the present application further provide an LED lighting device, which includes the wide-voltage non-isolated AC-DC constant current driver provided in any optional embodiment of the present application.

The embodiments of the present application have been described in detail, and specific embodiments thereof have been presented in the context of illustrating the principles and implementations of the present application.

Claims

1. A wide voltage non-isolated AC-DC constant current driver, comprising: the system comprises a non-isolated PFC main converter, a PFC controller, a DC-DC auxiliary converter and a DC-DC controller;

the non-isolated PFC main converter comprises a main conversion module and a main output port, wherein the main conversion module comprises a main output module and an auxiliary output module; the DC-DC auxiliary converter comprises an auxiliary input port and an auxiliary output port; the PFC controller comprises a main feedback port and a main control port; the DC-DC controller comprises an auxiliary feedback port and an auxiliary control port; the main output port and the auxiliary output port are connected in series to form a total output port;

the main output module is connected with the main output port, the auxiliary output module is connected with the auxiliary input port, the main feedback port is connected with the auxiliary output port, and the auxiliary feedback port is connected with the total output port; the main control port is connected with the non-isolated PFC main converter, and the auxiliary control port is connected with the DC-DC auxiliary converter;

the main voltage output by the main output module is transmitted to the main output port and the total output port; the auxiliary voltage output by the auxiliary output module is transmitted to the auxiliary input port and the main output port; after receiving the auxiliary voltage from the auxiliary input port, the DC-DC controller processes the auxiliary voltage and transmits the processed auxiliary voltage to the main feedback port through the auxiliary output port; after the PFC controller receives the auxiliary voltage from the main feedback port, the auxiliary voltage is used for controlling the non-isolated PFC main converter;

the total output port outputs total current after receiving the main voltage and the auxiliary voltage; the total current is transmitted to the secondary feedback port; and after receiving the total current from the auxiliary feedback port, the DC-DC controller controls the DC-DC auxiliary converter by using the total current.

2. The wide voltage non-isolated AC-DC constant current driver of claim 1, wherein the main conversion module comprises: the voltage converter comprises a main winding and an auxiliary winding; the PFC power conversion unit and the main winding form the main output module, and the PFC power conversion unit and the auxiliary winding form the auxiliary output module;

the output end of the PFC power conversion unit is connected with one end of the main winding; the other end of the main winding is connected with the main output port; the auxiliary winding is connected with the auxiliary input port; after receiving the alternating current, the PFC power conversion unit converts the alternating current so that the main output port outputs the main voltage and the auxiliary output port outputs the auxiliary voltage.

3. The wide voltage non-isolated AC-DC constant current driver of claim 2, wherein the non-isolated PFC main converter further comprises: a main power switch tube; the main power switch tube is connected between the output end of the PFC power conversion unit and one end of the main winding; or the main power switch tube is connected with the other end of the main winding;

the PFC controller also comprises a first main acquisition port, a main reference voltage port and a main reference sawtooth wave signal port; the first main acquisition port is connected with the auxiliary winding, and the main control port is connected with the control end of the main power switch tube;

the PFC controller also receives a voltage of the secondary winding from the first primary acquisition port, a primary reference voltage from the primary reference voltage port, and a primary reference sawtooth signal from the primary reference sawtooth signal port;

the controlling the non-isolated PFC main converter using the auxiliary voltage comprises: comparing the auxiliary voltage with the main reference voltage to form a voltage error signal; comparing the voltage error signal with the main reference sawtooth wave signal to form a stop pulse signal; forming a start pulse signal based on the voltage of the auxiliary winding; and controlling the on and off of the main power switch tube by using the stop pulse signal and the start pulse signal.

4. The wide-voltage non-isolated AC-DC constant current driver according to claim 3, wherein the PFC controller further comprises a second main acquisition port; the second main acquisition port is connected with the main power switch tube;

the PFC controller also receives the voltage of the main power switch tube from the second main acquisition port;

the comparing the voltage error signal and the main reference sawtooth wave signal to form a stop pulse signal includes: and comparing the voltage error signal with the voltage of the main power switch tube to form a comparison result, and comparing the main reference sawtooth wave signal with the comparison result to form a stop pulse signal.

5. The wide-voltage non-isolated AC-DC constant current driver according to claim 4, wherein the PFC controller comprises a main reference voltage source, a main reference sawtooth signal source, a first main comparator, a second main comparator, a third main comparator and a trigger; the flip-flop is provided with an S port, a Q port and an R port;

a negative input terminal of the first master comparator is connected to the master feedback port, a positive input terminal of the first master comparator is connected to the master reference voltage source through the master reference voltage port, and an output terminal of the first master comparator is connected to a positive input terminal of the second master comparator; the negative input end of the second main comparator is connected with the second main acquisition port, and the output end of the second main comparator is connected with the positive input end of the third main comparator; the negative input end of the third main comparator is connected with the main reference sawtooth wave signal source through the main reference sawtooth wave signal port, and the output end of the third main comparator is connected with the R port; the Q port is connected with the main control port, and the S port is connected with the first main acquisition port;

the first master comparator is to: comparing the auxiliary voltage with the main reference voltage to form a voltage error signal; the second master comparator is to: comparing the voltage error signal with the voltage of the main power switch tube to form a comparison result; the third master comparator is to: comparing the main reference sawtooth wave signal with the comparison result to form a stop pulse signal; the trigger is used for: forming a start pulse signal based on the voltage of the auxiliary winding; and controlling the on and off of the main power switch tube by using the stop pulse signal and the start pulse signal.

6. The wide voltage non-isolated AC-DC constant current driver of claim 1, wherein the DC-DC auxiliary converter further comprises: an auxiliary power switch tube; the DC-DC controller also comprises an auxiliary reference current port and an auxiliary reference sawtooth wave signal port; the auxiliary control port is connected with the control end of the auxiliary power switch tube;

the DC-DC controller also receives a secondary reference current from the secondary reference current port and a secondary reference sawtooth signal from the secondary reference sawtooth signal port;

the controlling the DC-DC auxiliary converter with the total current includes:

comparing the total current with the auxiliary reference current to form a voltage error signal; and comparing the voltage error signal with the auxiliary reference sawtooth wave signal to form a control signal, and transmitting the control signal to the control end of the auxiliary power switch tube.

7. The wide voltage non-isolated AC-DC constant current driver according to claim 6, wherein the DC-DC controller comprises: the auxiliary reference current source comprises a first auxiliary comparator, a second auxiliary comparator, an auxiliary reference current source and an auxiliary reference sawtooth wave signal source;

the negative input end of the first auxiliary comparator is connected with the auxiliary feedback port, the positive input end of the first auxiliary comparator is connected with the auxiliary reference current source through the auxiliary reference current port, and the output end of the first auxiliary comparator is connected with the positive input end of the second auxiliary comparator; the negative input end of the second auxiliary comparator is connected with the auxiliary reference sawtooth wave signal source through the auxiliary reference sawtooth wave signal port, and the output end of the second auxiliary comparator is connected with the auxiliary control port;

the first auxiliary comparator is to: comparing the total current with the auxiliary reference current to form a voltage error signal; the second auxiliary comparator is to: and comparing the voltage error signal with the auxiliary reference sawtooth wave signal to form a control signal, and outputting the control signal to the control end of the auxiliary power switch tube.

8. The wide voltage non-isolated AC-DC constant current driver according to any one of claims 1 to 7, wherein the non-isolated PFC main converter comprises one of a buck converter, a boost converter, a buck-boost converter, a Cuk converter, a single ended primary inductive converter, and a zero voltage switching converter.

9. The wide voltage non-isolated AC-DC constant current driver according to any one of claims 1 to 7, wherein the DC-DC auxiliary converter comprises one of a buck converter, a boost converter, a buck-boost converter, a flyback converter, a forward converter, a Cuk converter, a single-ended primary inductive converter, and a zero voltage switching converter.

10. An LED lighting device comprising the wide voltage non-isolated AC-DC constant current driver of any one of claims 1 to 9.